ANALOG DEVICES AD5504

High Voltage, Quad-Channel 12-Bit Voltage Output DAC AD5504 FEATURES GENERAL DESCRIPTION Quad-channel high voltage DAC The AD5504 is a quad-channel, 12-bit, serial input, digital-to- 12-bit resolution analog converter with on-chip high voltage output amplifiers Pin selectable 30 V or 60 V output range and an integrated precision reference. The DAC output voltage Integrated precision reference ranges are programmable via the range select pin (R_SEL). If Low power serial interface with readback capability R_SEL is held high, the DAC output ranges are 0 V to 30 V. If Integrated temperature sensor alarm function R_SEL is held low, the DAC output ranges are 0 V to 60 V. The Power-on reset on-chip output amplifiers allow an output swing within the LDAC Simultaneous updating via range of AGND + 0.5 V to V − 0.5 V. DD Wide operating temperature: −40°C to +105°C The AD5504 has a high speed serial interface, which is com- APPLICATIONS patible with SPI®-, QSPI™-, MICROWIRE™-, and DSP-interface standards and can handle clock speeds of up to 16.667 MHz. Programmable voltage sources High voltage LED drivers Receiver bias in optical communications FUNCTIONAL BLOCK DIAGRAM CLR R_SEL V V LOGIC DD LDAC 1713kΩ REFERENCE 122.36kΩ – SDI V INPUT DAC OUTA DACA REGISTER REGISTER + 12 12 A A SDO 1713kΩ INPUT SCLK CONTROL 122.36kΩ – LOGIC V INPUT DAC OUTB SYNC DAC B REGISTER REGISTER + B B 12 ALARM 1713kΩ 122.36kΩ – POWER-ON V RESET INPUT DAC OUTC DAC C REGISTER REGISTER + C C 12 1713kΩ 122.36kΩ – V INPUT DAC OUTD DAC D REGISTER REGISTER + 12 D D POWER-DOWN AD5504 CONTROL LOGIC TEMPERATURE SENSOR DGND AGND Figure 1. Rev. A Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 ©2009-2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 07994-001 AD5504 TABLE OF CONTENTS Features .............................................................................................. 1  Power-Down Mode .................................................................... 14  Applications ....................................................................................... 1  DAC Channel Architecture ....................................................... 14  General Description ......................................................................... 1  Selecting the Output Range ...................................................... 14  Functional Block Diagram .............................................................. 1  CLR Function.............................................................................. 14  Revision History ............................................................................... 2  LDAC Function .......................................................................... 14  Specif ica t ions ..................................................................................... 4  Temperature Sensor ................................................................... 15  AC Characteristics ........................................................................ 5  Power Dissipation....................................................................... 15  Timing Characteristics ................................................................ 6  Power Supply Sequencing ......................................................... 15  Absolute Maximum Ratings ............................................................ 8  Serial Interface ................................................................................ 16  Thermal Resistance ...................................................................... 8  Write Mode ................................................................................. 16  ESD Caution .................................................................................. 8  Read Mode .................................................................................. 16  Pin Configuration and Function Descriptions ............................. 9  Writing to the Control Register ................................................ 16  Typical Performance Characteristics ........................................... 10  Interfacing Examples ................................................................. 18  Terminology .................................................................................... 12  Outline Dimensions ....................................................................... 19  Theory of Operation ...................................................................... 14  Ordering Guide .......................................................................... 