SEMTECH SC631

SC631 Fixed 4.4V Output Charge Pump Regulator POWER MANAGEMENT Features Description „ Input voltage range — 2.9V to 5.5V The SC631 is a high-current voltage regulator using „ V tolerance — 4.4V ±3% Semtech’s proprietary low-noise charge pump technol- OUT „ Continuous output current — 250mA ogy. Performance is optimized for use in single Li-Ion „ Peak output current — 500mA battery cell applications. The regulator provides the per- „ Three charge pump modes: 1x, 1.5x and 2x formance of a linear, low drop-out (LDO) voltage regulator „ Output ripple ≤ 30mV for I ≤ 400mA when the input is greater than 4.4V. Unlike an LDO, drop- PP OUT „ Short circuit, over-voltage, and over-temperature out is avoided when the input is less than 4.4V. Instead, a protection charge pump is activated to provide voltage boost and „ Soft-start functionality the head-room needed for voltage regulation. „ Shutdown current — 0.1μA, typical Only two 2.2μF bucket capacitors are required to deliver „ Ultra thin package — 2 x 2 x 0.6 (mm) the full output current. The charge pump provides a low „ Fully WEEE and RoHS compliant EMI solution compared to inductive boost regulators. Applications The SC631’s charge pump has three modes of operation: „ Mobile phones 2x, 1.5x, and 1x modes. The 2x and 1.5x modes deliver „ Multi-LED backlit LCDs current to the load in each of two phases. The 1x mode „ PMPs turns off the charge pump, delivering current through an „ Digital video cameras LDO. When active, the charge pump provides low-ripple „ Digital still cameras operation at 200kHz, which is typically less than 30mVpp „ PDAs at the output. The SC631 is capable of delivering 250mA „ LED camera fl ash continuous current, with peak current to 500mA. A 22μF „ Audio amplifi er power output capacitor is used for decoupling the load and for smoothing mode transitions. Hysteresis is provided to prevent chatter between charge pump modes. The micro lead-frame package is both small and thermally effi cient, measuring 2 x 2 x 0.6 (mm). Typical Application Circuit V = 4.4V @ 250mA OUT IN OUT C C IN OUT V BAT 22μF 22μF SC631 Chip C1+ EN C 1 enable 2.2μF C1- C2+ C 2 GND 2.2μF C2- Patents Pending July 24, 2008 © 2008 Semtech Corporation 1 SC631 Pin Confi guration Ordering Information Device Package (1)(2) SC631ULTRT MLPD-UT-8 2x2 SC631EVB Evaluation Board Notes: (1) Available in tape and reel only. A reel contains 3,000 devices. GND 1 8 C2- (2) Lead-free package only. Device is WEEE and RoHS compliant. TOP VIEW C1+ 2 7 C2+ C1- 3 6 OUT T IN 5 EN 4 MLPD-UT-8; 2x2, 8 LEAD θ = 68°C/W JA Marking Information 631 yw yw = Datecode 2 SC631 Absolute Maximum Ratings Recommended Operating Conditions IN (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +6.0 Ambient Temperature Range (°C) . . . . . . . . -40 ≤ T ≤ +85 A OUT (V). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +6.0 IN (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.9 ≤ V ≤ 5.5 IN C1+, C2+ (V) . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to (V + 0.3) OUT Pin Voltage — All Other Pins (V) . . . . . . . . . -0.3 to (V + 0.3) IN Thermal Information OUT pin — Short Circuit Duration . . . . . . . . . . Continuous (1) (2) Thermal Resistance, Junction to Ambient (°C/W) . . . . 