PT79SR100 Series -1.5 Amp Negative Step-Down Integrated Switching Regulator SLTS061A (Revised 6/30/2000) • • • • Standard Application COM High Efficiency > 85% Self-Contained Inductor Short Circuit Protection Over-Temperature Protection The PT79SR100 is a line of Negative Input/Negative Output 3-terminal Integrated Switching Regulators (ISRs). These ISRs have a maximum output current of -1.5 Amps and an output voltage that is laser trimmed to most industry standard voltages. They have excellent line and load regulation, and are ideal for applications, such as RS232 and Ethernet communications, ECL logic, and op-amp circuitry. Pin-Out Information Ordering Information PT79SR1 Function 1 GND 2 -Vin Output Voltage Package Suffix 3 -Vout 05 = -5.0 Volts 52 = -5.2 Volts 06 = -6.0 Volts 08 = -8.0 Volts 09 = -9.0 Volts 12 = -12.0 Volts 15 = -15.0 Volts V = Vertical Mount S = Surface Mount H = Horizontal Mount COM C1 D1 1 -Vin 2 PT79SR1 C2 -Vout 3 Y XX Pin C1 = Optional ceramic (1µF) C2 = Optional ceramic (1-5µF) D1 = Zener diode required to clamp turn-on overshoot (See Application Note) Pkg Style 500 Specifications PT79SR100 SERIES Characteristics (Ta = 25°C unless noted) Symbols Conditions Min Typ Max Units Output Current Io Over Vin range -0.1* — -1.5 A Short Circuit Current Isc Vin=Vo-4V — -3.5 — Apk Input Voltage Range Vin Io=-0.1 to -1.5 A -0.1 ≥ Io ≥ -1.5 A -9 -19 — — -30 -30 V V Output Voltage Tolerance ∆Vo Over Vin range, Io=-1.5 A Ta=-20°C to shutdown — ±1.0 ±3.0 %Vo Line Regulation Regline Over Vin range — ±1.0 ±2.0 %Vo Load Regulation Regload -0.1 ≤ Io ≤ -1.5 A — ±0.5 ±1.0 %Vo Vo Ripple/Noise Vn Vin=-15V, Io=-1.0 A,Vo=-5V — 35 — mVpp Transient Response ttr 50% load change Vo=overshoot/undershoot — — 100 30 — — µSec %Vo Efficiency η Vin=-10V, Io=-1.0A, Vo=-5V — 85 — % Switching Frequency ƒo Over Vin and Io ranges 0.95 1.0 1.05 MHz Absolute Maximum Operating Temperature Range Ta -40 — +85 °C Recommended Operating Temperature Range Ta Free Air Convection, (40-60LFM) Over Vin and Io ranges -40 — +60** °C Thermal Resistance θja Free Air Convection, (40-60LFM) — 45 — °C/W Temperature Coefficient Tc Over Vin and Io ranges — ±0.5 ±1.5 mV/°C Storage Temperature Ts — -40 — +125 °C Mechanical Shock — Per Mil-STD-883D, Method 2002.3 — 500 — G’s Mechanical Vibration — Per Mil-STD-883D, Method 2007.2, 20-2000 Hz, soldered in a PC board — 5 — G’s Weight — — — 7.0 — Grams * ISR will operate down to no load with reduced specifications. Vo=-5V Vo=-15V ** See Thermal Derating chart. For technical support and more information, see inside back cover or visit www.ti.com/powertrends Typical Characteristics PT79SR100 Series -1.5 Amp Negative Step-Down Integrated Switching Regulator PT79SR105, -5.0 VDC PT79SR112, -12.0 VDC (See Note 1) Efficiency vs Output Current Efficiency vs Output Current 100 Efficiency vs Output Current Vin 9V 10.0V 15.0V 20.0V 25.0V 30.0V 80 70 60 90 Vin 16.0V 80 20.0V 70 25.0V 60 Efficiency - % 90 50 0.5 0.75 1 1.25 0 0.25 0.5 Iout-(Amps) 1 1.25 1.25 80 Vin 30.0V 60 25.0V 20.0V 0.5 0.75 1 1.25 0.6 19.0V 50˚C 0.75 0 0 70˚C 85˚C 50˚C 1.2 70˚C 1 0.8 0.6 85˚C 0 17 19 21 23 25 27 29 31 18 20 22 Power Dissipation vs Output Current 0.5 2 1.5 25.0V 20.0V 1 16.0V 1.5 Vin 2 30.0V 27.0V 24.0V 21.0V 19.0V 1.5 1 0 0 1.25 30 0.5 0.5 0 28 2.5 Vin 30.0V PD-(Watts) PD-(Watts) 1 26 Power Dissipation vs Output Current 2.5 30.0V 25.0V 20.0V 15.0V 10.0V 9V 24 Vin-(Volts) Vin 1.5 (See Note 2) 60˚C Vin-(Volts) 2 1.5 0.2 Vin-(Volts) Power Dissipation vs Output Current 1.25 0.4 15 9 11 13 15 17 19 21 23 25 27 29 31 1 1.4 0.6 0.2 Iout-(Amps) 0.5 1.6 60˚C 0.8 0.2 1 0.25 Thermal Derating (Ta) (See Note 2) 1 0.4 0.75 21.0V 0 1.2 0.4 0.5 24.0V 60 Iout-(Amps) Iout-(Amps) 0.8 0.25 27.0V Iout-(Amps) 1.4 70˚C 0 30.0V 90 1.5 1.6 85˚C 7 Vin 0 0.25 Thermal Derating (Ta) 50˚C 60˚C 1 1.5 30 0 1.5 (See Note 2) 1.4 1.25 120 Iout-(Amps) 1.6 1 150 Iout-(Amps) 1.2 0.75 Ripple vs Output Current 0 Thermal Derating (Ta) 0.5 16.0V 0 1 0.25 Iout-(Amps) 40 10 PD-(Watts) 0 20 0.75 30.0V 1.5 Ripple-(mV) 30 Ripple-(mV) Ripple-(mV) Vin 30.0V 25.0V 20.0V 15.0V 10.0V 9V 40 20 Iout-(Amps) 0.75 100 50 0.5 27.0V Ripple vs Output Current 60 0.25 24.0V Iout-(Amps) Ripple vs Output Current 0 21.0V 70 40 40 1.5 19.0V 80 50 40 0.25 Vin 90 60 30.0V 50 0 (See Note 1) 100 100 Efficiency - % Efficiency - % PT79SR115, -15.0 VDC (See Note 1) 0 0.25 0.5 0.75 1 1.25 1.5 0 0.25 0.5 Iout-(Amps) 0.75 1 1.25 1.5 Iout-(Amps) Note 1: All data listed in the above graphs, except for derating data, has been developed from actual products tested at 25°C. This data is considered typical data for the ISR. Note 2: Thermal derating graphs are developed in free air convection cooling of 40-60 LFM soldered in a printed circuit board. (See Thermal Application Notes.) For technical support and more information, see inside back cover or visit www.ti.com/powertrends 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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