19  Power-Up State ........................................................................... 14  REVISION HISTORY 10/10—Rev. 0 to Rev. A Changes to Figure 3 and Figure 4 ................................................... 7 7/09—Revision 0: Initial Version Rev. A | Page 2 of 20 AD5504 The serial interface offers the user the capability of both writing The AD5504 has an on-chip temperature sensor. When the to, and reading from, most of the internal registers. To reduce ALARM temperature on the die exceeds 110°C, the pin (an power consumption at power up, only the digital section of the active low CMOS output pin) flags an alarm and the AD5504 AD5504 is powered up initially. This gives the user the ability to enters a temperature power-down mode disconnecting the program the DAC registers to the required value while typically output amplifier thus removing the short-circuit condition. The only consuming 30 μA of supply current. The AD5504 incor- AD5504 remains in power-down mode until a software power-up porates power-on reset circuitry that ensures the DAC registers command is executed. power up in a known condition and remain there until a valid The AD5504 is available in a compact 16-lead TSSOP. The AD5504 write to the device has taken place. The analog section is is guaranteed to operate over the extended temperature range of powered up by issuing a power-up command via the SPI −40°C to +105°C. interface. The AD5504 provides software-selectable output loads while in the power-down mode. Table 1. Related Device Part No. Description AD5501 High Voltage, 12-Bit Voltage Output DAC Rev. A | Page 3 of 20 AD5504 SPECIFICATIONS VDD = 10 V to 62 V; VLOGIC = 2.3 V to 5.5 V; RL = 60 kΩ; CL = 200 pF; −40°C < TA < +105°C, unless otherwise noted. Table 2. 1 Parameter Symbol Min Typ Max Unit Test Conditions/Comments 2 ACCURACY Resolution 12 Bits Differential Nonlinearity DNL −1 1 LSB Integral Nonlinearity INL 60 V Mode −2 +2 LSB VDD = 62 V 30 V Mode −3 +3 LSB V = 62 V DD 3, 4, 5 V Temperature Coefficient 50 ppm/°C DAC code = half scale OUTX Zero-Scale Error V 100 mV DAC code = 0 ZSE 4 Zero-Scale Error Drift 60 μV/°C 60 V mode 6 Offset Error VOE −80 +120 mV 4 Offset Error Drift 60 μV/°C 60 V mode Full-Scale Error V −325 +275 mV FSE 4 Full-Scale Error Drift 1 mV/°C −40°C to +25°C; 60 V mode 350 μV/°C +25°C to +105°C; 60 V mode Gain Error −0.6 +0.6 % of FSR 4 Gain Temperature Coefficient 10 ppm of FSR/°C 60 V mode 4 DC Crosstalk R = 60 kΩ to AGND or V L DD Due to Single Channel Full-Scale 3 mV 60 V mode Output Change Due to Powering Down (Per Channel) 4 mV 60 V mode OUTPUT CHARACTERISTICS 7 Output Voltage Range AGND + 0.5 VDD − 0.5 V 4, 8 Short-Circuit Current 2 mA On any single channel 4 Capacitive Load Stability 1 V to 4 V step R = 60 kΩ to ∞ 1 nF L 4 Load Current −1 +1 mA On any single channel 4 DC Output Impedance 3 Ω 4 DC Output Leakage 10 μA DIGITAL INPUTS Input Logic High V 2.0 V V = 4.5 V to 5.5 V IH LOGIC 1.8 V VLOGIC = 2.3 V to 3.6 V Input Logic Low VIL 0.8 V VLOGIC = 2.3 V to 5.5 V Input Current IIL ±1 μA 4 Input Capacitance I 5 pF IC DIGITAL OUTPUTS Output High Voltage VOH VLOGIC − 0.4 V V ISOURCE = 200 μA Output Low Voltage V DGND + 0.4 V V I = 200 μA OL SINK Three-State Leakage Current SDI, SDO, SCLK, LDAC, CLR, R_SEL −1 +1 μA ALARM −10 +10 μA 4 Output Capacitance 5 pF POWER SUPPLIES VDD 10 62 V VLOGIC 2.3 5.5 V Quiescent Supply Current (IQUIESCENT) 2 3 mA Static conditions; DAC outputs = midscale Logic Supply Current (ILOGIC) 0.4 2 μA VIH = VLOGIC; VIL = DGND 4 DC PSRR DAC output = full-scale 60 V Mode 68 dB Rev. A | Page 4 of 20 AD5504 1 Parameter Symbol Min Typ Max Unit Test Conditions/Comments 30 V Mode 76 dB POWER-DOWN MODE Supply Current I DD_PWD Software Power-Down Mode 30 50 μA 8 Junction Temperature TJ 130 °C TJ = TA + PTOTAL × θJA 1 Typical specifications represent average readings at 25°C, VDD = 62 V and VLOGIC = 5 V. 2 Valid in output voltage range of (V − 0.5 V) to (AGND + 0.5 V). Outputs are unloaded. DD 3 Includes linearity, offset, and gain drift. 4 Guaranteed by design and characterization. Not production tested. 5 VOUTX refers to VOUTA, VOUTB, VOUTC, or VOUTD. 6 DAC code = 32 for 60 V mode; DAC code = 64 for 30 V mode. 7 The DAC architecture gives a fixed linear voltage output range of 0 V to 30 V if R_SEL is held high and 0 V to 60 V if R_SEL is held low. As the output voltage range is limited by output amplifier compliance, V should be set to at least 0.5 V higher than the maximum output voltage to ensure compliance. DD 8 If the die temperature exceeds 110°C, the AD5504 enters a temperature power-down mode putting the DAC outputs into a high impedance state thereby removing the short-circuit condition. Overheating caused by long term short-circuit condition(s) is detected by an integrated thermal sensor. After power-down, the AD5504 stays powered down until a software power-up command is executed. AC CHARACTERISTICS VDD = 10 V to 62 V; VLOGIC = 2.3 V to 5.5 V; RL = 60 kΩ; CL = 200 pF; −40°C < TA < +105°C, unless otherwise noted. Table 3. 