DEF_1

FB1

MODE/DATA

VIN

EN1

SW2

ADJ2

GND

EN2

Po

w

er

PA

D

SW1

1

2

3

4

5

10

9

8

7

6

TopviewDRCpackage

TPS62420, TPS62421

www.ti.com

SLVS676C – JUNE 2006 – REVISED JUNE 2010

DEVICE INFORMATION

PIN ASSIGNMENTS

TERMINAL FUNCTIONS

TERMINAL

I/O

DESCRIPTION

NO.

NAME

(QFN)

ADJ2

1

I

Input to adjust output voltage of converter 2. In adjustable version (TPS62420) connect a external

resistor divider between VOUT2, this pin and GND to set output voltage between 0.6V and VIN. If

EasyScale™ Interface is used for converter 2, this pin must be directly connected to the output.

MODE/DATA

2

I

This Pin has 2 functions:

1. Operation Mode selection: With low level, Power Save Mode is enabled where the device

operates in PFM mode at light loads and enters automatically PWM mode at heavy loads. Pulling

this PIN to high forces the device to operate in PWM mode over the whole load range.

2. EasyScale™ Interface function: One wire serial interface to change the output voltage of both

converters. The pin has an open drain output to provide an acknowledge condition if requested.

The current into the open drain output stage may not exceed 500mA. The interface is active if

either EN1 or EN2 is high.

VIN

3

I

Supply voltage, connect to VBAT, 2.5V to 6V

FB1

4

I

Direct feedback voltage sense input of converter 1, connect directly to Vout 1. An internal feed forward

capacitor is connected between this pin and the error amplifier. In case of fixed output voltage versions

or when the Interface is used, this pin is connected to an internal resistor divider network.

DEF_1

5

I/O

This pin defines the output voltage of converter 1. The pin acts in TPS62420 as an analog input for

output voltage setting via external resistors. In fixed default output voltage versions this pin is a digital

input to select between two fixed default output voltages, see table ordering information.

In TPS62420 an external resistor network needs to be connected to this pin to adjust the default output

voltage.

SW1

6

Switch Pin of Converter1. Connected to Inductor

EN1

7

I

Enable Input for Converter1, active high

GND

8

I

GND for both converters, this pin should be connected with the PowerPAD

EN2

9

I/O

Enable Input for Converter 2, active high

SW2

10

Switch Pin of Converter 2. Connected to Inductor.

PowerPAD™

Connect to GND

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Product Folder Link(s): TPS62420 TPS62421