NJM3776

NJM3776 DUAL CONTROLLER FOR HIGH-CURRENT STEPPER MOTOR s GENERAL DESCRIPTION The NJM3776 is a switch-mode (chopper), constant-current controller intended for controlling external transistors in a high current stepper motor application. The NJM3776 has two channels, one for each winding of a two-phase stepper motor. The NJM3776 is equipped with a Disable input to simplify half stepping operation. The NJM3776 contains a clock oscillator, which is common for both driver channels, a set of comparators and flip-flops implementing the switching control, and two output sections each containing four outputs, two source and two sink, intended to drive an external Hbridge. Voltage supply requirements are +5 V for logic and +10 to +45 V for the outputs. s PACKAGE OUTLINE NJM3776D2 s FEATURES Suitable to drive any external MOS FET or bipolar power transistor Cross conduction prevented by time delay Digital filter on chip eliminates external filtering components Package DIP24 s BLOCK DIAGRAM Phase 1 Dis 1 V R1 C1 SGND 1 Pwr GND 1 1 NJM3776 – T1BL R S Q T1AL T1AU Logic T1BU V CC V CC + VBB1 + – V BB2 T2BU Logic RC + – T2AU T 2AL T2BL S R Q Phase 2 Dis 2 V R2 C2 SGND 2 Pwr GND 2 Figure 1. Block diagram NJM3776 s PIN CONFIGURATION PWR GND 1 1 T1BL 2 T1BU 3 T1AL 4 T1AU 5 VBB1 6 SGND 1 7 VR1 8 C1 9 Phase 1 10 Dis 1 11 RC 12 24 PWR GND 23 T2BL 22 T2BU 21 T2AL 20 T2AU 2 NJM 3776D2 19 VBB 2 18 SGND 17 VR 16 C 2 2 2 2 15 Phase 14 Dis 13 Vcc 2 Figure 2. Pin...