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User's Guide

SLVU357–March 2010

Using the TPS650001/3/6 2.25 MHz Step-Down Converter

with Dual LDO

The TPS650001/3/6 is a single chip Power Management ICs for portable applications. The device

combines a single step-down converter with two low dropout regulators. The step-down converter enters a

low power mode at light load for maximum efficiency across the widest possible range of load currents.

For low noise applications the device can be forced into fixed frequency PWM mode. The step-down

converter allows the use of a small inductor and capacitors to achieve a small solution size. The

step-down converter has Power Good status output that can be used for sequencing. The LDOs are

capable of supplying 300mA and can operate with an input voltage range between 1.6V and 6.0V,

allowing them to be supplied from the step-down converter or directly from the main battery. The

step-down converter and the LDOs have separate voltage inputs and enables, allowing for design and

sequencing flexibility.

Contents

1 Introduction .................................................................................................................. 2

1.1 Applications ......................................................................................................... 2

1.2 Features ............................................................................................................. 2

2 TPS650001/3/6 EVM Electrical Performance Specifications .......................................................... 3

3 Schematic .................................................................................................................... 4

4 Connector and Test Point Description ................................................................................... 5

4.1 JP1 – ENDCDC .................................................................................................... 5

4.2 JP2 – ENLDO1 ..................................................................................................... 5

4.3 JP3 – ENLDO2 ..................................................................................................... 5

4.4 JP4 – MODE ........................................................................................................ 5

4.5 JP5 – VINLDO1 .................................................................................................... 5

4.6 JP6 – VINLOD2 .................................................................................................... 5

4.7 J1 – VIN/GND ...................................................................................................... 5

4.8 J2 – VODCDC/GND ............................................................................................... 5

4.9 J3 – VLDO1/GND .................................................................................................. 6

4.10 J4 – VLDO2/GND .................................................................................................. 6

4.11 J5 – PG .............................................................................................................. 6

5 4 TPS650001/3/6 Typical Performance Data and Characteristic Curves ........................................... 6

5.1 Efficiency ............................................................................................................ 6

5.2 Line and Load Regulation ......................................................................................... 6

5.3 Output Voltage Ripple ............................................................................................. 9

5.4 Startup Timing .................................................................................................... 10

6 EVM Assembly Drawings and Layout .................................................................................. 11

7 List of Materials ............................................................................................................ 14

List of Figures

1 TPS650001/3/6 EVM Schematic.......................................................................................... 4

2 TPS650001/3/6 Efficiency vs Load Current ............................................................................. 6

3 TPS650001/3/6 DCDC Converter Load Transient Response......................................................... 7

4 TPS650001/3/6 LDOx Transient Response ............................................................................. 7

5 TPS650001/3/6 DCDC Converter Line Transient Response.......................................................... 8

6 TPS650001/3/6 LDOx Line Transient Response ....................................................................... 8

SLVU357–March 2010 Using the TPS650001/3/6 2.25 MHz Step-Down Converter with Dual LDO

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Summary of content (15 pages)

