Falling

Edge

Deglitch

Enable

Comparator

1.8 V

VIN

2.94 V

Hysteresis: 0.03

V

2.5 µs

Falling

and

Rising

Edge

Deglitch

2.5 µs

VIN UVLO

Comparator

Hysteresis: 0.16

V

V

Feed-Forward

I

Compensation

−

+

Error

Amplifier

Thermal

Shutdown

145°C

SHUTDOWN

SS_DIS

PWM

Comparator

OSC

Leading

Edge

Blanking

100 ns

R

Q

S

Adaptive Dead-Time

and

Control Logic

SHUTDOWN

Sensefet

30 mΩ

VIN

REG

VBIAS

VIN

BOOT

VIN

PH

PGND

PWRGD

Falling

Edge

Deglitch

35 µs

VSENSE

SHUTDOWN

Hysteresis: 0.03 Vref

Power good

Comparator

AGND

VBIAS

ILIM

Comparator

VIN

FSEL

RT

VSENSE

SS/ENA

TPS5461x

30 mΩ

5 µA

Reference/

DAC

2 kΩ

40 kΩ

25 ns Adaptive

Deadtime

Internal/External

Slow-Start

(Internal Slow-Start Time

=

3.3 ms to 6.6 ms)

TPS54611, TPS54612, TPS54613

TPS54614, TPS54615, TPS54616

www.ti.com

SLVS400D – AUGUST 2001 – REVISED JANUARY 2015

7 Detailed Description

7.1 Overview

The SWIFT family of DC - DC regulators, the TPS54611, TPS54612, TPS54613, TPS54614, TPS54615, and

TPS54616 are low-input voltage high-output current synchronous-buck PWM converters integrate all required

active components. Included on the substrate are true, high-performance, voltage error amplifiers that provide

high performance under transient conditions; an under-voltage-lockout circuit to prevent start-up until the input

voltage reaches 3 V; an internally and externally set slow-start circuit to limit in-rush currents; and a powergood

output useful for processor/logic reset, fault signaling, and supply sequencing.

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Undervoltage Lock Out (UVLO)

The TPS5461x incorporates an UVLO circuit to keep the device disabled when the input voltage (VIN) is

insufficient. During power up, internal circuits are held inactive until VIN exceeds the nominal UVLO threshold

voltage of 2.95 V. Once the UVLO start threshold is reached, device start-up begins. The device operates until

VIN falls below the nominal UVLO stop threshold of 2.8 V. Hysteresis in the UVLO comparator, and a 2.5-µs

rising and falling edge deglitch circuit, reduces the likelihood of shutting the device down due to noise on VIN.

Copyright © 2001–2015, Texas Instruments Incorporated

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Product Folder Links: TPS54611 TPS54612 TPS54613 TPS54614 TPS54615 TPS54616