PT6721—12V 14 Amp Programmable Integrated Switching Regulator SLTS101A (Revised 10/31/2000) • +12V input • 5-bit Programmable: 1.3V to 3.5V@14A • High Efficiency • Input Voltage Range: 10.8V to 13.2V • Differential Remote Sense • 23-pin Space Saving Package • Solderable Copper Case • Short Circuit Protection • Over-Voltage Drive • Power Good Signal The PT6721 is a new high-performance, 14 Amp Integrated Switching Regulators (ISRs) housed in a unique, 23-pin space-saving package. The PT6721 operates from a standard 12V power bus to provide a high performance low-voltage power source for the industry’s latest high-speed, low-voltage µPs and bus drivers. The output voltage of the PT6721 can be easily programmed from 1.3V to 3.5V with a 5-bit input compatible with Intel’s Pentium Processor family. Patent pending on package assembly PT6700 Product Family Standard Application OVP DRV PROGRAMMING PINS VID0 VID1 VID2 VID3 VID4 VIN Input Vout Voltage Adjust REMOTE SENSE (+) 7 6 5 4 3 1 23 L1 PT6721 10 - 12 1µH R1 CIN 2 + 14 - 18 8 VOUT 19 - 22 13 COUT + LOAD PWR GOOD GND GND STBY* OVP/ PWRGD PT6701 5V VID 3 PT6702 3.3V VID 3 PT6705 5V Resistor PT6715 5V Resistor PT6721 12V VID PT6725 12V Resistor Needs 12VBias 3 3 REMOTE SENSE (-) Cin Cout L1 R1 Specifications = Required 1000µF electrolytic (See footnotes) = Required 330µF electrolytic (See footnotes) = Optional 1µH input choke (See footnotes) = Required 10kΩ pull-up when using Pwr Good signal. Pwr good output is high when the output voltage is within specification. PT6721 SERIES Characteristics (Ta = 25°C unless noted) Symbols Conditions Min Output Current Io Ta = +60°C, 200 LFM, pkg N Ta = +25°C, natural convection 0.1 0.1 Input Voltage Range Vin 0.1A ≤ Io ≤ 14A 10.8 Output Voltage Tolerance ∆Vo Vin = +12V, Io = 14A -40°C ≤ Ta ≤ +85°C Vo–0.03 — Vo+0.03 V Short-Circuit Threshold Isc Vin = +12V — 20 30 A Line Regulation Regline 10.8V ≤ Vin ≤ 13.2V, Io = 14A — ±5 — mV Load Regulation Regload Vin = +12V, 0.1 ≤ Io ≤ 14A — ±10 — mV Vo Ripple/Noise Vn Vin = +12V, Io = 14A — 35 — mV Transient Response with Cout = 330µF ttr Vos Io step between 7A and 14A Vo over/undershoot — — 50 70 — — µSec mV Efficiency η Vin = +12V, Io = 9A — — — — 90 88 83 81 — — — — % 350 400 — +85 Vo Vo Vo Vo = = = = 3.3V 2.5V 1.8V 1.5V Switching Frequency ƒo 10.8V ≤ Vin ≤ 13.2V 0.1A ≤ Io ≤ 14.0A 300 Absolute Maximum Operating Temperature Range Ta — -40 Storage Temperature Ts (1) (1) (2) Typ Max — — 14 14 Units A — 13.2 V kHz (3) °C — -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 Per Mil-STD-883D, Method 2007.2, 20-2000 Hz, Soldered in a PC board — 15 — G’s — — 26 — grams Weight Notes: (1) (2) (3) (4) — ISR-will operate down to no load with reduced specifications. 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 contact the factory for appropriate derating. If the Remote Sense Ground is note used, pin 13 must be connected to pin 14 for optimum output voltage accuracy. External Capacitors: The PT6721 requires a minimum output capacitance of 330µF, with a maximum ESR of 50mΩ @100kHz for proper operation. The maximum allowable output capacitance is 15,000µF. The input capacitance must be rated for a minimum of 1.6Arms of ripple current. For transient or dynamic load applications, additional capacitance may be required. For more 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 5ADC with a typical value of 1µH. For technical support and more information, see inside back cover or visit www.ti.com/powertrends PT6721—12V 14 Amp Programmable Integrated Switching Regulator Pin-Out Information Programming Information Pin Function Pin Function 1 2 OVP Drive Pwr Good 13 14 GND 3 4 VID0 VID1 15 16 GND GND 5 6 VID2 VID3 17 18 GND GND 7 8 VID4 STBY# 19 20 Vout Vout 9 10 Do not connect Vin 21 22 Vout Vout 11 12 Vin Vin 23 Remote Sense Vout Remote Sense Gnd VID3 VID2 VID1 VID0 (4) 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 #For STBY pin:open =output enabled ground =output disabled. 