For assistance or to order, call (800) 531-5782 Revised 1/13/99 PT7748 Series Application Notes Mechanical Outline Product Selector Guide 17 AMP “CURRENT BOOSTER” FOR PT7720 SERIES The PT7748 is a new high-performance 17 Amp “Current Booster” for the PT7720 Series housed in a 27-pin SIP package. Multiple PT7748 boosters will operate in parallel with the PT7720 Series boosting output current in increments of 17A . Combinations of PT7720 and PT7748 current boosters can easily supply enough power for virtually any multiple megaprocessor application. A PT7748 current booster adds a parallel output stage driven by the PT7720. As such, the system runs in perfect sychronization providing a low noise solution. The PT7748 only operates in combination with the PT7720 series and is not a stand-alone product. Therefore please refer the PT7720 series data sheet for performance specifications. The PT7748 also has the same mechanical dimensions and package options as the PT7720 series. Pin-Out Information Ordering Information Pin Function Pin Function PT7748❏ ❏ 1 Do not connect 14 GND Features 2 Do not connect 15 GND • • • • 3 Do not connect 16 GND PT Series Suffix (PT1234X) 4 Do not connect 17 GND 5 Do not connect 18 GND 6 Do not connect 19 GND 7 V in 20 Vout 8 V in 21 Vout Case/Pin Configuration Vertical Through-Hole Horizontal Through-Hole Horizontal Surface Mount 9 V in 22 Vout 10 V in 23 Vout 11 V in 24 Vout 12 Do not connect 25 Vout 13 GND 26 Do not connect 27 Sync In 17A Current Boost Automatically Tracks Vout of PT7720 High Efficiency Input Voltage Range: 11V to 14V • Synchronized with PT7720 • 27-pin SIP Package • Run up to 4 in Parallel - 85 Amps N A C (For dimensions and PC board layout, see Package Styles 1000 and 1010.) Standard Application PROGRAMMING PINS VID0 VID1 VID2 VID3 VID4 VIN REMOTE SENSE (+) 6 4 3 2 1 L1 PT7720 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 + PT7748 C in = Required 560µF electrolytic C out = Required 1200µF electrolytic L1 = Optional 1µH input choke 20 - 25 13 - 19 COUT + Output Capacitors: The PT7720 series requires a minimum output capacitance of 1200µF for proper operation. Do not use Oscon type capacitors. The maximum allowable output capacitance Is (57,000 ÷ Vout)µF, or 15,000µF, whichever is less. Input Filter: An input inductor is optional for most applications. The input inductor must be sized to handle 7ADC with a typical value of 1µH. The input capacitance must be rated for a minimum of 4.0 Arms of ripple current when operated at maximum output current and maximum output voltage. Contact an applications engineer for input capacitor selection for applications at other output voltages and output currents. 52 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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