1, 2 3 Parameter Min Typ Max Unit Test Conditions/Comments AC CHARACTERISTICS Output Voltage Settling Time ¼ to ¾ scale settling to ±1 LSB, RL = 60 kΩ 60 V Mode 45 55 μs 30 V Mode 25 35 μs Slew Rate 0.65 V/μs Digital-to-Analog Glitch Energy 300 nV-s 1 LSB change around major carry in 60 V mode Glitch Impulse Peak Amplitude 170 mV 60 V mode Digital Feedthrough 40 nV-s Digital Crosstalk 5 nV-s Analog Crosstalk 600 nV-s DAC-to-DAC Crosstalk 600 nV-s Peak-to-Peak Noise 140 μV p-p 0.1 Hz to 10 Hz; DAC code = 0x800 4 mV p-p 0.1 Hz to 10 kHz; DAC code = 0x800 1 Guaranteed by design and characterization; not production tested. 2 See the Terminology section. 3 Temperature range is −40°C to + 105°C, typical at 25°C. Rev. A | Page 5 of 20 AD5504 TIMING CHARACTERISTICS VDD = 30 V, VLOGIC = 2.3 V to 5.5 V and −40°C < TA < +105°C; all specifications TMIN to TMAX, unless otherwise noted. Table 4. 1 Parameter Limit Unit Test Conditions/Comments 2 t 60 ns min SCLK cycle time 1 t2 10 ns min SCLK high time t3 10 ns min SCLK low time t4 30 ns min SYNC falling edge to SCLK falling edge setup time t 15 ns min Data setup time 5 t 5 ns min Data hold time 6 t7 0 ns min SCLK falling edge to SYNC rising edge t8 20 ns min Minimum SYNC high time t9 20 ns min LDAC pulse width low t 50 ns min SCLK falling edge to LDAC rising edge 10 t 15 ns min CLR pulse width low 11 t 100 ns typ CLR pulse activation time 12 t13 20 μs typ ALARM clear time t14 110 ns min SCLK cycle time in read mode 3 t15 55 ns max SCLK rising edge to SDO valid 3 t 25 ns min SCLK to SDO data hold time 16 4 t 50 μs max Power-on reset time (this is not shown in the timing diagrams) 17 5 t18 50 μs max Power-on time (this is not shown in the timing diagrams) t19 5 μs typ ALARM clear to output amplifier turn on (this is not shown in the timing diagrams) 1 All input signals are specified with tr = tf = 1 ns/V (10% to 90% of VDD) and timed from a voltage level of (VIL + VIH)/2. 2 Maximum SCLK frequency is 16.667 MHz. 3 Under load conditions shown in Figure 2. 4 Time from when the V /V supplies are powered-up to when a digital interface command can be executed. DD LOGIC 5 Time required from execution of power-on software command to when the DAC outputs have settled to 1 V. 200µA I OL V (MIN) – V (MAX) OH OL TO OUTPUT PIN 2 C L 50pF 200µA I OH Figure 2. Load Circuit for SDO Timing Diagram Rev. A | Page 6 of 20 07994-002 AD5504 t 1 SCLK t t 2 8 t t 3 7 t 4 SYNC t 6 t 5 SDI R/W D0 t 9 1 LDAC t 10 2 LDAC t 11 CLR t 13 3 ALARM t 12 4 V OUTx 1 ASYNCHRONOUS LDAC UPDATE MODE. 2 SYNCHRONOUS LDAC UPDATE MODE. 3 IN THE EVENT OF OVERTEMPERATURE CONDITION. 4 V REFERS TO ANY OF V , V V OR V . OUTx OUTA OUTB, OUTC OUTD Figure 3. Write Timing Diagram t 14 SCLK SYNC X SDI R/W A2 A1 A0 X XXXXX t 16 t 15 D11 D10 D9 D8 D0 D2 D1 SDO Figure 4. Read Timing Diagram Rev. A | Page 7 of 20 07994-004 07994-003 AD5504 ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE TA = 25°C, unless otherwise noted. Transient currents of up to 100 mA do not cause SCR latch-up. θ is specified for the worst-case conditions, that is, a device JA soldered in a circuit board for surface-mount packages. Table 5. Thermal resistance is for a JEDEC 4-layer(2S2P) board. Parameter Rating V to AGND −0.3 V, + 64 V Table 6. Thermal Resistance DD Package Type θ Unit VLOGIC to DGND −0.3 V to +7 V JA 1 VOUTX to AGND −0.3 V to VDD + 0.3 V 16-Lead TSSOP 112.60 °C/W Digital Input to DGND −0.3 V to VLOGIC + 0.3 V SDO Output to DGND −0.3 V to V + 0.3 V LOGIC ESD CAUTION AGND to DGND −0.3 V to +0.3 V Maximum Junction Temperature 150°C (TJ Maximum) Storage Temperature Range −65°C to +150°C Reflow Soldering Peak Temperature 260°C Time at Peak Temperature Range 20 sec to 40 sec 1 VOUTX refers to VOUTA, VOUTB, VOUTC, or VOUTD. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Rev. A | Page 8 of 20 AD5504 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS 16 CLR 1 V LOGIC 2 SYNC 15 ALARM 3 14 SCLK V AD5504 DD TOP VIEW 4 SDI 13 R_SEL (Not to Scale) 5 12 SDO V OUTA 6 11 DGND V OUTB 7 10 AGND V OUTC 8 9 LDAC V OUTD Figure 5. TSSOP Configuration Table 7. Pin Function Descriptions Pin No. Mnemonic Description 1 CLR Asynchronous Clear Input. The CLR input is falling edge sensitive. When CLR is low, all LDAC pulses are ignored. When CLR is activated, the input register and the DAC register are set to 0x000 and the outputs to zero scale. 