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 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 (For dimensions and PC board layout, see Package Styles 1300 and 1310.) PT Series Suffix (PT1234X) Case/Pin Configuration Vertical Through-Hole N Horizontal Through-Hole A Horizontal Surface Mount C C H A R A C T E R I S T I C S Safe Operating Area Curves (Note B) (Note A) Efficiency vs Output Current Vout =3.3V, Pkg Suffix ‘N’ 90.0 100 80 VOUT 3.3V 2.5V 1.5V 70 60 50 Ambient Temperature (°C) 80.0 90 Efficiency - % PT6721o = 1.3 to 3.5 Volts 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 Logic 0 = Pin 13 potential (remote sense gnd) Logic 1 = Open circuit (no pull-up resistors) VID3 and VID4 may not be changed while the unit is operating. T Y P I C A L 12.0V Input Voltage 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 Ordering Information VID4=1 VID4=0 Vout Vout 70.0 Airflow 200LFM 120LFM 60LFM Nat conv 60.0 50.0 40.0 30.0 20.0 40 0 2 4 6 8 10 12 0.0 14 2.0 4.0 6.0 8.0 10.0 12.0 14.0 Iout (A) Iout (A) Ripple vs Output Current 25 Ripple - mV 20 VOUT 15 3.3V 2.5V 1.5V 10 5 0 0 2 4 6 8 10 12 14 Iout (A) Power Dissipation vs Output Current 7 6 Pd - Watts 5 VOUT 4 3.3V 2.5V 1.5V 3 2 1 0 0 2 4 6 8 10 12 14 Iout (A) Note: A All data listed in the above graphs has been developed from actual products tested at 25°C. This data is considered typical data for the ISR. Note: B SOA Curves represent the 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/powertrends Application Notes PT6701/PT6702/PT6721 Operating Features of the Programmable PT6700 “Excalibur™” Series ISRs Power Good Programmable versions of the PT6700 Series regulators incorporate a PWR Good output (pin 2). This output is open-drain and generates an acitve-high signal when the sensed output from the ISR is within a nominal ±10% of the programmed set point. When the regulated output is outside this range, pin 2 asserts a logic low (typically <0.1V). A 10kΩ pull-up resistor to a valid bus voltage is required. If the power good feature is not used, the pull-up resistor can be omitted. The maximum voltage that may be applied to the pull-up resistor is 15V. 2. The Standby input can also be interfaced to TTL or other bi-directional output device using a schottky diode. See Figure 1. 3. When placed in the standby mode, the regulator output may assert a low impedance to ground. If an external voltage is applied to the output, it will sink current and possibly over-stress the part. Table 1 Inhibit Control Threshold 2,3 Parameter Min Typ Enable (VIH) 3.0V Disable (VIL) -0.1V Max 0.4V Istby 1..0V 0.01mA Figure 1 Over-Voltage Protection (OVP) The PT6700 programmable regulators also incorporate an OVP function. The OVP DRV (pin 1) normally has a logic low output (typically <0.1V). When the ISR’s sensed output exceeds the programmed output setting by 15%, pin 1 produces a 60mA, +12V drive signal. This drive signal can trigger an SCR, which can be used to disable the input voltage, or alternatively interface to another external monitoring device. When the ISR output voltage returns to within 15% of its programmed setting, pin 1 reverts back to its low state. If the OVP function is not used, pin 1 may be left open circuit. OVP DRV 7 10-12 5V R1 