Data Sheet
26113
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
a73 Full-, Half-, Quarter-, Eighth-, or Sixteenth-Step Increments
a73 DC to 20 MHz Clock Input
a73 Power-On Reset
a73 Brown-Out Reset
a73 High-Speed CMOS Technology
a73 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
Supply Voltage, V
DD
.......................... 7.0 V
Input Voltage Range,
V
I
........................ -0.3 V to V
DD
+ 0.6 V
RESET Voltage, V
RESET
...................... 14 V
Input Clamp Current, I
IK
............... ±20 mA
Output Clamp Current, I
OK
............ ±20 mA
Operating Temperature Range,
T
A
.................................... 0°C to +70°C
Storage Temperature Range,
T
S
.............................. -55°C to +150°C
Caution: These CMOS devices have input
static protection (Class 3) but are still
susceptible to damage if exposed to extremely
high static electrical charges.
1
2
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7
8
9 10
11
12
13
14
15
16
17
18
Dwg. PP-071A
MODE SELECT0
DIRECTION
CONTROL IN
OSC/CLOCK IN
OSC/CLOCK OUT
SUPPLYVDD
PFDA
PHASEA
PFDB
PHASEB
MODE SELECT1
MODE SELECT2
STEP IN
RESET
GROUND
MONITOR OUT
SHIFT CLOCK
SERIAL DATA OUT
STROBE OUT
A4255CA