AS2916

AS2916 PTC | Alldatasheet

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250www.ptcc.com.tw AS2916 PWM Controller 5V Reg5V enable SNSB REG VCC UVLO AUX_ON GND OUTB OUTA GND 50µA VREG gm 2V5 2V5 BOK ON CMPB WBL RT/CT RAMP CMPA SNSA SS 6µA VREG OSC OSC 1V R 1V R (PWM) SS PWM (PWM) VCC VCC VCC (Blank) (Blank) AUX_ON CM PWM CM PWM S R Q (Bulk OK) (RUN) Functional Block Diagram

251www.ptcc.com.tw AS2916PWM Controller Pin Function Description Pin Number Function Description 1 OUTB This is the gate drive output for the Main FET. The totem pole output has equivalent of an extra 10 Ω resistor to limit the FET turn on speed and a pull down resistor to ensure the FET gate is never open. No external circuitry except for the FET is expected on this pin. The largest FET expected to be driven is IRFBC40. If a larger power FET is used, a buffer might be required. 2V CC Positive supply for the IC. Absolute maximum rating is 20 V. The running voltage shall be provided by the Auxiliary conver tor. 3 REG Output of 5 V series regulator. 4 SNSB This is the Main convertor current sense pin. An external RC filter from the Main power FET and slope compensation resis- tor from the RAMP pin is all the expected external circuitry. 5 CMPB This is the Main output control pin. An opto isolated control signal from the secondary side error amplifier is buffered and connected to the invert pin of the main output current mode comparator. A pull-up current of 1 mA is provided so the only external circuitry expected is a common emitter opto-isolator.

6 SS This pin provides a 6 µA current source to linearly charge an

external capacitor. This spin is compared to the RAMP pin in the soft start comparator, terminating output pulses when RAMP goes above the SS voltage. While this pin is held low, the main output is inhibited.

7 RAMP This pin is a level-shifted and buffered oscillator waveform,

used to provide slope compensation for the Main and Auxiliary converters. The pin also serves as the non-inverting input of the soft-start comparator.

8 OSC Oscillator frequency and maximum duty cycle are set by con-

necting the resistor (RT) to VREG and a capacitor (CT) to ground.

9 WBL Provides an FM modulation of the oscillator, approximately

±25% deviation frequency, at a modulation rate set by an exter- nal cap at WBL. Shorting to GND eliminates modulation.

10 ON This pin is used to remotely turn the main convertor ON/OFF

either for normal user application or for protection. 11 BOK Bulk OK. This is a brownout protection feature. The pin moni- tors the bulk voltage through a resistor divider. When BOK exceeds 2.5 V a 50 µA current is sourced from the pin for hys- teresis. When the pin drops below 2.5 V the hysteresis is turned off and SS is pulled low,inhibiting the main output. The Auxiliary output is not tied to BOK and will run as long as there is sufficient bias voltage.

252www.ptcc.com.tw AS2916 PWM Controller Pin Function Description Pin Number Function Description

12 CMPA This is the Auxiliary convertor error amplifier compensation pin

or if secondary controller is desired, the Auxiliary control input pin. A simple capacitor to ground is the only circuitry expected. Note: There is no external connection for voltage feedback. Voltage sensing is provided internally in such a way that VCC is not loaded until it reaches predefined threshold. If secondary control is required, it can be forced into the CMPA pin. 13 SNSA This is the Auxiliary convertor current sense pin. An external RC filter from the Auxiliary power FET and slope compensation resistor from the RAMP pin is all the expected external cir- cuitry. 14 OUTA This is the gate drive output for the Auxiliary FET. The totem pole output has equivalent of an extra 33 Ω resistor to limit the FET turn on speed and a pull down resistor to ensure the FET gate is never open. No external circuitry except for the FET is expected on this pin. The largest FET expected to be driven is IRF820. If a larger power FET is used, a buffer might be required. 15 GND Signal ground. 16 PGND Power ground. Absolute Maximum Ratings Parameter Symbol Rating Unit Reference Current I REF 200 mA Output Current I OUT 1A Supply Voltage V CC 20 V Output Voltage V OUT 20 V Continuous Power P D 500 mW Junction Temperature T J 150 °C Storage Temperature T STG –60 to +150 °C Lead Temperature (Soldering, 10 seconds) T L 300 °C