2 SYNC Falling Edge Synchronization Signal. This is the frame synchronization signal for the input data. When SYNC goes low, it enables the input shift register and data is transferred in on the falling edges of the following clocks. The selected DAC register is updated after the 16th clock cycle, unless SYNC is taken high before this edge, in which case the rising edge of SYNC acts as an interrupt, and the write sequence is ignored by the DAC. 3 SCLK Serial Clock Input. Data is clocked into the input shift register on the falling edge of the serial clock input. Data can be transferred at rates up to 16 MHz. 4 SDI Serial Data Input. This part has a 16-bit shift register. Data is clocked into the register on the falling edge of the serial clock input. 5 SDO Serial Data Output. CMOS output. This pin serves as the readback function for all DAC and control registers. Data is clocked out on the rising edge of SCLK and is valid on the falling edge of SCLK. 6 DGND Digital Ground Pin. 7 AGND Analog Ground Pin. 8 LDAC Load DAC Input. Pulsing this pin low allows any or all DAC registers to be updated if the input registers have new data. This allows all DAC outputs to update simultaneously. Alternatively, this pin can be tied permanently low. 9 VOUTD Buffered Analog Output Voltage from DAC D. 10 VOUTC Buffered Analog Output Voltage from DAC C. 11 VOUTB Buffered Analog Output Voltage from DAC B. 12 V Buffered Analog Output Voltage from DAC A. OUTA 13 R_SEL Range Select Pin. Tying this pin to DGND selects a DAC output range of 0 V to 60 V, alternatively tying R_SEL to VLOGIC selects a DAC output range of 0 V to 30 V. 14 VDD Positive Analog Power Supply. 10 V to 62 V for the specified performance. This pin should be decoupled with 0.1 μF ceramic capacitors and 10 μF capacitors. 15 ALARM Active Low CMOS Output Pin. This pin flags an alarm if the temperature on the die exceeds 110°C. 16 V Logic Power Supply; 2.3 V to 5.5 V. Decouple this pin with 0.1μF ceramic capacitors and 10 μF capacitors. LOGIC Rev. A | Page 9 of 20 07994-005 AD5504 TYPICAL PERFORMANCE CHARACTERISTICS 0.8 45.0025 0.4 45.0000 0 44.9975 –0.4 44.9950 –0.8 44.9925 32 1008 2048 3056 4064 0 0.05 0.10 0.15 0.20 CODE TIME (ms) Figure 6. Typical INL Figure 9. Output Settling Time (Low to High) 0.50 200 V = 62V DD V = 30V OUTx 0.25 100 0 0 –0.25 –100 –0.50 –200 32 1008 2048 3056 4064 0 2.5 5.0 7.5 10.0 CODE TIME (Seconds) Figure 7. Typical DNL Figure 10. Output Noise 15.0050 0.70 V = 62V DD V , V , AND V POWERED DOWN OUTB OUTC OUTD 15.0025 0.65 15.0000 0.60 14.9975 0.55 14.9950 0.50 0 0.05 0.10 0.15 0.20 0 15304560 TIME (ms) V (V) OUTA Figure 8. Output Settling Time (High to Low) Figure 11. I vs. V DD OUTA Rev. A | Page 10 of 20 V (V) OUTX DNL (LSB) INL (LSB) 07994-007 07994-006 07994-008 V (V) OUTX OUTPUT VOLTAGE (µV) I (mA) DD 07994-011 07994-010 07994-009 AD5504 2.2 0.20 V = 62V DD V = V = V = V OUTA OUTB OUTC OUTD 0.15 2.1 0.10 0.05 2.0 0 –0.05 1.9 –0.10 V = 30V; V SWITCHING OUTA OUTB V = 0V TO 30V –0.15 OUTB V = 0V TO 45V OUTB V = 0V TO 60V OUTB 1.8 –0.20 015 30 45 60 0241 6 80 OUTPUT VOLTAGE (V) TIME (µs) Figure 12. I vs. V to V Figure 15. DAC-to-DAC Crosstalk DD OUTA OUTD 2 6 V OUTD 0 5 –2 4 V OUTB –4 3 –6 2 V OUTC –8 1 V OUTA –10 0 0 5 10 15 –1.0 –0.501 0.5.0 TIME (ms) LOAD CURRENT (mA) Figure 13. Digital-to-Analog Negative Glitch Impulse Figure 16. DAC-to-DAC Mismatch 12 10 8 6 4 2 0 –2 –4 0 5 10 15 TIME (ms) Figure 14. Digital-to-Analog Positive Glitch Impulse Rev. A | Page 11 of 20 AMPLITUDE (LSB) AMPLITUDE (LSB) I (mA) DD 07994-014 07994-013 07994-012 LSBs V (ΔV) OUTA 07994-201 07994-202 AD5504 TERMINOLOGY Gain Temperature Coefficient Relative Accuracy The gain temperature coefficient is a measure of the change in For the DAC, relative accuracy, or integral nonlinearity (INL), gain with changes in temperature. It is expressed in (ppm of is a measure of the maximum deviation in LSBs from a straight full-scale range)/°C. line passing through the endpoints of the DAC transfer function. Digital-to-Analog Glitch Impulse Differential Nonlinearity Differential nonlinearity (DNL) is the difference between the Digital-to-analog glitch impulse is the impulse injected into the measured change and the ideal 1 LSB change between any two analog output when the input code in the DAC register changes adjacent codes. A specified differential nonlinearity of ±1 LSB state. It is normally specified as the area of the glitch in nV-s maximum ensures monotonicity. This DAC is guaranteed mono- and is measured when the digital input code is changed by tonic by design. 