For assistance or to order, call (800) 531-5782 PT6920 Revised 3/9/99 Series Application Notes Mechanical Outline Product Selector Guide 5V TO 3.3V/2.5V 25 WATT DUAL OUTPUT INTEGRATED SWITCHING REGULATOR The PT6920 is a new series of 25W dual output ISRs designed to power the latest generation DSP chips. Both output voltages are independently adjustable with external resistors. In addition, the second output voltage of the PT6921 can be selected for 2.5V or 1.8V to accommodate the next generation of DSP chips. The internal power sequencing of both outputs meet the latest requirements of TI’s ‘C6000 series DSPs. Features • Dual Outputs: +3.3V/6A +2.5V/2.2A or +1.8V/1.5A • • • • • • • Adjustable Output Voltage Remote Sense (both outputs) Standby Function Over-Temperature Protection Soft-Start Internal Sequencing 23-pin SIPPackage Patent Pending* Pin-Out Information Standard Application C 1 = Req’d 560µF electrolytic C 2 = Req’d 330µF electrolytic C 3 = Optional 100µF electrolytic V2 Sense STBY V1 Sense 3 VIN 4,5,6 22 1 PT6920 7-11 16 18-21 V2OUT 12-15 V1OUT 23 C1 GND R3 R1 C2 R4 + C3 + R2 GND Ordering Information Pin Function Pin Function 1 V1 Remote Sense 13 V1out 2 Do Not Connect 14 V1out 3 STBY 15 V1out 4 Vin 16 V1 Adjust 5 Vin 17 Do Not Connect 6 Vin 18 V2out 7 GND 19 V2out 8 GND 20 V2out 9 GND 21 V2out 10 GND 22 V2 Remote Sense 11 GND 23 V2 Adjust* 12 V1out PT6921❏ ❏ = +3.3 Volts +2.5/+1.8 Volts ❏ = +3.3 Volts PT6922❏ +1.5 Volts PT Series Suffix (PT1234X) Case/Pin Configuration Vertical Through-Hole Horizontal Through-Hole Horizontal Surface Mount N A C (For dimensions and PC board layout, see Package Styles 1100 and 1110.) Note: for PT6921 only: with pin 23 open, V2out=2.5V with pin 23 shorted to pin 22, V2out=1.8V Preliminary Specifications PT6920 SERIES Characteristics (Ta= 25°C unless noted) Symbols Output Current Io Conditions Typ Max Units V1 = 3.3V V2 = 2.5V V2 = 1.8V V2 = 1.2V 0.1 0 0 0 Min — — — — 5.5 2.2 1.75 1.2 A A A A Ta = +25°C, natural convection V1 = 3.3V V2 = 2.5V V2 = 1.8V V2 = 1.2V 0.1 0 0 0 — — — — 6.0 2.2 1.75 1.2 A A A A Ta = +60°C, 200 LFM, pkg N Input Voltage Range Vin 0.1A ≤ I o ≤ Imax 4.5 — 5.5 V Output Voltage Tolerance ∆Vo Vin = +5V, Io = Imax, both outputs 0°C ≤ Ta ≤ +65°C Vo-0.1 — Vo+0.1 V Line Regulation Regline 4.5V ≤ Vin ≤ 5.5V, Io = Imax V1 = 3.3V V2 = 2.5V — — ±7 ±7 ±17 ±13 mV mV Load Regulation Regload Vin = +5V, 0.1 ≤ Io ≤ Imax V1 = 3.3V V2 = 2.5V — — ±17 ±4 ±33 ±10 mV mV Vo Ripple/Noise Vn Vin = +5V, Io = Imax V1 = 3.3V V2 = 2.5V — — 50 25 — — mV mV Transient Response with C2 = 330µF t tr Vos Io step between 0.5xImax and Imax Vo over/undershoot V1 = 3.3V V2 = 2.5V — — — 25 60 60 — — — µSec mV mV Efficiency η Vin = +5V, Io = 4A total — 75 — % Switching Frequency ƒo 4.5V ≤ V in ≤ 5.5V 0.1A ≤ I o ≤ Imax 475 600 725 kHz Absolute Maximum Operating Temperature Range