PT7761—5V 40-A Programmable Integrated Switching Regulator Module SLTS152 (Revised 10/24/2001) Features • Single Device: 40ADC • +5V Input • 5-bit Programmable: 1.3V to 3.5V • 90% Efficiency • Differential Remote Sense • Short-Circuit Protection • Space-Saving Package • Solderable Copper Case • “Current Booster” Compatible • Shutdown Control Description The PT7761 is a high performance integrated switching regulator (ISR), housed in a solderable, 31-pin spacesaving copper package. Operating from and input voltage of +5V, the PT7761 provides up to 40A of lowvoltage power for the industry’s latest DSPs, and µ-Processors. The PT7761 performance extends both the flexibility and output current range of the “Big Hammer” series of Plug-in Power modules, and provides a state-of-the-art solution for highly integrated digital systems that de- mand high power supply currents at low output voltages. The PT7761 is programmable from 1.3V to 3.5V via a 5-bit input, which is compatible with Intel’s Pentium® series microprocessors. The PT7761’s features include a momentary-interrupt style of shortcircuit protection, a standby control, and a differential remote sense to compensate for voltage drop between the ISR and load. For additional output current the PT7761 can operate with up to three current boosters. Ordering Information PT7761o = 1.3 to 3.5V Regulator * PT7769o = 40-A Current Booster * Consult application notes for information on Current Booster operation PT Series Suffix (PT1234 x ) Case/Pin Configuration Order Suffix N A C Vertical Horizontal SMD Package Code (EKH) (EKF) (EKG) (Reference the applicable package code drawing for the dimensions and PC board layout) Standard Application VID0 VID1 VID2 VID3 VID4 PROGRAMMING PINS REMOTE SENSE(+) 5 L IN V IN 4 3 1 µH + 1 31 PT7761 9–14 C IN 2 7 6 16–22 VOUT 23–30 15 SYNC OUT L O A D + C OUT GND GND STBY* REMOTE SENSE(–) Cin = Required 1500µF electrolytic Cout = Required 330µF electrolytic Lin = Optional 1µH input choke For technical support and more information, see inside back cover or visit www.ti.com PT7761—5V 40-A Programmable Integrated Switching Regulator Module Programming Information Pin-Out Information VID4=1 VID4=0 Vout Vout Pin Function Pin Function Pin Function 1 VID0 11 Vin 21 GND 2 3 VID1 VID2 12 Vin VID3 Vin Vin GND Vout 4 13 14 22 23 24 Vout 5 VID4 15 Rem Sense GND 25 Vout 1.60V 1.65V 6 7 STBY * Sync 16 GND 1.70V 1.75V 8 No Connect GND GND Vout Vout 2.8V 2.9V 17 18 26 27 28 Vout 1 0 3.0V 3.1V 1.80V 1.85V 9 Vin 19 GND 29 Vout 10 Vin 20 GND 1 1 1 0 3.2V 3.3V 1.90V 1.95V 30 31 Vout Rem Sense V out 0 0 1 0 3.4V 3.5V 2.00V 2.05V VID3 VID2 VID1 VID0 1 1 1 1 1 1 1 0 2.0V 2.1V 1.30V 1.35V 1 1 1 1 0 0 1 0 2.2V 2.3V 1.40V 1.45V 1 1 0 0 1 1 1 0 2.4V 2.5V 1.50V 1.55V 1 1 0 0 0 0 1 0 2.6V 2.7V 0 0 1 1 1 1 1 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 2 * For STBY* pin: Open =Output Enabled Ground =Output Disabled Logic 0 = Pin 15 potential (Remote Sense GND) Logic 1 = Open circuit (no pull-up resistors) VID3 and VID4 may not be changed while the unit is operating. Specifications (Unless otherwise stated, T a =25°C, C in =1,500µF, C out =330µF, V in =5V, V o =3.3V, & Io =Iomax) PT7761 Characteristics Symbols Output Current Io Conditions Min T a =25°C, Natural convection T a =60°C, 200LFM, Pkg N 0.1 0.1 (1) (1) Typ Max Units — — 40 38 A Input Voltage Range Vin Over I o range 4.5 — 5.5 Set-Point Voltage Tolerance Votol All output voltages — — ±25 V Temperature Variation ∆Reg temp –40°C≤ Ta ≤85°C, Io =Io min — ±0.75 — %Vo Line Regulation ∆Reg line Over V in range — ±5 — mV Load Regulation ∆Regload Over load range — ±5 — mV Total Output Variation ∆Votol Includes set-point, line, load, –40°C ≤Ta ≤ +85°C — ±1 ±3 %Vo Efficiency η I o =20A Vo = 3.3V Vo = 2.5V Vo = 1.8V — — — 90 89 83 — — — % I o =40A