PT7708-3.3V Datasheet, PDF (1/4 Pages) Texas Instruments – Integrated Switching Regulator

PT7708—3.3V
20 Amp Programmable
Next Generation “Big Hammer”
Description
The PT7708 is a next generation
“Big Hammer”, a high-performance
Integrated Switching Regulator (ISR),
which is made available in Power
Trends’ aluminum 27-pin SIP pack-
age. The PT7708 improves on the
popular PT7706 with 20A of output
current and short circuit protection.
The PT7708 is suitable for exist-
ing 5V system designs that require
power for the latest high-speed, low-
SLTS083
(Revised 6/30/2000)
voltage µPs, and bus drivers.
The PT7708 output is program-
mable from 1.3V to 2.05V with a
4-bit input, which is compatible with
the Intel Pentium^ Processor. A differ-
ential remote sense is also provided to
compensate for voltage drop between
the ISR and load.
Only 330µF of output capacitance
are required for proper operation.
Pin-Out Information
Standard Application
PROGRAMMING PINS
VID0
VID1
VID2
VID3
L1
V_IN
1H
SYNC OUT ^CIN
REMOTE SENSE (+)
4321
VID3 - VID0
26
SNS(+)
7-11
Vin
PT7708
20-25
Vo
Synch
+
STBY Out GND
SNS(-)
+
5 27 13-19 12
C_OUT
V_OUT
LOAD
GND
GND
STBY*
REMOTE SENSE ( )
Specifications
Cin = Required 1500µF electrolytic
Cout= Required 330µF electrolytic
L1 = Optional 1µH input choke
Pin Function
1 VID0
2 VID1
3 VID2
4 VID3
5 STBY* - Stand-by
6 Do Not Connect
7 Vin
8 Vin
9 Vin
For STBY* pin:
open = output enabled
ground = output disabled.
Pin Function
10 Vin
11 Vin
12 Remote Sense Gnd (4)
13 GND
14 GND
15 GND
16 GND
17 GND
18 GND
Pin Function
19 GND
20 Vout
21 Vout
22 Vout
23 Vout
24 Vout
25 Vout
26 Remote Sense Vout
27 Sync Out
Characteristics
(T_a = 25°C unless noted)
Output Current
Input Voltage Range
Output Voltage Tolerance
Line Regulation
Load Regulation
V_o Ripple/Noise
Transient Response
with C_out = 330µF
Efficiency
Symbols
I_o
V_in
∆Vo
Regline
Regload
V_n
ttr
V_os
η
Switching Frequency
ƒo
Absolute Maximum
Ta
Operating Temperature Range
Storage Temperature
Ts
Mechanical Shock
Mechanical Vibration
Weight
—
Conditions
T_a = +60°C, 200 LFM, pkg N
Ta = +25°C, natural convection
0.1A ≤ I_o ≤ 20A
Vin = +3.3V, Io = 20A
0°C ≤ T_a ≤ +65°C
3.1V ≤ Vin ≤ 3.6V, Io = 20A
Vin = +3.3V, 0.1 ≤ Io ≤ 20A
V_in = +3.3V, I_o = 20A
Io step between 10A and 20A
V_o over/undershoot
Vin = +3.3V, Io = 10A
Vin = +3.3V, Io = 20A
3.1V ≤ Vin ≤ 3.6V
0.1A ≤ I_o ≤ 20A
Over Vin and Io Ranges
Vo = 1.8V
V_o = 1.5V
Vo = 1.8V
V_o = 1.5V
PT7708 SERIES
Min
Typ
Max
0.1(1)
—
19
0.1⁽¹⁾
—
20
3.1
—
3.6
Vo-0.03 —
Vo+0.03
—
±10
—
—
±10
—
—
50
—
—
50
—
—
100
—
—
85
—
—
82
—
—
78
—
—
74
—
300
350
400
–40 (2)
—
+85 (3)
Units
A
V
V
mV
mV
mV
µSec
mV
%
%
kHz
°C
—
Per Mil-STD-883D, Method 2002.3
1 msec, Half Sine, mounted to a fixture
Per Mil-STD-883D, Method 2007.2,
20-2000 Hz, Soldered in a PC board
Vertical/Horizontal
–40
—
+125
°C
—
500
—
G’s
—
10
—
G’s
—
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 PT7708 requires a minimum output capacitance of 330µF for proper operation. The PT7708 also requires an input capacitance of 1500µF,
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 1µH.
For technical support and more information, see inside back cover or visit www.ti.com/powertrends