Ordering number : ENN6087A Monolithic Digital IC LB1975 DC Fan Motor Driver Overview Package Dimensions The LB1975 is a three-phase brushless motor driver IC suited for use in direct PWM driving of DC fan motors for air conditioners, water heaters, and other similar equipment. Since a shunt regulator circuit is built in, single power supply operation sharing the same power supply for the motor is supported. unit: mm [LB1975] 28 15 12.7 11.2 R1.7 0.4 8.4 Features Withstand voltage 45 V, output current 2.5 A Direct PWM drive output 3 built-in output top-side diodes Built-in current limiter Built-in FG output circuit 1 14 20.0 4.0 26.75 4.0 • • • • • 3147C-DIP28H (1.81) 1.78 0.6 1.0 SANYO: DIP28H Any and all SANYO products described or contained herein do not have specifications that can handle applications that require extremely high levels of reliability, such as life-support systems, aircraft’s control systems, or other applications whose failure can be reasonably expected to result in serious physical and/or material damage. Consult with your SANYO representative nearest you before using any SANYO products described or contained herein in such applications. SANYO assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all SANYO products described or contained herein. SANYO Electric Co.,Ltd. Semiconductor Company TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN 21003AS (OT) / 52199RM (KI) No. 6087-1/12 LB1975 Specifications Absolute Maximum Ratings at Ta = 25°C Parameter Symbol Supply voltage Unit V VM max 45 V IO max 2.5 A 10 mA IREG max Allowable power dissipation Ratings 7 Output current Maximum input current Conditions VCC max VREG pin Pd max1 IC only Pd max2 With infinite heat sink 3 W 20 W Operating temperature Topr –20 to +100 °C Storage temperature Tstg –55 to +150 °C Ratings Unit Allowable Operating Ranges at Ta = 25°C Parameter Symbol Supply voltage range Conditions VCC 4.5 to 6.7 V VM 20 to 42 V Input current range IREG FG pin applied voltage VFG 0 to VCC FG pin output current IFG 0 to 10 VREG pin 1 to 5 mA V mA Allowable power dissipation, Pd max – W Pd max – Ta 24 20 With infinite heat sink 16 12 8 4 3 0 –20 Independent IC 0 20 40 60 80 100 120 Ambient temperature, Ta – ˚C No. 6087-2/12 LB1975 Electrical Characteristics at Ta = 25°C, VCC = 5 V, VM = 30 V Parameter Supply current Symbol Conditions ICC Ratings min typ 10 max Unit 14 18 mA VOsat1 (L) IO = 1.0 A, VO (sink) 1.1 1.4 V VOsat1 (H) IO = 1.0 A, VO (source) 0.9 1.3 V 2.0 2.6 V VOsat2 (L) IO = 2.0 A, VO (sink) 1.4 1.8 V VOsat2 (H) IO = 2.0 A, VO (source) 1.2 1.7 V 2.6 3.4 V 100 µA [Output Block] Output saturation voltage VOsat1 VOsat2 Output leak current Upper side diode forward voltage IO = 1.0 A, VO (sink) + VO (source) IO = 2.0 A, VO (sink) + VO (source) IOLeak (L) IOLeak (H) –100 µA VFH1 IO = 1.0 A 1.2 1.6 V VFH2 IO = 2.0 A 2.1 2.6 V [Hall Amplifier] Input bias current IHB –4 Common-mode input voltage range VICM 1.5 Hall input sensitivity VHIN 60 –1 µA VCC – 1.5 V mVp-p ∆VIN (HA) 23 32 39 mV Input voltage (low to high) VSLH 6 16 25 mV Input voltage (high to low) VSHL –25 –16 –6 mV Hysteresis width [FG Pin (speed pulse output)] Output low-level voltage VFGL 0.5 V Pull-up resistor value RFG 7.5 10 12.5 kΩ VRF 0.45 0.50 0.55 V 150 180 °C 40 °C IFG = 5 mA [Current Limiter] Limiter [Thermal Shutdown] Thermal shutdown operating temperature Hysteresis width TSD Desigh target Value (junction temperature) ∆TSD Desigh target Value (junction temperature) [Low-Voltage Protection] Operating voltage Non-operating voltage VLVSD 3.5 VLVSD (OFF) 3.8 4.1 V 4.3 4.5 V ∆VLSD 0.4 0.5 0.6 V Output high-level voltage VOH (OSC) 2.95 3.10 3.25 V Output low-level voltage VOL (OSC) 1.38 1.45 1.59 V VOSC 1.50 1.65 1.71 Vp-p kHz Hysteresis width [PWM Oscillator] Amplitude Ocillator frequency fOSC Charge current ICHG Discharge resistance C = 2200 pF RDCHG 19.6 23.0 27.6 –110 –94 –83 µA 1.6 2.1 2.6 kΩ [VREG Pin] Pin voltage VREG IREG = 1.5 mA 6.6 7.0 7.2 V VCTL1 Output duty 0% 1.1 1.4 1.7 V VCTL2 Output duty 100% 3.2 3.5 3.8 [VCTL Pin] Input voltage Input bias current IB1 (CTL) VCTL = 0 V –82 V µA