1 LSB at the major carry transition. Zero-Code Error DC and AC Power Supply Rejection Ratio (PSRR) Zero-code error is a measure of the output error when zero PSRR indicates how the output of the DAC is affected by changes code (0x000) is loaded into the DAC register. Ideally, the output in the supply voltage. PSRR is the ratio of the change in V , OUTA should be 0 V. The zero-code error is always positive in the V , V , or V to a change in V for full-scale output of OUTB OUTC OUTD DD AD5504 because the output of the DAC cannot go below 0 V. the DAC. It is measured in decibels. For dc PSRR, V is dc DD It is due to a combination of the offset errors in the DAC and varied ±10%. For ac PSRR, V is ac varied ±10%. DD output amplifier. Zero-code error is expressed in millivolts. DC Crosstalk Zero-Code Error Drift DC crosstalk is the dc change in the output level of one DAC in response to a change in the output of another DAC. It is measured Zero-code error drift is a measure of the change in zero-code with a full-scale output change on one DAC (or soft power-down error with a change in temperature. It is expressed in μV/°C. and power-up) while monitoring another DAC kept at midscale. Offset Error It is expressed in millivolts. A measure of the difference between V (actual) and V OUT OUT DC crosstalk due to load current change is a measure of the (ideal) expressed in millivolts in the linear region of the transfer impact that a change in load current on one DAC has to another function. Offset error is measured on the AD5504 with Code 32 DAC kept at midscale. It is expressed in μV/mA. loaded in the DAC registers for 60 V mode and with Code 64 Digital Feedthrough loaded in the DAC registers for 30 V mode. Offset error is Digital feedthrough is a measure of the impulse injected into expressed in millivolts. the analog output of a DAC from the digital input pins of the Offset Error Drift device but is measured when the DAC is not being written to Offset error drift is a measure of the change in offset error with SYNC ( held high). It is specified in nV-s and measured with a a change in temperature. It is expressed in μV/°C. full-scale change on the digital input pins, that is, from all 0s to Full-Scale Error all 1s or vice versa. Full-scale error is a measure of the output error when full-scale Analog Crosstalk code (0xFFF) is loaded into the DAC register. Full-scale error is Analog crosstalk is the glitch impulse transferred to the output expressed in millivolts. of one DAC due to a change in the output of another DAC. It is measured by loading one of the input registers with a full-scale Full-Scale Error Drift LDAC Full-scale error drift is a measure of the change in full-scale code change (all 0s to all 1s or vice versa) while keeping error with a change in temperature. It is expressed in μV/°C. LDAC high, and then pulsing low and monitoring the output of the DAC whose digital code has not changed. The area of the Gain Error glitch is expressed in nV-s. Gain error is a measure of the span error of the DAC. It is the deviation in slope of the DAC transfer characteristic from the ideal, expressed as a percentage of the full-scale range. Rev. A | Page 12 of 20 AD5504 DAC-to-DAC Crosstalk Capacitive Load Stability DAC-to-DAC crosstalk is the glitch impulse transferred to the Capacitive load stability refers to the ability of the amplifier to output of one DAC due to a digital code change and subsequent drive a capacitive load. An amplifier output is considered stable output change of another DAC. This includes both digital and if any overshoot or ringing has stopped before approximately analog crosstalk. It is measured by loading one of the DACs 1.5 times the settling time of the DAC has elapsed. with a full-scale code change (all 0s to all 1s or vice versa) with LDAC low and monitoring the output of another DAC. The energy of the glitch is expressed in nV-s. Rev. A | Page 13 of 20 AD5504 THEORY OF OPERATION The AD5504 contains four DACs, four output amplifiers, and a format for the AD5501 is straight binary and the output voltage precision reference in a single package. The architecture of a follows the formula single DAC channel consists of a 12-bit resistor string DAC D V = × Range OUT followed by an output buffer amplifier. The part operates from 4096 a single-supply voltage of 10 V to 62 V. The DAC output voltage where: R_SEL range