MITSUBISHI <CONTROL / DRIVER IC> M54670P 2-PHASE STEPPER MOTOR DRIVER DESCRIPTION PIN CONFIGURATION (TOP VIEW) The M54670P is a semiconductor IC to drive a bipolar stepper motor directly by controlling the coil current with the constant current method. Triangular wave CT 1 FEATURES Comparator reference input(B) Output current 30 Ph(B) direction switching(B) Output power 29 VMM1(B) supply(B) 31 VR(B) O1(A) 5 Output(A) 28 O1(B) Output(B) 6 27 7 26 M54670P ● Wide operating voltage range (10 – 35V) ● Wide output current control range (20 – 800mA) ● Bipolar and constant current drive ● Built in flywheel ● Current level can be changed by steps or continuously. ● Built in a thermal shutdown circuit 8 GND APPLICATION 9 Office automation equipment such as printer, FDD, HDD, and FAX Current sensor(A) E(A) 11 Output(A) O2(A) 12 The M54670P can drive a stepper motor by the 2-phase bipolar method and also control the coil current. Furthermore, it controls the direction of the coil current with Ph input pins (pins 3 and 30). The coil current value can be selected among four levels (0 to max.) by selecting the combination of three internal comparators by logic input (pins 14, 15, 18 and 19). It also can be continuously controlled with VR pins (pins 2 and 31). By selecting an I input pin among pins 14, 15, 18 or 19, the operation timing, 2-phase excitation, 1-2-phase excitation or microstep, can be selected. Because two control circuits are built in this IC, a stepper motor can be driven with a single IC by the 2-phase bipolar method. Output power supply(A) VMM2(A) Output current I0(A) value setting(A) Output current I1(A) value setting(A) Comparator C(A) input(A) 23 Current sensor(B) 21 O2(B) Output(B) Output power 13 20 VMM2(B) supply(B) 14 19 I0(B) 15 18 I1(B) 16 17 C(B) VMM1(A) Output power supply(A) O1(A) Output(A) O2(A) Output(A) VMM2(A) Output power supply(A) VMM1(B) Output power supply(B) O1(B) Output(B) O2(B) Output(B) VMM2(B) Output power supply(B) Ph(B) Output current direction switching(B) VR(B) Comparator input(B) 4 5 12 13 29 28 21 20 30 31 Control circuit Ph(A) Output current direction switching(A) 3 Control circuit VCC Circuit power supply 32 Output current value setting(B) 19 I0(B) 18 Output current value TSD 00 10 01 11 11 01 10 setting(B) I1(B) 00 23 – – 10 Output current value setting(B) Output current value setting(B) Comparator input(B) Outline 32P4B 6 GND 22 E(B) 2 Output current value setting(A) I0(A) 14 Output current value 15 setting(A) I1(A) GND 24 VR(A) Comparator reference input(A) BLOCK DIAGRAM 25 10 FUNCTION Circuit power supply 32 VCC Comparator reference input(A) VR(A) 2 Output current direction switching(A) Ph(A) 3 Output power supply(A) VMM1(A) 4 Power supply sensor 16 C(A) Comparator input(A) Triangular wave 1 CT Triangular wave Power supply sensor 11 E(A) 22 E(B) Current sensor(B) Current sensor(A) GND 27 17 C(B) Comparator input(B) MITSUBISHI <CONTROL / DRIVER IC> M54670P 2-PHASE STEPPER MOTOR DRIVER ABSOLUTE MAXIMUM RATINGS (Ta=25°C, unless otherwise noted) Symbol VCC VMM VI VC VR IO Pd Topr Tstg Parameter Conditions Supply voltage Output supply voltage Logic circuit input voltage Comparator input voltage Reference input voltage Output current Allowable power dissipation Operating temperature Storage temperature Mounted on a board Ratings Unit -0.3 – 7 -0.3 – 40 -0.3 – 6 VCC 7 ±1.0 1.92 -20 – 75 -55 – 125 V V V V V A W °C °C RECOMMENDED OPERATING CONDITIONS (VCC=5.0V, Ta=25°C, unless otherwise noted) Symbol VCC VMM VR IO tPLH tPHL TON Parameter Min. 4.75 10 0 20 Supply voltage Output supply voltage Reference input voltage Output current Logic input rise time Logic input fall time Thermal shutdown temperature * Limits Typ. 5.00 — Max. 5.25 35 5 800 2.0 2.0 175 Unit V V V mA µs µs °C * : Refer to "PRECAUTIONS FOR USE." ELECTRICAL CHARACTERISTICS (VCC=5.0V, VMM=10V, Ta=25°C, unless otherwise noted) Symbol VIH VIL VCH VCM VCL ICO IOFF Vsat fc td ICC IIH IIL Parameter Logic input voltage Test conditions “H” “L” VR=5V, I0=I1=0 VR=5V, I0=1, I1=0 VR=5V, I0=0, I1=1 I0=I1=1(Ta=25°C) Comparator threshold Comparator input current Output cutoff current Saturation voltage Voltage at sensing resistor is not included. I0=500mA PWM oscillator frequency Turn-off delay Supply current Logic input current VCC=5V “H” “L” VMM=10V, Cf=3900pF Ta=25°C, dV/dt≥50mV/µs VCC=5V VI=2.4V VI=0.4V