PT7749 Datasheet, PDF (1/2 Pages) Texas Instruments – 18 AMP “CURRENT BOOSTER” FOR PT7700 SERIES

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PT7749
Series
18 AMP “CURRENT BOOSTER”
FOR PT7700 SERIES
Application Notes
Mechanical Outline
Product Selector Guide
Revised 8/13/98
The PT7749 is a new high-perfor-
mance 18 Amp “Current Booster” for
the PT7700 Series housed in a 27-pin
SIP package.
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.
A PT7749 current booster adds a
parallel output stage driven by the PT7700.
As such, the system runs in perfect
sychronization providing a low noise solu-
tion.
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.
Pin-Out Information
Pin Function
Features
• Current Boost
• Automatically Tracks Vout of PT7700
• High Efficiency
• Input Voltage Range: 3V to 5.5V
• Synchronized with PT7700
• 27-pin SIP Package
• Run up to 4 in Parallel - 90 Amps
1 Do not connect
2 Do not connect
3 Do not connect
4 Do not connect
5 Do not connect
6 V_in
7 Vin
8 Vin
9 V_in
10 Vin
11 Vin
12 Do not connect
13 GND
Standard Application
14 GND
Pin Function
15 GND
16 GND
17 GND
18 GND
19 GND
20 Vout
21 Vout
22 V_out
23 Vout
24 Vout
25 V_out
26 Do not connect
27 Master Sync In
Ordering Information
PT7749t
(For dimensions and PC Board layout,
see Package Styles 800 and 810.)
PT Series Suffix (PT1234X)
Case/Pin
Configuration
Vertical Through-Hole N
Horizontal Through-Hole A
Horizontal Surface Mount C
PROGRAMMING PINS
VID0
VID1
VID2
VID3
VID4
V_IN
L1
1µH
64321
REMOTE SENSE (+)
26
PT7700 ^{7 - 11}
20 - 25
V_OUT
STBY*
GND
+
C_IN
27 13 - 19 5 12
+
C_OUT
REMOTE SENSE (-)
LOAD
GND
L1
1µH
+
C_IN
27
PT7749 ^{7 - 11}
20 - 25
13 - 19
+
C_OUT
When used with PT7705/7706:
Cin = Required 1200µF electrolytic
Cout = Required 1200µF electrolytic
L1 = Optional 1µH input choke
When used with PT7707:
Cin = Required 1200µF electrolytic
Cout = Required 330µF electrolytic
L1 = Optional 1µH input choke
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.
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Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 [phone] Fax: [phone] http://www.powertrends.com