is selected via the range select, , pin. The DAC D is the code loaded to the DAC. R_SEL output range is 0 V to 30 V if is held high and 0 V to R_SEL R_SEL Range = 30, if is high, and 60 if is low. R_SEL 60 V if is held low. Data is written to the AD5504 in a PRECISION 16-bit word format (see Table 8), via a serial interface. REFERENCE POWER-UP STATE INPUT DAC On power-up, the power-on reset circuitry clears the bits of the GAIN DAC V OUTx REGISTER REGISTER 12 12 control register to 0x40 (see Table 10). This ensures that the analog section is initially powered down, which helps reduce power consumption. The user can program the DAC registers AGND to the required values while typically consuming only 30 μA of Figure 17. DAC Channel Architecture (Single-Channel Shown) supply current. The power-on reset circuitry also ensures that all the input and DAC registers power up in a known condition, SELECTING THE OUTPUT RANGE 0x000, and remain there until a valid write to the device has The output range of the DACs is selected by the R_SEL pin. taken place. The analog section can be powered up by setting When the R_SEL pin is connected to Logic 1, the DAC output any or all of Bit C2 to Bit C5 of the control register to 1. R_SEL voltages can be set between 0 V and 30 V. When the pin POWER-DOWN MODE is connected to Logic 0, the DAC output voltages can be set Each DAC channel can be individually powered up or powered R_SEL between 0 V and 60 V. The state of can be changed any down by programming the control register (see Table 10). time when the serial interface is not being used, that is, not When the DAC channel is powered down, the associated analog during a read or write operation. When the R_SEL pin is circuitry turns off to reduce power consumption. The digital changed, the voltage on the output pin remains the same until section of the AD5504 remains powered up. The output of the the next write to the DAC register (and LDAC is brought low). DAC amplifier can be three-stated or connected to AGND via For example, if the user writes 0x800 to the DAC register when an internal 20 kΩ resistor, depending on the state of Bit C6 in R_SEL in 30 V mode ( = 1), the output voltage is 15 V (assuming the control register. The power-down mode does not change the LDAC is low or has been pulsed low). When the user switches contents of the DAC register to ensure that the DAC channel R_SEL to 60 V mode ( = 0), the output stays at 15 V until the returns to its previous voltage when the power-down bit is set to 1. LDAC user writes a new value to the DAC register. must be low The AD5504 also offers the user the flexibility of updating the or be pulsed low for the output to change. DAC registers during power-down. The control register can be read back at any time to check the status of the bits. CLR FUNCTION DAC CHANNEL ARCHITECTURE CLR The AD5504 has a hardware pin that is an asynchronous The architecture of a single DAC channel consists of a 12-bit clear input. The CLR input is falling edge sensitive. Bringing the resistor string DAC followed by an output buffer amplifier (see CLR line low clears the contents of the input register and the Figure 17). The resistor string section is simply a string of DAC registers to 0x000. The CLR pulse activation time, that is, resistors, each of Value R from VREF generated by the precision the falling edge of CLR to when the output starts to change, is reference to AGND. This type of architecture guarantees DAC typically 100 ns. monotonicity. The 12-bit binary digital code loaded to the DAC LDAC FUNCTION register determines at which node on the string the voltage is tapped off before being fed into the output amplifier. The The DAC outputs can be updated using the hardware LDAC output amplifier multiplies the DAC output voltage to give a pin. LDAC is normally high. On the falling edge of LDAC, data fixed linear voltage output range of 0 V to 60 V if R_SEL = 0 is copied from the input registers to the DAC registers, and the or 0 V to 30 V if R_SEL = 1. Each output amplifier is capable DAC outputs are updated simultaneously (asynchronous update of driving a 60 kΩ load while allowing an output swing within LDAC mode, see Figure 3). If the is kept low, or is low on the the range of AGND + 0.5 V and V − 0.5 V. th DD falling edge of the 16 SCLK, the appropriate DAC register and Because the DAC architecture gives a fixed voltage output range DAC output are updated automatically (synchronous update of 0 V to 30 V or 0 V to 60 V, the user should set V to at least DD mode, see Figure 3). 