SEMTECH SC1566

SC1566 Very Low Dropout 3.0 Amp Regulator With Enable POWER MANAGEMENT Description Features The SC1566 is a high performance positive voltage ‹ 350mV dropout @ 3A regulator designed for use in applications requiring very ‹ Adjustable output from 1.2V to 4.8V low dropout voltage at up to 3 Amps. Since it has ‹ 2.5V and 1.8V options (5 pin parts also adjustable superior dropout characteristics compared to regular externally using resistors) LDOs, it can be used to supply 2.5V on motherboards or ‹ Over current and over temperature protection 2.8V on peripheral cards from the 3.3V supply thus ‹ Enable pin allowing heat sink size reduction or elimination. ‹ 10µA quiescent current in shutdown Additionally, the five pin versions of SC1566 have an ‹ Low reverse leakage (output to input) enable pin, to further reduce power dissipation while shut ‹ Full industrial temperature range down. The SC1566 provides excellent regulation over ‹ TO-220 and TO-263 packages variations in line, load and temperature. Applications The SC1566 is available as three terminal fixed output voltage and five terminal fixed or adjustable output ‹ Battery powered systems voltage devices with enable. Two package options are ‹ Motherboards and notebook computers available: TO-263 and TO-220. ‹ Peripheral cards ‹ Network cards ‹ Set top boxes (1)(2) Typical Application Circuits ‹ Medical equipment U1 SC1566I5T-2.5 1 5 VIN VIN VO VO = See equation below 2 4 ENABLE EN ADJ GND R1 3 1.200 (R1+ R2) VO = Volts R2 C1 C2 R2 U1 SC1566I5T-2.5 1 5 VIN VIN VO VO = 2.5V 2 4 ENABLE EN ADJ GND C1 C2 3 U1 SC1566IT-1.8 1 3 VIN VO = 1.8V VIN VO GND Notes: C1 C2 (1) Maximum VO setpoint for 1.8V parts = 5.4V 2 (2) This device is designed to operate with ceramic input and output capacitors Revision: April 27, 2005 1 www.semtech.com SC1566 POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Parameter Sx ymbol Ms a Unit Input Voltage V 7V IN Power Dissipation PIW nternally Limited D Thermal Resistance Junction to Ambient TO-263-X θ 60 °C/W JA TO-220-X 50 Thermal Resistance Junction to Case TO-263-X θ 3 °C/W JC TO-220-X 3 Operating Ambient Temperature Range T -C 40 to +85 ° A Operating Junction Temperature Range T -C 40 to +150 ° J Storage Temperature Range T -C 65 to +150 ° STG Lead Temperature (Soldering) 10 Sec. T 3C 00 ° LEAD ESD Rating (Human Body Model) V 2V k ESD Electrical Characteristics Unless specified: V = V . Adjustable Option (V > V ): V = 2.2V to 5.5V and I = 10µA to 3A. EN IN ADJ TH(ADJ) IN O Fixed Options (V = GND): V = (V + 0.7V) to 5.5V and I = 0A to 3A. Values in bold apply over the full operating temperature range. ADJ IN O O Pl arameterSs ymboTn est Condition Mp i Tx y Ms a Unit VIN SV upply Voltage Range 25 .2 5. V IN QI uiescent Current V=5 3.3V 0.7 1.75 mA Q IN V = 5.5V, V=0 0V 1 35 µA IN EN VO (1) Output Voltage V V = V + 0.7V, I=% 10mA -V 1 +V 1% O IN O O O (Internal Fixed Voltage) -% 2% +2 (1) Line Regulation REG V = (V + 0.25V) to 5.5V, I=5 10mA 0.03 0.3 % (LINE) IN O OUT (1) Load Regulation REG V = V+2 0.7V 0. 0.4 % (LOAD) IN O (1)(2) Dropout Voltage V I=1 10mA 5 mV D O 10 I=5 500mA 701V 0 m O 150  2005 Semtech Corp. 2 www.semtech.com SC1566 POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specified: V = V . Adjustable Option (V > V ): V = 2.2V to 5.5V and I = 10µA to 3A. EN IN ADJ TH(ADJ) IN O Fixed Options (V = GND): V = (V + 0.7V) to 5.5V and I = 0A to 3A. Values in bold apply over the full operating temperature range. ADJ IN O O Pl arameterSs ymboTn est Condition Mp i Tx y Ms a Unit VO (Cont.) (1)(2) I=0 1.5A 20 0 3V 0 m Dropout Voltage O 400 I=0 3A 30 5 4V 5 m O 600 (3) Minimum Load Current I V = V+1 0.7V 10 µA O IN O CI urrent Limit 3.0 4.5 6.5 A CL ADJ (1) Reference Voltage V V = 2.2V, V = V , I=8 10mA 10 .1812 .201V .21 REF IN ADJ OUT O 14 .176 1.22 (4) Adjust Pin Current I V = V 10 200 nA ADJ ADJ REF (5) Adjust Pin Threshold V 0.10 0.20 0.40 V TH(ADJ) EN EI nable Pin Current V = 0V, V=5 3.3V 1. 