PT7712—3.3V 20-A Programmable Integrated Switching Regulator SLTS088A (Revised 6/27/2002) Features • 3.3V Input Voltage • 20-A Output Current • 4-Bit Programmable Output: 1.3V to 2.05V • High Efficiency (87%) • Differential Remote Sense • Over-Current Protection • 27-Pin Space-Saving Package • Solderable Copper Case • Compatible with PT7744 20A “Current Booster” Description Ordering Information Pin-Out Information The PT7712 Excalibur™ power module is a 20-A integrated switching regulator (ISR) housed a 27-pin space-saving copper package. Operating from a 3.3V input bus, the PT7712 produces a tightly regulated output voltage that is programmable over the range, 1.3V to 2.05V. The output voltage is selected via a 4-bit code, which is compatible with the VRM specifications defined by Intel®. This regulator is most suitable for microprocessor and DSP applications requiring core or I/O logic supply voltages as low as 1.3V. The PT7712 incorporates output short-circuit protection, and a differential remote sense to compensate for voltage drop between the regulator and load. PT7712o = 1.3 to 2.05 Volts PT7744o = 20-A Booster * * Consult the related application note for information on current booster operation. PT Series Suffix (PT1234 x ) Case/Pin Order Configuration Suffix Vertical Horizontal SMD N A C Package Code † Pin Function Pin Function 1 VID0 2 VID1 15 16 GND GND 3 VID2 17 GND 4 5 VID3 STBY * 18 GND 6 No Connect 19 20 GND Vout 7 Vin Vin Vin 21 22 Vout Vout 23 24 Vout Vout 25 26 Vout Rem Sense Vout 27 Sync Out 8 9 (ENE) (ENF) (ENG) 10 † Previously known as package styles 1420 & 1430 (Reference the applicable package code drawing for the dimensions and PC board layout) 11 Vin Vin 12 13 Rem Sense Gnd GND 14 GND For STBY* pin: open =output enabled ground =output disabled. Standard Application VID0 VID1 VID2 VID3 PROGRAMMING PINS REMOTE SENSE(+) 4 3 2 1 26 L1 V IN 7-11 1µH + C IN 27 5 13-19 V OUT 20-25 PT7712 12 SYNC OUT GND GND STBY* L O A D + C OUT REMOTE SENSE(–) Cin = Required 1500µF electrolytic Cout = Required 330µF electrolytic L 1 = Optional 1µH input choke For technical support and more information, see inside back cover or visit www.ti.com PT7712—3.3V 20-A Programmable Integrated Switching Regulator Programming Information VID3 VID2 VID1 VID0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 PT7710 Product Family Comparison Vout 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 Product 1.30V 1.35V 1.40V 1.45V 1.5V 1.55V 1.60V 1.65V 1.70V 1.75V 1.80V 1.85V 1.90V 1.95V 2.00V 2.05V Input Voltage Adjust Method Description Output Range PT7711 5V VID 5-Bit 1.3V– 3.5V PT7712 3.3V VID 4-Bit 1.3V– 2.05V PT7713 3.3V VID 4-Bit 1.8V– 2.55V PT7714 3.3V VID 5-Bit 0.8V–1.575V PT7715 5V VID 5-Bit 1.075V–1.85V PT7716 3.3V VID 5-Bit 1.075V–1.85V PT7744 3.3V Booster — — PT7745 5V Booster — — Logic 0 = Pin 12 potential (remote sense gnd) Logic 1 = Open circuit (no pull-up resistors) VID3 must not be changed while the unit is operating. Specifications (Unless otherwise stated, Ta =25°C, Vin =3.3V, Cin =1,500µF, Cout =330µF, Vo =1.8V, and Io =Iomax) PT7712 Characteristics Symbols Conditions Min Output Current Io T a = +25°C, Natural convection T a = +60°C, 200 LFM, pkg N Input Voltage Range Vin Over I o range 3.1 — 3.6 Set-Point Voltage Tolerance Vo tol All output voltages — ±10 ±25 Temperature Variation Regtemp –40°C ≤Ta ≤+85°C, I o =Iomin — ±0.75 — %Vo Line Regulation Regline Over V in range — ±5 — mV Load Regulation Regload Over I o range — ±5 — mV Total Output Voltage Variation ∆Vo tol Includes set-point, line, load, –40°C ≤T a ≤+85°C — ±1 ±3 %Vo Efficiency η I o =10A Vo =1.8V Vo =1.5V — — 87 85 — — % I o =20A Vo =1.8V Vo =1.5V — — 83 81 — — % mVpp 0.1 0.1 (1) (1) Typ Max Units — — 20 19 A V (2) mV Vo Ripple (pk-pk) Vr 20MHz bandwidth — 50 — Transient Response ttr 1A/µs load step, 50% and 100% I o max — 50 — µSec Vos V o over/undershoot — ±100 — mV Over-Current Threshold ITRIP Reset followed by auto-recovery — 32 — A Switching Frequency ƒo Over V in range 300 350 400 kHz — — 0.3 Open (3) 0.8 — V Pin 5 to GND 2.0 -0.2 — Pin 5 to GND — 30 — mA — 15,000 µF °C STBY* Input Requirements Input High Voltage Input Low Voltage Input Low Current Referenced to GND VIH VIL I IL Standby Input Current Iin standby External Capacitance Cout Operating Temperature Range Ta Over V in Range –40 — +85 Storage Temperature Ts — -40 — +125 °C Mechanical Shock — Per Mil-STD-883D, Method 2002.3 1 msec, Half Sine, mounted to a fixture — 500 — G’s Mechanical Vibration — Mil-STD-883D, Method 2007.2 20-2000 Hz — — 20 (6) 15 (6) — — G’s Weight — Vertical/Horizontal — 36 — grams Flammability — Materials meet UL 94V-0 330 Suffixes N, A Suffix C (4) (5) mA Notes: (1) ISR-will operate down to no load with reduced specifications. (2) If the remote sense ground is not used, pin 12 must be connected to pin 13 for optimum output voltage accuracy. (3) The STBY* control (pin 5) has an internal pull-up. If it is left open-circuit, the module will operate when input power is applied. A low-leakage (<1µA) MOSFET must be used to control this pin. The open-circuit voltage may be as high as Vin. (4) For operation below 0°C, Cin and Cout must have stable characteristics. Use either low ESR tantalum or Oscon® capacitors. (5) See safe Operating Area curves or consult factory for the appropriate derating. (6) 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 regulator requires a minimum output capacitance of 330µF for proper operation. An input capacitance of 1500µF is also required. This 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 Filter: An input filter inductor is optional for most applications. The inductor must be sized to handle 20ADC with a typical value of 1µH. For technical support and more information, see inside back cover or visit www.ti.com Typical Characteristics PT7712—3.3V 20-A Programmable Integrated Switching Regulator Performance Characteristics, Vin =3.3V Safe Operating Area Curves (See Note A) (See Note B) PT7712, Vin =3.3V Efficiency vs Output Current 100 90 Efficiency - % VOUT 80 1.8V 1.5V 70 60 Ambient Temperature (°C) 80 90 70 Airflow 200LFM 120LFM 60LFM Nat conv 60 50 40 30 50 0 4 8 12 16 20 20 0 Iout (A) 4 8 12 16 20 Iout (A) Ripple vs Output Current 50 Ripple - mV 40 VOUT 30 1.5V 1.8V 20 10 0 0 4 8 12 16 20 Iout (A) Power Dissipation vs Output Current 10 Pd - Watts 8 VOUT 6 1.8V 1.5V 4 2 0 0 4 8 12 16 20 Iout (A) Note A: All characteristic data in the above graphs has been developed from actual products tested at 25°C. This data is considered typical for the ISR. Note B: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures. For technical support and more information, see inside back cover or visit www.ti.com Application Notes PT7710 Family, PT7744/PT7745 Capacitor Recommendations for the PT7710 Series of Regulators and Current Boosters Input Capacitors The recommended input capacitance is determined by the 1.4 ampere minimum ripple current rating and 1500µF minimum capacitance. Capacitors listed below must be rated for a minimum of twice (2×) 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 1-1 below. Tantalum Characteristics Tantalum capacitors with a minimum 10-V 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 compared to the TPS series when determining power dissipation capability. Capacitor Table Table 1-1 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. Capacitors from other vendors are available with comparible specifications. The RMS ripple current rating and ESR (Equivalent Series Resistance at 100kHz) are the critical parameters necessary to insure both optimum regulator performance and long capacitor life. Table 1-1 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 Panasonic FC (SMT) 16V 35V 2200 330 0.038Ω 0.065Ω 2000mA 1205mA 18x16.5 12.5x16.5 1 1 1 EEVFC1C222N EEVFC1V331LQ FC (Radial) 10V 16V 560 1800 0.090Ω 0.032Ω 755mA 2000mA 10x12.5 18x15 1 1 EEUFC1A561 EEUFC1C182S United Chemi -Con LFZ Series 25V 16V 16V 330 1500 470 0.090Ω 0.038Ω 0.090Ω 760mA 1660mA 760mA 10x12.5 12.5x20 10x12.5 1 1 1 1 LXZ25VB331M10X12LL LXZ16VB222M12X20LL LXZ16VB471M10X12LL 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 (Radial) SVP (SMT) 10V 10V 330 330 0.025Ω÷4 =0.006Ω 0.02Ω÷4 =0.005Ω >9800mA >9800mA 10x10.5 9x8.3 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) 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 10SVP330M Application Notes PT7710 Series, PT7744, PT7745 Increasing the Output of the PT7710 Family of ISRs with a 20-A Compatible Current Booster Notes: 1. Each booster requires the same amount of input and output capacitance as recommended for a stand-alone regulator. Consult the individual data sheet of the applicable regulator, and the related application note regarding capacitor selection for this product family. The output of PT7710 family of regulators (PT7711– PT7716) can produce an additional 20-A output using a compatible current booster module. Two booster modules are available. They are the PT7744 and PT7745, which are compatible with regulators that operate off 3.3-V or 5-V input buses respectively. Refer to Table 2-1 for regulator/booster compatiblity. 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 20ADC at full output load. The booster modules are controlled directly by the regulator and effectively add a parallel output stage. They operate sychronously, to provide a low-noise solution. Up to two booster modules can be connected to a PT771x regulator. Each booster added increases the regulator’s output current by 20A, for up to 60A of output current. 3. The pin-out of the current booster modules include a number pins identified, “No Connect” (see Table 2-2). These pins are not connected internally to the module but must be soldered to a pad to preserve the unit’s mechanical integrity. Current boosters are not stand-alone products, and can only operate with a regulator. They are housed in the same package as the regulator, and share the same mechanical outline. Except for an increase in output current, the overall performance of a regulator/booster combination is identical to that of a stand-alone regulator. For more details refer to the applicable regulator specifications. 4. A similar PCB footprint and trace layout between the regulator and each booster will facilitate current sharing between all modules. Table 2-2; Booster Pin-Out Information Pin Function Table 2-1; Booster Compatibility Regulator P7744 Booster (3.3V Input Bus) PT7745 Booster (5V Input Bus) • PT7711 PT7712 PT7713 PT7714 • • • • PT7715 PT7716 • Pin Function Pin Function 1 No Connect 10 Vin 19 GND 2 No Connect 11 Vin 20 Vout 3 No Connect 12 No Connect 21 Vout 4 5 No Connect No Connect 13 GND 14 GND 22 Vout 23 Vout 6 No Connect 15 GND 24 Vout 7 Vin 16 GND 25 Vout 8 9 Vin Vin 17 GND 18 GND 26 No Connect 27 Sync In Figure 1-1; Current Booster Application Schematic VID0 VID1 VID2 VID3 VID4 PROGRAMMING PINS REMOTE SENSE (+) 6 4 3 2 VID4 - VID0 L IN V IN 7-11 1µH + 26 SNS(+) PT771x V IN STBY C IN 1 5 Synch Out 27 GND 13-19 VO VOUT 20-25 + SNS(-) 12 C OUT LOAD GND GND STBY* REMOTE SENSE (–) 27 Synch In L IN 7-11 1µH + C IN V IN PT7744/45 Booster GND 13-19 VO 20-25 + C OUT For technical support and more information, see inside back cover or visit www.ti.com Application Notes PT7710 Family Using the Standby Function on the PT7710 Excalibur™ Series of 20-A ISRs For applications requiring On/Off control of the output voltage, the PT7710 family of Excalibur ISRs incorporate a standby function. This feature may be used for power-up/shutdown sequencing, or to change the output voltage while input power is applied. See related notes: “Pin-Coded Output Voltage Adjustment of the PT7710 Excalibur™ Series of 20-A ISRs.” The standby function is provided by the STBY* control, pin 5. If pin 5 is left open-circuit the regulator operates normally, providing a regulated output whenever a valid supply voltage is applied to Vin (pins 7-11) with respect to GND (pins 13-19). Connecting pin 5 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 5 prior to power-up, the regulator output will be held at zero volts during the period that input power is applied. The standby input must be controlled with an opencollector (or open-drain) discrete transistor (See Figure 1). Table 3-1 gives the input requirements. Table 3-1 Standby Control Input Requirements (1, 