Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.ti.com/powertrends
For assistance or to order, call (800) 531-5782
PT7770
7 - 11
13 - 19
20 - 25
27
V
IN
GND
1H
GND
V
OUT
C
OUT
+
C
IN
+
12
26
1
L1
SYNC OUT
LOAD
REMOTE SENSE (+)
REMOTE SENSE (-)
VID1
VID2
VID3
VID4
PROGRAMMING PINS
2
3
4
STBY*
5
6
VID0
Series
Standard Application
Cin = Required 2400F electrolytic
Cout = Required 330F electrolytic
L1
= Optional 1H input choke
32 AMP PROGRAMMABLE
NEXT GENERATION “SLEDGE HAMMER”
PT7779
The PT7779 is a high-
performance, 32 Amp Integrated
Switching Regulator (ISR), in a 27-
pin SIP package. The PT7779 is the
next generation of the industry
benchmark PT7771, and now in-
cludes short circuit protection and
requires less output capacitance.
The 32A capability allows easy
integration of the latest high-speed,
low-voltage Ps, ASICs, DSPs, and
bus drivers into existing 5V systems.
The PT7779 output can be easily
programmed from 1.3V to 3.5V with
a 5 bit input, that is compatible with
Intel’s PentiumII Processors. A dif-
ferential remote sense is also provided
to compensate for any voltage drop
between the ISR and load.
An output capacitance of 330F
is required for proper operation.
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
7 V
in
8 V
in
9 V
in
10 V
in
11 V
in
12 Remote Sense Gnd
13 GND
Pin
Function
14 GND
15 GND
16 GND
17 GND
18 GND
19 GND
20 Vout
21 Vout
22 Vout
23 Vout
24 Vout
25 Vout
26 Remote Sense Vout
27 Sync Out
Specifications
Characteristics
PT7779
(T
a = 25°C unless noted)
Symbols
Conditions
Min
Typ
Max
Units
Output Current
Io
Ta = +60°C, 200 LFM, pkg N
0.1 (1)
—32
A
Ta = +25°C, natural convection
0.1 (1)
—
TBD
Input Voltage Range
Vin
0.1A
≤ Io ≤ 32A
4.5 (2)
—
5.5
V
Output Voltage Tolerance
Vo
Vin = +5V, Io = 32A
Vo-0.03
—
Vo+0.03
V
0°C
≤ Ta ≤ +55°C
Line Regulation
Regline
4.5V
≤ Vin ≤ 5.5V, Io = 32A
—
±10
—
mV
Load Regulation
Regload
Vin = +5V, 0.1 ≤ Io ≤ 32A
—
±10
—
mV
Vo Ripple/Noise pk-pk
Vn
Vin = +5V, Io = 32A
—
50
—
mV
Transient Response
ttr
Io step between 16A and 32A
—
100
—
Sec
with Cout = 330F
Vos
Vo over/undershoot
—
200
—
mV
Efficiency
η
Vin = +5V, Io = 20A, Vo = 3.3V
—
90
—
%
Switching Frequency
o
4.5V
≤ Vin ≤ 5.5V
300
350
400
kHz
0.1A
≤ Io ≤ 32A
Absolute Maximum
Ta
—
TBD
—
TBD
°C
Operating Temperature Range
Recommended Operating
Ta
Forced Air Flow = 200 LFM
TBD
—
+65
°C
Temperature Range
Over Vin and Io Ranges
Storage Temperature
Ts
—
-40
—
+125
°C
Weight
—
Vertical/Horizontal
—
53/66
—
grams
Notes:
(1)ISR-will operate down to no load with reduced specifications.
(2)The minimum input voltage is 4.5V or Vout+1.2V, whichever is greater.
Output Capacitors: The PT7779 requires a minimum output capacitance of 330F for proper operation. Do not use Oscon type capacitors.
Input Filter: An input filter is optional for most applications. The input inductor must be sized to handle 32ADC with a typical value of 1H. The input capacitance must
be rated for a minimum of 4.2Arms of ripple current. For transient or dynamic load applications, additional capacitance may be required.
Preliminary 2/16/2000
Advanced
Information
PT7779