For assistance or to order, call (800) 531-5782 Revised 1/13/99 PT7720 Series 17 AMP 12V INPUT “BIG-HAMMER II” PROGRAMMABLE ISR The PT7720 series is a new +12V input, 17A output, high-performance Integrated Switching Regulator (ISR) housed in a 27pin SIP package. The 17A capability allows easy integration of the latest high-speed, low-voltage µPs and bus drivers into +12V distributed power systems. The PT7720 series has been designed to work in parallel with one or more of the PT7748 current boosters for increased Iout in increments of 17A. The output voltage of the PT7721 can be easily programmed from 1.3V to 3.5V with a 5 bit input compatible with Intel’s Pentium IIProcessor. A differential remote sense is also provided which automatically compensates for any voltage drop from the ISR to the load. 1200µF of output capacitance is required for proper operation. Pin-Out Information Standard Application PROGRAMMING PINS VID0 VID1 VID2 VID3 VID4 VIN REMOTE SENSE (+) 6 4 3 2 1 L1 PT7720 7 - 11 1µH CIN + 26 27 13 - 19 5 VOUT 20 - 25 12 COUT + LOAD SYNC OUT GND GND STBY* REMOTE SENSE (-) Cin = Required 560µF electrolytic (See input filter note) C out = Required 1200µF electrolytic L1 = Optional 1µH input choke Application Notes Mechanical Outline Product Selector Guide Features Pin Function Pin Function 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 VID0 VID1 VID2 VID3 STBY* - Stand-by VID4 Vin Vin Vin Vin Vin Remote Sense Gnd GND GND • +12V bus input • 5-bit Programmable: 1.3V to 3.5V or 4.5V to 7.6V • High Efficiency • Differential Remote Sense • 27-pin SIP Package • Parallelable with PT7748 17A current boosters GND GND GND GND GND Vout Vout Vout Vout Vout Vout Remote Sense Vout Sync Out For STBY* pin: open = output enabled ground = output disabled. Specifications PT7720 SERIES Characteristics (Ta = 25°C unless noted) Symbols Conditions Min Typ Max Units Output Current Io Ta = +60°C, 200 LFM, pkg N, Vo ≤ 5V Ta = +25°C, natural convection, Vo ≤ 5V 0.1 * 0.1 * — — 17** 17** A A Output Power Po Ta = +60°C, 200 LFM, pkg N, Vo ≥ 5V Ta = +25°C, natural convection, Vo ≥ 5V — — — — 85 85 Watts Watts 11.0 — 14.0 V Vo-0.03 — — ±1.0% Vo+0.03 ±2.0% V % Vo mV Input Voltage Range Vin 0.1A ≤ Io ≤ 17A Output Voltage Tolerance ∆Vo Vin = +12V, Io = 17A 0°C ≤ Ta ≤ +60°C Line Regulation Regline 11V ≤ Vin ≤ 14V, Io = 17A (Using remote sense) — ±5 ±10 Load Regulation Regload Vin = +12V, 0.1 ≤ Io ≤ 17A (Using remote sense) — ±5 ±10 mV Vo Ripple/Noise Vn Vin = +12V, Io = 17A — — 50 100 — — mVpp mVpp Transient Response with Cout = 1200µF t tr Vos Io step between 7.5A and 15A Vo over/undershoot — — 100 200 — — µSec mV Efficiency η Vin = +12V, Io = 10A — — — — 90 88 85 78 — — — — % % % % Switching Frequency ƒo 11V ≤ Vin ≤ 14V 0.1A ≤ Io ≤ 17A 300 350 400 kHz Absolute Maximum Operating Temperature Range Ta — 0 — +85 °C Recommended Operating Temperature Range Ta Forced Air Flow = 200 LFM At Vin = 12V, Io = 12A 0 — +65*** °C Storage Temperature Ts — -40 — +125 °C Mechanical Shock Per Mil-STD-883D, Method 2002.3 , 1 msec, Half Sine, mounted to a fixture — TBD — G’s Mechanical Vibration Per Mil-STD-883D, Method 2007.2, 20-2000 Hz, Soldered in a PC board Vertical/Horizontal — TBD — G’s — 51/64 — grams Weight — (PT7721) (PT7722) (PT7721) (PT7722) Vo Vo Vo Vo = 5.0V = 3.3V = 2.5V = 1.5V * ISR-will operate down to no load with reduced specifications. Please note that this product is not short-circuit protected. ** The PT7720 series can be easily paralleled with one or more of the PT7748 Current Boosters to provide increased output current in increments of 17A. *** See Safe Operating Area chart. 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. 50 Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com Programming Information 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 PT7721❏ ❏ = 1.3 to 3.5 Volts ❏ = 4.5 to 7.6 Volts PT7722❏ PT7722 VID4=1 VID4=0 VID4=1 VID4=0 Vout Vout Vout Vout 2.0V 2.1V 2.2V 2.3V 2.4V 2.5V 2.6V 2.7V 2.8V 2.9V 3.0V 3.1V 3.2V 3.3V 3.4V 3.5V Series 1.30V 1.35V 1.40V 1.45V 1.50V 1.55V 1.60V 1.65V 1.70V 1.75V 1.80V 1.85V 1.90V 1.95V 2.00V 2.05V 4.5V 4.6V 4.7V 4.8V 4.9V 5.0V 5.1V 5.2V 5.3V 5.4V 5.5V 5.6V 5.7V 5.8V 5.9V 6.0V 6.1V 6.2V 6.3V 6.4V 6.5V 6.6V 6.7V 6.8V 6.9V 7.0V 7.1V 7.2V 7.3V 7.4V 7.5V 7.6V (For dimensions and PC board layout, see Package Styles 1000 and 1010.) PT Series Suffix (PT1234X) Case/Pin Configuration Vertical Through-Hole Horizontal Through-Hole Horizontal Surface Mount N A C Logic 0 = Pin 12 potential (remote sense gnd) Logic 1 = Open circuit (no pull-up resistors) VID3 and VID4 may not be changed while the unit is operating. C H A R A C T E R I S T I C Efficiency vs Output Current (@Vin=+12V) Safe Operating Area (@Vin=+12V, Vout=+3.3V, Pkg N) 100 Vout 80 5.0V 