Min. Limits Typ. Unit — 460 285 110 -2 0 Max. VCC 0.8 480 305 130 20 100 — 3.0 4.5 V 16.5 33 1.0 8.0 180 20 66 2.0 25 400 50 kHz µs mA µA µA 2.0 0 430 265 90 -20 — — — — — — V V mV mV mV µA µA MITSUBISHI <CONTROL / DRIVER IC> M54670P 2-PHASE STEPPER MOTOR DRIVER APPLICATION DESCRIPTION (1) PHASE INPUT TIMING CHART 2-phase excitation Phase input decides the output mode. PHASE O1 O2 H L H L H L Phase 1 Phase 2 I0, 1(A) = 0 I0, 1(B) = 0 (2) I0, I1 I0 and I1 fixed based on the comparative voltage VR decide the 1-2-phase excitation output current level. Phase 1 Phase 2 I0 I1 Current level H H 0 L H Low H L Typ L L High I0, 1(A) I0, 1(B) Microstep Phase 1 Phase 2 I0(A) (3) VR (Comparative voltage) I1(A) The current level can be continuously changed by changing the I0(B) voltage at VR continuously. I1(B) (4) Current sensor When the voltage fall at the current sensing resistor and the selected current level become of the same level, the output state is cut off for a certain time by inverting the comparator. During this cutoff time, the current volume decreases slightly due to the L component of the motor and falls short of the comparative level. During the time fixed based on the PWM frequency, the output stage goes in ON state and then in OFF state and this ON/OFF operation is repeated. (5) PWM oscillator A capacitor Cf is externally connected to CT pin in order to fix the PWM oscillator frequency. The frequency fc is calculated as follows. fc = 1 7.77 x 103 x Cf (6) Analog control The output current level can be continuously changed by changing the voltage at VR or the feedback voltage to the comparator. (7) Thermal shutdown function This IC has a function to protect itself against thermal damage which is caused when the chip temperature rises abnormally. Regarding this function, refer to “PRECAUTIONS FOR USE.” MITSUBISHI <CONTROL / DRIVER IC> M54670P 2-PHASE STEPPER MOTOR DRIVER TYPICAL CHARACTERISTICS (ABSOLUTE MAXIMUM RATINGS) Safety operating range 1.0 A : Recommended Output current IO (A) 0.8 B : Schottky diodes should be externally connected between output pin and power supply pin. B 0.6 C : Schottky diodes should be externally connected between output pin and power supply pin and between output pin and GND pin. 0.4 A 0.2 0 10 0 C 20 30 50 35 40 Output VMM (V) Thermal derating θj-c = 20°C/W C Allowable power dissipation (W) 4.0 A : Free air (θc-a = 50°C/W) B : With 10cm2 aluminum heat (θc-a = 25°C/W) 3.0 B C : With 100cm2 aluminum heat (θc-a = 10°C/W) 2.0 A Tj(max) = 150°C 1.0 0 0 10 20 30 40 50 Ambient (°C) 60 70 80 MITSUBISHI <CONTROL / DRIVER IC> M54670P 2-PHASE STEPPER MOTOR DRIVER APPLICATION EXAMPLE (Stepping motor driver) VR 1 CT VCC 32 2 VR(A) VR(B) 31 3 Ph(A) Ph(B) 30 4 VMM1(A) VMM1(B) 29 5 O1(A) O1(B) 28 VCC Cf Phase A 6 27 7 26 GND 9 M54670P 8 GND 25 23 E(A) E(B) 22 RS RS RC IN(A) VMM 40µF/50V 0.01 µF 24 10 11 Phase B 12 O2(A) O2(B) 21 13 VMM2(A) VMM2(B) 20 14 I0(A) I0(B) 19 15 I1(A) I1(B) 18 RC IN(B) CC CC 16 C(A) C(B) 17 Cf = 3900pF RS = 0.51Ω RC = 1kΩ CC = 820pF Stepper motor (3.7mH / 6Ω / phase) MITSUBISHI <CONTROL / DRIVER IC> M54670P 2-PHASE STEPPER MOTOR DRIVER PRECAUTIONS FOR USE (1) When the whole output current changes by a large margin (for example, when thermal shutdown operation causes intermittent flow of output current), the supply voltage may undergo a change. Therefore, selection and wiring of power supply should be conducted cautiously to avoid such a situation that the supply voltage exceeds the absolute maximum ratings. (2) When the supply voltage changes by a large margin, the operation of this IC may become unstable. In this case, the change of supply voltage can be controlled by connecting a capacitor between Vcc pin and GND pin. (3) Thermal shutdown function The state of thermal shutdown operation may differ according to the way of wiring within a board. Therefore, sufficient board evaluation should be conducted before use. When the board is changed, operation on the replacing board should be evaluated. The circuit board on which this IC is mounted is designed to realize low impedance between power supply and output pin. Therefore, it is desirable to take a safe measure such as fixing a fuse to avoid such a situation that the board is damaged by a fire when output pin is internally short-circuited by excessively applied surge voltage by accident.