10 µA EN EN IN EV nable Pin Threshold V = 3.3V 1.8 V IH IN V V = 3.3V 0.4 IL IN Over Temperature Protection HT igh Trip level 1C 75 ° HI HT ysteresis 1C 0 ° HYST Notes: (1) Low duty cycle pulse testing with Kelvin connections required. (2) Defined as the input to output differential at which the output voltage drops to 1% below the value measured at a differential of 0.7V. (3) Required to maintain regulation. Voltage set resistors R1 and R2 are usually utilized to meet this requirement. Adjustable versions only. (4) Guaranteed by design. (5) When V exceeds this threshold, the “Sense Select” switch disconnects the internal feedback chain from ADJ the error amplifier and connects V instead. ADJ  2005 Semtech Corp. 3 www.semtech.com SC1566 POWER MANAGEMENT Pin Configurations Ordering Information (1) Device Package SC1566 5-PIN SC1566IM-X.X.TR Versions (3) TO-263-3 (6) SC1566IM-X.XTRT Pn in Functio (2) SC1566I5M-X.X.TR 1N VI (3) TO-263-5 (2)(6) SC1566I5MX.XTRT 2N E SC1566IT-X.X 3D GN TO-263-5 (4) TO-220-3 (6) SC1566IT-X.XT 4J AD (2)(5) SC1566I5T-X.X 5O V (4) TO-220-5 (2)(5)(6) SC1566I5TX.XT TAB IS GND (2)(5) SC1566I5T-X.XSB TO-220-5 (4) TO-220-5 (2)(5)(6) SC1566I5TX.XSBT SC1566 3-PIN Notes: Versions (1) Where -X.X denotes voltage options. Available Pn in Functio voltages are: 2.5V and 1.8V. (2) Output voltage can be adjusted using external 1N VI resistors, see Pin Descriptions below. 2D GN (3) Only available in tape and reel packaging. A reel contains 800 devices. 3O V TO-263-3 (4) Only available in tube packaging. A tube contains 50 TAB IS GND devices. (5) T-XX = Straight in-line; T-XX-SB = Single Bend. (6) Lead free product. This product is fully WEEE and Note: RoHS compliant. (1) 3-pin versions are fixed output voltage only. TO-220-3 Pin Descriptions Pn in Name Pin Desciptio ADJ This pin, when grounded, sets the output voltage to that set by the internal feedback resistors. If external feedback resistors are used, the output voltage will be (See Application Circuits on page 1): 1.200 (R1 + R2) VO = Volts R2 EN Enable Input. Pulling this pin below 0.4V turns the regulator off, reducing the quiescent current to a fraction of its operating value. The device will be enabled if this pin is left open. Connect to VIN if not being used. GND Reference ground. Use the tab (electrically connected to GND) for heatsinking. VIN Input voltage. For regulation at full load, the input to this pin must be between (VO + 0.7V) and 5.5V. Minimum VIN = 2.2V. V. O This pin is the power output of the device  2005 Semtech Corp. 4 www.semtech.com SC1566 POWER MANAGEMENT Block Diagram * 5 lead versions only  2005 Semtech Corp. 5 www.semtech.com SC1566 POWER MANAGEMENT Typical Characteristics Dropout Voltage vs. Output Current Dropout Voltage vs. Junction vs. Junction Temperature Temperature vs. Output Current 500 500 150°C 450 450 I = 3A O 400 400 25°C 350 350 0°C 300 300 I = 1.5A O -40°C 250 250 200 200 150 150 I = 0.5A O 100 100 50 50 0 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 -50 -25 0 25 50 75 100 125 150 I (A) T (°C) O J Output Voltage (2.5V) vs. Junction Output Voltage (2.5V) vs. Junction Temperature vs. Output Current Temperature vs. Output Current 2.550 2.550 VIN = 3.2V VIN = 5.5V 2.540 2.540 2.530 2.530 2.520 2.520 2.510 2.510 I = 10mA I = 10mA O O 2.500 2.500 2.490 2.490 I = 3A O I = 3A O 2.480 2.480 2.470 2.470 2.460 2.460 2.450 2.450 -50 -25 0 25 50 75 100 125 150 -50 -25 0 25 50 75 100 125 150 T (°C) T (°C) J J Reference Voltage vs. Junction Reference Voltage vs. Junction Temperature vs. Output Current Temperature vs. Output Current 1.225 1.225 VIN = 2.2V VIN = 5.5V 1.220 1.220 1.215 1.215 1.210 1.210 1.205 1.205 I = 10mA O I = 3A O 1.200 1.200 1.195 1.195 I = 3A I = 10mA O O 1.190 1.190 1.185 1.185 1.180 1.180 1.175 1.175 -50 -25 0 25 50 75 100 125 150 -50 -25 0 25 50 75 100 125 150 T (°C) T (°C) J J  2005 Semtech Corp. 6 www.semtech.com V (V) VO (V) V (mV) REF D V (V) VO (V) V (mV) REF D SC1566 POWER MANAGEMENT Typical Characteristics (Cont.) Quiescent Current vs. Off-State Quiescent Current vs. Junction Temperature Junction Temperature 700 12 VIN = 5.5V VIN = 3.3V 690 10 680 670 8 660 650 6 640 4 630 620 2 610 