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