8-BIT

MICROCONTROLLER

The A4255CA and A4255CLN microcontrollers make designing

with step motors easy, inexpensive, and productive. A reference design

technique is integral to the implementation of a system that includes the

power circuitry, a low-cost, 8-bit, preprogrammed microcontroller and

the other components needed to complete the control hardware. The

A4255Cx eliminates the need for software development, expedites the

product creation, and hastens the time to market.

The reference design can be utilized directly or integrated into a

larger printed wiring board. A further benefit is the compactness of the

circuit layout. Power-driver output ratings presently available with these

devices are 50 V and

±1.5 A (with the A3955 or A3957). A similar

device for 46 V and either 1.5 A (with the SLA7042M) or 3 A (with the

SLA7044M) is planned. The reference design supports stepping formats

that include full-step, half-step, quarter-step, eighth-step, and sixteenth-

step (microstepping) increments for a two-phase stepping motor.

The A4255CA is furnished in an 18-pin dual in-line plastic package

for through-hole applications. The A4255CLN is furnished in a 20-lead

wide-body, shrink-pitch, small-outline plastic package (SSOP) with gull-

wing leads for minimum area, surface-mount applications.

FEATURES

I Full-, Half-, Quarter-, Eighth-, or Sixteenth-Step Increments

I DC to 20 MHz Clock Input

I Power-On Reset

I Brown-Out Reset

I High-Speed CMOS Technology

I Low Power, <20 mA @ 5 V, 20 MHz

(Typically 9 mA)

4255

Always order by complete part number:

Part Number

Package

A4255CA

18-pin DIP

A4255CLN

20-lead shrink-pitch SOIC

ABSOLUTE MAXIMUM RATINGS

Input Voltage Range,

Operating Temperature Range,

Storage Temperature Range,

Caution: These CMOS devices have input

static protection (Class 3) but are still

susceptible to damage if exposed to extremely

high static electrical charges.

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18

Dwg. PP-071A

DIRECTION

CONTROL IN

OSC/CLOCK IN

OSC/CLOCK OUT

SUPPLY

STEP IN

RESET

GROUND

MONITOR OUT

SHIFT CLOCK

SERIAL DATA OUT

STROBE OUT

A4255CA