AMC8520

Preliminary Specification aMC8520 SINGLE PHASE VARIABLE SPEED ADVANCED FAN CONTROLLER Product Description The aMC8520 is a full featured single phase brushless DC motor controller that contains all the required functions for an economical closed loop motor control solution that fulfills the balanced technology extended (BTX) requirements allowing a significant reduction of acoustic noise generation. Unique features of this device are a pulse width modulation (PWM) speed control input that is compatible with industry standard digital temperature monitors, thermistor input with adjustable gain and minimum temperature response threshold for temperature monitoring, programmable high and low temperature maximum RPM, programmable minimum RPM, current output error amplifier for easy control loop compensation. Additional features include a latching PWM for enhanced noise immunity, integrated fault timer with auto start retry, adaptive motor start timer to insure start up, combined frequency generator / rotor lock output, Hall amplifier with propriety noise immunity circuitry for proper drive sequencing, compatibility with differential non-buffered and buffered sensors, pinned out reference for Hall and circuit bias, fixed non-overlapping commutation delay for reduced power supply current spiking, two 40 V open drain top drivers, two 100 mA complementary MOSFET bottom drivers, programmable cycle-by-cycle current limiting, under voltage lockout and thermal shutdown protection, and an internal shunt regulator for use with higher voltage motors. Preliminary Specification – Subject to change without notice Preliminary Specification – Subject to change without notice Pin Configuration Phase 1 Bottom Drive Phase 2 Top Drive Signal Ground Reference Output Hall 1 24 Phase 2 Bottom Drive Phase 1 Top Drive VDD VD Driver Current Sense Input Driver Ground Signal Ground High Temp Maximum RPM Freq. Generator Rotor Lock Output Actual RPM Output PWM Control Input Required RPM Output Features • PWM closed loop speed control compatible with industry standard digital temperature monitors • Thermistor input with adjustable gain and minimum temperature response threshold • Programmable high and low temperature maximum RPM • Programmable minimum RPM • Current output error amp for easy loop compensation • Differential unbuffered and digital Hall compatibility with propriety noise immunity circuitry • Integrated fault timer with auto start retry • Adaptive motor start timer • Combined frequency generator / rotor lock output • Pinned out reference for Hall and circuit bias • Fixed non-overlapping commutation delay • Two 40 V open collector top drivers • Two 100 mA complementary MOSFET bottom drivers • Programmable cycle-by-cycle current limit protection • Under voltage lockout and thermal shutdown protection • Internal shunt regulator for higher voltage motors 2 23 3 22 4 21 5 20 Hall + Minimum RPM Gain Amp Output Gain Amp Input Thermistor Control Input Control Loop Compensation Low Temp Maximum RPM 6 19 aMC8520 7 18 8 17 9 16 10 15 11 14 Applications • PC, workstation and mainframe fans • Telecom, LAN server fans and blowers • Industrial control and instrumentation fans 12 13 Ordering Information Part Number aMC85020QS24 Package Operating Junction Temperature Range -40°C to 150°C -1www.andigilog.com Marking aMC8520 24-lead QSOP © Andigilog, Inc. 2007 April 2007 - 70A06005 Preliminary Specification aMC8520 QSOP 24 Package Outline Drawing Top View End View Preliminary Specification – Subject to change without notice Preliminary Specification – Subject to change without notice Side View Detail ‘A’ View Dimensions are in inches © Andigilog, Inc. 2007 -2www.andigilog.com April 2007 - 70A06005