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S e r i e s
P T 7 7 7 2
32 AMP HIGH-PERFORMANCE
“SLEDGE HAMMER” PROGRAMMABLE ISR
Revised 7/15/98
The PT7772 is a new series of
can be easily programmed from 1.3V
high-performance, 32 Amp Integrated
Switching Regulators (ISRs) housed in
a 27-pin SIP package. The 32A capa-
bility allows easy
integration of the latest high-speed,
low-voltage µPs, ASICs, DSPs, and
bus drivers into existing 3.3V systems.
The output voltage of the PT7772
to 2.05V with a 4-bit input compatible
with Intel’s Pentium Pro Processor. A
differential remote sense is also pro-
vided which automatically compensates
for any voltage drop from the ISR
to the load.
2400µF of output capacitance
are required for proper operation.
Pin-Out Information
Pin Function
Pin Function
14 GND
15 GND
16 GND
17 GND
Standard Application
PROGRAMMING PINS
1
2
3
4
5
6
7
8
VID0
VID1
VID0
VID1
VID2
VID3
VID2
REMOTE SENSE (+)
VID3
4
3
2
1
26
STBY*- Stand-by
18 GND
19 GND
L1
Do not connect
VIN
VOUT
7 - 11
20 - 25
PT7772
Vin
Vin
1µH
20
21
22
23
24
25
V
V
V
V
V
V
out
out
out
out
out
out
27
13 - 19
5
12
+
+
9
Vin
CIN
COUT
LOAD
10 Vin
11 Vin
12 Remote Sense Gnd
13 GND
SYNC OUT
GND
GND
STBY*
26 Remote Sense V
27 Sync Out
REMOTE SENSE (-)
out
C
C
= Required 2400µF electrolytic
= Required 2400µF electrolytic
in
out
For STBY* pin; open = output enabled;
ground = output disabled.
L1 = Optional 1µH input choke
Specifications
PT7772 SERIES
Characteristics
(T a = 25°C unless noted)
Symbols
Conditions
Min
Typ
Max
Units
(1)
Output Current
Io
Ta = +60°C, 200 LFM, pkg N
Ta = +25°C, natural convection
0.1
0.1
—
—
32
26
A
A
(1)
(2)
Input Voltage Range
Vin
0.1A ≤ Io ≤ 32A
3.1
—
3.6
V
Output Voltage Tolerance
∆Vo
Vin = +3.3V, Io = 32A
0°C ≤ Ta ≤ +55°C
Vo-0.03
—
Vo+0.03
V
Line Regulation
Regline
Regload
Vn
3.1V ≤ Vin ≤ 3.6V, Io = 32A
Vin = +3.3V, 0.1 ≤ Io ≤ 32A
Vin = +3.3V, Io = 32A
—
—
—
±10
±10
50
—
—
—
mV
mV
mV
Load Regulation
Vo Ripple/Noise pk-pk
Transient Response
with Cout = 2400µF
ttr
Vos
Io step between 16A and 32A
Vo over/undershoot
—
—
100
200
—
—
µSec
mV
Efficiency
η
Vin = +3.3V, Io = 20A, Vo = 1.8V
—
90
—
%
Switching Frequency
ƒo
3.1V ≤ Vin ≤ 3.6V
0.1A ≤ Io ≤ 32A
650
700
750
kHz
Absolute Maximum
Ta
—
0
0
—
—
+85
+65
°C
°C
Operating Temperature Range
Recommended Operating
Temperature Range
Ta
Forced Air Flow = 200 LFM
Over Vin and Io Ranges
Storage Temperature
Weight
Ts
—
—
-40
—
—
+125
—
°C
Vertical/Horizontal
53/66
grams
(1) ISR-will operate down to no load with reduced specifications. Please note that this product is not short-circuit protected.
(2) The minimum input voltage is 3.1V or Vout+1.2V, whichever is greater.
Output Capacitors: The PT7772 series requires a minimum output capacitance of 2400µF for proper operation. Do not use Oscon type capacitors.
The maximum allowable output capacitance is 30,000µF.
Input Filter: An input filter is optional for most applications. The input inductor must be sized to handle 32ADC with a typical value of 1µH.
The input capacitance must be rated for a minimum of 2.6Arms of ripple current. For transient or dynamic load applications, additional
capacitance may be required.
14
Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com