PT6935 Series 11-A 5V/3.3V-Input Dual Output Integrated Switching Regulator SLTS091B Revised (9/30/2001) Features • Dual Outputs • • • • • (See Ordering Information) • 5V/3.3V Input • • • • Outputs Adjustable Remote Sensing (Vo1 & Vo2) Standby Function Soft-Start Pin-Out Information Ordering Information Description PT6935o PT6936o PT6937o PT6938o PT6939o The PT6935 Excalibur™ series of power modules are dual output integrated switching regulators (ISRs) designed to power the latest mixed signal ICs. The dual output provides power for both the digital I/O logic and a DSP core from a single module. Both output voltages are internally sequenced during power-up and power-down to comply with the requirements of the latest DSP chips. Each output is independently adjustable or can be set to at least one alternative bus voltage with a simple pin-strap. The modules are made available in a space-saving solderable case. Features include an output current limit and short-circuit protection. = = = = = +2.5/1.8 +3.3/2.5 +3.3/1.8 +3.3/1.2 +2.5/1.2 Volts Volts Volts Volts Volts PT Series Suffix (PT1234x) Case/Pin Configuration Order Suffix Package Code N A C Vertical Horizontal SMD Internal Sequencing Short Circuit Protection 23-pin Space-Saving Package Solderable Copper Case Ideal Power Source for DSPs (ELF) (ELG) (ELH) (Reference the applicable package code drawing for the dimensions and PC layout) Pin Function Pin Function 1 Vo1 Sense 13 Vo1 2 No Connect 14 Vo1 3 STBY 15 Vo1 4 Vin 16 Vo1 Adjust * 5 Vin 17 No Connect 6 Vin 18 Vo2 7 GND 19 Vo2 8 GND 20 Vo2 9 GND 21 Vo2 10 GND 22 Vo2 Sense 11 GND 23 Vo2 Adjust * 12 Vo1 * Vo1 and Vo2 can be pin-strapped to another voltage. See application note on output voltage adjustment. Standard Application V o 2 Sense STBY V o 1 Sense 3 22 1 18-21 V IN 4,5,6 Vo 2 PT6935 12-15 Vo 1 + 7-11 C1 16 23 + C3 C2 GND GND C1 = Req’d 330µF * electrolytic C2 = Req’d 330µF * electrolytic C3 = Optional 100µF electrolytic * 300µF for Oscon® or low ESR tantalum -see notes For technical support and more information, see inside back cover or visit www.ti.com PT6935 Series 11-A 5V/3.3V-Input Dual Output Integrated Switching Regulator General Specifications (Unless otherwise stated, Ta =25°C, Vin =5V) Characteristic Symbol Short Circuit Current Switching Frequency Standby (Pin 3) Input High Voltage Input Low Voltage Input Low Current Standby Input Current External Output Capacitance Isc ƒo Maximum Operating Temperature Range Storage Temperature Mechanical Shock VIH V IL IIL Iin standby C2 C3 Ta Ts Mechanical Vibration Weight Flammability — — Conditions Min Io1 + Io2 combined Over Vin range Referenced to GND (pin 7) pin 3 to GND Over Vin Range — Per Mil-STD-883D, Method 2002.3 1 msec, ½ Sine, mounted Per Mil-STD-883D, Method 2007.2 20-2000 Hz, Soldered in a PC board Vertical/Horizontal Meets UL 94V-O PT6935 Series Typ Max Units — 300 17 350 — 400 A kHz — –0.1 — — 330 (2) 0 –40 (3) — — -0.5 7 — — — Open (1) +0.4 – 25 3,300 (2) 330 +85 (4) –40 — +125 °C — — 500 15 (5) — — G’s G’s — 26 — grams V mA mA µF °C Notes: (1) The Standby (pin 3) has an internal pull-up, and if it is left open circuit the module will operate when input power is applied. The open-circuit voltage is less than 15V. Refer to the application notes for interface considerations. (2) A value of 300µF is sufficient if Oscon® or low ESR tantalum type capacitors are used. The total combined ESR of all output capacitance at 100kHz must be (greater than) >12 mΩ, and (less or equal to) ≤150mΩ. (3) For operating temperatures below 0°C, Cin and Cout must have stable characteristics. Use either tantalum or Oscon® capacitors. (4) See Safe Operating Area curves for the specific output voltage combination, or contact the factory for the