LB1848MC Monolithic Digital IC Low-Voltage/Low Saturation Voltage Type Bidirectional Motor Driver http://onsemi.com Application Note Overview The LB1848MC is a 2-channel low-voltage, low saturation voltage type bidirectional motor driver IC that is optimal for use as 2-phase stepping motor driver in printers, floppy disk drives, cameras and other portable equipments. The output circuits are of the bipolar type, with pnp transistors in the upper side and npn transistors in the lower side, and they achieve low saturation output and low power characteristics despite being provided in a miniature package. The LB1848MC can directly control a motor from signals from a microcontroller. The LB1848M is optimal for 2-phase excitation drive for 2-phase stepping motors using 3-input logic (ENA, IN1, and IN2). The LB1848MC has a built-in thermal shutdown circuit to protect itself from operating at exceedingly high temperature even if the IC outputs are shorted. Additionally, the MFP-10S miniature package used supports reduced-space mounting. Function Optimal for 2 phase excitation drive for 2-phase stepping motor Low saturation voltage. VO(sat) = 0.55 V typical at IO = 400 mA Standby current: zero Thermal shutdown circuit Miniature package: MFP-10S (6.5 x 5.1 mm2) Through-current prevention circuit “Soft off” function that reduces power supply line noise when switching from drive to standby modes. (Requires the use of one external capacitor.) No limitations on the magnitude relationship between the power supply voltage (VCC) and the input voltage (VIN) Typical Applications Blu-ray pickup lens CCTV POS printer Security camera DSC Pin Assignment Semiconductor Components Industries, LLC, 2013 December, 2013 1/13 LB1848MC Application Note Package Dimensions Pdmax-Ta unit : mm (typ) Recommended Soldering Footprint 2/13 LB1848MC Application Note Block Diagram Note: When the “soft off” function is used, a capacitor must be connected to the SOF pin. If this function is not used, this pin must be left open with absolutely no signals or lines connected. Notes on Wiring and Lines Since large currents flow in the VCC and ground lines, oscillations may occur on these lines. The following points should be observed if such oscillations occur. (1) Lower the line impedances by making them shorter and thicker. (2) Attach capacitors close to the IC. (3) If the controller (CPU) is mounted on a separate printed circuit board, insert series resistors (of about 10kohm) between the controller outputs and this IC. 3/13 LB1848MC Application Note Specifications Absolute Maximum Ratings at Ta = 25C Parameter Symbol Maximum supply voltage Output voltage Input voltage Conditions Ratings VCC max -0.3 to +8.0 V VOUT VCC+VSF V VIN Ground pin outflow current -0.3 to +8.0 IGND Allowable power dissipation Unit Per channel V 800 mA Pd max1 Independent IC 350 mW Pd max2 When mounted.* 870 mW Operating temperature Topr -20 to +75 C Storage temperature Tstg -40 to +150 C Note: * On the specified circuit board (114.3mm76.2mm1.5mm, glass epoxy printed circuit 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. Recommended Operating Conditions at Ta = 25C Parameter Symbol Ratings Conditions min typ Unit max Supply voltage VCC 2.5 7.5 Input high-level voltage VIH 2.0 7.5 V V Input low-level voltage VIL -0.3 +0.7 V Electrical Characteristics at Ta 25C, VCC = 5.0V Parameter Symbol Current drain Output saturation voltage Ratings Conditions min typ Unit max ICC0 ENA = 0V, VIN = 3V or 0V 0.1 10 A ICC1 ENA = 3V, VIN = 3V or 0V 25 35 mA VOUT1 ENA = 3V, VIN = 3V or 0V, 0.27 0.4 V V VCC = 3 to 7.5V, IOUT = 200mA VOUT2 Input current 1 IIN Input current 2 IENA ENA = 3V, VIN = 3V or 0V, 0.55 0.8 VCC = 4 to 7.5V, IOUT = 400mA VIN = 5V 75 100 A ENA = 5V 85 110 A 30 A 1.7 V Spark killer Diode Reverse current IS(leak) Forward voltage VSF IOUT = 400mA Note: The thermal shutdown circuit function values are design guarantees, and are not tested. 