Vo = 3.3V Vo = 2.5V Vo = 1.8V — — — 86 85 80 — — — % (2) mV Vo Ripple (pk-pk) Vr 20MHz bandwidth — 50 — mV Transient Response t tr ∆Vtr 1A/µs load step from 50% to 100% I omax V o over/undershoot — — 50 100 — — µSec mV Short Circuit Threshold Isc(pk) Reset and auto-recovery — 75 — A Switching Frequency ƒs Over V in and Io ranges 300 350 400 kHz Standby Control (pin 6) Input High Voltage Input Low Voltage Input Low Current VIH VIL I IL Referenced to GND (pins 16–22) Pin 6 to GND 2 -0.2 — — — 0.4 Open (3) 0.8 — Quiescent Current Iin stby Pin 6 to GND — 30 — mA External Output Capacitance Cout Between +V o and GND 330 — 30,000 µF Operating Temperature Range Ta Over V in Range –40 — +85 (5) °C Storage Temperature Ts — -40 — +125 °C Mechanical Shock Mil-STD-883D, Method 2002.3 1 msec, Half Sine, mounted to a fixture — TBD — G’s Mechanical Vibration Mil-STD-883D, 20-2000 Hz Vertical Horizontal — — TBD (6) TBD (6) — — G’s — 55 — grams Weight — Vertical/Horizontal Flammability — Materials meet UL 94V-0 Notes: (1) (2) (3) (4) (5) (6) (4) V mA ISR-will operate down to no load with reduced specifications. If the Remote Sense Ground (Pin 15) is not used, it must be connected to pin 16 for optimum output voltage accuracy. The Standby control (pin 6) has an internal pull-up, and if left open-circuit the module will operate when input power is applied. For operation below 0°C, Cin and Cout must have stable characteristics. Use either low ESR tantalum or Oscon® capacitors. See safe Operating Area curves or consult factory for the appropriate derating. The case pins on the through-hole package types (suffixes N & A) must be soldered. For more information see the applicable package outline drawing. External Capacitors: The PT7761 series requires a minimum ouput capacitance of 330µF for proper operation. The PT7761 also requires a minimum input capacitance of 1,500µF, which must be rated for a minimum of 1.4Arms of ripple current. For transient or dynamic load applications, additional capacitance may be required. For further information refer to the application note regarding capacitor selection for this product. Input Inductor: An input inductor is optional for most applications. The input inductor must be sized to handle 30ADC with a typical value of 1µH. For technical support and more information, see inside back cover or visit www.ti.com Typical Characteristics PT7761—5V 40-A Programmable Integrated Switching Regulator Module Characteristic Data, VIN =5VDC Safe Operating Area Curves (See Note A) Efficiency vs. Output Current 90 100 (See Note B) PT7761 @Vin =5V Efficiency - % VOUT 80 3.3V 2.5V 1.8V 70 60 Ambient Temperature (°C) 80 90 70 Airflow 60 400LFM 200LFM Nat conv 50 40 30 50 20 0 8 16 24 32 40 0 Iout (A) 8 16 24 32 40 Iout (A) Ripple Voltage vs. Output Current 60 Ripple - mV 50 VOUT 40 2.5V 1.8V 3.3V 30 20 10 0 0 8 16 24 32 40 Iout (A) Power Dissipation vs. Output Current 20 16 Pd - Watts VOUT 12 3.3V 2.5V 1.8V 8 4 0 0 8 16 24 32 40 Iout (A) Note A: Note B: Characteristic data in the above graphs has been developed from actual products tested at 25°C. This data is considered typcial for the ISR. SOA curves represent conditions at which internal components are at or below manufacturer’s maximum operating temperatures. For technical support and more information, see inside back cover or visit www.ti.com Application Notes PT7761, PT7769 Increasing the PT7761 Output Current with the PT7769 Compatible Current Booster product data sheet. Recommendations on specific capacitor types are also detailed in the application note, “Capacitor Recommendations for the PT7761 Integrated Switching Regulator.” The PT7769 is a 40-A “Current Booster” module for the PT7761 regulator. The booster is controlled directly by the regulator, and effectively adds a parallel output stage. This allows the system to run sychronously, providing a low noise solution. Up to three booster modules can be connected to a single regulator. Each booster increases the available output current by 40A. Combinations of a regulator and booster modules can supply power for virtually any multi-processor application. 