Texas Instruments PT7721A, PT7721C, PT7721N, PT7722A, PT7722C Datasheet

PT7720

7 - 11

13 - 19

20 - 25

27

V

IN

GND

1µH

GND

V

OUT

C

OUT

+

C

IN

+

12

261

L1

SYNC OUT

LOAD

REMOTE SENSE (+)

REMOTE SENSE (-)

VID1
VID2
VID3
VID4

PROGRAMMING PINS

234

STBY*

5

6

VID0

For assistance or to order, call [phone]

Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 [phone] Fax: [phone] http://www.powertrends.com

50

Pin-Out Information

Pin Function

1 VID0
2 VID1
3 VID2
4 VID3
5 STBY* - Stand-by
6 VID4
7V

in

8V

in

9V

in

10 V

in

11 V

in

12 Remote Sense Gnd
13 GND
14 GND

Pin Function

15 GND
16 GND
17 GND

18 GND
19 GND
20 V

out

21 V

out

22 V

out

23 V

out

24 V

out

25 V

out

26 Remote Sense V

out

27 Sync Out

Standard Application

Cin= Required 560µF electrolytic

(See input filter note)

C

out

= Required 1200µF electrolytic

L1 = Optional 1µH input choke

For STBY* pin:
open = output enabled
ground = output disabled.

• +12V bus input

• 5-bit Programmable:

1.3V to 3.5V or

4.5V to 7.6V

• High Efficiency

• Differential Remote Sense

• 27-pin SIP Package

• Parallelable with PT7748

17A current boosters

Features

Series

17 AMP 12V INPUT “BIG-HAMMER II” PRO­GRAMMABLE ISR

PT7720

The PT7720 series is a new +12V input,
17A output, high-performance Integrated
Switching Regulator (ISR) housed in a 27­pin SIP package. The 17A capability allows
easy integration of the latest high-speed,
low-voltage µPs and bus drivers into +12V
distributed power systems.

The PT7720 series has been designed
to work in parallel with one or more of the
PT7748 current boosters for increased I

out

in increments of 17A.

The output voltage of the PT7721 can
be easily programmed from 1.3V to 3.5V
with a 5 bit input compatible with Intel’s
Pentium



IIProcessor. A differential re­mote sense is also provided which
automatically compensates for any voltage
drop from the ISR to the load.

1200µF of output capacitance is re-

quired for proper operation.

Output Capacitors: The PT7720 series requires a minimum output capacitance of 1200µF for proper operation. Do not use Oscon type capacitors. The maximum allowable output capacitance
Is (57,000 ÷ Vout)µF, or 15,000µF, whichever is less.

Input Filter: An input inductor is optional for most applications. The input inductor must be sized to handle 7ADC with a typical value of 1µH. The input capacitance must be rated for a

minimum of 4.0 Arms of ripple current when operated at maximum output current and maximum output voltage. Contact an applications engineer for input capacitor selection for applications
at other output voltages and output currents.