IB2 (CTL) VCTL = 5 V 92 µA [VCTL Amplifier] Reference voltage Output voltage VCREF 2.23 2.35 2.46 V VCOUT1 VCTL = 0 V 3.90 4.20 4.40 V VCOUT2 VCTL = 5 V 0.60 0.80 1.10 V [Start/Stop Pin] High-level input voltage range VIH (S/S) VCC – 1.5 VCC V Low-level input voltage range VIL (S/S) 0 1.5 V Input open voltage VIO (S/S) VCC – 0.5 VCC V Continued on next page. No. 6087-3/12 LB1975 Continued from preceding page. Parameter Symbol Ratings Conditions min ∆VIN (S/S) Hysteresis width typ max Unit 0.35 0.50 0.65 V High-level input current IIH (S/S) V (S/S) = VCC –10 0 10 µA Low-level input current IIL (S/S) V (S/S) = 0 V –280 –210 µA [Forward/Reverse Pin] High-level input voltage range VIH (F/R) VCC – 1.5 VCC V Low-level input voltage range VIL (F/R) 0 1.5 V Input open voltage VIO (F/R) VCC – 0.5 VCC V Hysteresis width ∆VIN (F/R) 0.35 0.50 0.65 V 10 µA High-level input current IIH (F/R) V (F/R) = VCC –10 0 Low-level input current IIL (F/R) V (F/R) = 0 V –280 –210 µA Pin Assignment – VCOUT VCTL OSC (NC) VCREF IN1 28 27 26 25 24 IN1+ IN2– IN2+ IN3– IN3+ FG1 22 21 20 19 18 17 23 FG2 GND1 16 15 LB1975 Top view 1 2 3 4 VCC VREG S/S F/R 13 14 (NC) OUT1 OUT2 OUT3 (NC) (NC) GND3 GND2 RF 5 6 7 8 9 10 11 12 VM A11950 Truth Table Input IN1 IN2 Forward/reverse control Output F/R Source → Sink L OUT2 → OUT1 H OUT1 → OUT2 IN3 1 H L H 2 H L L 3 H H L 4 L H L 5 L H H 6 L L H F/R Forward rotation Low Reverse rotation High L OUT3 → OUT1 H OUT1 → OUT3 L OUT3 → OUT2 H OUT2 → OUT3 L OUT1 → OUT2 H OUT2 → OUT1 L OUT1 → OUT3 H OUT3 → OUT1 L OUT2 → OUT3 H OUT3 → OUT2 FG output FG1 FG2 L L L H L L H H H L H H FG output 0 V to 1.5 V VCC – 1.5 V to VCC FG1 FG2 No. 6087-4/12 LB1975 Duty – VCTL characteristics 100 80 Duty — % 60 40 20 0 VCTL1 Control voltage, VCTL — V VCTL2 Block Diagram and Peripheral Circuit VREG VCC VCC S/S F/R FG1 FG2 Reg LVSD + + TSD VM Hys.Amp + IN1 VM – OUT1 OUT2 + IN2 Logic – OUT3 + IN3 – 31 kΩ VCTL Current limiter VCTL Amp – 40 kΩ PWM OSC + VCTL RF Rf 0.5 V 2.35 V + VCREF VCOUT OSC GND1 GND2 GND3 A11952 No. 6087-5/12 LB1975 Pin Functions Pin No. Pin name Pin voltage 1 VCC 4.5 V to 6.7 V Pin function Equivalent circuit Power supply for blocks other than the output block 2 2 VREG 0.0 V to 7.3 V Shunt regulator output pin (7 V) A11953 VCC Start/stop control pin Low: start High or Open: stop 3 S/S 20 kΩ 0.0 V to VCC Typical threshold voltage for VCC = 5 V: 3.8 kΩ approx. 2.8 V (low to high) 3 approx. 2.3 V (high to low) A11954 VCC Forward/reverse pin Low: forward High or Open: reverse 4 F/R 20 kΩ 0.0 V to VCC Typical threshold voltage for VCC = 5 V: 3.8 kΩ approx. 2.8 V (low to high) 4 approx. 2.3 V (high to low) A11955 6 OUT1 Output pin 1 7 OUT2 Output pin 2 8 OUT3 Output pin 3 VCC VM 14 6 7 13 RF 0.0 V to VCC Output current detect pin. Connect resistor RF between this pin and ground. Output current is limited to value set with VRF/Rf. (Current limiter operation) 8 0.5 V 200 Ω 13 14 VM 11 GND3 Output block power supply A11956 Output block ground Continued on next page. No. 6087-6/12 LB1975 Continued from preceding page. Pin No. Pin name 15 GND1 12 GND2 Pin voltage Pin function Equivalent circuit Ground for blocks other than the output block VCC 10 kΩ 17 FG1 0.0 V to VCC 16 FG2 Speed pulse output pin 1 with built-in pull-up resistor 16 17 Speed pulse output pin 2 with built-in pull-up resistor A11957 VCC 22 23 20 21 18 19 IN1+ IN1– IN2+ IN2– 1.5 V to VCC – 1.5 V IN3+ IN3– 18 Hall input pin IN+ > IN– : High input 20 IN+ < IN– : Low input 300 Ω 300 Ω 22 19 21 23 A11958 VCC 2V 26 OSC 1.0 V to VCC 94 µA 200 Ω This pin sets the PWM oscillation frequency. Connect a capacitor between this pin and ground. 