Outputvoltage

Vout (PWM)

Vout +1%

PFMComparator

threshold

VoltagePositioning

Lightload

PFMMode

moderatetoheavyload

PWMMode

TPS62290, TPS62291, TPS62293

SLVS764F – JUNE 2007 – REVISED JANUARY 2016

www.ti.com

Feature Description (continued)

Figure 5. Power Save Mode Operation

8.3.2 Enable

and the soft start circuit is activated. The EN input can be used to control power sequencing in a system with

various DC/DC converters. The EN pin can be connected to the output of another converter, to drive the EN pin

high and getting a sequencing of supply rails. With EN = GND, the device enters shutdown mode, in which all

internal circuits are disabled. In fixed output voltage versions, the internal resistor divider network is disconnected

from FB pin.

8.3.3 Mode Selection

The MODE pin allows mode selection between forced PWM mode and power save mode.

Connecting this pin to GND enables the power save mode with automatic transition between PWM and PFM

mode. Pulling the MODE pin high forces the converter to operate in fixed frequency PWM mode even at light

load currents. This allows simple filtering of the switching frequency for noise sensitive applications. In this mode,

the efficiency is lower compared to the power save mode during light loads.

The condition of the MODE pin can be changed during operation and allows efficient power management by

adjusting the operation mode of the converter to the specific system requirements.

8.3.4 Undervoltage Lockout

The undervoltage lockout circuit prevents the device from malfunctioning at low input voltages and from

excessive discharge of the battery and disables the output stage of the converter. The undervoltage lockout

8.3.5 Thermal Shutdown

mode, the high side and low side MOSFETs are turned-off. The device continues its operation when the junction

temperature falls below the thermal shutdown hysteresis.

8

Submit Documentation Feedback

Copyright © 2007–2016, Texas Instruments Incorporated

Product Folder Links: TPS62290 TPS62291 TPS62293