appropriate derating. (5) Only the case pins on through-hole pin configurations (N & A) must be soldered. For more information see the applicable package outline drawing. Input/Output Capacitors: The PT6935 series requires a 330µF electrolytic capacitor at both the input and output for proper operation (300µF for Oscon® or low ESR tantalum). In addition, the input capacitance must be rated for a minimum of 1.0Arms ripple current. For transient or dynamic load applications, additional capacitance may be required. Refer to the application notes for more information. Power-up Sequencing and Vo1/Vo2 Loading Power-up Sequencing The PT6935 series of regulators provide two output voltages, Vo1 and Vo 2. Each of the output voltage combinations offered by the PT6935 series provides power for both a lowvoltage processor core, and the associated digital support circuitry. In addition, each output is internally sequenced during power-up and power-down to comply with the requirements of most DSP and µP IC’s, and their accompanying chipsets. Figure 1 shows the typical waveforms of the output voltages, Vo1 and Vo2, from the instance that either input power is applied or the module is enabled via the Standby pin. Following a delay of about 10 to 15 milli-secs, the voltages at Vo1 and Vo2 rise together until Vo2 reaches its set-point. Then Vo1 continues to rise until both output voltages have reached full voltage. Figure 1; PT6935 Series Power-up V1 (1V/Div) Vo1/Vo2 Loading The output voltages from the PT6935 series regulators are independently regulated. The voltage at Vo1 is produced by a highly efficient switching regulator. The lower output voltage, Vo2, is derived from Vo1. The regulation method used for Vo 2 also provides control of this output voltage during power-down. Vo2 will sink current if the voltage at Vo1 attempts to fall below it. The load specifications for each model of the PT6935 series gives both a ‘Typical’ (Typ) and ‘Maximum’ (Max) load current for each output. For operation within the product’s rating, the load currents at Vo1 and Vo2 must comply with the following limits:• Io 2 must be less than Io2(max). • The sum-total current from both outputs (Io1 + Io2) must not exceed Io1(max). In the case that either Vo1 or Vo2 are adjusted to some other value than the default output voltage, the absolute maximum load current for Io2 must be revised to comply with the following equation. V2 (1V/Div) Io2 (max) Vstby (10V/Div) = 2.5 Vo1 – Vo2 Adc Consult the specification table for each model of the series for the actual numeric values. HORIZ SCALE: 5ms/Div For technical support and more information, see inside back cover or visit www.ti.com PT6935 11 Amp 5V/3.3V-Input Dual Output Integrated Switching Regulator PT6935 Performance Specifications (Unless otherwise stated, T a =25°C, Vin =5V, C 1 =330µF, C2 =330µF, Io1 =Io1typ, and Io2 =Io 2typ) Characteristic Symbol Conditions Output Current Ta =25°C, natural convection Input Voltage Range Set Point Voltage Tolerance Io1 Io2 Io1 Io2 Vin Vo tol Temperature Variation Line Regulation Regtemp Regline –40° >Ta > +85°C Over Vin range Load Regulation Regload Over Io range Total Output Voltage Variation ∆Votot Includes set-point, line, load, –40° >Ta > +85°C Efficiency Vo Ripple (pk-pk) η Vr Transient Response ttr Min Vo1 (2.5V) Vo2 (1.8V) Vo1 (2.5V) Vo2 (1.8V) Ta =60°C, 200LFM airflow 0.1 0 0.1 0 3.1 — — — — — — — — — — — — — — — Over Io Range Vo1 Vo2 Vo1 Vo2 Vo1 Vo2 Vo1 Vo2 20MHz bandwidth Vo1 Vo2 1A/µs load step, 50% to 100% Iotyp Vo over/undershoot ∆Vtr Vo1 Vo2 PT6935 (2.5V/1.8V) Typ Max 7 (ii) 2.5 (ii) 7 (ii) 2.5 (ii) — ±12 ±9 ±0.5 ±5 ±2 ±5 ±5 ±34 ±25 79 35 35 60 ±60 ±60 (i) (i) Units 9.5 (iii) 3.5 (iii) 10 (iii) 3.5 (iii) 5.5 ±38 ±27 — ±10 ±5 ±10 ±10 — — — — — — — — A A VDC mV %Vo mV mV mV % mVpp µs mV Notes: (i) Io1(min) current of 0.1A can be divided between both outputs, Vo1 or Vo2. The module will operate at no load with reduced specifications. (ii) The typical current is that which can be drawn simultaneously from both outputs under the stated operating conditions. (iii) The sum of Io1 and Io2 must be less than Io1max, and Io 2 must be less than Io2max. PT6935 Typical Characteristics Power Dissipation vs Io 1 (See Note A) 10 80 8 VIN 75 3.3V 5.0V 70 Pd - Watts Efficiency - % Efficiency vs Io1 (See Note A) 85 65 VIN 6 5.0V 3.3V 4 2 60 0 0 1 2 3 4 5 6 7 0 1 Io1 (A) [ Io2 fixed at Io2(typ) ] Vo1 Output Ripple vs Io1 (See Note A) 3 4 5 6 7 Safe Operating Area, V in =5V (See Note B) 90 60 80 VIN 40 5.0V 3.3V 30 20 10 Ambient Temperature (°C) 70 50 Ripple - mV 2 Io1 (A) [ Io2 fixed at Io2(typ) ] 70 Airflow 200LFM 120LFM 60LFM Nat conv 60 50 40 30 0 20 0 1 2 3 4 5 6 7 0 Io1 (A) [ Io2 fixed at Io2(typ) ] 1 2 3 4 5 Iout (A) Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter. Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures For technical support and more information, see inside back cover or visit www.ti.com 6 7 PT6936 11 Amp 5V/3.3V-Input Dual Output Integrated Switching Regulator PT6936 Performance Specifications (Unless otherwise stated, T a =25°C, Vin =5V, C 1 =330µF, C2 =330µF, Io1 =Io1typ, and Io2 =Io 2typ) Characteristic Symbol Conditions Output Current Ta =25°C, natural convection Input Voltage Range Set Point Voltage Tolerance Io1 Io2 Io1 Io2 Vin Vo tol Temperature Variation Line Regulation Regtemp Regline –40° >Ta > +85°C Over Vin range Load Regulation Regload Over Io range Total Output Voltage Variation ∆Votot Includes set-point, line, load, –40° >Ta > +85°C Efficiency Vo Ripple (pk-pk) η Vr Transient Response ttr Vo1 (3.3V) Vo2 (2.5V) Vo1 (3.3V) Vo2 (2.5V) Ta =60°C, 200LFM airflow 0.1 0 0.1 0 4.5 — — — — — — — — — — — — — — — Over Io Range Vo1 Vo2 Vo1 Vo2 Vo1 Vo2 Vo1 Vo2 20MHz bandwidth Vo1 Vo2 1A/µs load step, 50% to 100% Iotyp Vo over/undershoot ∆Vtr PT6936 (3.3V/2.5V) Typ Max Min Vo1 Vo2 8 (ii) 3 (ii) 8 (ii) 3 (ii) — ±16 ±12 ±0.5 ±5 ±2 ±5 ±5 ±29 ±34 81 35 35 60 ±60 ±60 (i) (i) 11 3 11 3 5.5 ±50 ±38 — ±10 ±5 ±10 ±10 — — — — — — — — Units (iii) (iii) A (iii) (iii) A VDC mV %Vo mV mV mV % mVpp µs mV Notes: (i) Io 1(min) current of 0.1A can be divided between both outputs, Vo1 or Vo2. The module will operate at no load with reduced specifications. (ii) The typical current is that which can be drawn simultaneously from both outputs under the stated operating conditions. (iii) The sum of Io 1 and Io2 must be less than Io1max, and Io 2 must be less than Io2max. PT6936 Typical Characteristics Power Dissipation vs Io 1 (See Note A) 10 80 8 VIN 75 5.0V 70 Pd - Watts Efficiency - % Efficiency vs Io1 (See Note A) 85 65 VIN 6 5.0V 4 2 60 0 0 1 2 3 4 5 6 7 8 0 1 2 Io1 out (A) [ Io2 fixed at Io2(typ) ] Vo1 Output Ripple vs Io 1 (See Note A) 4 5 6 7 8 Safe Operating Area, V in =5V (See Note B) 90 60 80 VIN 40 5.0V 30 20 Ambient Temperature (°C) 70 50 Ripple - mV 3 Io1 out (A) [ Io2 fixed at Io2(typ) ] Airflow 70 200LFM 120LFM 60LFM Nat conv 60 50 40 30 10 20 0 0 1 2 3 4 5 6 Io1 out (A) [ Io2 fixed at Io2(typ) ] 7 8 0 1 2 3 4 5 6 7 8 Io1 (A) [ Io2 fixed at Io2(typ) ] Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter. Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures For technical support and more information, see inside back cover or visit www.ti.com PT6937 11 Amp 5V/3.3V-Input Dual Output Integrated Switching Regulator PT6937 Performance Specifications (Unless otherwise stated, T a =25°C, Vin =5V, C 1 =330µF, C2 =330µF, Io1 =Io1typ, and Io2 =Io 2typ) Characteristic Symbol Conditions Output Current Ta =25°C, natural convection Input Voltage Range Set Point Voltage Tolerance Io1 Io2 Io1 Io2 Vin Vo tol Temperature Variation Line Regulation Regtemp Regline –40° >Ta > +85°C Over Vin range Load Regulation Regload Over Io range Total Output Voltage Variation ∆Votot Includes set-point, line, load, –40° >Ta > +85°C Efficiency Vo Ripple (pk-pk) η Vr Transient Response ttr Vo1 (3.3V) Vo2 (1.8V) Vo1 (3.3V) Vo2 (1.8V) Ta =60°C, 200LFM airflow 0.1 0 0.1 0 4.5 — — — — — — — — — — — — — — — Over Io Range Vo1 Vo2 Vo1 Vo2 Vo1 Vo2 Vo1 Vo2 20MHz bandwidth Vo1 Vo2 1A/µs load step, 50% to 100% Iotyp Vo over/undershoot ∆Vtr PT6937 (3.3V/1.8V) Typ Max Min Vo1 Vo2 8 (ii) 2 (ii) 8 (ii) 2 (ii) — ±16 ±9 ±0.5 ±5 ±2 ±5 ±5 ±29 ±25 81 35 35 60 ±60 ±60 (i) (i) Units 10 (iii) 2.25 (iii) 10 (iii) 2.25 (iii) 5.5 ±50 ±27 — ±10 ±5 ±10 ±10 — — — — — — — — A A VDC mV %Vo mV mV mV % mVpp µs mV Notes: (i) Io1(min) current of 0.1A can be divided between both outputs, Vo1 or Vo2. The module will operate at no load with reduced specifications. (ii) The typical current is that which can be drawn simultaneously from both outputs under the stated operating conditions. (iii) The sum of Io1 and Io2 must be less than Io1max, and Io 2 must be less than Io2max. PT6937 Typical Characteristics Efficiency vs Io1 (See Note A) Power Dissipation vs Io 1 (See Note A) 10 85 80 8 VIN 70 5.0V 65 Pd - Watts Efficiency - % 75 VIN 6 5.0V 4 60 2 55 50 0 0 1 2 3 4 5 6 7 0 8 1 2 Io1 (A) [ Io2 fixed at Io2(typ) ] Vo1 Output Ripple vs Io1 (See Note A) 4 5 6 7 8 Safe Operating Area, V in =5V (See Note B) 90 60 80 VIN 40 5.0V 30 20 10 Ambient Temperature (°C) 70 50 Ripple - mV 3 Io1 (A) [ Io2 fixed at Io2(typ) ] Airflow 70 200LFM 120LFM 60LFM Nat conv 60 50 40 30 0 20 0 1 2 3 4 5 6 7 8 0 Io1 (A) [ Io2 fixed at Io2(typ) ] 1 2 3 4 5 6 Io1 (A) [ Io2 fixed at Io2(typ) ] Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter. Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures For technical support and more information, see inside back cover or visit www.ti.com 7 8 PT6938 11 Amp 5V/3.3V-Input Dual Output Integrated Switching Regulator PT6938 Performance Specifications (Unless otherwise stated, T a =25°C, Vin =5V, C 1 =330µF, C2 =330µF, Io1 =Io1typ, and Io2 =Io 2typ) Characteristic Symbol Conditions Output Current Ta =25°C, natural convection Input Voltage Range Set Point Voltage Tolerance Io1 Io2 Io1 Io2 Vin Vo tol Temperature Variation Line Regulation Regtemp Regline –40° >Ta > +85°C Over Vin range Load Regulation Regload Over Io range Total Output Voltage Variation ∆Votot Includes set-point, line, load, –40° >Ta > +85°C Efficiency Vo Ripple (pk-pk) η Vr Transient Response ttr Vo1 (3.3V) Vo2 (1.2V) Vo1 (3.3V) Vo2 (1.2V) Ta =60°C, 200LFM airflow 0.1 0 0.1 0 4.5 — — — — — — — — — — — — — — — Over Io Range Vo1 Vo2 Vo1 Vo2 Vo1 Vo2 Vo1 Vo2 20MHz bandwidth Vo1 Vo2 1A/µs load step, 50% to 100% Iotyp Vo over/undershoot ∆Vtr PT6938 (3.3V/1.2V) Typ Max Min Vo1 Vo2 7 (ii) 1.6 (ii) 7 (ii) 1.6 (ii) — ±16 ±6 ±0.5 ±5 ±2 ±5 ±5 ±29 ±19 79 35 35 60 ±60 ±60 (i) (i) 8.6 1.6 8.6 1.6 5.5 ±50 ±18 — ±10 ±5 ±10 ±10 — — — — — — — — Units (iii) (iii) A (iii) (iii) A VDC mV %Vo mV mV mV % mVpp µs mV Notes: (i) Io 1(min) current of 0.1A can be divided between both outputs, Vo1 or Vo2. The module will operate at no load with reduced specifications. (ii) The typical current is that which can be drawn simultaneously from both outputs under the stated operating conditions. (iii) The sum of Io 1 and Io2 must be less than Io1max, and Io 2 must be less than Io2max. PT6938 Typical Characteristics Power Dissipation vs Io 1 (See Note A) 10 80 8 VIN 75 5.0V 70 Pd - Watts Efficiency - % Efficiency vs Io1 (See Note A) 85 6 5.0V 4 2 65 0 60 0 1 2 3 4 5 6 0 7 1 2 Vo1 Output Ripple vs Io 1 (See Note A) 4 5 6 7 Safe Operating Area, V in =5V (See Note B) 90 60 80 VIN 40 5.0V 30 20 10 Ambient Temperature (°C) 70 50 Ripple - mV 3 Io1 (A) [ Io2 fixed at Io2(typ) ] Io1 (A) [ Io2 fixed at Io2(typ) ] Airflow 70 200LFM 120LFM 60LFM Nat conv 60 50 40 30 0 20 0 1 2 3 4 5 Io1 (A) [ Io2 fixed at Io2(typ) ] 6 7 0 1 2 3 4 5 6 7 Io1 (A) [ Io2 fixed at Io2(typ) ] Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter. Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures For technical support and more information, see inside back cover or visit www.ti.com PT6939 11 Amp 5V/3.3V-Input Dual Output Integrated Switching Regulator PT6939 Performance Specifications (Unless otherwise stated, T a =25°C, Vin =5V, C 1 =330µF, C2 =330µF, Io1 =Io1typ, and Io2 =Io 2typ) Characteristic Symbol Conditions Output Current Ta =25°C, natural convection Input Voltage Range Set Point Voltage Tolerance Io1 Io2 Io1 Io2 Vin Vo tol Temperature Variation Line Regulation Regtemp Regline –40° >Ta > +85°C Over Vin range Load Regulation Regload Over Io range Total Output Voltage Variation ∆Votot Includes set-point, line, load, –40° >Ta > +85°C Efficiency Vo Ripple (pk-pk) η Vr Transient Response ttr Vo1 (2.5V) Vo2 (1.2V) Vo1 (2.5V) Vo2 (1.2V) Ta =60°C, 200LFM airflow 0.1 0 0.1 0 3.1 — — — — — — — — — — — — — — — Over Io Range Vo1 Vo2 Vo1 Vo2 Vo1 Vo2 Vo1 Vo2 20MHz bandwidth Vo1 Vo2 1A/µs load step, 50% to 100% Iotyp Vo over/undershoot ∆Vtr PT6939 (2.5V/1.2V) Typ Max Min Vo1 Vo2 7 (ii) 2 (ii) 7 (ii) 2 (ii) — ±12 ±6 ±0.5 ±5 ±2 ±5 ±5 ±34 ±19 75 35 35 60 ±60 ±60 (i) (i) Units 9 (iii) 2.2 (iii) 9 (iii) 2.2 (iii) 5.5 ±38 ±18 — ±10 ±5 ±10 ±10 — — — — — — — — A A VDC mV %Vo mV mV mV % mVpp µs mV Notes: (i) Io1(min) current of 0.1A can be divided between both outputs, Vo1 or Vo2. The module will operate at no load with reduced specifications. (ii) The typical current is that which can be drawn simultaneously from both outputs under the stated operating conditions. (iii) The sum of Io1 and Io2 must be less than Io1max, and Io 2 must be less than Io2max. PT6939 Typical Characteristics Power Dissipation vs Io 1 (See Note A) 10 80 8 VIN 75 3.3V 5V 70 Pd - Watts Efficiency - % Efficiency vs Io1 (See Note A) 85 65 VIN 6 5V 3.3V 4 2 60 0 0 1 2 3 4 5 6 7 0 1 Io1 (A) [ Io2 fixed at Io2(typ) ] Vo1 Output Ripple vs Io1 (See Note A) 3 4 5 6 7 Safe Operating Area, V in =5V (See Note B) 90 60 80 V IN 40 5V 3.3V 30 20 10 Ambient Temperature (°C) 70 50 Ripple - mV 2 Io1 (A) [ Io2 fixed at Io2(typ) ] Airflow 70 200LFM 120LFM 60LFM Nat conv 60 50 40 30 0 20 0 1 2 3 4 5 6 7 0 Io1 (A) [ Io2 fixed at Io2(typ) ] 1 2 3 4 5 Io1 (A) [ Io2 fixed at Io2(typ) ] Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter. Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures For technical support and more information, see inside back cover or visit www.ti.com 6 7 Application Notes PT6935 Series Capacitor Recommendations for the Dual-Output PT6935 Regulator Series Input Capacitors: The recommended input capacitance is determined by 1.0 ampere minimum ripple current rating and 330µF minimum capacitance (300µF for Oscon® or low ESR tantalum). Ripple current and <100mΩ equivalent series resistance (ESR) values are the major considerations, along with temperature, when designing with different types of capacitors. Tantalum capacitors have a recommended minimum voltage rating of 2 × the maximum DC voltage + AC ripple. This is necessary to insure reliability for input voltage bus applications Output Capacitors: C2(Required), C3(Optional) The ESR of the required capacitor (C2) must not be greater than 150mΩ. Electrolytic capacitors have poor ripple performance at frequencies greater than 400kHz but excellent low frequency transient response. Above the ripple frequency, ceramic capacitors are necessary