10k If the STBY* input (pin 8) is left open-circuit the regulator operates normally, providing a regulated output when a valid supply voltage is applied to Vin (pins 10-12) with respect to GND (pins 14-18). Connecting pin 8 to ground 1 places the regulator in standby mode, and reduces the input current to typically 20mA (30mA max). Applying a ground signal to pin 8 prior to power-up, will disable the output during the period that input power is applied. To ensure that the regulator output is fully enabled, pin 8 must be allowed to rise to a minimum of 3.0V. 23 SNS(+) 19-22 PT6700 Vin Pwr Good 2 + 1 OVP STBY 8 V o =2.5V Vo SNS(-) GND 14-18 C in 13 + C out L O A D Pwr Good Q1 BSS138 Inhibit COM COM 5V Stand-By Function The PT6700 series ISRs incorporate a standby function. This feature may be used for power-up sequencing, or wherever there is a requirement for the output voltage to be controlled by external circuitry. 6 5 4 3 VID4 - VID0 D1 BAT54 * * or equiv. Schottky diode Turn-On Time Turning Q1 in Figure 1 off, removes the low-voltage signal at pin 8 and enables the output. Following a brief delay of 10-15ms, the output voltage of the PT6700 regulator rises to full regulation within 30ms. Figure 2 shows the typical output voltage waveform of a PT6701 following the prompt turn-off of Q 1 at time t =0 secs. The output voltage was set to 2.5V. The waveforms were measured with a 5V input source voltage, and 10A resistive load. Figure 2 Vout (2V/Div) Notes: Iin (5A/Div) 1. The standby on the PT6700 series is ideally controlled with an open-collector (or open-drain) discrete transistor (See fig. 1). Table 1 gives the threshold requirements. Do Not use a pull-up resistor. The control input has an opencircuit voltage of about 4.0Vdc. To set the regulator output to zero, the control pin must be “pulled” to less than 1.0Vdc with a sink to ground. VPWGD (10V/Div) 0 5 10 15 20 t (milli - secs) For technical support and more information, see inside back cover or visit www.ti.com/powertrends 25 30 35 40 Application Notes continued PT6701/PT6702/PT6721 Series Pin-Coded Output Voltage Adjustment on Non-Isolated “Excalibur™” Series 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, or the 74C906 hex open-drain buffer are examples of appropriate devices. The PT6701/6702/6721 Excalibur™ ISRs incorporate a pin-coded voltage control to adjust the ouput voltage. The control pins are identified VID0 - VID4 (pins 3–7) respectively. When these 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 these ISRs can be programmed in incremental steps over the specified output voltage range. The program code and output voltage range of these ISRs is compatible with the voltage ID specification defined by Intel Corporation. The code is used in conjuction with voltage regulator modules (VRMs) that are used to power Intel’s Pentium® microprocessors. Refer to Figure 1 below for the connection schematic, and the respective device 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 8 (STBY) to the device GND during the period that the input voltage is applied to Vin. Releasing pin 8 will then allow the device output to initiate a soft-start power-up to the programmed voltage. Notes: 1. The programming convention is as follows:Logic 0: Connect to pin13 (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. To minimize output voltage error, always use pin 13 (Remote Sense Ground) as the logic “0” reference. While the regular ground (pins 14-18) can also be used for programming, doing so will degrade the load regulation of the product. Figure 1 7 6 5 4 3 1 VID4 - VID0 V in 10-12 1 