68 ESD Protection Level (kV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Maximum Junction Temperature (°C) . . . . . . . . . . . . . . +150 Storage Temperature Range (°C) . . . . . . . . . . . . -65 to +150 Peak IR Reflow Temperature (10s to 30s) (°C) . . . . . . . +260 Exceeding the above specifi cations may result in permanent damage to the device or device malfunction. Operation outside of the parameters specifi ed in the Electrical Characteristics section is not recommended. NOTES (1) Calculated from package in still air, mounted to 3 x 4.5 (in), 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards. (2) Tested according to JEDEC standard JESD22-A114-B. Electrical Characteristics Unless otherwise specifi ed: T = +25°C for Typ, -40°C to +85°C for Min and Max; C = C = 2.2μF (ESR < 0.03Ω); C = C = 22μF; V = 2.9V to 5.5V A 1 2 IN OUT IN Parameter Symbol Condition Min Typ Max Units Output Voltage V V = 4.2V, I = 1mA 4.27 4.4 4.53 V OUT IN OUT Output Voltage Ripple V I ≤ 400mA 30 mV PP OUT (1) Peak Load - thermally limited , 500 mA T <150°C, 3.33V ≤ V ≤ 5.5V J IN Maximum Output Current I OUT Continuous Load, T ≤ 55°C, 2.92V ≤ V ≤ 4.2V 325 mA A IN Continuous Load 250 mA Shutdown Current I Shutdown (EN = GND), V = 3.6V 0.1 2 μA SD IN Total Quiescent Current I EN high, I = 1mA 1.5 2.5 mA Q OUT Charge Pump Frequency f V = 3.2V 200 kHz PUMP IN (EN transitions from low to high), Start-Up Time t 400 μs SU 4.27V ≤ V ≤ 4.53V, No load OUT Line Regulation ΔV I = 1mA, 2.85V ≤ V ≤ 4.2V 21 mV LINE OUT IN Load Regulation ΔV V =4.2V, 1mA ≤ I ≤ 400mA 33 mV LOAD IN OUT 3 SC631 Electrical Characteristics (continued) Parameter Symbol Condition Min Typ Max Units EN Input High Threshold V V = 5.5V 1.6 V IH IN EN Input Low Threshold V V = 2.7V 0.4 V IL IN EN Input High Current I V = 5.5V 2 μA IH IN EN Input Low Current I V = 5.5V 2 μA IL IN 1x mode 0.25 Ω Open-Loop Output Resistance R 1.5x mode, V = 3.7V 2.85 Ω OUT IN 2x mode, V = 3.1V 2.9 Ω IN V I = 200mA 4.41 V TRANS 1X OUT (2) Mode Transition Voltage V I = 200mA 3.31 V TRANS 1.5X OUT Fault Protection Short-Circuit Current I V = 0V, I = I 300 600 980 mA SC OUT OUT IN V > 2V, 1x mode 0.6 1.2 2.0 A OUT Input Current Limit I V > 2V, 1.5x and 2x modes 1.2 2.0 2.8 A LIMIT OUT V ≤ 2V, I = I 700 mA OUT OUT IN T Rising Threshold 165 °C OTP Over Temperature (3) T Hysteresis 20 °C HYS Notes: (1) Thermal limitation is dependent upon the thermal performance of the printed circuit board in support of the package standard of 68° C/W. (2) Voltage at the IN pin where a mode transition takes place in the charge pump with V falling. IN (3) Guaranteed by design - not tested in production. 4 SC631 Typical Characteristics Load Regulation Line Regulation V = 4.4V, V = 4.2V OUT IN V = 4.4V, I = 1mA OUT OUT 25 25 20 T =25°C A 85°C 20 15 TA=85°C 25°C 10 15 3.6V, 0mV -40°C 5 10 0 T =-40°C A -5 5 -10 0 -15 0 90 180 270 360 450 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Output Current (mA) Input Voltage (V) PSRR versus Frequency — 1.5x Mode PSRR versus Frequency — 2x Mode V = 3.6V, V = 4.4V, I = 50mA IN OUT OUT V = 2.9V, V = 4.4V, I = 50mA IN OUT OUT 0 0 C =C =22μF (0805) C =C =22μF (0805) IN OUT IN OUT -10 -10 C =C =2.2μF (0603) C =C =2.2μF (0603) 1 2 1 2 -20 -20 -30 -30 -40 -40 -50 -50 -60 -60 -70 -70 -80 -80 -90 -90 -100 -100 10000 10 100 1000 10000 10 100 1000 Frequency [Hz] Frequency [Hz] 5 Output Voltage Variation —ΔV (mV) Gain [dB] LOAD Output Voltage Variation —ΔV (mV) Gain [dB] LINE SC631 Typical Characteristics (continued) Effi ciency — 