2. The 1-µH filter choke located at the input of each regulator and booster module (Lin) is optional for most applications. If specified, each inductor must be sized to handle 30ADC at full output load. 3. The pin-out of the current booster modules include a number pins identified, “No Connect” (see Table 1). These pins are not connected internally to the module but must be soldered to a pad to preserve the unit’s mechanical integrity. 4. A similar PCB footprint and trace layout between the regulator and each booster will facilitate current sharing between all modules. A current booster is not a stand-alone product, and can only operate with a regulator. It is housed in the same package as its compatible regulator, and shares the same mechanical outline. Except for an increase in output current, the overall performance of a PT7761/booster combination is identical to that of a stand-alone regulator. Refer to the appropriate data sheet for the performance specifications. Table 1; PT7769 Pin-Out Information Pin Function Notes: 1. Each booster requires the same amount of input and output capacitance as recommended for a stand-alone regulator. See the Standard Application schematic and the respective input/output filter notes in the PT7761 Pin Function Pin Function 1 2 No Connect No Connect 11 Vin 12 Vin 21 GND 22 GND 3 No Connect 13 Vin 23 Vout 4 No Connect 14 Vin 24 Vout 5 6 No Connect No Connect 15 No Connect 16 GND 25 Vout 26 Vout 7 Sync 17 GND 27 Vout 8 No Connect 18 GND 28 Vout 19 GND 20 GND 29 Vout 30 Vout 9 Vin 10 Vin 31 No Connect Current Booster Application Schematic VID0 VID1 VID2 VID3 VID4 PROGRAMMING PINS REMOTE SENSE (+) 5 4 3 2 1 VID0 - VID4 V IN L IN 9–14 1µH Sns (+) PT7761 V IN Stby Sync + 6 C IN 31 7 GND V OUT Sns (–) 16–22 V OUT 23–30 + 15 C OUT LOAD GND GND STBY* REMOTE SENSE (–) 7 Synch L IN 9–14 1µH V OUT PT7769 V OUT 23–30 GND + C IN 16–22 To Additional Boosters + C OUT For technical support and more information, see inside back cover or visit www.ti.com Application Notes PT7761, PT7769 Capacitor Recommendations for the PT7761 Integrated Switching Regulator Input Capacitors The recommended input capacitance is determined by 1.4 ampere minimum ripple current rating and 1500µF minimum capacitance. Capacitors listed below must be rated for a minimum of 2x the input voltage with +5V operation. Ripple current and ≤100mΩ Equivalent Series Resistance (ESR) values are the major considerations along with temperature when selecting the proper capacitor. Output Capacitors The minimum required output capacitance is 330µF with a maximum ESR less than or equal to 100mΩ. Failure to observe this requirement may lead to regulator instability or oscillation. Electrolytic capacitors have poor ripple performance at frequencies greater than 400kHz, but excellent low frequency transient response. Above the ripple frequency ceramic decoupling capacitors are necessary to improve the transient response and reduce any microprocessor high frequency noise components apparent during higher current excursions. Preferred low ESR type capacitor part numbers are identified in the Table 1 below. Tantalum Characteristics Tantalum capacitors with a minimum 10V rating are recommended on the output bus, but only the AVX TPS series, Sprague 594/595 series, or Kemet T495/T510 series. These AVX, Sprague, and Kemet capacitors are specified over other types due to their higher surge current, excellent power dissipation, and ripple current ratings. As