3.3V 2.5V 1.5V 70 60 50 Ambient Temperature (°C) 90 90 Efficiency (%) D A T A 40 80 70 200LFM Operating Temperature 120LFM 60LFM 50 Nat conv 40 30 20 0 2 4 6 8 10 12 14 16 18 0 20 2 4 6 Output Current (A) 8 10 12 14 16 18 20 Output Current (A) Output Ripple vs Output Current (@Vin=+12V) Safe Operating Area (@Vin=+12V, Vout=+5.0V, Pkg N) 90 14 12 Vout 5.0V 3.3V 2.5V 1.5V 10 8 6 4 2 0 Ambient Temperature (°C) 16 Ripple (mVpp) Airflow Recommended Maximum 60 80 70 Airflow Recommended Maximum 200LFM Operating Temperature 60 120LFM 60LFM 50 Nat conv 40 30 20 0 2 4 6 8 10 12 14 16 18 0 20 Output Current (A) 2 4 6 8 10 12 14 16 18 20 Output Current (A) Power Dissipation vs Output Current (@Vin=+12V) 16 14 Pd (Watts) 12 Vout 5.0V 3.3V 2.5V 1.5V 10 8 6 4 2 0 0 2 4 6 8 10 12 14 16 18 20 Output Current (Amps) Note: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures. Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com 51 DATA SHEETS 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 PT7720 5V12V to 3.x BusConverters Products 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 (800) 531-5782 Ordering Information PT7721 VID3 VID2 VID1 VID0 For assistance or to order, call For assistance or to order, call Application Notes (800) 531-5782 PT7720 Series More Application Notes Pin-Coded Output Voltage Adjustment on the “Big Hammer II” Series ISRs ming, doing so will degrade the load reglation of the product. 4. If active devices are used to ground the voltage control pins, low-level open drain MOSFET devices should be used over bipolar transistors. The inherent Vce (sat) in bipolar devices introduces errors in the device’s internal divider network. Discrete transistors such as the BSS138, 2N7002, IRLML2402, or the 74C906 hex open-drain buffer are examples of appropriate devices. Power Trends PT7720 series ISRs incorporate pin-coded voltage control to adjust the ouput voltage. The control pins are identified VID0 - VID4 (pins 1, 2, 3, 4, & 6) respectively. When the control pins are left open-circuit, the ISR output will regulate at its factory trimmed output voltage. Each pin is internally connected to a precision resistor, which when grounded changes the output voltage by a set amount. By selectively grounding VID0 -VID4, the output voltage of each ISR in the PT7720 series ISRs can be programmed in incremental steps over its specified output voltage range. The output voltage ranges offered by these regulators provide a convenient method of output voltage selection for many applications. In addition, the program code and output voltage range of the PT7721 model ISR is compatible with the voltage ID specification defined by Intel Corporation for voltage regulator modules (VRMs) used to power Pentium® microprocessors. Refer to Figure 1 below for the connection schematic, and the PT7720 Data Sheet for the appropriate programming code information. Active Voltage Programming: Special precautions should be taken when making changes to the voltage control progam code while the unit is powered. It is highly recommended that the ISR be either powered down or held in standby. Changes made to the program code while Vout is enabled induces high current transients through the device. This is the result of the electrolytic output capacitors being either charged or discharged to the new output voltage set-point. The transient current can be minimized by making only incremental changes to the binary code, i.e. one LSB at a time. A minimum of 100µs settling time between each program state is also recommended. Making non-incremental changes to VID3 and VID4 with the output enabled is discouraged. If they are changed, the transients induced can overstress the device resulting in a permanent drop in efficiency. If the use of active devices prevents the program code being asserted prior to power-up, pull pin 5 (STBY) to the device GND during the period that the input voltage is applied to Vin. Releasing pin 5 will then allow the device output to execute a soft-start power-up to the programmed voltage. Notes: 1. The programming convention is as follows:Logic 0: Logic 1: Connect to pin12 (Remote Sense Ground). Open circuit/open drain (See notes 2, & 4) 2. Do not connect pull-up resistors to the voltage programming pins. 3. To minimize output voltage error, always use pin 12 (Remote Sense Ground) as the logic “0” reference. While the regular ground (pins 13-19) can also be used for program- Figure 1 6 4 3 2 1 26 VID4 - VID0 +12V 7-11 1µ H (Optional) SNS(+) PT7720 Vin STBY 5 Synch Out 27 GND 13-19 20-25 Vo SNS(-) 12 + Cin + Cout L O A D STBY COM Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com 3 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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