Ta — 0 — +85 °C Recommended Operating Temperature Range Ta Forced airflow = 200 LFM Over Vin and Io Ranges 0 — +65 °C Storage Temperature Ts — -40 — +125 °C Weight — Vertical/Horizontal — 29 — grams Note: The PT6920 series requires a 560µF electrolytic capacitor on the input and a 330µF electrolytic capacitor on the output for proper operation in all applications. * This product is the subject of one or more patents. Other patents pending. Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com For assistance or to order, call (800) 531-5782 PT6920 CHARACTERISTIC Series DATA PT6921, V2out = 2.5V, I2out = 2.2A (See Note 1) Total Efficiency vs I1out 100 90 Efficiency (%) Vin 80 4 .5 V 5 .0 V 70 5 .5 V 60 50 40 0 1 2 3 4 5 6 I1out (A) Total Power Dissipation vs I1out 10 8 PD (Watts) Vin 4 .5 V 6 5 .0 V 5 .5 V 4 2 0 0 1 2 3 4 5 6 I1out (A) V1out Ripple vs I1out 50 40 Ripple (mV) Vin 4 .5 V 30 5 .0 V 5 .5 V 20 10 0 0 1 2 3 4 5 6 I1out (A) Safe Operating Area vs I1out 90 80 Ta (°C) 70 N at co nv. Recommended Maximum Operating Temperature 60 6 0 LF M 2 0 0L F M 50 40 30 0 1 2 3 4 5 6 I1out (A) Note 1: 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. Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com For assistance or to order, call Application (800) 531-5782 Notes PT6920 Series More Application Notes Adjusting the Output Voltage of the PT6920 Dual Output Voltage ISR tion to adjust V1, and in the (R1) or R2 location to adjust V2. Place the resistor as close to the ISR as possible. Both output voltages from the Power Trends PT6920 series ISRs can be independantly adjusted higher or lower than their factory trimmed pre-set voltage. In each case only a single external resistor is required to adjust either V1 (the voltage at V1out, or V2 (the voltage at V2out). Table 1 gives the permissible adjustment range for both V1 and V2 for each model in the series as Va(min) and Va(max). Note: V2 must always be lower than V1. V1 Adjust Up: To increase the output, add a resistor R4 between pin 16 (V1 Adjust) and pins 7-11 (GND). V1 Adjust Down: Add a resistor (R3), between pin 16 (V1 Adjust) and pin 1 (V1 Remote Sense). V2 Adjust Up: Add a resistor R2 between pin 23 (V2 Adjust) and pins 7-11 (GND). V2 Adjust Down: Add a resistor (R1) between pin 23 (V2 Adjust) and pin 22 (V2 Remote Sense). Refer to Figure 1 and Table 2 for both the placement and value of the required resistor. 5. Never connect capacitors to either the V1 Adjust or V2 Adjust pins. Any capacitance added to these control pins will affect the stability of the respective regulated output. 