µH (Optional) OVP 23 SNS(+) 19-22 PT6700 Vin Pwr Good 2 STBY GND 8 14-18 V out Vo SNS(-) 13 + + C in C out L O A D Q1 STBY COM COM For technical support and more information, see inside back cover or visit www.ti.com/powertrends Application Notes PT6721/6725 Series Capacitor Recommendations for the PT6721 and PT6725 Series Regulators Input Capacitors The recommended input capacitance is determined by 1.6 ampere minimum ripple current rating and 1000µF minimum capacitance. Tantalum capacitors listed below cannot be used on the input bus since they are not rated for 12V operation. Ripple current and 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 50mW. 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 are recommended on the output bus but only TPS Series, Sprague 593D/594/595 Series, or Kemet T495/T510 Series. The AVX TPS Series, Sprague Series or Kemet Series tantalum capacitors are recommended over other manufacturer’s due to their higher surge current, excellent power dissipation and ripple current ratings. As an example, 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 a less reliable compared to the TPS series when comparing 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 Capac i t or Vendor / Ser i es Capac i t or Char ac t er i st i c s Quant i t y Wor k i ng Vol t age Val ue( µF) ( ESR) Equi val ent Ser i es Resi st anc e 1 0 5 ° C Maxi mum Ri ppl e Cur r ent ( I r ms) Physi c al Si ze( mm) I nput Bus Out putt Bus Panasonic FC Series FA Series 35V 25V 25V 680 1000 1000 0.043Ω 0.038Ω 0.038Ω 1655mA 1655mA 1690mA 12.5x20 12.5x20 16x15 2 1 1 1 2 1 EEUFC1V681 EEUFC1E102 EEUFC1E102S United Chemi -con LFVSeries 35V 35V 16V 680 1000 470 0.034Ω 0.038Ω 0.084Ω/2=042Ω 1690mA 1630mA 825mA x2 12.5x25 16x20 10x16 2 1 N/R(1) 1 1 2 LXV35VB680M12X25LL LXV35VB102M16X20LL LXV16VB471M10X16LL Nichicon PL Series PM Series 35V 25V 35V 680 1200 1000 0.036Ω 0.039Ω 0.034Ω 1660mA 1600mA 1770mA 12.5x25 18x15 16x20 2 1 1 1 1 1 UPL1V681MHH UPL1E122MHH6 UPM1V102MHH6 Panasonic FC Series Surface Mtg 35V 25V 35V 1000 1000 470 0038Ω 0.038Ω 0.0430Ω 2000mA 2000mA 1690mA 18x16.5 18x16.5 16x16.5 1 1 2 1 1 1 EEVFC1V102N EEVFC1E102N EEVFC1V471N OsconSS/SV Series 10V 10V 330 330 0.025Ω 0.020Ω 3500mA 3800mA 10x10.5 10.3x10.3 1 1 10SS330M( If Output <5V) 10SV330( If Output <5V) Surface Mount(SV) AVX Tantalum TPS Series 10V 330 0.100Ω/2=0.050Ω >2500mA 2 TPSE337M010R0100 330 0.060Ω/2=0.030Ω >3000mA 7.3L x 5.7W x 4.1H N/R(1) 10V N/R(1) 2 TPSV337M010R0060 Surface Mount Kemet Tantalum T510/T495 Series 10V 330 0.033Ω 1400mA 1 510X337M010AS 220 0.070Ω/2=0.035Ω >2000mA 4.3Wx7.3L x4.0H N/R(1) 10V N/R(1) 2 T495X227M0100AS Surface Mount Sprague Tantalum 594D Series 10V 330 0.045Ω 2360mA 7.2L x 6W x 4.1H N/R(1) 1 594D337X0010R2T Surface Mount Note: (N/R) 10V tantalums are not recommend for the input bus. For technical support and more information, see inside back cover or visit www.ti.com/powertrends N/R(1) N/R(1) Vendor Number 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 acknowledgment, 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. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. Customers are responsible for their applications using TI components. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other intellectual property right of TI covering or relating to any combination, machine, or process in which such semiconductor products or services might be or are used. TI’s publication of information regarding any third party’s products or services does not constitute TI’s approval, warranty or endorsement thereof. Copyright 2000, Texas Instruments Incorporated