26 2.1 kΩ A11959 31 kΩ VCC Output duty cycle control pin • VCTL ≤ VCTL1 Duty cycle 0% 27 VCTL 0.0 V to 6.7 V • VCTL1 < VCTL < VCTL2 Duty cycle is controlled by VCTL • VCTL ≥ VCTL2 2.35 V 40 kΩ 27 Duty cycle 100% A11960 Continued on next page. No. 6087-7/12 LB1975 Continued from preceding page. Pin No. Pin name Pin voltage Pin function Equivalent circuit VCC 100 µA 24 VCREF 0.0 V to VCC – 2.0 V V CTL amplifier internal reference voltage pin (2.35 V) 200 Ω 24 23.5 kΩ A11961 28 31 kΩ VCC 28 VCOUT 0.7 V to VCC – 0.7 V VCTL amplifier output pin 200 Ω A11962 No. 6087-8/12 LB1975 IC Description Direct PWM Drive This IC (LB1975) employs the direct PWM drive principle. Motor rotation speed is controlled by varying the output duty cycle according to an analog voltage input (VCTL). This eliminates the need to alter the motor power supply voltage. Compared to previous ICs using the PAM principle (such as the Sanyo LB1690), this allows simplification of the power supply circuitry. The VCTL input can be directly supplied by a microcontroller, motor speed can, therefore, be controlled directly from the microcontroller. For PWM, the source-side output transistors are switched on and off so that the ON duty tracks the VCTL input. The output duty cycle can be controlled over the range of 0% to 100% by the VCTL input. PWM Frequency The PWM oscillator frequency fPWM [Hz] is set by the capacitance C [pF] connected between the OSC pin and GND. The following equation applies: fPWM ≈ 1 / (1.97 × C) × 108 Because output transistor on/off switching is subject to a delay, setting the PWM frequency to a very high value will cause the delay to become noticeable. The PWM frequency therefore should normally be kept below 40 kHz (typ.), which is achieved with a capacitance C of 1300 pF or higher. For reference, the source-side output transistor switching delay time is about 2 µs for ON and about 4 µs for OFF. Output Diodes Because the PWM switching operation is carried out by the source-side output transistors, Schottky barrier diodes must be connected between the OUT pins and GND (OUT1 to OUT3). Use diodes with an average forward current rating in the range of 1.0 to 2.0 A, in accordance with the motor type and current limiting requirements. If no Schottky barrier diodes are connected externally, or if Schottky barrier diodes with high forward voltage (VF) are used, the internal parasitic diode between OUT and GND becomes active. When this happens, the output logic circuit may malfunction, resulting in feedthrough current in the output which can destroy the output transistors. To prevent this possibility, Schottky barrier diodes must be used and dimensioned properly. The larger the VF of the externally connected Schottky barrier diodes, or the hotter the IC is, the more likely are the parasitic diodes between OUT and GND to become active and the more likely is malfunction to occur. The VF of the Schottky barrier diodes must be determined so that output malfunction does not occur also when the IC becomes hot. If malfunction occurs, choose a Schottky barrier diode with lower VF. Protection circuits • Low voltage protection circuit When the VCC voltage falls below a stipulated level (VLVSD), the low voltage protection circuit cuts off the source-side output transistors to prevent VCC related malfunction. • Thermal shutdown circuit (overheat protection circuit) When the junction temperature rises above a stipulated value (TSD), the thermal shutdown circuit cuts off the sourceside output transistors to prevent IC damage due to overheating. Design the application heat characteristics so that the protection circuit will not be triggered under normal circumstances. • Current limiter The current limiter cuts off the source-side output transistors when the output current reaches a preset value (limiter value). This interrupts the source current and thereby limits the output current peak value. By connecting the resistance Rf between the RF pin and ground, the output current can be detected as a voltage. When the RF pin voltage reaches 0.5 V (typ.), the current limiter is activated. It performs on/off control of the source-side output transistors, thereby limiting the output current to the value determined by 0.5 /Rf. No. 6087-9/12 LB1975 Hall Input Circuit The Hall input circuit is a differential amplifier with a hysteresis of 32 mV (typ.). The operation DC level must be within the common-mode input voltage range (1.5V to VCC – 1.5 V). To prevent noise and other adverse influences, the input level should be at least 3 times the hysteresis (120 to 