FB

VIN

VCC

SW

AGND

BST

2.0V

VILIM

LM5160

RON

CURRENT LIMIT

COMPARATOR

+

-

VCC UVLO

ON/OFF

TIMERS

CONSTANT

ON-TIME

CONTROL

LOGIC

1.24V

VCC REGULATOR

FEEDBACK

COMPARATOR

DISABLE

THERMAL

SHUTDOWN

EN/UVLO

STANDBY

SHUTDOWN

BIAS

REGULATOR

0.35V

20µA

FPWM

SS

CURRENT

LIMIT TIMER

PGND

GM ERROR

AMP

DIODE

EMULATION

L

11

LM5160A, LM5160

www.ti.com

SNVSA03C – OCTOBER 2014 – REVISED AUGUST 2016

Product Folder Links: LM5160A LM5160

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7 Detailed Description

7.1 Overview

The LM5160 family of step-down switching regulators features all the functions needed to implement a low-cost,

efficient buck converter capable of supplying 2 A to the load. This high voltage regulator contains 65-V N-channel

buck and synchronous rectifier switches and is available in the 12-pin WSON package. The regulator operation is

maintains a relatively constant operating frequency with load and input voltage variations. A constant ON-time

switching regulator requires no loop compensation resulting in fast load transient response. Peak current limit

detection circuit is implemented with a forced OFF-time during current limiting which is inversely proportional to

end equipment systems requiring efficient step-down regulation from higher input voltages. This regulator is well

suited for 24-V industrial systems as well as 48-V Telecom and PoE voltage ranges. The LM5160 integrates an

undervoltage lockout (EN/UVLO) circuit to prevent faulty operation of the device at low input voltages and

features intelligent current limit and thermal shutdown to protect the device during overload or short circuit.

The LM5160 device name is used generically throughout this document and represents both the LM5160 and

LM5160A unless stated otherwise. The only difference between the two is the ability to connect an external

voltage source to the VCC pin of the LM5160A.

7.2 Functional Block Diagram