For assistance or to order, call Application Notes Mechanical Outline Product Selector Guide (800) 531-5782 PT7749 Series 18 AMP “CURRENT BOOSTER” FOR PT7700 SERIES The PT7749 is a new high-performance 18 Amp “Current Booster” for the PT7700 Series housed in a 27-pin SIP package. Multiple PT7749 boosters will operate 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 solution. The PT7749 only operates in combination 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 Ordering Information PT7749❏ Pin Function Do not connect 15 GND 2 Do not connect 16 GND 3 Do not connect 17 GND 4 Do not connect 18 GND 5 Do not connect 19 GND 6 V in 20 V out PT Series Suffix (PT1234X) 7 V in 21 V out 8 V in 22 V out 9 V in 23 V out 10 V in 24 V out 11 V in 25 V out Case/Pin Configuration Vertical Through-Hole Horizontal Through-Hole Horizontal Surface Mount 12 Do not connect 26 Do not connect 13 GND 27 Master Sync In 14 GND 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 Standard Application Pin Function 1 Features • • • • • • • Revised 8/13/98 (For dimensions and PC Board layout, see Package Styles 800 and 810.) N A C PROGRAMMING PINS VID0 VID1 VID2 VID3 VID4 VIN REMOTE SENSE (+) 6 4 3 2 1 L1 PT7700 7 - 11 1µH CIN 27 + 26 13 - 19 5 VOUT 20 - 25 12 COUT + LOAD STBY* GND GND REMOTE SENSE (-) When used with PT7705/7706: Cin = Required 1200µF electrolytic Cout = Required 1200µF electrolytic L1 = Optional 1µH input choke 27 L1 7 - 11 1µH CIN + PT7749 20 - 25 13 - 19 COUT + 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. 40 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. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. 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