NTE1681 Integrated Circuit High Power Switching Regulator Description: The NTE1681 is a stepdown power switching regulator in a 15−Lead Staggered SIP type package delivering 4A at a voltage variable from 5.1V to 40V. Features of this device include soft start, remote inhibit, thermal protection, a reset output for microprocessors and a PWM comparator input for synchronization in multichip configurations. Efficient operation at switching frequencies up to 200kHz allows a reduction in the size and cost of external filter components. A voltage sense input and SCR drive output are provided for optional crowbar overvoltage protection with an external SCR. Features: D 4A Output Current D 5.1V to 40V Output Voltage Range D 0 to 100% Duty Cycle Range D Precise (±2%) On−Chip Reference D Switching Frequency up to 200kHz D Very High Efficiency (Up to 90%) D Very Few External Components D Soft Start D Reset Output D Control Circuit for Crowbar SCR D Input for Remote Inhibit and Synchronous PWM D Thermal Shutdown Absolute Maximum Ratings: Input Voltage (Pin3), Vi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50V Input −to−Output Voltage Differenct, Vi − V2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V Output DC Voltage, V2 Continuous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −1V Peak (t = 0.1µs, f = 200kHz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −7V Voltage at Pin1 and Pin12, V1, V12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10V Voltage at Pin15, V15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15V Voltage at Pin4, Pin5, Pin7, Pin9, and Pin13, V4, V5, V7, V9, V13 . . . . . . . . . . . . . . . . . . . . . . . . . 5.5V Voltage at Pin10 and Pin6, V10, V6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V Voltage at Pin14 (I14 ≤ 1mA), V14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vi Absolute Maximum Ratings (Cont’d): Pin9 Sink Current, I9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1mA Pin11 Source Current, I11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20mA Pin14 Sink Current (V14 < 5V), I14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA Power Dissipation (TC ≤ +90°C), Ptot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20W Operating Junction Temperature Range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40° to +150°C Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40° to +150°C Maximum Thermal Resistance, Junction−to−Case, RthJC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3°C/W Maximum Thermal Resistance, Junction−to−Ambient, RthJA . . . . . . . . . . . . . . . . . . . . . . . . . 35°C/W Electrical Characteristics: (Vi = 35V, TJ = +25°C unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Vref − 40 V Dynamic Characteristics (Pin6 to GND unless otherwise specified) Output Voltage Range VO Vi = 46V, IO = 1A Input Voltage Range Vi VO = Vref to 36V, IO ≤ 3A − − 46 V VO = Vref to 36V, IO = 4A, Note 1 − − 46 V Line Regulation Regline Vi = 10V to 40V, VO = Vref, IO = 2A − 15 50 mV Load Regulation Regload Vo = Vref IO = 2A to 4A − 10 30 mW IO = 0.5A to 4A − 15 45 mW 5.0 5.1 5.2 V TJ = 0° to +125°C, IO = 2A − 0.4 − mV/°C IO = 4A − 2.0 3.2 V IO = 2A − 1.3 2.1 V 4.5 − 7.5 A Internal Reference Voltage (Pin10) Vref Average Temperature Coefficient of Reference Voltage