to improve the transient response and reduce any high frequency noise components apparent during higher current excursions. Preferred low ESR type capacitor part numbers are identified in Table 1. The optional 100µF capacitor (C3) for V2out can have an ESR of up to 200mΩ for optimum performance and ripple reduction. (Note: Vendor part numbers for the optional capacitor, C3, are not identified in the table. Use the same series selected for C2) Tantalum Capacitors Tantalum type capacitors can be used for the output but only the AVX TPS series, Sprague 593D/594/595 series or Kemet T495/T510 series. These capacitors are recommended over many other tantalum types due to their higher rated surge, power dissipation, and ripple current capability. As a caution the TAJ series by AVX is not recommended. This series has considerably higher ESR, reduced power dissipation, and lower ripple current capability. The TAJ series is less reliable than the AVX TPS series when determining power dissipation capability. Tantalum or Oscon® types are recommended for applications where ambient temperatures fall below 0°C. Capacitor Table Table 1 identifies the characteristics of capacitors from a number of vendors with acceptable ESR and ripple current (rms) ratings. The number of capacitors required at both the input and output buses is identified for each capacitor type. This is not an extensive capacitor list. Capacitors from other vendors are available with comparable specifications. Those listed are for guidance. The RMS ripple current rating and ESR (Equivalent Series Resistance at 100kHz) are critical parameters necessary to insure both optimum regulator performance and long capacitor life. Table 1: Input/Output Capacitors Capacitor Vendor/ Component Series Capacitor Characteristics Quantity Working Voltage Value(µF) (ESR) Equivalent Series Resistance 85°C Maximum Ripple Current(Irms) Physical Size(mm) Input Bus Output Bus Panasonic FC 25V 35V 35V 560µF 390µF 330µF 0.0065Ω 0.065Ω 0.117Ω 1205mA 1205mA 555mA 12.5x15 12.5x15 8x11.5 1 2 N/R 1 1 1 EEUFC1E561S EEUFC1V391S EEUFC1C331 United Chemi-Con LXV/FS/ LXZ 16V 35V 10V 20V 330µF 470µF 330µF 150µF 0.120Ω 0.052Ω 0.025Ω 0.030÷2 Ω 555mA 1220mA 3500mA 3200mA 8x12 10x20 10x10.5 10x10.5 N/R 1 1 2 1 1 1 2 LXZ16VB331M8X12LL LXZ35VB471M10X20LL 10FS330M 20FS150M Nichicon PL/ PM 35V 35V 50V 560µF 330µF 470µF 0.048Ω 0.065÷2 Ω 0.046Ω 1360mA 1020mA 1470mA 16x15 12.5x15 18x15 1 1 1 1 1 1 UPL1V561MHH6 UPL1V331MHH6 UPM1H4711MHH6 Panasonic FC (Surface Mtg) 10V 35V 16V 1000µF 330µF 330µF 0.043Ω 0.065Ω 0.150Ω 1205mA 1205mA 670mA 12x16.5 12.5x16 10x10.2 1 1 N/R 1 1 1 EEVFC1A102LQ EEVFC1V331LQ EEVFC1C331P Oscon- SS SV 10V 10V 20V 330µF 330µF 150µF 0.025Ω 0.025Ω 0.024÷2 Ω >3500mA >3800mA 3600mA 10.0x10.5 10.3x10.3 10.3x10.3 1 1 2 1 1 2 10SS330M 10SV300M 20SV150M SV= Surface Mount AVX Tantalum TPS 10V 10V 10V 330µF 330µF 220µF 0.100÷2 Ω 0.100÷2 Ω 0.095Ω >2500mA >3000mA >2000mA 7.3Lx 4.3Wx 4.1H 2 2 2 1 1 2 TPSV337M010R0100 TPSV337M010R0060 TPSV227M0105R0100 10V 10V 330µF 220µF 0.033Ω 0.07Ω÷2 =0.035Ω 1400mA >2000mA 7.3Lx5.7W x 4.0H 2 2 1 2 T510X337M010AS T495X227M010AS 10V 10V 330µF 220µF 0.045Ω 0.065Ω 2350mA >2000mA 7.3Lx 6.0Wx 4.1H 2 2 1 2 4D337X0010R2T 594D227X0010D2T Kemet T510/ T495 Sprague 594D Vendor Number N/R –Not recommended. The voltage rating does not meet the minimum operating limits. For technical support and more information, see inside back cover or visit www.ti.com Application Notes PT6935 Series Adjusting the Output Voltage of the PT6935 Dual Output Voltage ISRs Each output voltage from the PT6935 series of ISRs can be independantly adjusted higher or lower than the factory trimmed pre-set voltage. The voltages, Vo1 and Vo2 may each be adjusted either up or down using a single external resistor 1. Table 1 gives the adjustment range for both Vo1 and Vo2 for each model in the series as Va(min) and Va(max). Note that Vo2 must always be lower than Vo1 2. 