10mA Effi ciency — 50mA V = 4.4V, I = 10mA OUT OUT V = 4.4V, I = 50mA OUT OUT 100 100 1.5x Mode 1.5x Mode 90 90 80 80 Mode Transition 70 70 Hysteresis Mode Transition 2x Mode Hysteresis 2x Mode 60 60 50 50 4.2 3.9 3.6 3.3 3.0 2.7 4.2 3.9 3.6 3.3 3.0 2.7 VIN (V) VIN (V) Effi ciency — 100mA Effi ciency — 200mA V = 4.4V, I = 200mA OUT OUT V = 4.4V, I = 100mA OUT OUT 100 100 1.5x Mode 90 90 1.5x Mode 80 80 70 70 Mode Mode Transition Transition 2x Mode Hysteresis Hysteresis 60 60 2x Mode 50 50 4.2 3.9 3.6 3.3 3.0 2.7 4.2 3.9 3.6 3.3 3.0 2.7 V (V) V (V) IN IN Effi ciency — 300mA Effi ciency — 400mA V = 4.4V, I = 300mA V = 4.4V, I = 400mA OUT OUT OUT OUT 100 100 90 90 1.5x Mode 1.5x Mode 80 80 Mode Transition 70 70 Hysteresis 60 60 2x Mode 2x Mode 50 50 4.2 3.9 3.6 3.3 3.0 2.7 4.2 3.9 3.6 3.3 3.0 2.7 VIN (V) V (V) IN 6 Efficiency(%) Efficiency(%) Efficiency(%) Efficiency(%) Efficiency(%) Efficiency(%) SC631 Typical Characteristics (continued) Ripple — 1.5x Mode Ripple — 1x Mode V = 5.2V, V = 4.4V, I = 400mA V = 4.2V, V = 4.4V, I = 400mA IN OUT OUT IN OUT OUT V (100mV/div) IN -PP V (20mV/div) IN -PP V (20mV/div) OUT -PP V (100mV/div) OUT -PP 400mA 400mA I (200mA/div) OUT I (200mA/div) OUT C =C =22μF (0805) IN OUT C =C =22μF (0805) IN OUT C =C =2.2μF (0603) 0mA 1 2 0mA C =C =2.2μF (0603) 1 2 Time (10μs/div) Time (10μs/div) Ripple — 2x Mode Startup (No Load) V = 3.2V, V = 4.4V, I = 400mA IN OUT OUT V = 3.6V, I = 0mA IN OUT V (50mV/div) IN -PP V (2V/div)– EN 0V— V (50mV/div) OUT -PP 400mA I (200mA/div) OUT V (2V/div)– OUT C =C =22μF (0805) IN OUT 0V— C =C =2.2μF (0603) 1 2 C =C =22μF (0805) IN OUT 0V— C =C =2.2μF (0603) 0mA 1 2 I (200mA/div) OUT Time (200μs/div) Time (10μs/div) Quiescent Current Startup (400mA) V = 5V, I = 1mA V = 3.6V, I = 400mA OUT OUT IN OUT 2.5 85C 25C 2.0 V (2V/div)– EN 0V — 1.5 -45C V (2V/div)– OUT 0V— 1.0 C =C =22μF (0805) IN OUT 0V— C =C =2.2μF (0603) 1 2 I (200mA/div)– OUT 0.5 Time (200μs/div) 4.20 3.94 3.68 3.42 3.16 2.90 V (V) IN 7 I (mA) Q SC631 Pin Descriptions Pin Pin Name Pin Function 1 GND Ground — connect to ground plane with multiple vias 2 C1+ Positive terminal of bucket capacitor 1 3 C1- Negative terminal of bucket capacitor 1 4 IN Input supply voltage 5EN Chip enable — active-high 6 OUT Output 7 C2+ Positive terminal of bucket capacitor 2 8 C2- Negative terminal of bucket capacitor 2 This pad is for heat sinking and is not connected internally. It must be connected to a ground plane using T Thermal Pad multiple vias. 8 SC631 Block Diagram IN LDO 4 2 C1+ 200kHz 3 C1- 7 C2+ Logic EN 5 8 Control C2- CHARGE PUMP 6 OUT Reference Voltage Generator 1 GND 9 SC631 Applications Information temperature limit while operating the SC631 within the General Description specifi ed electrical conditions. A poor layout may allow The SC631 is a 4.4V output charge pump regulator the junction temperature to reach the over temperature designed to support up to 325mA (T ≤ 55°C, 2.92V ≤ V ≤ A IN limit, so it is important to maintain adequate ground 5.5V) and 250mA (T ≤ 85°C, 2.90V ≤ V ≤ 5.5V) of continu- A IN plane around the device to maximize heat transfer to the ous current. SC631 applications include power for LEDs PCB. and audio amplifi ers in portable handheld equipment. SC631 may be used in conjunction with regulated current Temperature Derating sink devices such as the SC620 Octal LED Driver or with The V supply range and ambient