
For technical support and more information, see inside back cover or visit www.ti.com/powertrends
Standard Application
For STBY* pin:
open = output enabled
ground = output disabled.
Pin-Out Information
Pin Function
1
VID0
2
VID1
3
VID2
4VID3
5
STBY* - Stand-by
6
VID4
7Vin
8Vin
9Vin
Pin Function
10
Vin
11
Vin
12
Remote Sense Gnd (4)
13
GND
14GND
15
GND
16
GND
17
GND
18
GND
Description
The PT7709 is a next generation
“Big Hammer”, high-performance
Integrated Switching Regulator (ISR),
which is made available in Power
Trends’ aluminum 27-pin SIP pack-
age. The PT7709 improves on the
popular PT7705 with 20A of output
current and short circuit protection.
The PT7709 is suitable for exist-
ing 5V system designs that require
power for the latest high-speed, low-
voltage Ps, and bus drivers.
The PT7709 output is program-
mable from 1.3V to 3.5V with a 5-bit
input, which is compatible with the
Intel Pentium Processor. A differential
remote sense is also provided to com-
pensate for voltage drop between the
ISR and load.
Only 330F of output capacitance
are required for proper operation.
Cin = Required 1500F electrolytic
Cout= Required 330F electrolytic
L1 = Optional 1H input choke
Pin Function
19
GND
20
Vout
21
Vout
22
Vout
23
Vout
24Vout
25
Vout
26
Remote Sense Vout
27
Sync Out
C
IN
+
C
OUT
+
LOAD
V
IN
VID0
VID1
VID2
VID3
VID4
V
OUT
GND
SYNC OUT
STBY*
L1
1H
REMOTE SENSE ( )
REMOTE SENSE (+)
PROGRAMMING PINS
PT7709
64
32
1
2 6
20-25
12
5
13-19
27
7-11
Vo
Vin
GND
SNS(+)
SNS(-)
Synch
Out
STBY
VID4 - VID0
Specifications
Characteristics
PT7709 SERIES
(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)
—20
A
Ta = +25°C, natural convection
0.1(1)
—20
A
Input Voltage Range
Vin
0.1A
≤ Io ≤ 20A
4.5
—
5.5
V
Output Voltage Tolerance
Vo
Vin = +5V, Io = 20A
Vo-0.03
—
Vo+0.03
V
0°C
≤ Ta ≤ +65°C
Line Regulation
Regline
4.5V
≤ Vin ≤ 5.5V, Io = 20A
—
±10
—
mV
Load Regulation
Regload
Vin = +5V, 0.1
≤ Io ≤ 20A
—
±10
—
mV
Vo Ripple/Noise
Vn
Vin = +5V, Io = 20A
—
50
—
mV
Transient Response
ttr
Io step between 10A and 20A
—
50
—
Sec
with Cout = 330F
Vos
Vo over/undershoot
—
100
—
mV
Efficiency
η
Vin = +5V, Io = 10A
Vo = 3.3V
—
92
—
%
Vo = 2.5V
—
90
—
%
Vo = 1.8V
—
87
—
%
Vin = +5V, Io = 20A
Vo = 3.3V
—
90
—
%
Vo = 2.5V
—
87
—
%
Vo = 1.8V
—
82
—
%
Switching Frequency
o
4.5V
≤ Vin ≤ 5.5V
300
350
400
kHz
0.1A
≤ Io ≤ 20A
Absolute Maximum
Ta
Over Vin and Io Ranges
–40 (2)
—+85 (3)
°C
Operating Temperature Range
Storage Temperature
Ts
—
–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
Notes: (1) ISR-will operate down to no load with reduced specifications.
(2) For operation below 0°C, Cin and Cout must have stable characteristics. Use either low ESR tantalum or Oscon capacitors.
(3) See Safe Operating Area curves or contact the factory for the appropriate derating.
(4) If the Remote Sense Ground is not used, pin 12 must be connected to pin 13 for optimum output voltage accuracy.
External Capacitors: The PT7709 requires a minimum output capacitance of 330F for proper operation. The PT7709 also requires an input capacitance of 1500F,
which must be rated for a minimum of 1.4Arms of ripple current. For transient or dynamic load applications, additional capacitance may be required. For more
information refer to the application note regarding capacitor selection for this product.
Input Filter: An input filter inductor is optional for most applications. The inductor must be sized to handle 20ADC with a typical value of 1H.
PT7709—5V
20 Amp Programmable
Next Generation “Big Hammer”
SLTS084
(Revised 6/30/2000)