2) Parameter Min Typ Max Enable Disable Istby (low) Vstby (o/c) 2V –0.2V Open Cct. 0.8V 0.5mA 1 Figure 3-1 6 4 3 2 1 26 Rem Sns (+) VID4 - VID0 7-11 5V 20-25 PT7711 Vin Synch STBY Out 5 GND 27 V o =3.3V Vo Rem Sns (–) 13-19 12 + L O A D + C in C out Q1 BSS138 Inhibit COM COM Turn-On Time: Turning Q1 in Figure 3-1 off, removes the low-voltage signal at pin 5 and enables the output. After a delay of approximately 10ms, the output voltage of a PT771x regulator rises to full regulation within 30ms 3. Figure 3-2 shows the typical output voltage waveform of a PT7711 following the turn-off of Q1 at time t =0 secs. The output voltage in Figure 3-1 is set to 3.3V by connecting VID0 (pin 1), VID2 (pin 3), and VID3 (pin 4) to the ‘Rem Sense Gnd’ (pin 12)*. The waveform was measured with a +5V input source voltage, and 10-A resistive load. Vin Notes: 1. The Standby input on the PT7710 regulator family 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. Figure 3-2 Vo (2V / 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 with the PT7710 family. 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. Iin 10A / Div) 0 5 10 15 20 t (milli - secs) * 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 25 30 Application Notes PT7710 Family Pin-Coded Output Voltage Adjustment of the PT7710 Excalibur™ Series of 20-A 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 divider network. Discrete transistors such as the BSS138, 2N7002, or IRLML2402 are examples of appropriate devices. The PT7710 Excalibur™ family of converters incorporate a pin-coded control to adjust the output voltage. This feature uses the control pins VID0–VID4 (pins 1–6). When the control pins are left open-circuit, the ISR output regulates at its default output voltage. Each control pin is internally connected to a precision resistor, which when grounded applies a weighted change to the output voltage. By selectively grounding VID0–VID4, the output voltage of these ISRs can be programmed in incremental steps over the specified output voltage range. The program codes and output voltage range offered by these ISRs are compatible with the Voltage ID specifications defined by Intel Corporation for VRMs (voltage regulator modules). The codes are used by both the Pentium® and Athlon® microprocessors. Refer to Figure 4-1 for the connection schematic, and the respective device Data Sheet for the programming code information. Active Voltage Programming: Special precautions should be taken when making changes to the output voltage progam code while the unit is powered. This activity can induce current transients through the device as a 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 or VID4 is discouraged. When active devices are used to program the output voltage, their state should be asserted prior to the input power being applied. An alternative is to pull pin 5 (STBY) control to GND during the application of input voltage, then assert the required program code and release pin 5. The module will then intiate a soft-start power-up to the desired program voltage. For more information on the use of the Standby function, consult the related application note, “Using the Standby Function on the PT7710 Excalibur™ Series of 20-A ISRs.” Notes: 1. The programming convention is as follows:Logic 0: Logic 1: Connect to pin 12 (Remote Sense Ground). Open circuit/open drain (See notes 2, & 4) 2. Do not connect pull-up resistors to the voltage programming pins. 3. Use pin 12 (Remote Sense Ground) as the logic “0” reference. While the regular ground (pins 13-19) can also be used for programming, doing so will degrade the load reglation of the product. If the remote sense ground is not used, pin 12 must be connected to pin 13 for optimum output voltage accuracy. Figure 4-1 6 4 3 2 1 26 VID4 - VID0 +5V 7-11 1µH (Optional) SNS(+) PT7710 Vin STBY 5 Synch Out 27 GND 13-19 20-25 Vo SNS(-) 12 + Cin + Cout L O A D STBY COM For technical support and more information, see inside back cover or visit www.ti.com 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. 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