Low Voltage 0.5x Regulated Step Down Charge Pump Product Datasheet VPA1000 Features Description Low cost alternative to buck regulator Saves up to ~500mW compared to standard LDO Small PCB footprint 1.2V, 1.5V, or 1.8V fixed output voltages 300mA maximum output current 3.3V to 1.2V with 72% efficiency High frequency (2.4MHz) reduces size of external components Short-circuit current protection Over-temperature protection Soft start TSOT-6 package The VPA1000 is a low voltage 0.5x regulated step-down charge pump. It is designed as a low cost replacement for inductor-based step-down switching regulators (buck), or a high efficiency replacement for linear regulators (LDO). At full load, it can save nearly 500mW of power compared to a standard LDO, making it ideal for low cost battery powered applications. The VPA1000 can also be put in a micro-power shutdown mode with 1A nominal input current to extend battery life when not in use. The VPA1000 is available in a TSOT-6 package and characterized over the industrial temperature range of -40C to +85C. Applications Notebook computers Handsets Battery powered equipment Typical Application Circuit Figure 1. VPA1000DYGI-12 Typical Application Circuit January 21, 2010 1 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet Table of Contents Absolute Maximum Ratings...............................................3 Power Efficiency...........................................................9 Specification Table............................................................4 Application ......................................................................10 Typical Performance Characteristics.................................5 Enable/Shutdown .......................................................10 Pin Configuration & Description ........................................7 Capacitor Selection ....................................................10 Functional Diagram ...........................................................8 Thermal Considerations .............................................10 Theory of operation ...........................................................9 Layout Considerations................................................10 Description ...................................................................9 Package outline drawing.................................................11 Minimum Input Voltage.................................................9 Ordering Guide ...............................................................12 Soft Start ......................................................................9 Short-circuit and Over-temperature Protection.............9 Revision History January 2010 - Rev 1.0: Initial Version January 21, 2010 2 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet ABSOLUTE MAXIMUM RATINGS Table 1. Absolute Maximum Ratings Summary Table 2. Package Thermal Resistivity PIN MAXIMUM RATING [NOTE 1] PACKAGE THERMAL RESISTIVITY (JA) [NOTE 3] VIN, VOUT, ENBL, C1N, C1P to GND Operating Ambient Temperature Range Storage Temperature Junction Temperature Lead Temperature (10 seconds) Maximum Power Dissipation -0.3V to +6V TSOT-6 118 C/W [Note 3] This thermal rating was calculated based on JEDEC standard conditions (EIA-JESD 51-2 for natural convection & JESD 51 6 for forced convection). The board type is 2S2P recommended by JEDEC (4-layers: 2 oz copper surface traces/ 1 oz copper buried planes, 4" x 4.5" board size). Actual thermal resistivity will be affected by PCB size, solder joint quality, PCB layer count, copper thickness, air flow, altitude, and other unlisted variables. -40C to +85C -55C to +150C -40C to +125C +260C Internally limited [Note 2] [Note 1] Stresses greater than those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability. [Note 2] The maximum power dissipation is PD(MAX) = (TJ(MAX) -TA) / JA where TJ(MAX) is 125C. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the device will enter thermal shutdown. January 21, 2010 3 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet SPECIFICATION TABLE VIN = 2.7V to 5V; ENBL = HIGH; CIN = 2.2F, CFLY = 1F, COUT = 4.7F. Unless otherwise specified, all specifications are tested under TA = 25C. The denotes specifications that apply for TA = -40C to +85C. [Note 4] Table 3. Input Specification SYMBOL PARAMETER VIN IOUT Operating input voltage range Maximum output current UVLO Under voltage lockout Under voltage lockout hysteresis VIN quiescent current VIN shutdown current IQ ISD Output voltage accuracy under all conditions Output voltage load regulation Output voltage line regulation Output voltage temperature regulation fOSC ISC VDO Charge pump switching frequency Short circuit current (folded back current) Charge pump dropout voltage Req Equivalent series resistance TSD Over-temperature protection trip point Over-temperature protection hysteresis Soft start time ENBL pin low level ENBL pin high level tSS VENBL_l VENBL_h CONDITIONS MIN 2.7 300 150 3V < VIN < 5V 2.7V < VIN 3V VIN rising 2.1 0.1 1.65 1 VIN = 3.3V VIN = 3.3V, VOUT = 0V, ENBL = 0V IOUT = 30mA to 300mA Over full input range, IOUT = 30mA Over full input range, IOUT = 30mA IOUT = 30mA VOUT = 0V, VIN = 3.3V