24-pin plastic DIP package, narrow

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.

Figure 1. Block diagram.

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.

RC

PBL 3776/1

V

CC

V

CC

S

R

Q

Logic

S

R

Q

+

–

+

–

+

–

Logic

Phase 2

Phase 1

Dis2

C2

SGND 2

Pwr GND 2

1BL

T

1AU

T

1AL

T

BB2

V

2AU

T

2AL

T

2BL

T

Dis 1

C1

SGND 1

Pwr GND 1

1

February 1999

1