LB1838M Monolithic Digital IC Low-Voltage, Low-Saturation http://onsemi.com Bidirectional Motor Driver Application Note Overview The LB1838M is a low-saturation two-channel bidirectional motor driver IC for use in low-voltage applications. The LB1838M is a bipolar stepper-motor driver IC that is ideal for use in printers, cameras and other portable devices. Functions Low voltage operation (2.5V min) Low saturation voltage (upper transistor + lower transistor residual voltage: 0.40V at 400mA) Built-in through-current prevention circuit Separate logic power supply and motor power supply Built-in spark killer diodes Built-in thermal shutdown circuit Compact package: MFP14S Typical Applications Automotive speed meter Security camera Thermal Printer Unit Camera POS, Card Terminal Pin Assignment GND ENA2 OUT3 VS2 14 13 12 11 OUT4 IN2 10 9 Vcont 8 LB1838M 1 2 3 4 5 VCC ENA1 OUT1 VS1 OUT2 6 7 IN1 GND Note: Both GND pins should be connected to ground. Semiconductor Components Industries, LLC, 2013 December, 2013 1/11 LB1838M Application Note Package Dimensions unit: mm (typ) Pd max -- Ta 8.0 8 1 1.0 0.35 0.15 0.1 (1.5) (1.0) 7 1.7MAX 0.63 4.4 6.4 14 SANYO : MFP14S(225mil) Allowable power dissipation, Pd max -- mW 1000 800 600 550 Specified board: 20×30×1.5mm3 glass epoxy board. With specified board Independent IC 480 400 330 200 0 -20 0 20 40 60 80 100 Ambient temperature, Ta -- °C Recommended Soldering Footprint (Unit:mm) Reference Symbol MFP14S (225mil) eE 5.70 e 1.00 b3 0.47 l1 1.10 2 / 11 LB1838M Application Note Block Diagram 10μF VCC 60kΩ 80kΩ ENA1 VS1 OUT1 Control block IN1 VS2 Stepping Motor OUT2 60kΩ 80kΩ Thermal shutdown 60kΩ 80kΩ ENA2 OUT3 Control block IN2 OUT4 60kΩ 80kΩ GND GND Vcont Note: As long as the voltages applied to VCC, VS1, VS2, ENA1, ENA2, IN1, and IN2 are within the limits set by the absolute maximum ratings, there are no restrictions on the relationship of each voltage level in comparison with the others (regarding which is higher or lower). (ex. VCC = 3V, VS1, 2 = 2V, ENA = IN = 5V) Specifications Absolute Maximum Ratings at Ta = 25C Parameter Maximum supply voltage Symbol Conditions Ratings Unit VCC max -0.3 to +10.5 VS max -0.3 to +10.5 V VS+VSF V Output applied voltage VOUT Input applied voltage VIN Ground pin flow-out current IGND Allowable power dissipation Pd max Per channel V -0.3 to +10 V 1.0 A Independent IC 550 mW Mounted on a specified board * 800 mW Operating temperature Topr -20 to +75 C Storage temperature Tstg -40 to +125 C * Specified board: 20mm 30mm 1.6mm, glass epoxy board. Caution 1) Absolute maximum ratings represent the value which cannot be exceeded for any length of time. Caution 2) Even when the device is used within the range of absolute maximum ratings, as a result of continuous usage under high temperature, high current, high voltage, or drastic temperature change, the reliability of the IC may be degraded. Please contact us for the further details. Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. 3 / 11 LB1838M Application Note Recommended Operating Conditions at Ta = 25C Parameter Supply voltage Symbol Conditions Ratings min typ Unit max VCC 2.5 9.0 V VS 1.8 9.0 V Input high-level voltage VIH 1.8 9.0 V Input Low-level voltage VIL -0.3 +0.7 V Electrical Characteristics at Ta 25C, VCC = 3V Parameter Current drain Output saturation voltage Input current Output sustaining voltage Symbol Conditions Ratings min typ Unit max ICC0 ENA1,2 = 0V, VIN1 = 3V or 0V 0.1 10 A ICC1 ENA1 = 3V, VIN1 = 3V or 0V 12 18 mA VOUT1 ENA = 3V, VIN = 3V or 0V, IOUT = 200mA 0.2 0.28 VOUT2 ENA = 3V, VIN = 3V or 0V, IOUT = 400mA 0.4 0.6 V IIN VCC = 6V, VIN = 6V 200 A 200 A IENA VCC = 6V, ENA = 6V VO(SUS) IOUT = 400mA 9 V V Spark killer diode Reverse current IS(leak) VCC1, VS = 7V 30 A Forward voltage VSF IOUT = 400mA 1.7 V 4 / 11 LB1838M Application Note Pin function Pin No. 1 Pin name VCC Pin function Power-supply voltage pin. （signal supply） VCC voltage is impressed. The permissible operation voltage is from 2.5 to 9.0(V). The capacitor is connected for stabilization for GND pin (7pin,14pin). 4 11 VS1 VS2 Power-supply voltage pin.（ motor supply） The permissible operation voltage is from 1.8 to 9.0(V). The capacitor is connected for stabilization for GND pin (7pin,14pin). 