30.5 V or 60.5 V to use the maximum DAC resolution. The data Rev. A | Page 14 of 20 07994-015 AD5504 T = T + (P × θ ) TEMPERATURE SENSOR J A TOTAL JA where: The AD5504 has an integrated temperature sensor that causes T is the package junction temperature. the part to enter thermal shutdown mode when the temperature J on the die exceeds 110°C. In thermal shutdown mode, the TA is the ambient temperature. analog section of the device powers down and the DAC outputs PTOTAL is the total power being consumed by the AD5504. are disconnected, but the digital section remains operational, θJA is the thermal impedance of the AD5504 package (see the which is equivalent to setting the power-down bit in the control Absolute Maximum Ratings section for this value). register. To indicate that the AD5504 has entered temperature POWER SUPPLY SEQUENCING shutdown mode, Bit 0 of the control register is set to 1 and the The power supplies for the AD5504 can be applied in any order ALARM pin goes low. The AD5504 remains in temperature without affecting the device. However, the AGND and DGND shutdown mode with Bit 0 set to 1 and the ALARM pin low, even pins should be connected to the relevant ground plane before if the die temperature falls, until Bit 0 in the control register is the power supplies are applied. None of the digital input pins cleared to 0. SYNC R_SEL CLR (SCLK, SDI, , and ) should be allowed to float POWER DISSIPATION during power up. The digital input pins can be connected to Drawing current from any of the voltage output pins causes a pull-up (to VLOGIC) or pull-down (to DGND) resistors as temperature rise in the die and package of the AD5504. The required. package junction temperature (T ) should not exceed 130°C for J normal operation. If the die temperature exceeds 110°C, the AD5504 enters thermal shutdown mode as described in the previous section. The amount of heat generated can be calculated using the formula Rev. A | Page 15 of 20 AD5504 SERIAL INTERFACE The AD5504 has a serial interface (SYNC, SCLK, SDI, and initiate the next write sequence. Operate all interface pins close to the supply rails to minimize power consumption in the SDO), which is compatible with SPI interface standards, as well digital input buffers. with as most DSPs. The AD5504 allows writing of data, via the serial interface, to the input and control registers. The DAC READ MODE registers are not directly writeable or readable. The AD5504 allows data readback via the serial interface from The input shift register is 16 bits wide (see Table 8). The 16-bit every register directly accessible to the serial interface, which is W word consists of one read/write (R/ ) control bit, followed by all registers except the DAC registers. To read back a register, it three address bits and 12 DAC data bits. Data is loaded MSB first. is first necessary to tell the AD5504 that a readback is required. W This is achieved by setting the R/ bit to 1. The three address WRITE MODE bits then determine the register from which data is to be read W To write to a register, the R/ bit should be 0. The three back. Data from the selected register is then clocked out of the address bits in the input register (see Table 9) then determine SDO pin on the next twelve clocks of the same frame. the register to update. The address bits (A2 to A0) are used for The SDO pin is normally three-stated but becomes driven on either DAC register selection or for writing to the control the rising edge of the fifth clock pulse. The pin remains driven register. Data is clocked into the selected register during the until the data from the register has been clocked out or the remaining 12 clocks of the same frame. Figure 3 shows a timing SYNC pin is returned high. Figure 4 shows the timing diagram of a typical AD5504 write sequence. The write requirements during a read operation. Note that due to timing SYNC sequence begins by bringing the line low. Data on the requirements of t (110 ns), the maximum speed of the SPI 14 SDI line is clocked into the 16-bit shift register on the falling interface during a read operation should not exceed 9 MHz. edge of SCLK. On the 16th falling clock edge, the last data bit is clocked in and the programmed function is executed (that is, a WRITING TO THE CONTROL REGISTER change in the selected DAC/DACs input register/registers or a The control register is written when Bits[DB14:DB12] are 1. change in the mode of operation). The AD5504 does not The control register sets the power-up state of the DAC outputs. require a continuous SCLK and dynamic power can be saved by A write to the control register must