For assistance or to order, call Application Notes Mechanical Outline Product Selector Guide (800) 531-5782 PT7746 Series 32 AMP “CURRENT BOOSTER” FOR PT7770 SERIES The PT7746 is a new high-performance 32 Amp “Current Booster” for the PT7770 Series housed in a 27-pin SIP package. Multiple PT7746 boosters will operate in parallel with the PT7770 boosting output current in increments of 32A. Combinations of PT7770s and PT7746 current boosters can easily supply enough power for virtually any multiple mega-processor application. A PT7746 current booster adds a parallel output stage driven by the PT7770. As such, the system runs in perfect sychronization providing a low noise solution. 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❏ Pin Function Features • 32A Current Boost • Automatically Tracks Vo of PT7770 • High Efficiency • Input Voltage Range: 3V to 5.5V • Synchronized with PT7770 • 27-pin SIP Package • Run up to 2 in Parallel 96 Amps Revised 8/13/98 Pin Function 1 Do not connect 14 GND 2 Do not connect 15 GND 3 Do not connect 16 GND 4 Do not connect 17 GND 5 Do not connect 18 GND 6 Do not connect 19 GND 7 V in 20 V out 8 V in 21 V out 9 V in 22 V out Horizontal Through-Hole 10 V in 23 V out Horizontal Surface Mount 11 V in 24 V out 12 Do not connect 25 V out 13 GND 26 Do not connect 27 Master Sync In Standard Application (For dimensions and PC Board layout, see Package Styles 1020 and 1030.) PT Series Suffix (PT1234X) Case/Pin Configuration Vertical Through-Hole N A C PROGRAMMING PINS VID0 VID1 VID2 VID3 VID4 VIN REMOTE SENSE (+) 6 4 3 2 1 L1 PT7770 7 - 11 1µH CIN 27 + 26 13 - 19 5 VOUT 20 - 25 12 COUT + LOAD STBY* GND GND REMOTE SENSE (-) 27 L1 7 - 11 1µH CIN + PT7746 20 - 25 13 - 19 COUT + When Cin Cout L1 used with PT7771/7772: = Required 2400µF electrolytic = Required 2400µF electrolytic = Optional 1µH input choke When Cin Cout L1 used with PT7777: = Required 2400µF electrolytic = Required 680µF electrolytic = Optional 1µH input choke 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 IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. 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