Application Notes
Mechanical Outline
For assistance or to order, call (800) 531-5782
Product Selector Guide
P T 7 7 4 6 S e r i e s
32 AMP “CURRENT BOOSTER”
FOR PT7770 SERIES
Revised 8/13/98
The PT7746 is a new high-perfor-
A PT7746 current booster adds a parallel
mance 32 Amp “Current Booster” for
the PT7770 Series housed in a 27-pin
SIP package.
output stage driven by the PT7770. As such,
the system runs in perfect sychronization
providing a low noise solution.
Multiple PT7746 boosters will
operate in parallel with the PT7770
boosting output current in incre-
ments of 32A. Combinations of
PT7770s and PT7746 current
boosters can easily supply enough
power for virtually any multiple
mega-processor application.
The PT7746 only operates in
combination with the PT7770 series and is
not a stand-alone product. Therefore, please
refer to the PT7771, PT7772, or PT7777
series data sheet for performance
specifications. The PT7746 also has the
same mechanical dimensions and package
options as the PT7770 series.
Pin-Out Information
Ordering Information
PT7746❏
(For dimensions and PC Board layout,
see Package Styles 1020 and 1030.)
Pin Function
Pin Function
14 GND
15 GND
16 GND
17 GND
18 GND
19 GND
20 Vout
1
2
3
4
5
6
7
8
9
Do not connect
Features
Do not connect
Do not connect
Do not connect
Do not connect
Do not connect
Vin
• 32A Current Boost
• Automatically Tracks
Vo of PT7770
• High Efficiency
• Input Voltage Range:
3V to 5.5V
PT Series Suffix
(PT1234X)
Case/Pin
Configuration
Vin
21 Vout
Vertical Through-Hole
N
A
C
• Synchronized with PT7770
• 27-pin SIP Package
• Run up to 2 in Parallel -
96 Amps
Vin
22 Vout
Horizontal Through-Hole
Horizontal Surface Mount
10 Vin
23 Vout
11 Vin
24 Vout
12 Do not connect
13 GND
25 Vout
26 Do not connect
27 Master Sync In
Standard Application
PROGRAMMING PINS
VID0
VID1
VID2
VID3
VID4
REMOTE SENSE (+)
6
4
3
2
1
26
L1
VIN
VOUT
7 - 11
20 - 25
PT7770
1µH
27
13 - 19
5
12
+
+
CIN
COUT
LOAD
STBY*
GND
GND
REMOTE SENSE (-)
When used with PT7771/7772:
27
C
= Required 2400µF electrolytic
= Required 2400µF electrolytic
= Optional 1µH input choke
in
C
out
L1
7 - 11
20 - 25
L1
PT7746
1µH
When used with PT7777:
13 - 19
+
+
C
= Required 2400µF electrolytic
= Required 680µF electrolytic
= Optional 1µH input choke
CIN
COUT
in
C
L1
out
Output Capacitors: When used with a PT7771 or PT7772, the PT7746 requires a minimum ouput capacitance of 2400µF. When used with a PT7777,
the PT7746 requires a minimum ouput 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.
4
Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com