IOUT = 300mA, [Note 5] VIN = 3V, IOUT = 300mA, [Note 6] [Note 6] [Note 6] TYP -3 MAX UNITS 5 2 V mA mA V V mA A 3 % 0.4 % % 2.4 0.5 0.004 2.0 %/C 2.4 120 200 2.8 300 MHz mA mV 0.6 1 133 15 75 0.4 1.6 C C s V V [Note 4] Specifications over the -40C to +85C operation ambient temperature are guaranteed by design, characterization and statistical correlation. [Note 5] Minimum input voltage is measured when output voltage is reduced by 2% as compared to the nominal condition under full load. Dropout is calculated as VIN(MIN)/2 - VOUT. [Note 6] Guaranteed by design, not 100% production tested. January 21, 2010 4 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet 1.30 1.28 1.26 1.24 1.22 1.20 1.18 1.16 1.14 1.12 1.10 100 90 80 70 60 50 40 30 20 10 0 V IN=3.3V TA=25C Efficiency (%) V OUT (V) TYPICAL PERFORMANCE CHARACTERISTICS 0 50 100 150 IOUT (mA) 200 250 V OUT=1.2V TA=25C V IN=3.3V V IN=4.2V 300 0 50 100 150 IOUT (m A) 200 250 300 Figure 3. Efficiency vs. Output Current 3.0 1.30 1.28 1.26 1.24 1.22 1.20 1.18 1.16 1.14 1.12 1.10 T A=25C TA=-40C 2.5 IQ (mA) V OUT (V) Figure 2. Output Voltage vs. Output Current IOUT=0mA IOUT=300mA IOUT=150m A 2.0 TA=25C TA=85C 1.5 1.0 3 3.5 4 4.5 5 5.5 3 3.5 V IN (V) 4 4.5 5 5.5 V IN (V) Figure 4. Output Voltage vs. Input Voltage Figure 5. Quiescent Current vs. Input Voltage 3.0 3.00 Minimum Input Voltage (V) Switching Frequency (MHz) V IN=3.0V 2.8 2.6 TA=-40C 2.4 TA=25C 2.2 TA=85C V OUT=1.2V 2.90 2.80 TA=25C T A=85C 2.70 2.60 T A=-40C 2.50 2.40 2.30 2.0 3 3.5 4 4.5 5 0 5.5 V IN (V) Figure 6. Charge Pump Switching Frequency vs. Input Voltage January 21, 2010 50 100 150 200 Output Current (mA) 250 300 Figure 7. Minimum Input Voltage vs. Output Current 5 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet EN 2V /div VIN 1V /div VOUT 500mV /div VOUT 500mV /div IOUT 100mA /div Figure 8. Power Up with No Load and VIN = 3.3V Figure 9. Enable/Disable with IOUT = 150mA and VIN = 3.3V VOUT 50mV /div AC VOUT 50mV /div AC IOUT 50mA /div IOUT 50mA /div Figure 10. Load Transient Response for IOUT = 0mA to 150mA Figure 11. Load Transient Response for IOUT = 50mA to 150mA and VIN = 3.3V VIN 2V /div VOUT 10mV /div AC IOUT 50mV /div AC Figure 13. Output Voltage Ripple for IOUT = 150mA and VIN = 3.3V Figure 12. Line Transient Response from VIN = 3.3V to 4.3V for IOUT = 200mA January 21, 2010 6 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet PIN CONFIGURATION & DESCRIPTION Figure 14. VPA1000 Pin Assignment (Top View) Table 4. Pin Descriptions NUMBER LABEL I/O DESCRIPTION 1 2 3 VIN GND ENBL Input 4 5 C1N VOUT 6 C1P Power supply input voltage. Place a decoupling 1F capacitor next to this pin. Ground connection for the IC. Enable input. Apply logic high for normal operation. When logic low is applied, the charge pump enters a micro-power shutdown mode. Negative terminal of the flying capacitor. Output voltage of the regulated charge pump. Connect a 4.7F ceramic capacitor from this pin to ground. Positive terminal of the flying capacitor. January 21, 2010 Input Output 7 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet FUNCTIONAL DIAGRAM C1P C1N VOUT VIN 2 Phase Charge Pump ENBL Soft Start 2.4MHz Oscillator Over Temp Protection Short Circuit Protection + - IMAX Error Amplifier + - VREF GND Figure 15. VPA1000 Functional Diagram January 21, 2010 8 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet To regulate the output voltage, the error amplifier controls the input P-channel MOSFET gate driver voltage, which controls the amount of current flowing into the flying capacitor during the charging phase. Thus, the flying capacitor's differential voltage is charged up to be equal to the output voltage. THEORY OF OPERATION Description The VPA1000 is a 0.5x regulated charge pump operating at constant frequency with 50% duty cycle. During the first phase, flying capacitor CFLY is placed in series with output capacitor COUT. The input current charges both the flying capacitor and output capacitor, and supplies the output load. During the second phase, the output capacitor and the flying capacitor are placed in parallel, and both capacitors are discharged to supply the output load. Since VIN conducts to VOUT with 50% duty cycle, the average input current is equal to 50% of the output current. Thus, the efficiency is approximately double than that of a standard LDO. Minimum Input Voltage For different output voltage options and output current loads, the minimum input voltage requirement is different in order to keep the output voltage regulation within 2% of its nominal level. For the 1.2V output, the minimum input voltage for a 300mA load is 2.85V. For a 150mA load, the minimum input voltage is 2.65V (refer to Figure 7). The VPA1000 guarantees the maximum dropout voltage for a 300mA load at 300mV over full temperature range. Thus, the minimum input voltage is calculated as: VIN(MIN) = 2 x (300mV + VOUT x 0.98) VIN VOUT CFLY 1F [1] Soft Start COUT 4.7F The VPA1000 has a built-in soft start circuitry to limit inrush current during start up. The soft start time is fixed with a nominal value of 75s. Phase 1 Short-circuit and Over-temperature Protection VIN The short-circuit protection ensures the maximum output current is limited to 120mA during short-circuit conditions. When the junction temperature of the VPA1000 reaches thermal shutdown threshold, the over-temperature protection will activate and shut down the charge pump and the gate driver. The device will resume to its previous operating condition when the junction temperature drops by 15C. VOUT CFLY 1F COUT 4.7F Phase 2 Figure 16. 