cv

S

R

R

Q

GND

FB

SW

VIN

EN

+

-





DRIVER

Artificial

Ramp

SHDN

Thermal

SHDN

OVP

1.6 MHz

Comp

Internal -

SENSE

I

LIMIT

I

LDO

Internal -

START

SOFT -

PFET

SENSE

I

ENABLE and UVLO

15

.

1

x

REF

V

Control Logic

VREF = 0.6V

LM2830, LM2830-Q1

SNVS454E – AUGUST 2006 – REVISED DECEMBER 2014

www.ti.com

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Soft-Start

This function forces VOUT to increase at a controlled rate during start up. During soft-start, the error reference

voltage of the amplifier ramps from 0 V to its nominal value of 0.6 V in approximately 600 µs. This forces the

regulator output to ramp up in a controlled fashion, which helps reduce inrush current.

7.3.2 Output Overvoltage Protection

The overvoltage comparator compares the FB pin voltage to a voltage that is 15% higher than the internal

reference VREF. Once the FB pin voltage goes 15% above the internal reference, the internal PMOS control

switch is turned off, which allows the output voltage to decrease toward regulation.

7.3.3 Undervoltage Lockout

Undervoltage lockout (UVLO) prevents the LM2830 device from operating until the input voltage exceeds 2.73 V

(typical). The UVLO threshold has approximately 430 mV of hysteresis, so the part will operate until VIN drops

below 2.3V (typical). Hysteresis prevents the part from turning off during power up if VIN is nonmonotonic.

10

Submit Documentation Feedback

Copyright © 2006–2014, Texas Instruments Incorporated

Product Folder Links: LM2830 LM2830-Q1