Ordering number: EN3519A Monolithic Digital IC LB1860,1860M,1861,1861M Variable Speed Fan Motor Driver Overview The LB1860 series ICs are drivers for two-phase unipolar drive DC brushless fan motors. They have functions such as driving, lock protection, restart and speed control. Package Dimensions unit: mm 3098B-DIP10S [LB1860, 1861] Features and Functions . Two-speed mode select function requiring less external . . . . . . component additions: Full speed and Low speed. Or, thermistor-controlled continuous variable-speed function according to ambient operation temperatures. → Motor starts rotating at a low speed. Motor lock protection and automatic return circuit built in Output transistors: Output current IO = 1.5 A, output circuit protection Zener diodes (LB1860: M-Vz = 57 V/ LB1861: M-Vz = 32 V) → Enables low-level noise protection with chip capacitor. Built-in thermal shutdown circuit Built-in rotation detect function (Drive mode: ‘‘L’’, Stop mode: ‘‘H’’) The LB1860 series can be operated from either 12 V or 24 V power supply by changing an external resistor. (Strong protection against power supply surge) Connectable direct to a Hall element SANYO : DIP10S unit: mm 3111-MFP14S [LB1860M, 1861M] SANYO : MFP14S SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN 73096HA(II)/4060TA,TS No.3519-1/6 LB1860,1860M,1861,1861M Specifications Absolute Maximum Ratings at Ta = 25 °C, ( ): LB1860M, LB1861M Parameter Symbol Conditions Ratings t % 20 ms Unit Maximum input current ICC max Output supply voltage VOUT Internal V Output current IOUT 1.5 A RD flow-in current IRD 10 mA RD supply voltage VRD 50 V Pd1 max 1.1 W (0.8) W Allowable power dissipation Pd2 max 200 Mounted on 20 × 15 × 1.5 mm glass epoxy board mA Operating temperature Topr –30 to +80 °C Storage temperature Tstg –55 to +125 °C Allowable Operating Ranges at Ta = 25 °C Parameter Symbol Input current range Conditions Ratings ICC Common-mode input voltage range Unit 6.0 to 50 VICM mA 0 to VIN –1.5 V Electrical Characteristics at Ta = 25 °C, ICC = 10 mA Parameter Output limiting voltage Output saturation voltage Input voltage Amp input offset voltage Amp input bias current RD output saturation voltage C flow-out current C discharge current Comparator input threshold voltage Ct discharge voltage Rt input current Rt comparator voltage Thermal protection circuit operating voltage Thermal protection circuit hysteresis Symbol Conditions LB1860, 1860M: IO = 0.1 A LB1861, 1861M: IO = 0.1 A IO = 0.5 A IO = 1.0 A IO = 1.5 A ICC = 7.0 mA VOLM1 VO sat1 VO sat2 VO sat3 VIN VOFF IBA VRD (sat) min 54 30 6.4 –7.0 –250 IRD = 5 mA typ 57 32 0.95 1.15 1.4 6.7 0 max 60 34 1.2 1.5 2.0 7.0 7.0 Unit V V V V V V mV nA 0.15 0.3 V 3.9 0.50 0.8 VIN 0.47 VIN 0.2 VIN –350 0.62 VIN 5.0 0.65 0.83 0.50 0.22 –240 0.65 µA µA V V V µA V IC1 IC2 VTH1 VTH2 Vct IRT VRT VRT = GND RT = OPEN TSD Design target 180 °C ∆TSD Design target 40 °C C = GND C = VIN 2.7 0.35 0.77 0.44 0.18 –440 0.59 Pin Assignments Top view Top view No.3519-2/6 LB1860,1860M,1861,1861M Block Diagram and Application Circuit Constant current circuit 0.47 to 10 µ Output timing control ( Unit (resistance: Ω, capacitance: F) ): MFP14S Figure 1 Truth Table ( ): LB1860M, 1861M IN+ IN– Ct Rt1 Rt2 CR OUT1 OUT2 RD Mode H L H L — L H L L Full speed L H H L — L L H L Full speed (H) (L) — — (H) (L) (H) (L) (L) (Full speed) (L) (H) — — (H) (L) (L) (H) (L) (Full speed) — — L H L L H H L Low speed — — — — — H H H H Lock protection Designer’s Notes (1) Variable-speed circuit (Rt and Ct pins) — Refer to the application circuit diagram The time constant gained by external components C2 and R2 is used to set the length of an ‘off’ operation time period after phase switching. This means that the variable-speed operations can be performed by changing the ‘on’ operation time of each phase through the duty control. The sawtooth waveform signals are generated by the C2-R2 time constant. The voltage of this signal (Ct pin voltage) increases from 1.3 V to 4.0 V (Vct) at each phase switching. That is, during this period, the driver becomes inactive (toff), in which output circuit is turned off. If VCC ^ 4.0 V, the driver IC remains active (ton) until the next phase switching. During this period, output circuit is turned on. If the active drive time of each phase is assumed to ‘to’, the following relation can be established: . . . . to = toff + ↑ Fixed constant ton ↑ Rotation speed proportional constant toff = 0.69 c C2 c R2 ........................................ 1 No.3519-3/6 LB1860,1860M,1861,1861M . From this relation, it can be observed that the ‘t ’ and ‘t . o on’ are in proportional relation with each other, and that the ‘ton/to’ equals the ‘on’ time duty. As a result, a certain rotation speed can be fixed despite the fact that rotation speed exclusively depends on each motor. At the start, the ‘ton’ value becomes longer while the ‘toff’ value remains unchanged. This means that the ‘toff/to’ duty becomes small enough compared to normal rotation mode. Therefore, the same start torque as that of the full speed rotation can be obtained because the ‘on’ operation time duty increases. This enables the motor to start at a very low speed. voltage (V pin) .