Vi = 9V to 46V, IO = 2A Dropout Voltage Between Pin2 & Pin3 Vd Current Limiting Threshold (Pin2) I2L Pin4 Open, Vi = 9V to 40V, VO = Vref to 36V Input Average Current ISH Vi = 46V, Output Short−Circuited − 60 100 mA IO = 3A VO = Vref − 75 − % VO = 12V − 85 − % 50 56 − dB 85 100 115 kHz Efficiency Supply Voltage Ripple Rejection Switching Frequency η SVR ∆Vi = 2Vrms, VO = Vref, IO = 2A, fripple = 100Hz f Voltage Stability of Switching Frequency Vi = 9V to 46V − 0.5 − % Temperature Stability of Switching Frequency TJ = 0° to +125°C − 1 − % VO = Vref, IO = 1A 200 − − kHz 135 145 − °C Maximum Operating Switching Frequency fmax Thermal Shutdown Junction Temperature Tsd Note 1. Using min. 7A Schottky Diode. Electrical Characteristics (Cont’d): (Vi = 35V, TJ = +25°C unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit V6 = 0V − 66 85 mA V6 = 3V − 30 40 mA DC Characteristics Quiescent Drain Current Output Leakage Current I3Q Vi = 46V, V7 = 0V, S1: B, B S2: B −I2L Vi = 46V, V6 = 3V, V7 = 0V, S1: B, S2: A − − 2 mA Source Current I5 so V6 = 0V, V5 = 3V 80 130 150 µA Sink Current I5 si V6 = 3V, V5 = 3V 50 70 120 µA Low Input Voltage V6L −0.3 − 0.8 V High Input Voltage V6H Vi = 9V to 46V, V7 = 0V, S!: B, B S2: B 2.0 − 5.5 V Input Current with Low Input Voltage −I6L V6 = 0.8V − − 10 µA Input Current with High Input Voltage −I6H Vi = 9V to 46V, 0V V7 = 0V, S1: B, S2: B V6 = 2V − − 3 µA High Level Output Voltage V9H V10 = 4.7V, I9 = 100µA, S1: A, S2: A 3.5 − − V Low Level Output Voltage V9L V10 = 5.3V, I9 = 100µA, S1: A, S2: E − − 0.5 V Sink Output Current I9 si V10 = 5.3V, S1: A, S2: B 100 150 − µA Source Output Current I9 so V10 = 4.7V, S1: A, S2: D 100 150 − µA Soft Start Inhibit Error Amplifier Input Bias Current I10 V10 = 5.2V, S1: B − 2 10 µA DC Open Loop Gain Gv V9 = 1V to 3V, S1: A, S2: C 46 55 − dB Input Bias Current of PWM Comparator −I7 V7 = 0.5V to 3.5V − − 5 µA Oscillator Source Current −I11 V11 = 2V, S1: A, S2: B 5 − − mA Vref −150mV Vref −100mV Vref −50mV V 4.75 Vref −150mV Vref −100mV V 4.3 4.5 4.7 V − 100 − mV I14 = 16mA, V12 = 4.7V, S1, S2: B − − 0.4 V V12 = 0V to Vref, S1: B, S2: B − 1 3 µA V13 = 3V, S1: A, S2: B V12 = 5.3V 70 110 140 µA V12 = 4.7V 10 − − mA − − 100 µA Oscillator and PWM Comprator Reset Rising Threshold Voltage V12 R Falling Threshold Voltage V12 F Delay Threshold Voltage V13 D Delay Threshold Voltage Hysteresis V13 H Output Saturation Voltage V12 S Input Bias Current Delay Source Current Delay Sink Current Output Leakage Current I12 −I13 so Vi = 9V to 46V, S1: B, S2: B V12 = 5.3V, S1: A, S2: B I13 si I14 Vi = 46V, V12 = 5.3V, S1: B, S2: A Input Threshold Voltage V1 S1: B 5.5 6.0 6.4 V Output Saturation Voltage V15 Vi = 9V to 46V, V1 = 5.4V, I15 = 5mA, S1: A − 0.2 0.4 V V1 = 6V, S1: B − − 10 µA Vi = 9V to 46V, V1 = 6.5V, V15 = 2V, S1: B 70 100 − mA Crowbar Input Bias Current Output Source Current I1 −I15 Pin Connection Diagram (Front View) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 T A B Crowbar Output Reset Output Reset Delay Reset Input OSC Feedback Input Gain Adjust GND/Tab Sync Input Inhibit Input Soft−Start External Current Limiter VCC Output Crowbar Input .196 (4.99) .791 (20.1) .069 (1.75) .860 (21.8) .150 (3.81) Dia Max .699 (17.7) .689 (17.5) 1 .110 (2.79) 15 .050 (1.27) .008 (.203) .200 (5.08) .169 (4.29)