0.5x Charge Pump Two Phase Operation Power Efficiency Since the input current is about half of the output current, the VPA1000 efficiency is much better than a conventional LDO. The efficiency can be calculated with the following equation: Efficiency (%) = 2 x [2] For example, with VIN = 3.3V, VOUT = 1.2V, and IOUT = 150mA, the VPA1000 efficiency is 72.7% while a conventional LDO efficiency is 36.4% under the same conditions. Figure 17. Input Current Flowing Diagram January 21, 2010 VOUT x 100% VIN 9 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet APPLICATION The VPA1000 is designed as a low cost replacement for a switching buck regulator, or a high efficiency replacement for a standard linear regulator (LDO). With a simple application circuit and small PCB footprint, the VPA1000 is an ideal component for low power, low cost systems. Thermal Considerations To prevent the device from exceeding its maximum power handling capability, it is important to keep the device junction temperature below 125C. Use the following equations to calculate the maximum allowable power dissipation. CFLY 1F PD(MAX) = C1P VIN 3.3V CIN 1F OFF ON C1N VIN VOUT COUT 4.7F (TJ(MAX) - TA ) JA [3] where TA is the ambient temperature, and JA is the package thermal resistance from junction to ambient, which is 118C/W for TSOT-6 with JESD51 standards. VOUT 1.2V Thus, the power dissipation for the charge pump can be calculated as: ENBL GND PD = IOUT (0.5VIN - VOUT ) [4] For example, with VIN = 3.3V, VOUT = 1.2V, IOUT = 150mA, and TA = 25C and using the above equations, the maximum allowable power dissipation is: Figure 18. VPA1000DYGI-12 Typical Application Circuit Enable/Shutdown PD(MAX) = The VPA1000 is enabled and shut down by applying a logic high or logic low to the ENBL pin. When the device is in shut down mode, the supply current will drop to 1A. If this feature is not used, the ENBL pin should be tied to VIN to permanently enable the device. (125C - 25C) = 0.85W 118C/W [5] and the power dissipated by the charge pump is 0.0675W with the above conditions. If power dissipation exceeds the maximum allowable power dissipation, a larger copper area or extra heat sink may be required. Capacitor Selection Layout Considerations The VPA1000 requires one input capacitor, one flying capacitor, and one output capacitor. Low ESR ceramic capacitors should be chosen, and X5R and X7R are recommended for their better performance over the -40C to 85C and -40C to 125C temperature ranges, respectively. A minimum 1F input capacitor should be used to bypass the input voltage. The flying capacitor value should be between 0.1F and 1F. To optimize the device performance, keep all capacitors close to the device pins, and connect all ground connections to a ground plane. Smaller flying capacitor will reduce the output overshoot during startup while larger flying capacitor will reduce the output ripple. To ensure stability over its operating current range, at least a 4.7F output capacitor is required. Higher output capacitance will help to reduce the output ripple and will have better transient response performance. January 21, 2010 10 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet PACKAGE OUTLINE DRAWING Figure 19. Package Outline Drawing January 21, 2010 11 (c) 2010 Integrated Device Technology, Inc. VPA1000 Product Datasheet ORDERING GUIDE Table 5. Ordering Summary PART NUMBER MARKING VOLTAGE OPTION PACKAGE AMBIENT TEMP. RANGE SHIPPING CARRIER QUANTITY VPA1000DYGI-12 VPA1000DYGI-128 00A0I 00A0I 1.2V 1.2V TSOT-6 TSOT-6 -40C to +85C -40C to +85C Tape or Canister Tape and Reel 25 2,500 OTHER VOLTAGE OPTIONS ARE AVAILABLE UPON REQUEST. www.IDT.com 6024 Silver Creek Valley Road San Jose, California 95138 Tel: 800-345-7015 DISCLAIMER Integrated Device Technology, Inc. (IDT) and its subsidiaries reserve the right to modify the products and/or specifications described herein at any time and at IDT's sole discretion. All information in this document, including descriptions of product features and performance, is subject to change without notice. Performance specifications and the operating parameters of the described products are determined in the independent state and are not guaranteed to perform the same way when installed in customer products. The information contained herein is provided without representation or warranty of any kind, whether express or implied, including, but not limited to, the suitability of IDT's products for any particular purpose, an implied warranty of merchantability, or non-infringement of the intellectual property rights of others. This document is presented only as a guide and does not convey any license under intellectual property rights of IDT or any third parties. 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