temperature range of ballast resistors. IN the application should be compared with the following The SC631 has three operating modes — 1x, 1.5x, and 2x. derating curve to determine the maximum safe continu- The 1x mode is a linear series regulation mode with a low ous load current. The DC operating points beneath each open-loop output resistance of only 250mΩ. The 1x mode curve are in the safe operating temperature range of the functions as a low-noise linear regulator. The 1.5x and 2x MLP package. modes are a low noise, constant frequency, constant duty 450 cycle switch mode, using two bucket capacitors. One bucket supports the full output current while the other 400 bucket charges from the input. The two buckets exchange Derating for V < 4.2V IN roles in the next phase, supplying continuous output current in both phases and reducing the need for a large 350 output decoupling capacitor. The constant frequency, constant duty cycle operation also produces predictable 300 Derating for V < 5.5V constant frequency harmonics. IN 250 Mode Transition Hysteresis Hysteresis is provided to prevent chatter between charge 200 pump modes for input steps of up to 120mV. For optimum transient performance, it is recommended for the supply decoupling capacitance be large enough to prevent steps 150 35 45 55 65 75 85 greater than 120mV. Normally C = 22uF is suffi cient to Ambient Temp (°C) IN minimize supply transients during the charge pump mode Maximum Continuous Output transitions. Protection Circuitry Thermal Resistance The SC631 also provides protection circuitry that pre- vents the device from operating in an unspecifi ed state. The SC631 package is thermally effi cient when the circuit These functions include: board layout connects the thermal pad through multiple vias to the ground plane. The thermal resistance rating is • Over-Current Protection (OCP) dependent upon the connection between the thermal • Short-Circuit Current Protection (SCCP) pad and the ground plane. A layout that is done correctly • Over-Temperature Protection (OTP) should keep the junction temperature below the over- 10 I (mA) OUT SC631 Applications Information (continued) Over-Current Protection When selecting capacitors for the application, the DC Over-current protection is provided to limit the output voltage characteristic of the capacitor should be consid- current. When V is greater than 2V, OCP limits the output ered. The value of capacitance at the DC operating voltage OUT to 1A typical. The 2V threshold allows the device to may be considerably lower than the rated value. The fol- recover from excessive voltage droop during an over- lowing table lists recommended capacitor values which current event. have been chosen to minimize the impact of this limitation. Short-Circuit Current Protection Short-circuit current protection is provided to limit the Table 1 — Recommended Capacitors current that can be sourced when the output is shorted to Value Case ground. When a short circuit forces V to drop below 2V, Capacitor Notes OUT μF Size the SCCP detects the condition and limits the output current to 600mA (typical). Typical output V ≤ 20mV in all PP charge pump modes C , C 22 0805 IN OUT Over-Temperature Protection Typical input ripple ≤ 100mV in all The over-temperature circuit helps prevent the device charge pump modes from overheating and experiencing a catastrophic