160 mVp-p). If noise at the Hall input is a problem, a noisecanceling capacitor (about 0.01 µF) should be connected across the Hall input IN+ and IN– pins. FG Output Circuit The Hall input signal at IN1, IN2, and IN3 is combined and subject to waveform shaping before being output. The signal at FG1 has the same frequency as the FG1 Hall input, and the signal at FG2 has a frequency that is three times higher. Start/Stop Control Circuit The start/stop control circuit turns the source-side output transistors OFF (motor stop) when a High signal is input at the S/S pin or when the pin is Open. When a Low signal is input at the S/S pin, the source-side output transistors are turned ON, and the normal operation state is established (motor start). Forward/Reverse Switching This IC is designed under the assumption that forward/reverse switching is not carried out while the motor is running. If switching is carried out while the motor is running, reverse torque braking occurs, leading to a high current flow. If the current limiter is triggered, the source-side output transistors are switched off, and the sink-side output transistors go into the short brake condition. However, because the current limiter of this IC cannot control the current flowing in the sinkside output transistors, these may be destroyed by the short brake current. Therefore F/R switching while the motor is running is permissible only if the output current (IO) is limited to a maximum of 2.5 A using the motor coil resistance or other suitable means. F/R switching should be carried out only while a High signal is input to the S/S pin or the pin is Open (stop condition), or while the VCTL pin conforms to the following condition: VCTL ≤ VCTL1 (duty cycle 0%). In any other condition, F/R switching will result in feedthrough current. The F/R pin should therefore be fixed to Low (forward) or High or Open (reverse) during use. VCC, VM Power Supplies When the power supply voltage (VCC, VM) rises very quickly when a power is first applied, a feedthrough current may occur at the output. If the current remains below about 0.2 A to 0.3 A, it does not pose a problem, but such a possibility should still be prevented by slowing down the voltage rise at power-on. Especially if the F/R pin is set to High or Open (reverse), a quick rise in VCC is likely to cause feedthrough current. This should be prevented by ensuring that ∆VCC / ∆t = 0.2 V/µs or less. Feedthrough current can also be prevented by first switching on VCC and then VM during power-on. The sequence at power-down should be as follows. Provide a stop input to the S/S pin or a duty ratio 0% input to the VCTL pin. When the motor has come to a full stop, switch off VM and then VCC. If power is switched off while the motor is still rotating or a current is flowing in the motor coil (including motor restraint or inertia rotation), a counterelectromotive current or kickback current may flow on the VM side, depending on the motor type and power-off procedure. If this current cannot be absorbed by the VM power supply or a capacitor, VM voltage may rise and exceed the absolute maximum VM rating for the IC. Ensure that this does not happen through proper design of the VM power supply or through use of a capacitor. Because the IC (LB1975) incorporates a shunt regulator, it can be used on a single power supply. In this case, supply VCC (6.3 typ.) to the VREG pin via an external NPN transistor and resistor. When not using the regulator, leave the VREG pin open. No. 6087-10/12 LB1975 Power Supply Stabilizing Capacitors If the V CC line fluctuates drastically, the low-voltage protection circuit may be activated by mistake, or other malfunctions may occur. The VCC line must therefore be stabilized by connecting a capacitor of at least several µF between VCC and GND. Because a large switching current flows in the VM line, wiring inductance and other factors can lead to VM voltage fluctuations. As the GND line also fluctuates, the VM line must be stabilized by connecting a capacitor of at least several µF between VM and GND, to prevent exceeding VMmax or other