P

VOUT

EN/BYP

SW

Rectifying

Switch

Overvoltage

Protection

Bypass

Switch

Startup Circuit

VIN

Control Logic

Thermal Shutdown

Undervoltage

Lockout

Driver

GND

Main

Switch

Vref

integrated FB divider

network with disconnect

BYP/EN

VSEL

Bypass Switch

Control

VOUT

VIN

Current

Sense

Voltage Error

Amplifier

N

N

Reference Vref

VIN

TPS61291

www.ti.com

SLVSBX9A – SEPTEMBER 2014 – REVISED SEPTEMBER 2014

7 Detailed Description

7.1 Overview

The TPS61291 provides two operating modes: high efficiency boost mode to generate an output voltage higher

than the input voltage and bypass mode, which connects the output of the device directly to the input.

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Bypass / Boost Mode Operation EN/BYP

The EN/BYP pin selects the operating mode of the device. With the EN/BYP pin pulled low, the device operates

in bypass mode. With a high level on the EN/BYP pin, the device operates as a boost converter. The EN/BYP

pin is usually controlled by an I/O pin of a MCU, powered from the output of the TPS61291 and should not be left

floating. See Figure 8. See also sections Boost Mode Operation and Bypass Mode Operation for more detailed

descriptions.

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Product Folder Links: TPS61291