NJM3772 DUAL STEPPER MOTOR DRIVER n GENERAL DESCRIPTION n PACKAGE OUTLINE The NJM3772 is a stepper motor driver, which circuit is especially developed for use in microstepping applications in conjunction with the matching dual DAC (Digital-to-Analog Converter) NJU39610. The NJM3772 contains a clock oscillator, which is common for both driver channels, a set of comparators and flip-flops implementing the switching control, and two H-bridges with internal recirculation diodes. Voltage supply requirements are +5 V for logic and +10 to +45V for the motor. Maximum output NJM3772FM2 NJM3772D2 current is 1000mA per channel. n FEATURES Dual chopper driver 1000mA continuous output current per channel Specially matched to the Dual DAC NJU39610 Packages DIP22 / PLCC28 n BLOCK DIAGRAM E Phase V C V 1 1 R1 1 MM1 NJM 3772 V V CC CC R Q + S M A1 M Logic B1 V BB1 + V BB2 M B2 Logic M A2 RC S Q + R Phase V C GND V E 2 R2 2 MM2 2 Figure 1. Block diagramNJM3772 n PIN CONFIGURATIONS RC 1 22 V CC C 2 21 C 2 1 V 3 20 V R2 R1 V 5 25 V BB2 R2 Phase 4 19 Phase 2 1 E 6 24 C 2 2 M 7 23 RC B2 GND 5 18 GND M 8 22 V B1 CC NJM NJM3772FM2 GND 6 17 GND GND 9 21 C 1 3772D2 E 10 20 V 1 R1 V 7 16 V MM2 MM1 V 11 19 Phase BB1 1 M 8 15 M A2 A1 V 9 14 V BB2 BB1 E 10 13 E 2 1 M 11 12 M B2 B1 Figure 2. Pin configurations n PIN DESCRIPTION PLCC DIP Symbol Description 1-3, 9, 5, 6 GND Ground and negative supply. Note: these pins are used thermally for heat-sinking. 13-17 17, 18 Make sure that all ground pins are soldered onto a suitably large copper ground 28 plane for efficient heat sinking. 48 M Motor output A, channel 2. Motor current flows from M to M when Phase is HIGH. A2 A2 B2 2 59 V Collector of upper output transistor, channel 2. For lowest possible power dissipation, connect a BB2 series resistor R to V . See Applications information, External components. B2 MM2 610 E Common emitter, channel 2. This pin connects to a sensing resistor R to ground. 2 S 711 M Motor output B, channel 2. Motor current flows from M to M when Phase is HIGH. B2 A2 B2 2 812 M Motor output B, channel 1. Motor current flows from M to M when Phase is HIGH. B1 A1 B1 1 10 13 E Common emitter, channel 1. This pin connects to a sensing resistor R to ground. 1 S 11 14 V Collector of upper output transistor, channel 1. For lowest possible power dissipation, connect a BB1 series resistor R to V . See Applications information, External components. B1 MM1 12 15 M Motor output A, channel 1. Motor current flows from M to M when Phase is HIGH. A1 A1 B1 1 18 16 V Motor supply voltage, channel 1, +10 to +40 V. V and V should be connected together. MM1 MM1 MM2 19 19 Phase Controls the direction of motor current at outputs M and M . Motor current flows from M to M 1 A1 B1 A1 B1 when Phase is HIGH. 1 20 20 V Reference voltage, channel 1. Controls the threshold voltage for the comparator and hence the R1 output current. 21 21 C Comparator input channel 1. This input senses the instantaneous voltage across the sensing 1 resistor, filtered by an RC network. The threshold voltage for the comparator is V = 0.18 V V , CH1 R1 i.e. 450 mV at V = 2.5 V. R1 22 22 V Logic voltage supply, nominally +5 V. CC 23 1 RC Clock oscillator RC pin. Connect a 15 kohm resistor to V and a 3300 pF capacitor to ground to CC obtain the nominal switching frequency of 26.5 kHz. 24 2 C Comparator input channel 2. This input senses the instantaneous voltage across the sensing 2 resistor, filtered by an RC network. The threshold voltage for the comparator is V = 0.18 V V , CH2 R2 i.e. 450 mV at V = 2.5 V. R2 25 3 V Reference voltage, channel 2. Controls the threshold voltage for the comparator and hence the R2 output current. 26 4 Phase Controls the direction of motor current at outputs M and M . Motor current flows from M to M 2 A2 B2 A2 B2 when Phase is HIGH. 2 27 7 V Motor supply voltage, channel 2, +10 to +40 V.V and V should be connected together. MM2 MM1 MM2 M 12 4 M A1 A2 GND 13 3 GND GND 14 2 GND GND 15 1 GND GND 16 28 GND GND 17 27 V MM2 V 18 26 Phase MM1 2