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PT7779

4 321

26

20-25

12

5

13-19

27

7-11

L

O

A

D

C

OUT

+

C

IN

+

PROGRAMMING PINS

V

IN

V

OUT

SYNC OUT

GND

REMOTE SENSE(+)

REMOTE SENSE(–)

STBY*

VID0

VID1

VID2

VID3

L1

1µH

GND

VID4

6

Standard Application

Cin = Required 2400µF electrolytic

Cout = Required 330µF electrolytic

L1

= Optional 1µH input choke

Description

The PT7779 is a high-output 32A

Integrated Switching Regulator (ISR),

housed in a 27-pin SIP package. The

PT7779 is the next generation of the

industry benchmark PT7771. The

PT7779 includes short circuit pro-

tection and requires only 330µF of

output capacitance for proper oper-

ation.

The 32A output capability allows

the easy integration of the latest

high-speed, µPs, ASICs, DSPs into

existing 5V systems. For additional

current, the PT7779 is designed to

operate with up to two PT7741

32A compatible current boosters.

The output voltage is programmable

from 1.3V to 3.5V using a 5-bit input,

II Processors. A differential remote

sense compensates for any voltage

drop between the ISR and load.

For STBY* pin; open = output enabled;

ground = output disabled.

Pin-Out Information

Pin

Function

Pin

Function

SLTS116

(Revised 8/31/2000)

PT7779—5V

32 Amp Programmable Integrated

Switching Regulator

Specifications

Characteristics

PT7779

(T

Symbols

Conditions

Min

Typ

Max

Units

Output Current

—31

A

—32

Input Voltage Range

0.1A

4.5

—

5.5

V

Output Voltage Tolerance

—

V

–40°C

Line Regulation

4.5V

—

±10

—

mV

Load Regulation

—

±10

—

mV

—

50

—

mV

Transient Response

—

100

—

µSec

—

200

—

mV

Efficiency

η

—

90

—

%

Switching Frequency

4.5V

300

350

400

kHz

0.1A

Absolute Maximum

–40

—

°C

Operating Temperature Range

Storage Temperature

—

-40

—

+125

°C

Mechanical Vibration

Per Mil-STD-883D, Method 2007.2,

—

10/15

—

G’s

20-20,000Hz, Soldered in a PC board

Weight

—

Vertical/Horizontal

—

53/66

—

grams

Notes:

(1) ISR-will operate down to no load with reduced specifications.

(2) Consult the Safe Operating Area curves, or contact the factory for the appropriate derating.

(3) If the remote sense ground is not used, pin 12 must be connected to pin13 for optimum output voltage accuracy.

External Capacitors: The PT7779 requires a minimum output capacitance of 330µF for proper operation. The PT7779 also requires an input capacitance of 2400µF,

which must be rated for a minimum of 2.0Arms of ripple current. For transient or dynamic load applications, additional capacitance may be required. For further infor-

mation, see the accompanying application note on capacitor selection for this product.

Input Filter: An input filter inductor is optional for most applications. The input inductor must be sized to handle 32ADC with a typical value of 1µH.