4. Adjusting the Vo1 output voltage of either the PT6935 (2.5V/1.8V model) or PT6939 (2.5V/1.2V) higher than the factory pre-trimmed output voltage, may increase the minimum input voltage specified for the part. These models must comply with the following requirements. PT6935/PT6939: Vin(min) =(Va + 0.6)V or 3.1V, whichever is greater. 5. Never connect capacitors to either the Vo1 Adjust or Vo2 Adjust pins. Any capacitance added to these control pins will affect the stability of the respective regulated output. Vo1 Adjust Up: To increase the output, add a resistor R4 between pin 16 (V1 Adjust) and pins 7-11 (GND) 1. Vo1 Adjust Down: Add a resistor (R3), between pin 16 (Vo1 Adjust) and pin 1 (Vo1 Sense) 1. 6. Adjusting either voltage (Vo1 or Vo2) may increase the power dissipation in the regulator, and change the maximum current available at either output. Consult the note on p.2 of the data sheet regarding Vo1/Vo2 loading. Vo2 Adjust Up: Add a resistor R2 between pin 23 (Vo2 Adjust) and pins 7-11 (GND) 1. Vo2 Adjust Down: Add a resistor (R1) between pin 23 (Vo2 Adjust) and pin 22 (Vo2 Sense) 1. Refer to Figure 1 and Table 2 for both the placement and value of the required resistor. Notes: 1. Use only a single 1% resistor in either the (R3) or R4 location to adjust Vo1, and in the (R1) or R2 location to adjust Vo2. Place the resistor as close to the ISR as possible. 2. Vo2 must always be at least 0.2V lower than Vo1. 3. Both the Vo1 and Vo2 may be adjusted down to an alternative bus voltage by making, (R3) or (R1) respectively, a zero ohm link. Refer to the Table 1 footnotes for guidance. The adjust up and adjust down resistor values can also be calculated using the following formulas. Be sure to select the correct formula parameter from Table 1 for the output and model being adjusted. 10 (Va – Vr ) Vo – Va – Rs kΩ – Rs kΩ (R1) or (R3) = (R2) or (R4) = Where: Vo Va Vr Rs = Original output voltage, (Vo1 or Vo2) = Adjusted output voltage = The reference voltage from Table 1 = The series resistance from Table 1 10 · Vr Va – Vo Figure 1 22 1 Vo 2 (sns) Vo 1 (sns) Vo 2 4,5,6 V IN Vo 2 12 - 15 Vo 1 PT6935 Vin Vo 1 STBY 3 + 18 - 21 GND 7 - 11 Vo 2 (adj) 23 Vo 1 (adj) 16 (R3) Adj Down (R1) C1 + C2 R4 Adjust Up + C3 L O A D L O A D R2 COM COM Adjust Vo 1 For technical support and more information, see inside back cover or visit www.ti.com Adjust Vo 2 Application Notes PT6935 Series Table 1 ADJUSTMENT RANGE AND FORMULA PARAMETERS Vo1 Bus Series Pt # Adj. Resistor Vo(nom) Va(min) Va(max) Vr Ω) Rs (kΩ Ref. Note 3: PT6935/39 (R3)/R4 PT6936/37/38 (R3)/R4 Vo2 Bus (2) PT6938/39 (R1)/R2 PT6935/37 (R1)/R2 PT6936 (R1)/R2 2.5V 1.8V * 3.6V (4) 1.27V 7.5 3.3V 2.5V * 3.6V 1.27V 15.4 1.2V 1.0V † 1.5V # 0.6125V 20.0 1.8V 1.5V † 2.4V 1.0V 16.9 2.5V 1.8V † 3.0 1.0V 11.5 Vo2 Bus Series Pt # Adj. Resistor PT6938/39 (R1)/R2 PT6935/37 (R1)/R2 PT6936 (R1)/R2 1.2V 1.8V 2.5V * (R3) = Zero-ohm link †(R1) = Zero-ohm link # (R2) = Zero-ohm link Table 2 ADJUSTMENT RESISTOR VALUES Vo1 Bus Series Pt # Adj. Resistor Vo(nom) Va(req’d) 1.8 1.85 1.9 1.95 2.0 2.05 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 PT6935/39 (R3)/R4 PT6936/37/38 (R3)/R4 2.5V 3.3V (0.0) (1.4)kΩ (3.0)kΩ (4.9)kΩ (7.1)kΩ (9.8)kΩ (13.3)kΩ (23.5)kΩ (44.0)kΩ (106.0)kΩ 120.0kΩ 56.0kΩ 34.8kΩ 24.3kΩ 17.9kΩ 13.7kΩ 10.6kΩ 8.4kΩ 6.6kΩ 5.2kΩ 4.1kΩ (0.0)kΩ (3.6)kΩ (8.4)kΩ (15.2)kΩ (25.4)kΩ (42.3)kΩ (76.1)kΩ (178.0)kΩ 112.0k 48.1k 26.9k Vo(nom) Va(req’d) 1.0 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4 1.45 1.5 1.55 1.6 1.65 1.7 1.75 1.8 1.85 1.9 1.95 2.0 2.05 