253www.ptcc.com.tw AS2916PWM Controller

Electrical Characteristics

Electrical characteristics are guaranteed over the full junction temperature range (0-105°). Ambient temperature must be derated based upon power dissipation and package thermal characteristics. The conditions are: VCC = 15 V, BOK = 3 V, ON = 3 V, RT = 680 Ω , CT = 10 nF, and CWBL = 2.2 nF, unless otherwise specified. To override UVLO, VCC should be raised above UVLOHIGH prior to test. Parameter Symbol Test Condition Min. Typ. Max. Unit

5 V Regulator

Output Voltage V REG TJ = 25°C, IREG = 1 mA 4.90 5.00 5.10 V Line Regulation PSRR 12 ≤ VCC ≤ 18 V 5 15 mV Load Regulation 1.0 ≤ IREG ≤ 20 mA 5 15 mV Temperature Stability TC REG 0.2 0.4 mV/°C Total Output Variation Line, Load, Temperature 4.85 5.15 V Long-Term Stability Over 1,000 hrs at 25°C 5.0 25 mV Output Noise Voltage V NOISE 10 ≤ f ≤ 100 kHz, TJ = 25°C 50 µV Maximum Source Current I MAX VREG = 4.8 V 30 120 180 mA Oscillator Initial Frequency f OSC TA = 25°C, VWBL = 0 V 117 132 143 kHz Voltage Stability 8.5 V ≤ VCC ≤ 18V 0.2 1.0 % Temperature Stability TC F TMIN ≤ TJ ≤ TMAX 5% Amplitude V OSC VOSC peak-to-peak 1.55 V Upper Trip Point V H VWBL = 0 V 2.8 V Lower Trip Point V L VWBL = 0 V 1.25 V Discharge Current I DSC VOSC = 3 V 7.5 8.7 9.5 mA Duty Cycle Limit R T = 680 Ω , CT = 10 nF, 46 50 54 % TJ = 25°C Over-Temperature Shutdown TOT 140 °C Wobble Oscillator Wobble Rate F WBL 2.2 nF WBL to GND 3.4 4.5 6.0 kHz OSC Frequency Deviation DEV Change in main oscillator freq. +30 +40 +50 kHz Amplitude V WBL VWBL peak-to-peak 1.8 V Upper Trip Point V H 2.7 V Lower Trip Point V L 0.9 V Charge Current I CHRG VWBL = 0.7 V –25 –36 –50 µA Discharge Current I DSC VWBL = 4.8 V 25 36 50 µA

254www.ptcc.com.tw AS2916 PWM Controller Electrical characteristics are guaranteed over the full junction temperature range (0-105°). Ambient temperature must be derated based upon power dissipation and package thermal characteristics. The conditions are: VCC = 15 V, BOK = 3 V, ON = 3 V, RT = 680 Ω , CT = 10 nF, and CWBL = 2.2 nF, unless otherwise specified. To override UVLO, VCC should be raised above UVLOHIGH prior to test. Parameter Symbol Test Condition Min. Typ. Max. Unit Auxiliary PWM Comparator Input (CMPA) Regulation Voltage V CCREG 13.4 14.5 15.7 V Transconductance G m 1.0 mS Output Sink Current I CMPALow VCC = 16 V, VCMPA = 1.1 V 2.0 6.0 mA Output Source Current I CMPAHigh VCC = 12 V, VCMPA = 5 V –0.5 -1.1 mA Output Swing High V CMPAHigh VCC = 12 V, ICMPA = 0.5 mA 5.4 5.7 V Output Swing Low V CMPALow VCC = 16 V, ICMPA = 2 mA 0.2 1.1 V Auxiliary Current Sense Comparator (SNSA) Transfer Gain A VSNSA –0.2 ≤ VSNSA ≤ 0.8 V 3.0 V/V CMPA Level Shift V LS VSNSA = 0 V 1.5 V Current Sense Threshold V SNSA VCMPA = 5 V 0.95 1.05 1.15 V Input Bias Current I BIAS –1.0 –10 µA Propagation Delay to Output tPD 80 150 ns Main PWM Comparator Input (CMPB) Comp Source Current I CMPB VCMPB = 2.5 V –1.0 –1.4 mA Comp Source Impedance Z CMPB 10 15 20 k Ω Comp Source High V CMPBHigh 5.4 5.6 V Main Current Sense Comparator (SNSB) Transfer Gain A VSNSB –0.2 ≤ VSNSB ≤ 0.8 V 3.0 V/V CMPB Level Shift V LS VSNSB = 0 V 1.5 V Current Sense Threshold V SNSB VCMPB = 5 V 0.95 1.05 1.15 V Input Bias Current I BIAS –1.0 –10 µA Propagation Delay to Output tPD 80 150 ns Soft Start Comparator SS Charge Current I Charge SS VSS ≤ VRAMP –4.0 –6.0 –10 µA SS Discharge Current I Dsc SS VSS = 1 V, VON <1.5 V 2.0 10 mA SS Lower Clamp V SS low 0.05 0.2 V Propagation Delay to Output tPB 50 100 ns RAMP High Level V RAMPH TJ = 25°C 2.0 2.15 2.3 V RAMP Low Level V RAMPL TJ = 25°C 0.45 0.6 0.75 V RAMP Levels TC Note: RAMP waveform is same –2.0 mV/°C as OSC waveform, but level shifted down one diode drop. RAMP Sink Current I RAMPL TJ = 25°C 0.1 0.2 mA RAMP Source Current I RAMPH TJ = 25°C –2.0 –10 mA