a caution, the TAJ series by AVX is not recommended. This series exhibits considerably higher ESR, reduced power dissipation and lower ripple current capability. The TAJ series is also less reliable than the TPS series when determining power dissipation capability. Capacitor Table Table 1 identifies the characteristics of capacitors from a number of vendors with acceptable ESR and ripple current (rms) ratings. The suggested minimum quantities per regulator for both the input and output buses are identified. This is not an extensive capacitor list. The table below is a selection guide for input and output capacitors. Other capacitor vendors are available with comparable RMS ripple current rating and ESR (Equivalent Series Resistance at 100kHz). These critical parameters are necessary to insure both optimum regulator performance and long capacitor life. Table 1 Capacitors Characteristic Data Capacitor Vendor/ Series Capacitor Characteristics Quantity Working Voltage Value(µF) (ESR) Equivalent Series Resistance 105°C Maximum Ripple Current(Irms) Physical Size(mm) Input Bus Output Bus 16V 35V 2200 330 0.038Ω 0.065Ω 2000mA 1205mA 18x16.5 12.5x16.5 1 1 1 EEVFC1C222N EEVFC1V331LQ 10V 16V 680 1800 755mA 2000mA 10x12.5 18x15 1 1 EEUFA1A681 EEUFA1C182A United Chemi -Con LFVSeries 25V 16V 16V 330 2200 470 0.084Ω 0.038Ω 0.084Ω÷2 =0.042Ω 825mA 1630mA 825mA x2 10x16 16x20 10x16 1 1 1 1 LXV25VB331M10X16LL LXV16VB222M16X20LL LXV16VB471M10X16LL Nichicon PL Series PM Series 10V 10V 25V 680 1800 330 0.090Ω 0.044Ω 0.095Ω 770mA 1420mA 750mA 10x15 16x15 10x15 1 1 1 1 UPL1A681MHH6 UPL1A182MHH6 UPL1E331MPH6 Oscon SS SV 10V 10V 330 330 0.025Ω÷4 =0.006Ω 0.02Ω÷4 =0.005Ω >9800mA >9800mA 10x10.5 10.3x12.6 4 4 N/R (Note) AVX Tanatalum TPS- Series 10V 10V 330 330 0.1Ω÷5 =0.02Ω 0.06Ω 3500mA 1826mA 7.3Lx 4.3Wx 4.1H 5 5 1 1 TPSV337M010R0100 TPSV337M010R0060 Sprague Tantalum 595D/594D 10V 10V 330 680 0.045Ω÷4 =0.011Ω 0.09Ω >4500mA >1660mA 7.3L x 5.7W x 4.0H 5 2 1 1 594D337X0010R2T 595D687X0010R2T (Surface Mount) Kemet Tantalum T510/T495 Series 10V 330 0.035Ω 2000mA 5 1 510X337M010AS 10V 220 0.07Ω÷2 =0.035Ω 4.3Wx7.3L x4.0H >2000mA 6 2 T495X227M010AS (Surface Mount) Sanyo Poscap TPB 10V 220 0.04Ω 3000mA 6 2 10TPB220M (Surface Mount) Panasonic FC Surface Mtg FA 0.090Ω 0.032Ω 7.2L x 4.3W x 3.1H Note: (N/R) is not recommended for this application, due to extremely low Equivalent Series Resistance (ESR) For technical support and more information, see inside back cover or visit www.ti.com 1 Vendor Number 10SS330M 10SV330M (Surface Mount) Application Notes continued PT7761 Using the Standby Function on the PT7761 Excalibur™ Integrated Switching Regulator For applications requiring output voltage On/Off control, the PT7761 integrated switching regulator (ISR) module incorporates a standby function. This feature may be used for power-up/shutdown sequencing, and to change the output voltage while input power is applied. See related application notes: “Pin-Coded Output Voltage Adjustment of PT7761 Excalibur ISRs.” Figure 1 5 4 3 9–14 +5V The standby input must be controlled with an opencollector (or open-drain) discrete transistor (See Figure 1). Table 1 gives the threshold requirements. Table 1 Standby Control Input Requirements (1) Parameter Min Typ Max Enable Disable Istby Vstby (o/c) 2V –0.2V Open Cct. 0.8V 0.4mA 1 1 31 Sns (+) PT7761 V IN Stby Sync The standby function is provided by the STBY* control, pin 6. If pin 6 is left open-circuit the regulator operates normally, providing a regulated output whenever a valid supply voltage is applied to Vin (pins 9–14) with respect to GND (pins 16–22). Connecting pin 6 to ground 1 will set the regulator output to zero volts 2. This places the regulator in standby mode, and reduces the input current to typcially 30mA (60mA max). If a ground signal is applied to pin 6 prior to power-up, the regulator output will be held at zero volts during the period that input power is applied. 