PBL3776-1

February 1999 PBL 3776/1 Dual Controller IC for High Current Stepper Motor Applications Description The PBL 3776/1 is a switch-mode (chopper), constant-current controller IC intended for controlling external transistors in a high current stepper motor application.The IC has two channels one for each winding of a two-phase stepper motor. The circuit is similar to Ericsson´s PBL 3775/1. PBL 3776/1 is equipped with a Disable input to simplify half-stepping operation. The PBL 3776/1 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 H-bridge. Voltage supply requirements are +5 V for logic and +10 to +45 V for the outputs. The close match between the two driver channels guarantees consistent output current ratios and motor positioning accuracy. Key Features Suitable to drive any external Mos Fet or bipolar power transistor. 0°C to +85°C operation. Few external components. Crossconduction prevented by time delay. Close matching between channels for high positioning accuracy. Digital filter on chip eliminates external filtering components. Plastic 24-pin "narrow" DIP package. Phase 1 Dis 1 V R1 C1 SGND 1 Pwr GND 1 1 PBL 3776/1 – T1BL R S Q T1AL T1BU T1AU Logic V CC V CC + + – V BB2 T2BU Logic RC + – T2AU T 2AL T2BL S R Q 24-pin plastic DIP package, nar...