PT7777 Datasheet, PDF (1/3 Pages) Texas Instruments – 32 AMP HIGH-PERFORMANCE SLEDGE HAMMER” PROGRAMMABLE ISR

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PT7777 Series
32 AMP HIGH-PERFORMANCE
“SLEDGE HAMMER” PROGRAMMABLE ISR
Revised 7/31/98
The PT7777 is a new series of
high-performance, 32 Amp Inte-
grated Switching Regulators (ISRs)
housed in a 27-pin SIP package.
The 32A capability allows easy
integration of the latest high-speed,
low-voltage µPs, ASICs, DSPs, and
bus drivers into existing 5V systems.
The output voltage of the PT7777
can be easily programmed from 1.3V
to 3.5V with a 5 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.
680µF of output capacitance
is required for proper operation.
Standard Application
PROGRAMMING PINS
VID0
VID1
VID2
VID3
VID4
V_IN
L1
1µH
6432 1
26
7 - 11 _PT7777
REMOTE SENSE (+)
20 - 25
V_OUT
SYNC OUT
GND
STBY*
Specifications
+
C_IN
27 13 - 19 5 12
+
C_OUT
LOAD
Cin = Required 2400µF electrolytic
Cout = Required 680µF electrolytic
L1 = Optional 1µH input choke
GND
REMOTE SENSE (-)
Pin-Out Information
Pin Function
Pin Function
1 VID0
2 VID1
3 VID2
4 VID3
14 GND
15 GND
16 GND
17 GND
5 STBY*- Stand-by
6 VID4
7 V_in
8 V_in
9 V_in
10 V_in
11 V_in
1 2 Remote Sense Gnd
13 GND
18 GND
19 GND
20 Vout
21 Vout
22 Vout
23 Vout
24 Vout
25 Vout
2 6 Remote Sense Vout
27 Sync Out
For STBY* pin; open = output enabled;
ground = output disabled.
Characteristics
(T _a = 25°C unless noted)
Output Current
Symbols
Io
Input Voltage Range
Vin
Output Voltage Tolerance
∆V_o
Line Regulation
Load Regulation
Vo Ripple/Noise pk-pk
Transient Response
with Cout = 680µF
Efficiency
Switching Frequency
Reg_line
Regload
Vn
t_tr
Vos
η
ƒo
Absolute Maximum
Ta
Operating Temperature Range
Conditions
Ta = +60°C, 200 LFM, pkg N
Ta = +25°C, natural convection
0.1A ≤ Io ≤ 32A
V_in = +5V, I_o = 32A
0°C ≤ Ta ≤ +55°C
4.5V ≤ V_in ≤ 5.5V, I_o = 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
—
PT7777 SERIES
Min
Typ
0. 1 ⁽¹⁾
—
0. 1 ⁽¹⁾
—
4. 5 ⁽²⁾
—
Vo-0.03 —
—
±10
—
±10
—
50
—
100
—
200
—
90
650
700
0
—
Recommended Operating
Ta
Temperature Range
Storage Temperature
Ts
Weight
—
Forced Air Flow = 200 LFM
Over V_{in and} I_o Ranges
—
Vertical/Horizontal
0
—
-40
—
—
53/66
(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 V_out+1.2V, whichever is greater.
Max
32
26
5.5
Vo+0.03
—
—
—
—
—
—
750
Units
A
A
V
V
mV
mV
mV
µSec
mV
%
kHz
+85
°C
+65
+125
—
°C
°C
grams
Output Capacitors: The PT7777 series requires a minimum output capacitance of 680µF 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.
Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 [phone] Fax: [phone] http://www.powertrends.com