(2)TheSupply LB1860 has the internal parallel regulator which supplies power to the Hall amplifier circuit and the control block. IN . . . Therefore, the driver ICs are not affected by power source fluctuations and kickbacks from the motor. They maintain the stable operations even if noise signals such as surge are generated. Set the resistance R1 between VCC and VIN so that the ICC current of 6 mA to 50 mA can flow onto the VIN pin within the supply voltage range of a fan motor. VIN is 6.7 V typ at ICC = 7 mA. The current flowing into VIN is calculated using the equation shown below. ICC . Consideration given to surge voltage . The maximum allowable current at V IN Vsurge – = = VCC – VIN R1 ............................ 2 pin is 200 mA. Therefore, the pin is designed to withstand abnormal positive voltage of: VIN + R1 × 200 mA ............................................ 3 + input pin voltage (Pins IN , IN ) .(3)SetHall the voltage levels of the input pin for the Hall element output and the Hall element output voltage to within the range of – 1.5 V. . 0TheV togainV between the hall input pin and the output pin is 100 dB or greater. The offset voltage of the hall input amp is ±7 mV, IN therefore, the hall element output must be set with the offset voltage (±7 mV) considered. (4) Output transistor (Pins OUT1, OUT2) Output current IO = 1.5 A max Output saturation voltage VO sat = 1.15 V/1.0 A typ Output limiting voltage VOLM = 57 V typ (LB1860, 1860M) VOLM = 32 V typ (LB1861,1861M) Since the LB1860 series have a protect zener diode between collector and base, the kickback voltage induced by the coil is cut at VOLM = 57 V (32 V). When external capacitors are connected between OUT and GND, the capacitance should not exceed 10 µF. . . . . (5) Output protection function (C pin) Capacitor pin used in forming an automatic return circuit. If rotation is stopped due to overload, the pin voltage level increases and then forces the output to become inactive. In this case, after proper load adjustment, the output returns to the ‘drive’ mode from the ‘stop’ mode automatically. By changing the capacitor value, the lock detect time period can be set. . . For C marked with 1 µF Rotation Output ON Lock Lock detect time Lock protect time (output ON) (output OFF) Output OFF Output ON Approximately 2 sec. Approximately 1 sec. Approximately 6 sec. Output OFF Rotation Lock release Automatic Return Circuit C Pin Voltage No.3519-4/6 LB1860,1860M,1861,1861M 1 When a fan is rotating, the capacitor is charged at 4 µA (typ) and discharged through the C with pulses according to the rotational speed. 2 When a fan is locked, no discharge occurs through the C and the C voltage rises, turning OFF the output at 0.8 × VIN. 3 When the output is turned OFF, discharge occurs through the C at 0.5 µA (typ). If the lock is not released when the C voltage drops to VTH2, the capacitor is charged to VTH1 again. (At this moment, the output is turned ON.) These operations 2 and 3 repeated at a cycle of approximately ton : toff = 1:6 protect a motor. 4 If the lock is released when the C voltage drops to VTH2, the output is turned ON, starting rotation. Rotation detect signal (RD pin) .(6)Open collector output (Drive mode: ‘‘L’’, Stop mode: ‘‘H’’) (7) Radio noise reducing (Pins B1, B2) Base pin of Darlington connection output transistor If radio noises need to be processed properly, the following actions should be taken: 1 Connect a capacitor of 0.01 µ to 0.1 µF between B1 and B2. 2 Connect a capacitor of 0.001 µ to 0.01 µF between OUT and B. If output causes oscillation, add a resistor of 200 Ω to 1 kΩ in series with a capacitor. . . (8) Thermal shutdown function Shutdown the driver output in case of coil short-circuiting and abnormal IC heating. . Thermistor-controlled Application Circuit Example Noise elimination capacitor Use of a thermistor enables motor speed to be sensitive to the operating ambient temperature. The Rt pin voltage at Ta = 20 °C has 1.42 ms of ‘toff’ as calculated in expression 4 with the application constant of Figure 2. However, the Rt pin voltage at Ta = 40 °C is reduced into less than the Vct (= 1.3 V) level, which results in a 0 of ‘toff’. This means the 100% duty. t = –C2 c R2 c 1n Figure 2 ( (VIN – VRt) ............. 4 VIN – VCt ): MFP14S Unit (resistance: Ω, capacitance: F) Output Timing Chart Hall input Discharge pulse Ct voltage Output ‘off’ signal OUT1 current All-phase ON waveform OUT2 current Control output waveform Figure 3 No.3519-5/6 LB1860,1860M,1861,1861M Number of rotation, n − rpm Top Speed Ambient temperature, Ta − °C No products described or contained herein are intended for use in surgical implants, life-support systems, aerospace equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like, the failure of which may directly or indirectly cause injury, death or property loss. Anyone purchasing any products described or contained herein for an above-mentioned use shall: 1 Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors and all their officers and employees, jointly and severally, against any and all claims and litigation and all damages, cost and expenses associated with such use: 2 Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees jointly or severally. Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or implied regarding its use or any infringements of intellectual property rights or other rights of third parties. This catalog provides information as of July, 1996. Specifications and information herein are subject to change without notice. No.3519-6/6