Application Notes
Mechanical Outline
For assistance or to order, call (800) 531-5782
Product Selector Guide
P T 7 7 4 9 S e r i e s
18 AMP “CURRENT BOOSTER”
FOR PT7700 SERIES
Revised 8/13/98
The PT7749 is a new high-perfor-
parallel output stage driven by the PT7700.
mance 18 Amp “Current Booster” for
the PT7700 Series housed in a 27-pin
SIP package.
As such, the system runs in perfect
sychronization providing a low noise solu-
tion.
Multiple PT7749 boosters will oper-
ate in parallel with the PT7700 boosting
output current in increments of 18A .
Combinations of PT7700s and PT7749
current boosters can easily supply enough
power for virtually any multiple
megaprocessor application.
The PT7749 only operates in combina-
tion with the PT7700 series and is not a
stand-alone product. Therefore please refer
the PT7705, PT7706, or PT7707 series
data sheet for performance specifications.
The PT7749 also has the same mechanical
dimensions and package options as the
PT7700 series.
A PT7749 current booster adds a
Pin-Out Information
Ordering Information
PT7749❏
Pin Function
Pin Function
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
• Current Boost
(For dimensions and PC Board layout,
Do not connect
Do not connect
Do not connect
Do not connect
Vin
see Package Styles 800 and 810.)
• Automatically Tracks Vout of PT7700
• High Efficiency
• Input Voltage Range: 3V to 5.5V
• Synchronized with PT7700
• 27-pin SIP Package
PT Series Suffix
(PT1234X)
Vin
21 Vout
Case/Pin
Configuration
Vin
22 Vout
• Run up to 4 in Parallel - 90 Amps
Vertical Through-Hole
Horizontal Through-Hole
Horizontal Surface Mount
N
A
C
Vin
23 Vout
10 Vin
24 Vout
11 Vin
25 Vout
12 Do not connect
13 GND
14 GND
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
PT7700
1µH
27
13 - 19
5
12
+
+
CIN
COUT
LOAD
STBY*
GND
GND
REMOTE SENSE (-)
When used with PT7705/7706:
27
C
C
L1
= Required 1200µF electrolytic
= Required 1200µF electrolytic
= Optional 1µH input choke
in
out
L1
7 - 11
20 - 25
PT7749
1µH
When used with PT7707:
13 - 19
+
+
C
= Required 1200µF electrolytic
= Required 330µF electrolytic
= Optional 1µH input choke
in
CIN
COUT
C
L1
out
Output Capacitors: When used with a PT7705or PT7706, the PT7749 requires a minimum ouput capacitance of 1200µF. When used with a PT7707, the PT7749
requires a minimum ouput capacitance of 330µF for proper operation. Do not use Oscon type capacitors. The maximum allowable output capacitance is 15,000µF.
Input Filter: An input filter is optional for most applications. The input inductor must be sized to handle 18ADC with a typical value of 1µH. 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.
40
Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com