6. To comply with the ISRs power dissipation limits, changes made to either output voltage (V1 or V2) may affect the maximum current available from both outputs. For more information, consult the related applications note, “Determining the Maximum Output Current for the PT6920 Series Dual Output ISR.” The adjust up and adjust down resistor values can also be calculated using the following formulae. Be sure to select the correct formula parameter from Table 1 for the output and model being adjusted. (R1)/(R3) = Ro (Va – 1) Vo – Va R2/R4 = Ro Va – Vo Where: Vo Va Ro Rs Notes: 1. The voltage at V1out and V2out may be adjusted independantly. – Rs – Rs kΩ kΩ = Original output voltage, (V1 or V2) = Adjusted output voltage = The resistance value from Table 1 = The series resistance from Table 1 Table 1 PT6920 ADJUSTMENT RANGE AND FORMULA PARAMETERS 2. V2 must always be at least 0.2V lower than V1. 3. If V1 is increased above 3.3V, the minimum input voltage to the ISR must also be increased. The minimum required input voltage must be (V1 + 1.2)V or 4.5V, whichever is greater. Do not exceed 6.0V 4. Use only a single 1% resistor in either the (R3) or R4 loca- Output Bus Series Pt # Adj. Resistor V1 out PT6921/22 (R3)/R4 V2 out PT6921 (R1)/R2 PT6922 (R1)/R2 Vo(nom) 3.3V 2.5V 1.5 Va(min) 2.3V 1.8V 1.2 Va(max) 4.2V 3.0V 3.0 Ro (kΩ) 12.1 10.0 9.76 Rs (kΩ) 12.1 11.5 6.49 Figure 1 22 V2(sns) 1 V1(sns) V2out Vin 4,5,6 V1out STBY GND 3 C1 330 µ F + 18 - 21 V2 out 12 - 15 V1 out PT6920 Vin 7 - 11 Vo2(adj) Vo 1(adj) 23 16 (R3) Adj Down (R1) C2 330 µ F R4 Adjust Up + C3 100 µ F + L O A D L O A D R2 COM COM Adjust V1 out Adjust V2 out Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com 3 For assistance or to order, call (800) 531-5782 Application PT6920 Series Notes Table 2 PT6920 ADJUSTMENT RESISTOR VALUES Output Bus Series Pt # Adj Resistor Vo(nom) V1 out PT6921/22 (R3)/R4 3.3Vdc V2 out PT6921 (R1)/R2 2.5Vdc PT6922 (R1)/R2 1.5Vdc Va(req’d) 1.2 (0.0)kΩ 1.25 (3.3)kΩ 1.3 (8.2)kΩ 1.35 (16.3)kΩ 1.4 (32.6)kΩ 1.45 (81.4)kΩ 1.5 1.55 189.0kΩ 1.6 91.1kΩ 1.65 58.6kΩ 1.7 42.3kΩ 1.75 32.6kΩ 1.8 (0.0)kΩ 26.0kΩ 1.85 (1.6)kΩ 21.4kΩ 1.9 (3.5)kΩ 17.9kΩ 1.95 (5.8)kΩ 15.2kΩ 2.0 (8.5)kΩ 13.0kΩ 2.05 (11.8)kΩ 11.3kΩ 2.1 (16.0)kΩ 9.8kΩ 2.15 (21.4)kΩ 8.5kΩ 2.2 (28.5)kΩ 7.5kΩ 2.25 (38.5)kΩ 6.5kΩ 2.3 (3.6)kΩ (53.5)kΩ 5.7kΩ 2.35 (5.1)kΩ (78.5)kΩ 5.0kΩ 2.4 (6.7)kΩ (129.0)kΩ 4.4kΩ 2.45 (8.5)kΩ (279.0)kΩ 2.5 (10.6)kΩ 2.55 (12.9)kΩ 189.0kΩ 2.8kΩ 2.6 (15.6)kΩ 88.5kΩ 2.4kΩ 2.65 (18.6)kΩ 55.2kΩ 2.0kΩ 2.7 (22.2)kΩ 38.5kΩ 1.6kΩ 2.75 (26.4)kΩ 28.5kΩ 1.3kΩ 2.8 (31.5)kΩ 21.8kΩ 1.0kΩ 2.85 (37.6)kΩ 17.1kΩ 0.7kΩ 2.9 (45.4)kΩ 13.5kΩ 0.5kΩ 2.95 (55.3)kΩ 10.7kΩ 0.2kΩ 3.0 (68.6)kΩ 8.5kΩ 0.0kΩ 3.05 (87.1)kΩ 3.1 (115.0)kΩ 3.15 (161.0)kΩ 3.2 (254.0)kΩ 3.25 (532.0)kΩ 3.8kΩ 3.3kΩ 3.3 3.4 109.0kΩ 3.5 48.4kΩ 3.6 28.2kΩ 3.7 18.2kΩ 3.8 12.1kΩ 3.9 8.1kΩ 4.0 5.2kΩ 4.1 3.0kΩ 4.2 R1/R3 = (Red) 4 1.3kΩ R2/R4 = Black Power Trends, Inc. 27715 Diehl Road, Warrenville, IL 60555 (800) 531-5782 Fax: (630) 393-6902 http://www.powertrends.com 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. 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