PT7740—3.3V
32 Amp “Current Booster” for
PT7778 Regulator
SLTS117
(Revised 8/31/2000)
Description
The booster adds a parallel output
stage that is driven directly by the
regulator. Both operate in perfect
sychronization for a low noise solution.
The PT7740 only operates with a
PT7778 regulator and is not a stand-
alone product. Please refer to the
PT7778 data sheet for the perfor-
mance specifications. The current
booster has the same package options
as its companion regulator.
The PT7740 is a high-output 32
Amp “Current Booster” designed to
operate with the PT7778 regulator.
Up to two PT7740 boosters will
operate in parallel with a PT7778,
boosting output current in increments
of 32A. Combinations of a PT7778
series regulator and PT7740 current
boosters can supply enough power for
virtually any multiple mega-processor
application.
Pin-Out Information
Ordering Information
PT7740❏
Pin Function
14 GND
15 GND
16 GND
17 GND
18 GND
19 GND
20 Vout
Pin Function
Features
(For dimensions and PC Board layout,
1
2
3
4
5
6
7
8
9
Do not connect
• 32A Current Boost
• Tracks Vo of a PT7778
• High Efficiency
• Input Voltage Range:
3.1V to 3.6V
• Synchronized with PT7778
• 27-pin SIP Package
• Run up to 2 in Parallel (96A)
see Package Styles 1020 and 1030.)
Do not connect
Do not connect
Do not connect
Do not connect
Do not connect
Vin
PT Series Suffix
(PT1234X)
Case/Pin
Configuration
21 Vout
Vin
22 Vout
Vin
Vertical Through-Hole
Horizontal Through-Hole
Horizontal Surface Mount
N
A
C
10 Vin
23 Vout
24 Vout
11 Vin
25 Vout
12 Do not connect
13 GND
26 Do not connect
27 Master Sync In
Standard Application
P R O G R A M M I N G P I N S
REMOTE SENSE (+)
VID0
VID1
VID2
VID3
4
VID3
3
-
2
VID0
1
26
SNS(+)
VOUT
L 1
7-11 Vin
20-25
Vo
VIN
PT7778
1 µH
Synch
Out
STBY
5
GND
SNS(-)
+
+
LOAD
27
13-19
12
CIN
COUT
G N D
G N D
STBY*
REMOTE SENSE (–)
27
Synch
In
L 1
7-11 Vin
20-25
Vo
PT7740
1 µH
GND
+
+
13-19
CIN
COUT
External Capacitors: When used with a PT7778, the PT7740 requires a minimum ouput capacitance of 330µF. The maximum allowable output capacitance is
30,000µF. The PT7740 also requires a minimum input capacitance of 2400µF, which must be rated for a minimum of 2.0Arms of ripple current. For transient
or dynamic load applications, additional capacitance may be required. For further information, see the accompanying application note on capacitor selection for this
product.
Input Filter: An input filter inductor is optional for most applications. The input inductor must be sized to handle 32ADC with a typical value of 1µH.
For technical support and more information, see inside back cover or visit www.ti.com/powertrends