failure. Required for the full rated output When the junction temperature exceeds 165°C, the device C 2.2 0603 BUCKET current is disabled. It remains disabled until the junction tempera- Useful for load current up to ture drops below this threshold. Hysteresis is included C 2.2 0402 BUCKET 300mA that prevents the device from re-enabling until the junc- tion temperature is reduced by 20°C. NOTE: Use only X5R type capacitors, with a 6.3V rating or higher Capacitor Selection The highest capacitance values in the smallest package The SC631 is designed to use low-ESR ceramic capacitors sizes tend to have poor DC voltage characteristics. The for the input and output bypass capacitors as well as the highest value 0402 size capacitor retains as little as 35% of charge pump bucket capacitors. Ideal performance is its rated value at 5VDC. The same value chosen in the next achieved when the bucket capacitors are exactly equal. larger package size (0603) retains about 60% of its rated The value of input and output decoupling capacitors will value at 5VDC. vary with system requirements. For best ripple perfor- mance C and C are normally 22μF and the bucket IN OUT capacitors C and C are 2.2μF. For low profi le designs, two 1 2 10μF capacitors may be used in place of each 22μF. 11 SC631 Applications Information (continued) 2. Place the input and output decoupling capacitors PCB Layout Considerations as close as possible to the device and connect these Poor layout can degrade the performance of the regula- capacitors’ ground pads together to the ground plane tor and can be a contributory factor in EMI problems, using multiple vias through a short wide copper ground bounce, thermal issues, and resistive voltage area. losses. Poor regulation and instability can result. 3. Connect pin 1 directly to the copper area under the The following design rules are recommended: thermal pad. 4. The thermal pad at the center of the device is not 1. Place the bucket capacitors as close to the device as electrically connected. Connect this pad to the possible and on the same side of the board. Use short ground plane using multiple vias. wide copper areas between the capacitor pins and 5. Use a ground plane to further reduce noise the device pins. interference on sensitive circuit nodes. SC631 C 2 C2- C2+ C C1+ 1 GND GND V C1- OUT EN V IN C OUT C IN EN 12 SC631 Outline Drawing — MLPD-UT-8 2x2 B A D DIMENSIONS INCHES MILLIMETERS DIM MIN NOM MAX MIN NOM MAX - - E A .020 .024 0.50 0.60 PIN 1 - - A1 .000 .002 0.00 0.05 INDICATOR (.006) (0.1524) A2 (LASER MARK) b .007 .010 .012 0.18 0.25 0.30 D .075 .079 .083 1.90 2.00 2.10 D1 .061 .067 .071 1.55 1.70 1.80 E .075 .079 .083 1.90 2.00 2.10 E1 .026 .031 .035 0.65 0.80 0.90 e .020 BSC 0.50 BSC A SEATING L .012 .014 .016 0.30 0.35 0.40 PLANE aaa C 8 8 N aaa .003 0.08 A2 A1 C bbb .004 0.10 D1 1 2 LxN E/2 E1 N bxN bbb C A B e e/2 D/2 NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. 13 SC631 Land Pattern — MLPD-UT-8 2x2 H DIMENSIONS R DIM INCHES MILLIMETERS (.077) (1.95) C G .047 1.20 H .067 1.70 Z (C) K G K .031 0.80 .020 0.50 P R .006 0.15 Y X .012 0.30 Y .030 0.75 Z .106 2.70 P X NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD 3. SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR FUNCTIONAL PERFORMANCE OF THE DEVICE. Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111 Fax: (805) 498-3804 www.semtech.com 14