FAN8902 Fairchild Semiconductor, FAN8902 Datasheet
FAN8902
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FAN8902 Summary of contents
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... Typical Application • DC for Motor Control for Automotive ©2002 Fairchild Semiconductor Corporation www.fairchildsemi.com Description The FAN8902 is a monolithic integrated circuit, designed for the PWM control fan motor current in an automotive systems. It allows the fan motor speed to be controlled linearly and efficiently. 14-DIP-300 ...
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... Motor Current Command Input Optional OP Amplifier Output Optional OP Amplifier (-) Input Signal GND Oscillator Time Constant Voltage Reference (5V) Maximum Current Reference Input No Connection Minimum Current Reference Input Motor Current Sense Voltage Input Power GND Drive Output V CC Motor Current Maximum Reference Input FAN8902(KA3902 VCC 12 OUT ...
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... FAN8902(KA3902) Internal Block Diagram 6 Vref CH 7 1.3V CMD CMDa 2 3 CMDb 3 UVLO Vref + + PWM LOGIC PWM Comparator + Oscillator OVP 36V TSD 12 OUT 11 PGND SGND ...
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... Power Supply Voltage Temperature Characteristics Parameter Vref Temperature Stability Frequency Stability Operating Temperature Storage Temperature Symbol CMD I OPK P D Symbol Min. V 9.0 CC Symbol Temp V - - OPR T - STG FAN8902(KA3902) Value Unit 0 Typ. Max Unit 12.0 32.0 V Value Unit 200 -40 ~ +90 C -60 ~ +150 C 4 ...
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... FAN8902(KA3902) Electrical Characteristics (Unless otherwise, Ta= =5V Parameter REFERENCE Reference Voltage Line Regulation Load Regulation UNDER VOLTAGE LOCKOUT (UVLO) Start Threshold Voltage Threshold Hysteresis PROTECTION Over Voltage OSCILLATOR (R =75k , Frequency Duty Cycle CURRENT SENSING INPUT Threshold Voltage OUTPUT DRIVER Output Voltage Switching Limit ...
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... When the chip, temperature rises up to 150 C, the thermal shutdown (TSD) circuit is activated and the output driver turn off, and then turn on again at 125 6mA Vref & output driver 1mA 8.0V H(ST) 1.2V HYS PWM comparator PWM Logic Current amplifier =20[A] M(MAX) FAN8902(KA3902 6.8V TH(ST BAT ...
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... For example, if fosc = 25kHz and duty = 95 – 1000 pF R 1.875 fosc 1.875 25kHz 1000pF = Current Command Input Section The current command I* selects the lower value between V CMD =3.0 H Logic V =1.75 L Vref V – and V . CMD La V CMD FAN8902 T=40 =39.0 C Td=1.0 Logic + ...
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... The ramp voltage for slope compensation is as follow, R14 V RAMP V OSC = ---------- - R11 R12 V CMD Slop Compensation 7. Motor Stall Current Limitation FAN8902 V CMD 1 CMD R14 Vref TR2 R11 + VBAT Buffer-OP-amp Logic 12 + PWM COMP FAN8902(KA3902 PWM _ Comparator FAN8902 6 OSC R10 ...
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... FAN8902(KA3902) In the steady state, the terminal voltage on a motor is consisted of a back EMF and the voltage drop on the armarture resistors. When the motor happens to be stalled, the back EMF becomes zero, and the motor current (I maximum values. Therefore the duty of the pin #12 output becomes lower because of the increase of the sense voltage (V voltage ( lowered, then it makes the duty become lower again ...
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... If the voltage, V 36[V], the output (pin #12) is grounded, and the switching device (power MOSFET) is turned-off, and BAT the motor is stopped. Then if the voltage, V 10. Totem-pole Output The FAN8902 has a single totem-pole output driver which can be drive current to peak 0.8[A]. V CMD V La ...
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... FAN8902(KA3902) Test Circuit CMD Iout SW 2 Cid VCC OUT CMDa CMDb 10k 1nF 75k 10k VREF Iout ...
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... Typical Application R12 Current command NC NC R11 R14 BAT CMD CMDa VCC 12 3 CMDb OUT VREF FAN8902(KA3902 R10 ...
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... FAN8902(KA3902) 13 ...
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... FAN8902(KA3902) DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. ...