600 0 -50 -25 0 25 50 75 100 125 150 -50 -25 0 25 50 75 100 125 150 T (°C) T (°C) J J Applications Information Introduction to choose an appropriate output capacitor for a given stability requirement. The SC1566 is intended for applications such as graphics cards where high current capability and very low Noise immunity: in very electrically noisy environments, dropout voltage are required. It provides a very simple, it is recommended that 0.1µF ceramic capacitors be low cost solution that uses very little pcb real estate and placed from IN to GND and OUT to GND as close to the typically does not require a heatsink. Additional features device pins as possible. include an enable pin to allow for a very low power consumption standby mode, and a fully adjustable External voltage selection resistors (5-pin parts): the output (5-pin versions). use of 1% resistors, and designing for a current flow ≥ 10µµA is recommended to ensure a well regulated Component Selection output (thus R2 ≤ 120kΩ). Input capacitor: a 4.7µF or 10µF ceramic capacitor is Thermal Considerations recommended. This allows for the device being some distance from any bulk capacitance on the rail. The power dissipation in the SC1566 is approximately Additionally, input droop due to load transients is reduced, equal to the product of the output current and the input improving load transient response. Additional capacitance to output voltage differential: may be added if required by the application. () P ≈ VIN − VOUT • I D O Output capacitor: a minimum bulk capacitance of 2.2µF, along with a 0.1µF ceramic decoupling capacitor is The absolute worst-case dissipation is given by: recommended. Increasing the bulk capacitance will improve the overall transient response. The use of P =() VIN − VOUT • I + VIN • I D(MAX ) (MAX ) (MIN ) O (MAX ) (MAX ) Q (MAX ) multiple lower value ceramic capacitors in parallel to achieve the desired bulk capacitance will not cause For a typical scenario, V = 3.3V ± 5%, V = 2.8V and IN OUT stability issues. Although designed for use with ceramic I = 2.5A, therefore: O output capacitors, the SC1566 is extremely tolerant of output capacitor ESR values and thus will also work V = 3.465V, V = 2.744V and I = 1.75mA, IN(MAX) OUT(MIN) Q(MAX) comfortably with tantalum output capacitors. For refer- ence, the phase-margin contour of Figure 1. can be used Thus P = 1.81W. D(MAX)  2005 Semtech Corp. 7 www.semtech.com I (µA) Q I (µA) Q(OFF) SC1566 POWER MANAGEMENT Applications Information (Cont.) Using this figure, and assuming T = 85°C, we can This should be achievable for the TO-263 package using A(MAX) calculate the maximum thermal impedance allowable to pcb copper area to aid in conducting the heat away from maintain T ≤ 150°C (see page 7): the device, such as a large (~2 squ. inch) pad connected J to the tab of the device. Internal ground/power planes () T − T () 150 − 85 J(MAX ) A(MAX ) and air flow will also assist in removing heat. For higher R = = = 36°C / W TH(J−A )(MAX ) P 1.81 D(MAX ) power dissipations it may be necessary to use a small R = 3°C / W and R = 0°C / W, TH(J−C)(MAX ) TH(C−S) heatsink and the TO-220 package. therefore R = 33°C / W TH(S−A )(MAX ) Co=22uF, Stable Region: Co=2.2uF, Stable Region: Unstable Region: Unstable Region: 3mA 3mA 30mA 30mA Load Load 300mA 300mA 3A 3A 0.001 0.01 0.1 1 10 0.001 0.01 0.1 1 10 ESR(Ohms) ESR(Ohms) Co=220uF, Stable Region: Unstable Region: 3mA 30mA Load 300mA 3A 0.001 0.01 0.1 1 10 ESR(Ohms) Figure 1. Phase-margin Contour Plot  2005 Semtech Corp. 8 www.semtech.com SC1566 POWER MANAGEMENT Outline Drawing - T0-263-3 Minimum Land Pattern - TO-263-3  2005 Semtech Corp. 9 www.semtech.com SC1566 POWER MANAGEMENT Outline Drawing - TO-263-5 Minimum Land Pattern - TO-263-5  2005 Semtech Corp. 10 www.semtech.com SC1566 POWER MANAGEMENT Outline Drawing - TO-220-3 Outline Drawing - TO-220-5  2005 Semtech Corp. 11 www.semtech.com SC1566 POWER MANAGEMENT Outline Drawing - TO-220-5 (T-XX-SB Option) Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804  2005 Semtech Corp. 12 www.semtech.com