www.fairchildsemi.com FAN8408D 2 Phase Half Wave BLDC Motor Driver Features Description • • • • • • • The FAN8408D is a monolithic integrated circuit, and suitable for DC cooling fan motors. A wide range of operation voltage: 4V to 15V Built-in motor lock detector. Automatic restart function Hall output for a motor speed detection Built-in thermal shut down circuits Built-in reverse current protection diode Compact package: 8-SOP-225 8-SOP-225 1 Typical Applications • DC cooling fan motor Ordering Information Device Package Operating Temp. FAN8408D 8-SOP-225 −25°C ~ 85°C FAN8408DTF 8-SOP-225 −25°C ~ 85°C Rev.1.0.4 ©2002 Fairchild Semiconductor Corporation FAN8408D Block Diagram OUTB 1 OUTA 7 VCC 4 GND 8 3 LD 2 HO 5 IN+ 6 IN- Commutation & Control & TSD Pin Definitions 2 Pin Number Pin Name I/O Pin Function Description Remark 1 OUTB O Motor output B 2 HO O Hall output 3 LD - Triangle pulse generator for lock detector and automatic restart - 4 VCC - Supply voltage - 5 IN+ I Hall input + - 6 IN− I Hall input − - 7 OUTA O Motor output A - 8 GND - Ground - Open Collector FAN8408D Equivalent Circuits Description Pin No. OUTB 1 OUTA 7 Internal Circuit 1 7 Commutation HO 2 2 Commutation LD 3 Lock detector & Automatic restart 3 Commutation VLDCP VLDCL IN+ 5 IN- 6 5 6 Commutation 3 FAN8408D Absolute Maximum Ratings (Ta = 25°C) Parameter Symbol Maximum power supply voltage Value Unit 18 V VCCMAX Maximum power dissipationnote1 429note2 PDMAX mW 620note3 291.61note2 Thermal resistancenote1 ΘJA Maximum output voltage VOMAX 30 V Maximum output current IOMAX 1.2note4 A Hall output current IHO 10 mA Hall output withstanding voltage VHO 36 V VHACMAX 6 V Maximum hall input ac level °C/W 201.52note3 Operating temperature TOPR −25 ~ 85 °C Storage temperature TSTG −55 ~ 150 °C Note1: PCB Condition: Thickness(1.6mm), Dimension(76.2mm * 114.3mm) Refer: EIA/J SED 51-3 & EIA/J SED 51-7 Note2: Air condition (0m/s) Note3: Air condition (3m/s) Note4: Should not exceed PD or ASO value Pd[W] Power Dissipation Curve (Air condition = 0m/s) 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 0 20 40 60 80 Tc or Ta[°C] 4 100 120 140 160 FAN8408D Air Speed & ΘJA 350 JA[°C/W] 300 250 200 150 100 50 0 0 1 2 3 4 5 6 Air Speed[m/s] Recommended Operating Conditions (Ta = 25°C) Parameter Symbol Min. Typ. Max. Unit VCC 4.0 − 15.0 V Function compensation operating voltage Electrical Characteristics (Ta=25°C, VCC=12V unless otherwise specified) Parameter Symbol Conditions Min. Typ. Max. Unit - - 3.0 mA Supply current ICC When output is off. Lock detector charging current ILDC VLD=1.8V 2.38 3.40 4.42 µA Lock detector discharging current ILDD VLD=1.8V 0.48 0.68 0.88 µA RCD RCD=ILDC/ILDD 3.0 5.0 7.0 − Lock detector capacitor clamp voltage VLDCL - 2.4 2.85 3.3 V Lock detector capacitor comparator voltage VLDCP - 0.7 0.99 1.2 V - 0.9 1.2 V 0 10 µA Lock detector charging/discharging ratio Output low level voltage VOL Output leakage current IOL - 28 30 32 V - 0.2 0.5 V IO=200mA Output zener voltage VOZ Clamp current=10mA Hall output pin low level voltage VHLL IO=10mA Hall output pin leakage current IHLL - - 0 10 µA Hall input dc range VHDC - 1 - VCC2V V Hall input offset VHOF VREF=6V -10 - 10 mV 5 FAN8408D Application Information 1. Lock Detection & Automatic Restart Hall Input Output TOFF TON VLDCL VLDCP Motor lock detected Motor lock Motor lock cleared Motor restart FAN8408D features a lock detection and an automatic restart. The functions can be operated as follows. 1) When the hall signal stop switching, a motor can be locked. 2) The voltage, VLD on pin 3, is increasing until it reaches VLDCL. 3) If LD pin is connected to GND, the lockup protection is disabled. 4) While a motor is locked, the output repeats switching ON / OFF, but the other output is always OFF. The switching time can be determined by an external capacitor on charging / discharging time of the capacitor, switching ON / OFF time can be calculated as follows. × (V – VLDCP ) C LD LDCL T ON = ------------------------------------------------------------------------I LDC T OFF C × (V – VLDCP ) LD LDCL = ------------------------------------------------------------------------I LDD Where, The CLD is an external capacitor connected to pin 3, LD. The VLDCL is the clamp voltage on pin 3, LD. The VLDCP is the comparator voltage on pin 3, LD. The ILDC is the charging current on pin 3, LD. The ILDD is the dischaging current on pin 3, LD. 2. Thermal Shut Down TSD On: All the outputs are off.(Typ. 175°C) TSD Off: The circuit can be reactivated and begin to operate in a normal condition. (Typ. 150°C) 6 FAN8408D 3. Hall Amplifier Input Block VCC R1 C1 IN+ 5 FAN8408D C2 R2 Hall Sensor 6 IN- R3 The hall current (IH) is determined by R1, R2 and R3. V CC I H = -----------------------------------R1 + R2 + R3 Where, the R2 is the impedance of hall sensor. An external capacitor, C1, can be used to reduce a power supply noise. In addition, C2 is to remove a noise which is caused in case the line is long from the hall sensor output to the hall input (pin 5 / 6) of the device. The input bias voltage of hall amplifier is between 1V and VCC-2V as following figure. VCC VCC-2V VCC / 2 1V GND It is recommended that R1 and R3 should have the same value to make the output signal of hall sensor centered as VCC/2. 7 FAN8408D Operation Truth Table IN+ IN- OUTA OUTB HO High Low High Low Low Low High Low High High Test Circuits VCC 1K 50 50 1 OUTB GND 8 2 HO OUTA 7 3 LD IN- 6 4 VCC IN+ 5 ILDC / ILDD A VLD A ICC VCC 8 FAN8408D Typical Application Circuits LD 3 1 OUTB 2 7 HO Commutation & Control & TSD OUTA VCC VCC 4 IN+ 8 GND 5 Hall 6 IN- Precaution In case of improper connection (change between power and ground), diode is required to protect motor. 9 FAN8408D Package Dimensions (Unit: mm) 8-SOP-225 10 FAN8408D 11 FAN8408D 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. LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com 10/17/02 0.0m 001 Stock#DSxxxxxxxx 2002 Fairchild Semiconductor Corporation