be followed by another transmitting clock pulses during a serial write only. At this write operation. The second write operation can be a write to a SYNC stage, the line can be kept low or be brought high. In DAC input register or a NOP write. Figure 18 shows some either case, it must be brought high for a minimum of 20 ns typical combinations. SYNC before the next write sequence for a falling edge of to Table 8. Input Register Bit Map DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 W A2 A1 A0 Data R/ Table 9. Input Register Bit Functions Bit Description W Indicates a read from or a write to the addressed register. R/ A2, A1, A0 These bits determine if the input registers or the control register are to be accessed. A2 A1 A0 Function/Address 0 0 0 No operation 0 0 1 DAC A input register 0 1 0 DAC B input register 0 1 1 DAC C input register 1 0 0 DAC D input register 1 0 1 Write data contents to all four DAC input registers 1 1 0 Reserved 1 1 1 Control register D11:D0 Data bits Rev. A | Page 16 of 20 AD5504 Table 10. Control Register Functions 1 DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 2 2 2 2 2 W 1 1 1 X X X X X C6 C5 C4 C3 C2 C1 C0 R/ 1 Read-only bit. This bit should be 0 when writing to the control register. 2 X is don’t care. Table 11. Control Register Function Bit Descriptions Bit No. Bit Name Description DB0 C0 C0 = 0: the device is not in thermal shutdown mode. C0 = 1: the device is in thermal shutdown mode. DB1 C1 C1 = 0: reserved. This bit should be 0 when writing to the control register. 1 DB2 C2 C2 = 0: DAC Channel A power-down (default). C2 = 1: DAC Channel A power-up. 1 DB3 C3 C3 = 0: DAC Channel B power-down (default). C3 = 1: DAC Channel B power-up. 1 DB4 C4 C4 = 0: DAC Channel C power-down (default). C4 = 1: DAC Channel C power-up. 1 DB5 C5 C5 = 0: DAC Channel D power-down (default). C5 = 1: DAC Channel D power-up. DB6 C6 C6 = 0: outputs connected to AGND through a 20 kΩ resistor (default). C6 = 1: outputs are three-stated. 1 If Bit C2 to Bit C5 are set to 0, the part is placed in power-down mode. WRITE TO NOP CONTROL REGISTER WRITE TO WRITE TO CONTROL REGISTER DAC REGISTER WRITE TO WRITE TO NOP CONTROL REGISTER CONTROL REGISTER WRITE TO WRITE TO WRITE TO CONTROL REGISTER CONTROL REGISTER DAC REGISTER WRITE N WRITE N + 1 WRITE N + 2 Figure 18. Control Register Write Sequences Rev. A | Page 17 of 20 07994-120 AD5504 The Analog Devices ADSP-21065L is a floating point DSP with INTERFACING EXAMPLES two serial ports (SPORTs). Figure 20 shows how one SPORT The SPI interface of the AD5504 is designed to allow it to be can be used to control the AD5504. In this example, the transmit easily connected to industry-standard DSPs and microcon- frame synchronization (TFS) pin is connected to the receive trollers. Figure 19 shows how the AD5504 can be connected to frame synchronization (RFS) pin. The transmit and receive the Analog Devices, Inc., Blackfin® DSP. The Blackfin has an clocks (TCLK and RCLK) are also connected together. The user integrated SPI port that can be connected directly to the SPI can write to the AD5504 by writing to the transmit register. When a pins of the AD5504. Programmable input/output pins are also read operation is performed, the data is clocked out of the AD5504 available and can be used to read or set the state of the digital on the last 12 SCLKs. The DSP receive interrupt can be used to input or output pins associated with the interface. indicate when the read operation is complete. ADSP-21065L AD5504 AD5504 TFSx SYNC SYNC SPISELx RFSx SCLK SCK TCLKx RCLKx SCLK MOSI SDI DTxA SDI SDO MISO DRxA SDO PF10 R_SEL FLAG R_SEL 0 ADSP-BF531 PF9 LDAC FLAG LDAC 1 PF8 CLR FLAG CLR 2 ALARM PF7 ALARM FLAG 3 Figure 20. Interfacing to an ADSP-21065L DSP Figure 19. Interfacing to a Blackfin DSP Rev. A | Page 18 of 20 07994-016 07994-017 AD5504 OUTLINE DIMENSIONS 5.10 5.00 4.90 16 9 4.50 6.40 4.40 BSC 4.30 1 8 PIN 1 1.20 MAX 0.15 0.20 0.05 0.75 0.09 8° 0.60 0.30 0.65 0° 0.45 0.19 SEATING BSC PLANE COPLANARITY 0.10 COMPLIANT TO JEDEC STANDARDS MO-153-AB Figure 21. 16-Lead Thin Shrink Small Outline Package [TSSOP] (RU-16) Dimensions shown in millimeters ORDERING GUIDE 1 Model Temperature Range Package Description Package Option AD5504BRUZ −40°C to +105°C 16-Lead Thin Shrink Small Outline Package [TSSOP] RU-16 AD5504BRUZ-REEL −40°C to +105°C 16-Lead Thin Shrink Small Outline Package [TSSOP] RU-16 EVAL-AD5504EBZ Evaluation Board 1 Z = RoHS Compliant Part.. Rev. A | Page 19 of 20 AD5504 NOTES ©2009-2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D07994-0-10/10(A) Rev. A | Page 20 of 20