SLTS054A Datasheet, PDF (1/4 Pages) Texas Instruments – The PT7771 is a high-output Integrated grated Switching Regulator (ISR)

PT7771—5V
32 Amp “Sledge Hammer”
Programmable ISR
SLTS054A
(Revised 6/30/2000)
The PT7771 is a high-output Inte-
grated Switching Regulator (ISR)
housed in a 27-pin SIP package. The
PT7771 operates off a standard 5V bus
to provide a 32 amp low-voltage power
source for the industry’s latest high-
speed µPs, ASICs, DSPs.
The PT7771 has been designed to
work in parallel with one or more of
the PT7746 -32A current boosters to
increase the load current capability in
increments of 32A.
The output voltage is program-
mable from 1.3V to 3.5V via a 5-bit
input, compatible with Intel’s Pentium^â
Pro Processor. A differential remote
sense is also provided to compensate
for voltage drop between the ISR and
load.
An output capacitance of 2400µF is
required for proper operation.
Note that this product does not
include short circuit protection.
Standard Application
PROGRAMMING PINS
VID0
VID1
VID2
VID3
VID4
V_IN
L1
1H
6432 1
26
7 - 11 _PT7770
REMOTE SENSE (+)
20 - 25
V_OUT
SYNC OUT
GND
STBY*
Specifications
+
C_IN
27
13 - 19 5 12
Cin = Required 2400µF electrolytic
Cout = Required 2400µF electrolytic
L1 = Optional 1µH input choke
+
C_OUT
LOAD
GND
REMOTE SENSE (-)
Pin-Out Information
Pin Function
Pin Function
1 VID0
14 GND
2 VID1
15 GND
3 VID2
16 GND
4 VID3
17 GND
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
18 GND
19 GND
20 Vout
21 Vout
22 Vout
23 Vout
24 Vout
25 Vout
26 Remote Sense Vout
27 Sync Out
For STBY* pin; open = output enabled;
ground = output disabled.
Characteristics
(T _a = 25°C unless noted)
Output Current
Input Voltage Range
Output Voltage Tolerance
Line Regulation
Load Regulation
Vo Ripple/Noise pk-pk
Transient Response
with Cout = 2400µF
Efficiency
Switching Frequency
Absolute Maximum
Operating Temperature Range
Storage Temperature
Weight
Symbols
Io
Vin
∆Vo
Regline
Regload
Vn
t_tr
Vos
η
ƒo
Ta
Ts
—
Conditions
Ta = +60°C, 200 LFM, pkg N
Ta = +25°C, natural convection
0.1A ≤ Io ≤ 32A
Vin = +5V, Io = 32A
0°C ≤ Ta ≤ +55°C
4.5V ≤ Vin ≤ 5.5V, Io = 32A
Vin = +5V, 0.1 ≤ Io ≤ 32A
Vin = +5V, Io = 32A
I_o step between 16A and 32A
Vo over/undershoot
V_in = +5V, I_o = 20A, V_o = 3.3V
4.5V ≤ Vin ≤ 5.5V
0.1A ≤ I_o ≤ 32A
Over Vin Range
—
Vertical/Horizontal
Min
0.1 (1)
0.1 (1)
4.5 (2)
Vo-0.03
—
—
—
—
—
—
650
PT7771
Typ
—
—
—
—
±10
±10
50
100
200
90
700
0
—
-40
—
—
53/66
Max
32
26
5.5
Vo+0.03
—
—
—
—
—
—
750
Units
A
A
V
V
mV
mV
mV
µSec
mV
%
kHz
+85 ⁽³⁾
+125
—
°C
°C
grams
Notes: (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 4.5V or Vout +1.2V, whichever is greater.
(3) Consult the SOA curves or contact the factory for the appropriate derating.
Output Capacitors: The PT7771 regulator 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.
For technical support and more information, see inside back cover or visit www.ti.com/powertrends