problems. Especially when long wiring runs (VM, VCC, GND) are used, sufficient capacitance should be provided to ensure power supply stability. VCREF Pin, VCOUT Pin These pins are always used in the Open condition. If chattering occurs in the PWM switching output, connect a capacitor (about 0.1 µF) between VCREF and ground or between VCOUT and GND. IC Heat Dissipation Fins A heat sink may be mounted to the heat dissipation fins of this IC, but it may not be connected to GND. The sink should be electrically open. Sample calculation for internal power dissipation (approximate) The calculation assumes the following parameters: VCC = 5 V VM = 30 V Source-side output transistor ON duty cycle 80% (PWM control) Output current IO = 1 A (RF pin average current) • ICC power dissipation P1 P1 = VCC × ICC = 5 V × 14 mA = 0.07 W • Output drive current power dissipation P2 P2 = VM × 11 mA = 30 V × 11 mA = 0.33 W • Source-side output transistor power dissipation P3 P3 = VO (source) × IO × Duty (on) = 0.9 V × 1 A × 0.8 = 0.72 W • Sink-side output transistor power dissipation P4 P4 = VO (sink) × IO = 1.1 V × 1 A = 1.10 W • Total internal power dissipation P P = P1 + P2 + P3 + P4 = 2.22 W IC temperature Rise Measurement Because the chip temperature of the IC cannot be measured directly, measurement according to one of the following procedures should always be carried out. • Thermocouple measurement A thermocouple element is mounted to the IC heat dissipation fin. This measurement method is easy to implement, but it will be subject to measurement errors if the temperature is not stable. • Measurement using internal diode characteristics of IC This is the recommended measurement method. It makes use of the parasitic diode incorporated in the IC between FG1 and GND. Set FG1 to High and measure the voltage VF of the parasitic diode to calculate the temperature. (Sanyo data: for IF = –1 mA, VF temperature characteristics are about –2 mV/°C) NC Pins Because NC pins are electrically open, they may be used for wiring purpose etc. No. 6087-11/12 LB1975 Specifications of any and all SANYO products described or contained herein stipulate the performance, characteristics, and functions of the described products in the independent state, and are not guarantees of the performance, characteristics, and functions of the described products as mounted in the customer’s products or equipment. To verify symptoms and states that cannot be evaluated in an independent device, the customer should always evaluate and test devices mounted in the customer’s products or equipment. SANYO Electric Co., Ltd. strives to supply high-quality high-reliability products. However, any and all semiconductor products fail with some probability. It is possible that these probabilistic failures could give rise to accidents or events that could endanger human lives, that could give rise to smoke or fire, or that could cause damage to other property. When designing equipment, adopt safety measures so that these kinds of accidents or events cannot occur. Such measures include but are not limited to protective circuits and error prevention circuits for safe design, redundant design, and structural design. In the event that any or all SANYO products (including technical data, services) described or contained herein are controlled under any of applicable local export control laws and regulations, such products must not be exported without obtaining the export license from the authorities concerned in accordance with the above law. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, or any information storage or retrieval system, or otherwise, without the prior written permission of SANYO Electric Co., Ltd. Any and all information described or contained herein are subject to change without notice due to product/technology improvement, etc. When designing equipment, refer to the “Delivery Specification” for the SANYO product that you intend to use. 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 February, 2003. Specifications and information herein are subject to change without notice. PS No. 6087-12/12