PAGE 1
User's Guide SLVU357 – March 2010 Using the TPS650001/3/6 2.25 MHz Step-Down Converter with Dual LDO The TPS650001/3/6 is a single chip Power Management ICs for portable applications. The device combines a single step-down converter with two low dropout regulators. The step-down converter enters a low power mode at light load for maximum efficiency across the widest possible range of load currents. For low noise applications the device can be forced into fixed frequency PWM mode.
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Introduction 7 8 9 10 11 12 www.ti.com ................................................................ TPS650001/3/6 Output Voltage Ripple (MODE = high) ............................................................... TPS650001/3/6 DCDC Converter Startup Timing..................................................................... TPS650001/3/6 EVM Component Placement (Viewed from Top) .................................................. TPS650001/3/6 EVM Top Copper (Viewed from Top) .........................
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TPS650001/3/6 EVM Electrical Performance Specifications www.ti.com 2 TPS650001/3/6 EVM Electrical Performance Specifications Table 2. TPS650001/3/6EVM Electrical and Performance Specifications PARAMETER NOTES AND CONDITIONS MIN NOM MAX UNITS INPUT CHARACTERISTICS VIN VIN_UVLO Hysteresis Input Voltage Input UVLO 2.3 VIN falling 1.72 6.0 1.77 1.82 V V 160 mV VIN = Nom, IOUT = Nom, TPS650001, TPS650006 1.2 V VIN = Nom, IOUT = Nom, TPS650003 1.
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Schematic 3 www.ti.com Schematic For Reference Only, See Table 4: Bill of Materials for Specific Values Figure 1. TPS650001/3/6 EVM Schematic 4 Using the TPS650001/3/6 2.
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Connector and Test Point Description www.ti.com 4 Connector and Test Point Description 4.1 JP1 – ENDCDC Placing a shorting bar between ENDCDC and ON ties the EN pin of the DCDC converter to VIN, thereby enabling the DCDC converter. Placing a shorting bar between ENDCDC and OFF ties the EN pin of the DCDC converter to GND, thereby disabling the DCDC converter. 4.2 JP2 – ENLDO1 Placing a shorting bar between ENLDO1 and ON ties the EN pin of LDO1 to VIN, thereby enabling LDO1.
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4 TPS650001/3/6 Typical Performance Data and Characteristic Curves 4.9 www.ti.com J3 – VLDO1/GND This header is the output of LDO1. This output voltage is internally fixed for the TPS650001/3/6 (see Table 1). VLDO2 is capable of sourcing up to 300-mA. A load can be connected between J3 pins 1 and 2 (positive connection) and J3 pins 3 and 4 (GND). 4.10 J4 – VLDO2/GND This header is the output of LDO2. This output voltage is internally fixes for the TPS650001/3/6 (see Table 1).
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4 TPS650001/3/6 Typical Performance Data and Characteristic Curves www.ti.com Ch2: DCDC Load Current 200mA/div Ch1: VDCDC 50mV/div VINDCDC = 3.6V o TA = 25 C DCDC Load Current = 60mA to 540 mA Mode = GND t - Time - 100ms/div VINLDOx = 3.6V TA = 25oC LDOx Load Current = 15mA to 100mA VLDOx = 1.2V EN_DCDC = GND Ch2: VLDOx 20mV/div Ch1: LDOx Load Current 50mA/div Figure 3. TPS650001/3/6 DCDC Converter Load Transient Response t - Time - 200ms/div Figure 4.
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www.ti.com VINDCDC = 3.6 V to 4.2V to 3.6V o TA = 25 C DCDC Load Current = 50mA Mode = VINDCDC Ch2: VDCDC 20mV/div Ch1: VINDCDC 500mV/div 4 TPS650001/3/6 Typical Performance Data and Characteristic Curves t - Time - 100ms/div Ch2: VLDOx 20mV/div Ch1: VINLDOx 500mV/div Figure 5. TPS650001/3/6 DCDC Converter Line Transient Response VINLDOx = 1.6 V to 2.3V to 1.6V o TA = 25 C VLDOx = 1.007V LDOx Load Current = 1mA EN_DCDC = GND t - Time - 100ms/div Figure 6.
PAGE 9
4 TPS650001/3/6 Typical Performance Data and Characteristic Curves www.ti.com Output Voltage Ripple Ch3: Load Current DCDC 20mAdiv Ch2: SW 2V/div Ch1: VDCDC 10mV/div 5.3 VINDCDC = 3.6 V o TA = 25 C VDCDC = 1.2 V Load Current = 60mA EN_DCDC = high EN_LDO1 = low EN_LDO2 = low t - Time - 2ms/div Ch4: Load Current DCDC 20mAdiv Ch2: SW 2V/div Ch1: VDCDC 10mV/div Figure 7. TPS650001/3/6 Output Voltage Ripple (MODE = low) VINDCDC = 3.6 V o TA = 25 C VDCDC = 1.
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4 TPS650001/3/6 Typical Performance Data and Characteristic Curves Startup Timing Ch3: SW 20V/div Ch2: VDCDC Ch1: EN_DCDC 500mV/div 2V/div 5.4 www.ti.com VINDCDC = 3.6 V o TA = 25 C VDCDC = 1.2 V Load DCDC = 100mA EN_DCDC = 0V to 3.6V EN_LDO1 = low EN_LDO2 = low t - Time - 100ns/div Figure 9. TPS650001/3/6 DCDC Converter Startup Timing 10 Using the TPS650001/3/6 2.
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EVM Assembly Drawings and Layout www.ti.com 6 EVM Assembly Drawings and Layout The following figures (Figure 10 through Figure 12) show the design of the TPS650001/3/6EVM printed circuit board. The EVM has been designed using a 2-Layer, 1oz copper-clad circuit board 2.0” x 2.4” (50.8mm x 61.09mm). Figure 10. TPS650001/3/6 EVM Component Placement (Viewed from Top) SLVU357 – March 2010 Submit Documentation Feedback Using the TPS650001/3/6 2.
PAGE 12
EVM Assembly Drawings and Layout www.ti.com Figure 11. TPS650001/3/6 EVM Top Copper (Viewed from Top) 12 Using the TPS650001/3/6 2.
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EVM Assembly Drawings and Layout www.ti.com Figure 12. TPS650001/3/6 EVM Bottom Copper (Viewed from Bottom) SLVU357 – March 2010 Submit Documentation Feedback Using the TPS650001/3/6 2.
PAGE 14
List of Materials 7 www.ti.com List of Materials Table 3 lists the EVM components as configured according to the schematic shown in Figure 1. Table 3. TPS650001/3/6EVM Bill of Materials Count RefDes Value Description Size Part Number MFR 0 C1, C6 open Capacitor, Ceramic, 10V, X5R, 10%, l 0805 Std Std 4 C2, C5, C7, C8 10µF Capacitor, Ceramic, 10V, X5R, 10%, e 0805 Std Std 2 C3, C4 2.
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