2 VID0 - VID4 6 GND 7 V OUT 23–30 +3.3V Sns (–) 16–22 15 + L O A D + C in C out Q1 BSS138 Inhibit COM COM Turn-On Time: Turning Q1 in Figure 1 off, removes the lowvoltage signal at pin 6 and enables the output. Following a brief delay of approximately 10ms 3, the output voltage of the PT7761 series regulators rise to full regulation within 15ms 3. Figure 2 shows the typical output voltage waveform of the PT7761 following the prompt turn-off of Q1 at time t =0 secs. The output voltage in Figure 1 is set to 3.3V by connecting VID0 (pin 1), VID2 (pin 3), and VID3 (pin 4) to the Rem Sense GND (pin 15)*. The waveform in Figure 2 was measured with a +5V input source voltage, and 10A resistive load. Vin Figure 2 Notes: 1. The Standby input on the PT7761 regulator must be controlled using an open-collector (or open-drain) discrete transistor. Do Not use a pull-up resistor. The control input has an open-circuit voltage equal to Vin. To set the regulator output to zero, the control pin must be “pulled” to less than 0.8Vdc with a 0.5mA sink to ground. Vo (1V/Div) Iin (5A/Div) 2. When placed in the standby mode, the regulator output discharges the output capacitance with a low impedance to ground. 3. The turn-off time of Q1, or rise time of the standby input is not critical for the PT7761. Turning Q1 off slowly, over periods up to 100ms, will not affect regulator operation. However, a slow turn-off time will increase both the initial delay and rise-time of the output voltage. Vstby (5V/Div) HORIZ SCALE: 5ms/Div * Consult the data sheet for details on other VID codes. For technical support and more information, see inside back cover or visit www.ti.com Application Notes PT7761 Pin-Coded Output Voltage Adjustment of PT7761 “Excalibur™” ISRs 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 voltage control circuit. Discrete transistors such as the BSS138, 2N7002, IRLML2402, are examples of appropriate devices. The PT7761 Excalibur power module incorporates a pin-coded output voltage control. These regulators include five control pins, identified VID0–VID4 (pins 1–5) respectively. By selectively grounding VID0-VID4, the output voltage of this regulator can be programmed in incremental steps over the output voltage range, 1.3V to 3.5V. The program code and voltage range is designed to be compatible with the “Voltage ID” specification defined for popular microprocessors. Refer to Figure 1 for the connection schematic, and the applicable data sheet for the program code. 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. If the program code cannot be asserted prior to power-up, pull pin 6 (STBY) to GND during the period that the input voltage is applied. The release of pin 6 will then to allow the device to initiate a soft-start power-up to the program voltage. Notes: 1. The programming convention is as follows:Logic 0: Connect to pin15 (Remote Sense Ground). Logic 1: Open circuit/open drain (See notes 2, & 4) 2. Do not connect pull-up resistors to the voltage programming pins. 3. Use pin 15 (Rem Sense Gnd) as the logic “0” reference. While the regular ground (pins 16–22) can also be used for programming, doing so will degrade the load regulation of the product. If the remote sense ground is not used, pin 15 must be connected to pin 16 for optimum output voltage accuracy. Figure 1 5 4 3 2 1 VID0 - VID4 +5V 9–14 1µH (Optional) 31 Sns (+) PT7761 VIN Stby Sync 6 7 GND VOUT 23–30 Sns (–) 16–22 15 + C in STBY COM For technical support and more information, see inside back cover or visit www.ti.com + C out L O A D IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. 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