Specifications

Characteristics

PT7720 SERIES

(Ta = 25°C unless noted) Symbols Conditions Min Typ Max Units

Output Current I

o

Ta = +60°C, 200 LFM, pkg N, V

o

≤ 5V 0.1

*

—17**A

Ta = +25°C, natural convection, V

o

≤ 5V 0.1

*

—17**A

Output Power P

o

Ta = +60°C, 200 LFM, pkg N, V

o

≥ 5V — — 85 Watts

Ta = +25°C, natural convection, V

o

≥ 5V — — 85 Watts

Input Voltage Range V

in

0.1A ≤ I

o

≤ 17A 11.0 — 14.0 V

Output Voltage Tolerance ∆V

o

V

in

= +12V, Io = 17A (PT7721) Vo-0.03 — Vo+0.03 V

0°C ≤ Ta ≤ +60°C (PT7722) — ±1.0% ±2.0% % Vo

Line Regulation Reg

line

11V ≤ V

in

≤ 14V, I

o

= 17A (Using remote sense) — ±5 ±10 mV

Load Regulation Reg

load

Vin = +12V, 0.1 ≤ I

o

≤ 17A (Using remote sense) — ±5 ± 10 mV

V

o

Ripple/Noise V

n

V

in

= +12V, Io = 17A (PT7721) — 50 — mVpp

(PT7722) — 100 — mVpp

Transient Response t

tr

Io step between 7.5A and 15A — 100 — µSec

with C

out

= 1200µF V

os

Vo over/undershoot — 200 — mV

Efficiency η V

in

= +12V, Io = 10A Vo = 5.0V — 90 — %

V

o

= 3.3V — 88 — %

V

o

= 2.5V — 85 — %

V

o

= 1.5V — 78 — %

Switching Frequency ƒ

o

11V ≤ V

in

≤ 14V

300 350 400 kHz

0.1A ≤ I

o

≤ 17A

Absolute Maximum T

a

—0—+85°C

Operating Temperature Range
Recommended Operating T

a

Forced Air Flow = 200 LFM

0—+

65

***

°C

Temperature Range At V

in = 12V, Io

= 12A

Storage Temperature T

s

— -40 — +125 °C

Mechanical Shock Per Mil-STD-883D, Method 2002.3 , 1 msec,

— TBD — G’s

Half Sine, mounted to a fixture

Mechanical Vibration Per Mil-STD-883D, Method 2007.2,

20-2000 Hz, Soldered in a PC board

— TBD — G’s

Weight — Vertical/Horizontal — 51/64 — grams

* ISR-will operate down to no load with reduced specifications. Please note that this product is not short-circuit protected.
** The PT7720 series can be easily paralleled with one or more of the PT7748 Current Boosters to provide increased output current in increments of 17A.

*** See Safe Operating Area chart.

Revised 1/13/99

Application Notes

Mechanical Outline

Product Selector Guide

For assistance or to order, call [phone]

Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 [phone] Fax: [phone] http://www.powertrends.com

51

CHARACTERISTIC DATA

5V to 3.x Converters

12V Bus Products

DATA SHEETS

Programming Information

PT7721 PT7722

VID4=1 VID4=0 VID4=1 VID4=0

VID3 VID2 VID1 VID0 Vout Vout Vout Vout

1 1 1 1 2.0V 1.30V 4.5V 6.1V
1 1 1 0 2.1V 1.35V 4.6V 6.2V
1 1 0 1 2.2V 1.40V 4.7V 6.3V
1 1 0 0 2.3V 1.45V 4.8V 6.4V
1 0 1 1 2.4V 1.50V 4.9V 6.5V
1 0 1 0 2.5V 1.55V 5.0V 6.6V
1 0 0 1 2.6V 1.60V 5.1V 6.7V
1 0 0 0 2.7V 1.65V 5.2V 6.8V
0 1 1 1 2.8V 1.70V 5.3V 6.9V
0 1 1 0 2.9V 1.75V 5.4V 7.0V
0 1 0 1 3.0V 1.80V 5.5V 7.1V
0 1 0 0 3.1V 1.85V 5.6V 7.2V
0 0 1 1 3.2V 1.90V 5.7V 7.3V
0 0 1 0 3.3V 1.95V 5.8V 7.4V
0 0 0 1 3.4V 2.00V 5.9V 7.5V
0 0 0 0 3.5V 2.05V 6.0V 7.6V

Series

40

50

60

70

80

90

100

02468101214161820

5.0V

3.3V

2.5V

1.5V

Efficiency vs Output Current (@Vin=+12V)

Efficiency (%)

Output Current (A)

Safe Operating Area (@Vin=+12V, V

out

=+3.3V, Pkg N)

Output Current (A)

Ambient Temperature (°C)

Airflow

Recommended Maximum

Operating Temperature

0

2

4

6

8

10

12

14

16

0 2 4 6 8 10 12 14 16 18 20

5.0V

3.3V

2.5V

1.5V

0

2

4

6

8

10

12

14

16

0 2 4 6 8 10 12 14 16 18 20

5.0V

3.3V

2.5V

1.5V

Output Ripple vs Output Current (@Vin=+12V)

Power Dissipation vs Output Current (@Vin=+12V)

Output Current (A)

Output Current (Amps)

Ripple (mVpp)Pd (Watts)

Safe Operating Area (@Vin=+12V, V

out

=+5.0V, Pkg N)

Output Current (A)

Ambient Temperature (°C)

AirflowRecommended Maximum

Operating Temperature

Note: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.

PT7720

Ordering Information

PT7721

❏❏

❏❏

❏ = 1.3 to 3.5 Volts

PT7722

❏❏

❏❏

❏ = 4.5 to 7.6 Volts

(For dimensions and PC board layout,
see Package Styles 1000 and 1010.)

VV

VV

V

outout

outout

out

VV

VV

V

outout

outout

out

VV

VV

V

outout

outout

out

Logic 0 = Pin 12 potential (remote sense gnd)
Logic 1 = Open circuit (no pull-up resistors)
VID3 and VID4 may not be changed while the unit is operating.

PT Series Suffix

(PT1234X)

Case/Pin
Configuration

Vertical Through-Hole

N

Horizontal Through-Hole

A

Horizontal Surface Mount

C

20

30

40

50

60

70

80

90

0 2 4 6 8101214161820

200LFM
120LFM
60LFM
Nat conv

20

30

40

50

60

70

80

90

0 2 4 6 8 101214161820

200LFM
120LFM
60LFM
Nat conv