Texas Instruments PT7705A, PT7705C, PT7705N Datasheet

Standard Application

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

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

Pin Function

10 V

in

11 V

in

12 Remote Sense Gnd
13 GND
14 GND
15 GND
16 GND
17 GND
18 GND

SeriesPT7705

The PT7705 is a new series of
high-performance, 18 Amp Integrated
Switching Regulators (ISRs) housed in
a 27-pin SIP package. The 18A capa­bility allows easy integration of the
latest high-speed, low-voltage µPs and
bus drivers into existing 5V systems.

The PT7705 series has been de­signed to work in parallel with one or
more of the PT7749 - 18A current
boosters for increased I

out

in incre-

ments of 18A.

The output voltage of the PT7705
can be easily programmed from 1.3V
to 3.5V with a 5 bit input compatible
with Intel’s Pentium



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

1200µF of output capacitance are

required for proper operation.

For assistance or to order, call [phone]

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

38

Cin= Required 1200µF electrolytic
C

out

= Required 1200µF electrolytic

L1 = Optional 1µH input choke

PT7705

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

18 AMP “BIG-HAMMER” PROGRAMMABLE
INTEGRATED SWITCHING REGULATOR

Pin Function

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

Specifications

Characteristics

PT7705 SERIES

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

Output Current I

o

Ta = +60°C, 200 LFM, pkg N 0.1

*

—18**A

Ta = +25°C, natural convection 0.1

*

—15**A

Input Voltage Range V

in

0.1A ≤ I

o

≤ 15A 4.5

***

— 5.5 V

Output Voltage Tolerance ∆V

o

V

in

= +5V, Io = 15A

V

o-0.03 — Vo+0.03 V

0°C ≤ Ta ≤ +65°C

Line Regulation Reg

line

4.5V ≤ V

in

≤ 5.5V, I

o

= 15A — ±10 — mV

Load Regulation Reg

load

Vin = +5V, 0.1 ≤ I

o

≤ 15A — ±10 — mV

Vo Ripple/Noise V

n

V

in

= +5V, Io = 15A — 50 — mV

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

= +5V, Io = 10A Vo = 3.3V — 89 — %

V

o

= 2.9V — 87 — %

V

o

= 2.5V — 85 — %

V

o

= 1.8V — 79 — %

V

o

= 1.5V — 77 — %

Switching Frequency ƒ

o

4.5V ≤ V

in

≤ 5.5V

650 700 750 kHz

0.1A ≤ I

o

≤ 15A

Absolute Maximum T

a

—0—+85°C

Operating Temperature Range
Recommended Operating T

a

Forced Air Flow = 200 LFM

0 — +65**** °C

Temperature Range Over V

in and Io

Ranges

Storage Temperature T

s

— -40 — +125 °C

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

1 msec, Half Sine, mounted to a fixture — 500 — G’s

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

—10—G’s

20-2000 Hz, Soldered in a PC board

Weight — Vertical/Horizontal — 31/41 — grams

* ISR-will operate down to no load with reduced specifications. Please note that this product is not short-circuit protected.
**The PT7705 series can be easily paralleled with one or more of the PT7749 Current Boosters to provide increased output current in increments of 18A.
*** The minimum input voltage is 4.5V or V

out

+1.2V, whichever is greater. ****See SOA curves.

Output Capacitors:

The PT7705 series requires a minimum ouput capacitance of 1200µF for proper operation. Do not use Oscon type capacitors. The maximum

allowable output capacitance is 15,000µF. See Capacitor Application Note.

Input Filter:

An input filter is optional for most applications. The input inductor must be sized to handle 15ADC with a typical value of 1µH. The input capacitance must be

rated for a minimum of 1.3Arms of ripple current. For transient or dynamic load applications, additional capacitance may be required.

Application Notes

Mechanical Outline

Product Selector Guide

Revised 5/15/98

Programming Information

VID4=1 VID4=0

VID3 VID2 VID1 VID0 Vout Vout

1 1 1 1 2.0V 1.30V
1 1 1 0 2.1V 1.35V
1 1 0 1 2.2V 1.40V
1 1 0 0 2.3V 1.45V
1 0 1 1 2.4V 1.50V
1 0 1 0 2.5V 1.55V
1 0 0 1 2.6V 1.60V
1 0 0 0 2.7V 1.65V
0 1 1 1 2.8V 1.70V
0 1 1 0 2.9V 1.75V
0 1 0 1 3.0V 1.80V
0 1 0 0 3.1V 1.85V
0 0 1 1 3.2V 1.90V
0 0 1 0 3.3V 1.95V
0 0 0 1 3.4V 2.00V
0 0 0 0 3.5V 2.05V

• Single-Device: +5V input

• 5-bit Programmable:

1.3V to 3.5V@18A

• High Efficiency

• Input Voltage Range:

4.5V to 5.5V

• Differential Remote Sense

• 27-pin SIP Package

• Parallelable with PT7749

18A “Current Boosters”

Features

For assistance or to order, call [phone]

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

www.powertrends.com

39

5V to 3.x Converters

5V Bus Products

DATA SHEETS

CHARACTERISTIC DATA

PT7705, Vo = 3.3 VDC (See Note 1)

Efficiency vs Output Current

Ripple vs Output Current

Power Dissipation vs Output Current

Efficiency - %Ripple-(mV)PD-(Watts)

Iout-(Amps)

Iout-(Amps)

Iout-(Amps)

Note 1:Note 1:

Note 1:Note 1:

Note 1: All data listed in the above graphs has been developed from actual products tested at 25°C. This data is considered typical data for the ISR.

Safe Operating Area Curves (@Vin=+5V)

Ambient Temperature (°C)

Output Current (Amps)

Airflow

Airflow

Ambient Temperature (°C)

Output Current (Amps)

PKG SUFFIX N

Note 2:Note 2:

Note 2:Note 2:

Note 2: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.

Recommended Maximum

Operating Temperature

0

10

20

30

40

50

60

0 3 6 9 121518

5.5V

5.0V

4.5V

Vin

40

50

60

70

80

90

100

0 3 6 9 12 15 18

4.5V

5.0V

5.5V

Vin

0

2

4

6

8

10

12

14

0 3 6 9 12 15 18

5.5V

5.0V

4.5V

Vin

SeriesPT7705

Ordering Information

PT7705

❏❏

❏❏

❏ = 1.3 to 3.5 Volts

(For dimensions and PC board layout,
see Package Styles 800 and 810.)

Recommended Maximum

Operating Temperature

PT7705, Vo = 3.3 VDC (See Note 1)

PKG SUFFIX A, C

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

024681012141618

Nat Conv
60LFM
100LFM
200LFM

20

30

40

50

60

70

80

90

024681012141618

Nat Conv
60LFM
100LFM
200LFM

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.