
For technical support and more information, see inside back cover or visit www.ti.com/powertrends
SLTS046A
(Revised 6/30/2000)
Standard Application
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
Do not connect
7Vin
8Vin
9Vin
Pin Function
10
Vin
11
Vin
12
Remote Sense Gnd
13
GND
14
GND
15
GND
16
GND
17
GND
18
GND
The PT7706 is a high-performance
18-Amp Integrated Switching Regulator
(ISR), housed in a 27-pin SIP package.
The 18A capability allows easy integra-
tion of the latest high-speed, low-voltage
Ps, DSPs, ASICs, and bus drivers into
existing 3.3V systems.
The PT7706 series has been designed
to work in parallel with one or more of
the PT7749 - 18A current boosters for
increased I
out in increments of 18A.
The output voltage of the PT7706 can
be easily programmed with a 4 bit input
compatible with Intel’s Pentium II Pro-
cessor. A differential remote sense is also
provided which automatically compen-
sates for any voltage drop from the ISR to
the load.
An input capacitance of 1200F, and
output capacitance of 330F are required
for proper operation.
Cin = Required 1200F electrolytic
Cout= Required 330F electrolytic
L1 = Optional 1H input choke
PT7706
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
PROGRAMMING PINS
2
3
4
STBY*
5
VID0
Pin Function
19
GND
20
Vout
21
Vout
22
Vout
23
Vout
24
Vout
25
Vout
26
Remote Sense Vout
27
Sync Out
Specifications
Characteristics
PT7706 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)
—18 (2)
A
Ta = +25°C, natural convection
0.1 (1)
—15 (2)
Input Voltage Range
Vin
0.1A
≤ Io ≤ 15A
3.1 (3)
—
3.6
V
Output Voltage Tolerance
Vo
Vin = +3.3V, Io = 18A
Vo-0.03
—
Vo+0.03
V
0°C
≤ Ta ≤ +65°C
Line Regulation
Regline
3.1V
≤ Vin ≤ 3.6V, Io = 18A
—
±10
—
mV
Load Regulation
Regload
Vin = +3.3V, 0.1 ≤ Io ≤ 18A
—
±10
—
mV
Vo Ripple/Noise
Vn
Vin = +3.3V, Io = 18A
—
50
—
mV
Transient Response
ttr
Io step between 9A and 18A
—
100
—
Sec
with Cout = 330F
Vos
Vo over/undershoot
—
200
—
mV
Efficiency
η
Vin = +3.3V, Io = 10A
Vo = 1.8V
—
79
—
%
Vo = 1.5V
—
77
—
%
Switching Frequency
o
3.1V
≤ Vin ≤ 3.6V
650
700
750
kHz
0.1A
≤ Io ≤ 18A
Absolute Maximum
Ta
—0
—
+85 (4)
°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) The ISR will operate down to no load with reduced specifications. Please note that this product is not short-circuit protected.
(2) The PT7706 series can be easily paralleled with one or more of the PT7749 Current Boosters to provide increased output current in increments of 18A.
(3) The minimum input voltage is 3.1V or Vout+1.2V, whichever is greater.
(4) See Safe Operating Area curves.
Output Capacitors: The PT7706 series requires a minimum ouput capacitance of 330F for proper operation. Do not use Oscon type capacitors. The maximum
allowable output capacitance is 15,000F.
Input Filter: An input filter is optional for most applications. The input inductor must be sized to handle 18ADC with a typical value of 1H. The input capacitance must
be rated for a minimum of 1.3Arms of ripple current. For transient or dynamic load applications, additional capacitance may be required.
PT7706—3.3V
18 Amp “Big-Hammer” Programmable
Integrated Switching Regulator