2 ENA1 Motor stand-by (start-stop pin) control input pin. Start-stop control input pin of OUT1 (3pin) and OUT2 (5pin). . The digital input it, range of the "L" level input is 0 to 0.7(V), range of the "H" level input is from 1.8 to 9.0(V). Pull-down resistance 30(kΩ) is built into in the pin. It combines with ENA2 pin (4pin) and it uses it. Equivalent Circuit 30KΩ 6 IN1 Motor forward-reverse (direction pin) control input pin. Direction control input pin of OUT1 (3pin) and OUT2 (5pin). It combines with IN2 pin (9pin) and it uses it. With built-in pull-down resistance. 13 ENA2 Motor stand-by (start-stop pin) control input pin. Start-stop control input pin of OUT3 (12pin) and OUT4 (10pin). It combines with ENA1 pin (2pin) and it uses it. With built-in pull-down resistance. 9 IN2 Motor forward-reverse (direction pin) control input pin. Direction control input pin of OUT3 (12pin) and OUT4 (10pin). It combines with IN1 pin (6pin) and it uses it. PWM can be input. With built-in pull-down resistance. Ground pin. Pre-drive monitor terminal. Please refer to Vcontpin explanation. 7,14 8 GND Vcont 30K 300Ω 30K Continued on next page. 5 / 11 LB1838M Application Note Continued from preceding page. 10 OUT4 Driving output pin. The motor coil is connected between terminal OUT3 (12pin). 12 OUT3 Driving output pin. The motor coil is connected between terminal OUT4 (10pin). 5 OUT2 Driving output pin. The motor coil is connected between terminal OUT1 (3pin). 3 OUT1 Driving output pin. The motor coil is connected between terminal OUT2 (5pin). VCC OUT1 (OUT3) OUT2 (OUT4) GND Operation explanation 1. LB1838M Input-Output Logic Truth Table IN1,2 ENA1,2 OUT1,3 OUT2,4 Mode L H H L Forward H H L H Reverse L L OFF OFF Standby H L OFF OFF Standby 2. Stepping motor operation Sequence Example of current wave type in each excitation mode when stepping motor parallel input is controlled. 2 phase excitation 1-2 phase excitation 6 / 11 LB1838M Application Note 3. Theory Full-Step MODE The motor moves 90 degrees in an electric corner when I input 1Step. IOUT IOUT Half-Step MODE The motor moves 45 degrees in an electric corner when I input 1Step IOUT IOUT 4. Vcont pin VCC VS OUT IN 300Ω M ID OUT VZ ID = Vcont VZ ( = Constant) r As shown in the left diagram, the Vcont pin outputs the voltage of the band gap Zener VZ +VF (= 1.93V). In normal use, this pin is left open. The drive current ID is varied by the Vcont voltage. However, because the band gap Zener is shared, it functions as a bridge. The motor can stop by making vcont terminal GND in emergency. 7 / 11 LB1838M Application Note 5. Thermal Shutdown circuit The thermal shutdown circuit in incorporated and the output is turned off when junction temperature Tj exceeds 180C and the abnormal state warning output is turned on. As the temperature falls by hysteresis, the output turned on again (automatic restoration). The thermal shutdown circuit does not guarantee the protection of the final product because it operates when the temperature exceed the junction temperature of Tjmax=150C. TSD = 180C (typ) TSD = 40C (typ) Application Circuit Example Example of applied circuit with one stepping motor 8 / 11 LB1838M Application Note Eva-Board Manual 1. Eva-Board circuit diagram Bill of Materials for LB1838M Evaluation Board Footprint Manufacturer Manufacturer Part Number Substitution Allowed Lead Free MFP14S (225mil) ON semiconductor LB1838M No Yes KOA GRM188B11A 105K Yes Yes Murata GRM188R72A 104KA35D Yes Yes Switch MIYAMA MS-621-A01 Yes Yes Test points MAC8 ST-1-3 Yes Yes Designator Qty Description Value IC1 1 Motor Driver C1 1 VCC Bypass capacitor 1µF 50V C2 １ Vs Bypass capacitor 0.1u 100v SW1-SW4 4 TP1-TP11 14 Tol 2. (1) One stepping motor drive 9/11 LB1838M Application Note (2) Stepping motor drive connection explanation Connect a stepping motor with OUT1, OUT2, OUT3 and OUT4. Connect the motor power supply with the terminal VCC, the control power supply with the terminal VIN. Connect the GND line with the terminal GND. STP motor drives it in an 2 phase excitation, 1-2 phase excitation by inputting an input signal such as follows into ENA1,N1,ENA2,IN2. Waveform of LB1838M evaluation board when driving stepping motor Full-Step Drive VCC=5V, VS=5V 1000pps Half-Step Drive VCC=5V, VS=5V 1600pps 10/11 LB1838M Application Note ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent-Marking.pdf. SCILLC reserves the right to make changes without further notice to any products herein. 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