Thermal

Shutdown

UVLO

Gate Driver

Pulse Modulator

Soft Start

Control

OVP & Short

Protection

3

5

4

Logic

2

VOUT

VOUT

VIN

SW

EN

FB

VIN

6

GND

REF

Current Sense

1

OFF

ON

L

7

R1

R2

VOUT

Copyright © 2016, Texas Instruments Incorporated

8

TPS61230A

SLVSCZ5A – JULY 2016 – REVISED AUGUST 2016

www.ti.com

Product Folder Links: TPS61230A

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Copyright © 2016, Texas Instruments Incorporated

8 Detailed Description

8.1 Overview

The TPS61230A is a high efficiency synchronous boost converter with integrating the 21-m

Ω low side FET and

18-m

Ω high side FET. The device could deliver up to 12-W output power with 5.5-V maximum output voltage

from single cell Li-Iron battery. TPS61230A uses a quasi constant on-time valley current mode which provides an

excellent transient response. The TPS61230xA typically operates at a quasi-constant 1.15-MHz frequency pulse

width modulation (PWM) at the moderate to heavy load currents, allows the use of small inductor and capacitors

to achieve a compact solution size.

During the PWM operation, a simple circuit predicts the required on time (with the VIN / VOUT ratio) of the ow-

side FET. At the beginning of each switching cycle, the low-side FET turns on and the inductor current ramps up

to the peak current determined by the on-time and the inductance. Once the on-timer expires, the high-side FET

turns on and the inductor current decays to a preset valley current threshold determined by the Error Amplifier’s

output. The switching cycle repeats again by calculating the on time and activating the low-side FET.

At the light load currents, TPS61230A operates in Power Save Mode with pulse frequency modulation (PFM) and

improves the efficiency under the light load.

Internal soft-start and loop compensation simplifies the design process and minimizes the number of external

components.

8.2 Functional Block Diagram