MOSFET

CONTROL

LOGIC

CURRENT

COMP

ERROR

AMPLIFIER

VCON

FB

MAIN CONTROL

EN

VIN

PGND

VREF

SGND

VOUT

Integrated

Inductor

REFERENCE

VOLTAGE

OSCILLATOR

VIN

UVLO

L

COMP

CURRENT SENSE

UVLO

TSD

LMZ10500

www.ti.com

SNVS723F – OCTOBER 2011 – REVISED FEBRUARY 2015

7 Detailed Description

7.1 Overview

The LMZ10500 SIMPLE SWITCHER® nano module is an easy-to-use step-down DC-DC solution capable of

driving up to 650 mA load in space-constrained applications. Only an input capacitor, an output capacitor, a small

footprint package with an integrated inductor. The LMZ10500 operates in fixed 2.0 MHz PWM (Pulse Width

Modulation) mode, and is designed to deliver power at maximum efficiency. The output voltage is typically set by

positive input to the error amplifier. The output voltage of the LMZ10500 can also be dynamically adjusted

overload protection, and thermal shutdown are also provided.

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Current Limit

The LMZ10500 current limit feature protects the module during an overload condition. The circuit employs

positive peak current limit in the PFET and negative peak current limit in the NFET switch. The positive peak

current through the PFET is limited to 1.2A (typ.). When the current reaches this limit threshold the PFET switch

is immediately turned off until the next switching cycle. This behavior continues on a cycle-by-cycle basis until the

overload condition is removed from the output. The typical negative peak current limit through the NFET switch is

–0.6A (typ.).

The ripple of the inductor current depends on the input and output voltages. This means that the DC level of the

output current when the peak current limiting occurs will also vary over the line voltage and the output voltage

level. Refer to the DC Output Current Limit plots in the Typical Characteristics section for more information.

Copyright © 2011–2015, Texas Instruments Incorporated

Submit Documentation Feedback

9

Product Folder Links: LMZ10500