50 140 120 40 IIN(uA) ICC (mA) 100 30 20 80 60 40 10 ENA 20 0 IN 0 0 1 2 3 4 5 6 VCC (V) Figure 1 ICC vs VCC (ENA=VCC) 7 8 9 0 1 2 3 4 5 6 7 8 9 VIN (V) Figure 2 IIN vs VIN (VCC=5V) 4/13 1.0 5 0.8 4 0.6 3 VOUT(V) VOUT(V) LB1848MC Application Note 0.4 0.2 2 1 0.0 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 0.5 1 1.5 IOUT(A) 2 2.5 3 3.5 4 4.5 5 VIN (V) Figure 3 VOUT vs IOUT (VCC=VIN=4V) Figure 4 VOUT vs VIN (VCC=3.3V,VM=5V) 100 30 25 80 IIN(uA) ICC1 (mA) 20 15 60 40 10 ENA 20 5 IN 0 0 ‐50 0 50 100 150 ‐50 0 50 100 150 Temp(deg) Temp(deg) Figure 6 IIN vs Temperature (VCC=VIN=5V) Figure 5 ICC1 vs Temperature (VCC=ENA=5V) 0.8 0.7 VOUT(V) 0.6 0.5 0.4 0.3 0.2 VCC=4V,Io=400mA 0.1 VCC=3V,Io=200mA 0.0 ‐50 0 50 100 150 Temp(deg) Figure 7 VOUT vs Temperature (VCC=VIN) 5/13 LB1848MC Application Note Pin Functions Pin No. Pin name Pin Function 3 ENA Control signal input pin 5 IN1 Control signal input pin 2 IN2 Control signal input pin 4 SOF Capacitor connection pin Equivalent Circuit VCC 43kΩ 300Ω ENA GND 8 OUT1 Outpin 7 OUT2 Outpin 9 OUT3 Outpin 10 OUT4 Outpin 1 VCC Power supply voltage pin 6 GND Ground pin 6/13 LB1848MC Application Note Truth Table ENA L H IN1 IN2 OUT1 OUT2 OUT3 OUT4 Notes Standby - - OFF OFF OFF OFF L L H L H L L H H L L H H H L H L H H L L H H L 2-phase excitation Note: “ - ” indicates a “don’t care” input. SOF Pin (“Soft Off” Function) Operation The soft off function reduces power supply line noise due to the kickback current generated when the stepping motor drive mode is switched from drive to standby. The “soft off” function provided by this IC operates when a capacitor (0.001 to 0.01 μF) is connected between the SOF pin and ground. (Leave the SOF pin open to disable the soft off function.) The waveforms for each pin are shown below. Timing chart for stepping motor 2phase excitation 7/13 LB1848MC Application Note *Mechanism of the kickback noise generation 8/13 LB1848MC Application Note *) Effect of the SOF function SOF=open ‘drive’ ‘standby’ Ch1 ENA 10V/div Ch2 VOUT1 5V/div Ch3 SOF 5V/div Kickback spike noise Ch4 VCC 20mV/div(AC) T=0.5ms/div VCC=5V, 2phase excitation SOF-GND: 0.01uF Ch1 ENA 10V/div Ch2 VOUT1 5V/div Ch3 SOF 5V/div Ch4 VCC 20mV/div(AC) T=0.5ms/div SOF-GND: 0.1uF Ch1 ENA 10V/div Ch2 VOUT1 5V/div Ch3 SOF 5V/div Ch4 VCC 20mV/div(AC) T=0.5ms/div 9/13 LB1848MC Application Note Operation explanation Overheating protection function (Thermal Shutdown circuit) The device has a built-in overheating protection circuit that turns-off when the junction temperature (Tj) exceeds 180C. Once the temperature decreases below 140C, the device is turned on again (automatic restoration). The overheating protection circuit hysteresis is 40C. The overheating protection circuit doesn't secure protection and the destruction prevention of the set because it becomes operation by the area where ratings Tjmax = 150C of the junction temperature was exceeded. TSD = 180C (typ) TSD = 40C (typ) Evaluation board manual Overview Circuit diagram 10/13 LB1848MC Application Note Bill of Materials for LB1848MC Evaluation Board Footprint Manufacturer Manufacturer Part Number Substitution Allowed Lead Free MFP10S (225mil) ON semiconductor LB1848MC No Yes SUN Electronic Industries 50ME10HC Yes Yes Switch MIYAMA Electric MS-621C-A01 Yes Yes Test points MAC8 ST-1-3 Yes Yes Designator Qty Description IC1 1 Motor Driver C1 1 VCC Bypass capacitor SW1-SW3 3 TP1-TP11 11 Value 10µF 50V Tol ±20% Stepping motor driving method 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. The Stepping motor is drived in 2-phase excitation by inputting signals into ENA, IN1 and IN2(Refer to the waveform diagram below) Check the stepping motor is rotating. Check the waveform of the output voltage and current. (Please refer to the following waveform example.) 11/13 LB1848MC Application Note Input signal ENA L H H H H H H H H H L IN1 L L H H L L H H L L L IN2 L L L H H L L H H L L OUT1 OFF H L L H H L L H H OFF OUT2 OFF L H H L L H H L L OFF OUT3 OFF H H L L H H L L H OFF OUT4 OFF L L H H L L H H L OFF Output voltage IOUT1 Output current IOUT2 Stepping motor driving waveform example Ch1 IN1 10V/div Ch2 VOUT1 5V/div Ch3 VOUT2 5V/div Ch4 IOUT1 100mA/div T=1ms/div VCC=ENA=5V, SOF=open 2phase excitation, 1000pps 12/13 LB1848MC 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. 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