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 (0.0)kΩ (9.2)kΩ (28.8)kΩ (87.5)kΩ 101.5kΩ 41.2kΩ 20.8kΩ 10.6kΩ 4.5kΩ 0.0kΩ (0.0)kΩ (5.1)kΩ (13.1)kΩ (26.4)kΩ (53.1)kΩ (133.0)kΩ 183.0kΩ 83.1kΩ 49.8kΩ 33.1kΩ 23.1kΩ 16.4kΩ 8.1kΩ 3.1kΩ 0.0kΩ (0.0)kΩ (1.6)kΩ (3.5)kΩ (5.8)kΩ (8.5)kΩ (11.8)kΩ (16.0)kΩ (28.5)kΩ (53.5)kΩ (129.0)kΩ 88.5kΩ 38.5kΩ 21.8kΩ 13.5kΩ 8.5kΩ R1/R3 = (Blue), R2/R4 = Black For technical support and more information, see inside back cover or visit www.ti.com Application Notes PT6935 Series Using the Standby Function on the PT6935 Series of Dual-Output Voltage Regulators Both output voltages of the 23-pin PT6935 dual-output converter may be disabled using the regulator’s ‘Standby’ function. This function may be used in applications that require power-up/shutdown sequencing, or wherever there is a requirement to control the output voltage On/Off status with external circuitry. The standby function is provided by the STBY* control (pin 3). If pin 3 is left open-circuit the regulator operates normally, and provides a regulated output at both Vo1 (pins 12–15) and Vo2 (pins 18–21) whenever a valid supply voltage is applied to Vin (pins 4, 5, & 6) with respect to GND (pins 7-11). If a low voltage1 is then applied to pin-3 both regulator outputs will be simultaneously disabled and the input current drawn by the ISR will drop to a typical value of 7mA. The standby control may also be used to hold-off both regulator outputs during the period that input power is applied. The standby pin is ideally controlled using an open-collector (or open-drain) discrete transistor (See Figure 1). The open-circuit voltage is typically 12.6V. Table 1 gives the circuit parameters for this control input. Table 1 Standby Control Parameters Parameter Min Enable (VIH) Disable (VIL) VSTBY (open circuit) ISTBY (IIL) — –0.1V 12.6V 2 — 1, 2 Max Open circuit 0.4V 1 15V –0.5mA Figure 1 22 1 V o 2(sns) V o 1 (sns) V o2 4, 5, 6 V in + 18 - 21 Vo 2 12 - 15 Vo 1 PT6935 V o1 STBY 3 GND 7 - 11 V o 2 (adj) V o 1 (adj) 23 16 C1 + C2 + C3 Q1 BSS138 Inhibit COM COM Turn-On Time: Turning Q1 in Figure 1 off removes the lowvoltage signal at pin 3 and enables the PT6935 regulator. Following a delay of about 15ms, Vo1 and Vo2 rise together until the lower voltage, Vo2, reaches its set output. Vo1 continues to rise until both outputs reach full regulation voltage. The total power-up time is less than 30ms, and is relatively independent of load, temperature, and output capacitance. Figure 2 shows waveforms of the output voltages, Vo1 and Vo2, for a PT6937 (3.3V/1.8V). The turn-off of Q1 corresponds to the rise in VSTBY. The waveforms were measured with a 5V input voltage, and with resistive loads of 4.5A and 1.9A at the Vo1 and Vo2 outputs respectively. Figure 2 Notes: 1. The standby control input is Not compatible with TTL or other devices that incorporate a totem-pole output drive. Use only a true open-collector device, preferably a discrete bipolar transistor (or MOSFET). To ensure the regulator output is disabled, the control pin must be pulled to less than 0.4Vdc with a low-level 0.5mA sink to ground. V1 (1V/Div) V2 (1V/Div) 2 The standby control input requires no external pull-up resistor. The open-circuit voltage of the STBY* pin is typically 12.6V. 3. When the regulator output is disabled the current drawn from the input source is typically reduced to 7mA. VIN Vstby (10V/Div) HORIZ SCALE: 5ms/Div 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. 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. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third–party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. Mailing Address: Texas Instruments Post Office Box 655303 Dallas, Texas 75265 Copyright 2001, Texas Instruments Incorporated