ML4423
PIN DESCRIPTION
PIN
NAME
FUNCTION
PIN
NAME
FUNCTION
1
FB A
Differential input which, in
conjunction with FB C, feeds back the
voltage applied across motor winding
A-C.
Input which feeds back the voltage
applied to motor winding C. Reference
voltage for windings A and B.
Differential input which, in
conjunction with FB C, feeds back the
voltage applied across motor winding
B-C.
The voltage on this pin sets the
minimum sinewave amplitude at low
speeds.
The voltage on this pin sets the
frequency and amplitude of the
sinewaves generated at SINE
A
and
SINE
B
.
An external resistor to ground provides
a variable current to the sinewave
generator. The current is proportional
to V
SPEED
.
8V reference output which can be
used for setting V
SPEED
and V
MIN
.
An external resistor to ground provides
a constant current used for setting the
PWM frequency in conjunction with
C
T
.
An external resistor to ground sets the
deadtime in the output stage to
prevent cross-conduction in the power
devices.
A test output for observing the
internally generated sinewave used for
motor winding A-C.
A test output for observing the
internally generated sinewave used for
motor winding B-C.
An external capacitor to ground sets
the sinewave frequency in conjunction
with V
SPEED
and R
SPEED
.
13
C
T
An external capacitor to ground sets
the PWM triangle frequency in
conjunction with the external resistor
R
REF
.
A logic low input causes all output
drive transistors to turn OFF. An
internal pull-up drives
COAST
to V
DD
if left unconnected.
A logic high input causes phase A to
lead phase B, while a logic low input
causes phase A to lag phase B. An
internal pull-up drives F/R to V
DD
if
left unconnected.
Motor current sense input.
Signal and power ground.
Leaving this pin unconnected selects
3-phase drive. Connecting this pin to
V
DD
selects single/2-phase drive.
Low side drive output for phase B.
Low side drive output for phase C.
Low side drive output for phase A.
High side drive output for phase B.
High side drive output for phase C.
High side drive output for phase A.
Input to select 5V or 12V output drive.
Leaving this pin unconnected selects
5V output drive levels at the driver
outputs. Connecting this pin to V
CC
selects 12V output drive levels at the
driver outputs.
12V power supply input.
An external capacitor to ground sets a
pole in the feedback loop.
An external capacitor to ground sets a
pole in the feedback loop.
2
FB C
14
COAST
3
FB B
15
F/R
4
V
MIN
16
17
18
I
SENSE
GND
3PH/2PH
5
V
SPEED
6
R
SPEED
19
20
21
22
23
24
25
LB
LC
LA
HB
HC
HA
5V/12V
SELECT
7
8
V
REF
R
REF
9
R
DT
10
SINE A-C
26
27
28
V
DD
C
GM1
C
GM2
11
SINE B-C
12
C
O
3
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
