TPPM0115

SWITCH MODE SYNCHRONOUS BUCK CONTROLLER

SLVS371A− MARCH 2001 − REVISED JUNE 2001

1

POST OFFICE BOX 655303

features

1 V to 2.5 V

±2%

Components

applications

System Power

Mode Controller

description

The TPPM0115 is a synchronous buck controller capable of driving two external power FETs 180

° out of phase.

The device requires a minimum of external standard filter components and switching FETs to regulate the

desired output voltage. This is achieved with an internal switching frequency of 200 kHz (typical).

The TPPM0115 switch mode controller and associated circuitry provide efficient voltage regulation of greater

than 85%. The output voltage is set by two external resistors. During power up, when the output voltage reaches

90% of the desired value, the power good (PWRGD) output is transitioned high after a short delay of 1 ms to

5 ms. During power down, when the output voltage falls below 90% of the set value, the PWRGD output is pulled

low without any delay.

In the event the set output is in an over-voltage condition due to a system fault, the drive to the lower FET turns

on to correct the fault. There is a dead time between switching one FET ON while the other FET is switching

OFF to prevent cross conduction.

The TPPM0115 is capable of driving high static load currents with minimal ripple on the output (<2%). The phase

sense input is used to sense the flow of current through the inductor during flyback to minimize ripple on the

output.

To optimize output filter capacitance, the voltage mode control is based on a fixed ON time during the start of

the cycle and hysteretic control during load transients. This allows the device to respond and maintain the set

regulation voltage.

Copyright

 2001, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

NC − No internal connection

1

2

3

4

8

7

6

5

PWRGD

NC

PHASE

GND

SEN

DRVL

DRVH

SO (D) PACKAGE

(TOP VIEW)