鈥?/div>
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
V
DD
(+V)
F/R
S3
S2
S1
BRAKE
BRAKE SELECT
PWM CONTROL
TOP DRIVER POLARITY SELECT
V
R
V
SS
(-V)
OUT 1
OUT 2
OUT 3
HALL
SENSORS
ENABLE 2
3
4
5
6
7
8
9
LS7560N
CURRENT SENSE (+) 10
CURRENT SENSE (-) 11
OUT 6 12
OUT 5 13
OUT 4 14
S1, S2, S3 Inputs
(Pins 24, 25, 26)
Hall Sensor inputs which are decoded to determine the Motor
Commutation Sequence. An invalid input code disables all motor
outputs. Inputs have Schmitt Trigger buffers for noise immunity.
BRAKE Input
(Pin 23)
With the Brake Select input Low, a High on the Brake input forces
the Top Drivers to an Off condition and the Bottom Drivers to a
PWM On condition. If the Motor is under Closed Loop control, the
Loop must be opened and the error amplifier output connected to
the Error Amp (-) input. By controlling the voltage at the Error Amp
(+) input, the PWM duty cycle is controlled during braking (see Fig-
ure 8). This manner of braking prevents the Bottom Motor Drivers
from drawing excessive current, a condition which can occur during
normal braking, when the Bottom Drivers are turned ON un-
conditionally. With the Brake Select input High, a High on the
Brake input unconditionally causes the Top Drivers to turn Off and
the Bottom Drivers to turn On. The Brake function has priority over
all other functions.
BRAKE SELECT Input
(Pin 22)
A Low on this input selects PWM control of braking and a High se-
lects unconditional braking.
ENABLE Input
(Pin 2)
When the Enable input is above V
R
/2, all Output Drivers are en-
abled and when it is below V
R
/2.2, all Output Drivers are disabled.
This input has a nominal hysteresis of 0.05V
R
, where V
R
is the in-
ternally generated Reference Voltage available on Pin 19. Because
the Enable input is level sensitive, it can easily be used to control
operation of the IC based on an Analog Fault Condition.
1
2
3
4
5
6
7
8