255www.ptcc.com.tw AS2916PWM Comtroller Electrical characteristics are guaranteed over the full junction temperature range (0-105°). Ambient temperature must be derated based upon power dissipation and package thermal characteristics. The conditions are: VCC = 15 V, BOK = 3 V, ON = 3 V, RT = 680 Ω , CT = 10 nF, and CWBL = 2.2 nF ,unless otherwise specified. To override UVLO, VCC should be raised above UVLOHIGH prior to test. Parameter Symbol Test Condition Min. Typ. Max. Unit Main Output Output Low Level V OUTBL ISINK = 10 mA 0.1 0.4 V Output Low Level V OUTBL ISINK = 150 mA 1.5 2.2 V Output High Level V OUTBH ISOURCE = 10 mA, VCC = 15 V 12 13 V Output High Level V OUTBH ISOURCE = 150 mA, VCC = 15V 10 10.7 V On Resistance High 10 Ω Rise Time t R C L = 1.3 nF, 10% to 90% 50 150 ns Fall Time t F C L = 1.3 nF, 90% to 10% 50 150 ns Output Impedance to GND Z OUT VCC = 6 V 20 k Ω in UVLO State Auxiliary Output Output Low Level V OUTBL ISINK = 10 mA 0.1 0.4 V Output Low Level V OUTBL ISINK = 150 mA 1.5 2.2 V Output High Level V OUTBH ISOURCE = 10 mA, VCC = 15V, 12 13 V VCMPA = 5 V Output High Level V OUTBH ISOURCE = 110 mA, VCC = 15V, 7 8 V VCMPA = 5 V On Resistance High 33 Ω Rise Time t R C L =350 pF, 10% to 90% 70 150 ns Fall Time t F C L = 350 pF, 90% to 10% 50 150 ns Output Impedance to GND Z OUT VCC = 6 V 20 k Ω in UVLO State Under-Voltage Lockout Start-Up Threshold V CC(ON) 12.4 13.5 14.7 V Stop Threshold V CC(OFF) 7 7.5 8 V Start-Up Current I CC 0.1 25 µA Operating Supply Current ICC VCC = 15 V 18 25 mA Housekeeping BOK UV Threshold V BOK UV TJ = 25°C 2.50 2.537 2.575 V BOK UV Hysteresis Current IHYST BOK VBOK = 2.6 V 42 50 58 µA BOK Input Bias Current I BOK VBOK = 2.4 V –0.1 –1.0 µA ON Threshold V ON 2.35 2.5 2.65 V ON Hysteresis ∆VON –0.7 –0.9 –1.1 V ON Bias Current I BIAS ON VON = 2.3 V –0.5 –10 µA

256www.ptcc.com.tw