PBL 3774/1
26
Phase
2
RC
1
C
2 2
V
R2 3
22
V
CC
21
C
1
20
V
R1
19
Phase
1
18
GND
3
GND
2
GND
1
GND
28
GND
27
Dis
2
4
M
A2
V
MM2 5
E
2 6
M
B2 7
M
B1 8
GND
9
E
1 10
V
MM1 11
25
24
23
V
R2
C
2
RC
V
CC
C
1
V
R1
Phase
1
Phase
2 4
GND
5
GND
6
Dis
2 7
M
A2 8
V
MM2 9
PBL 3774/1QN
22
21
20
19
PBL
3774/1N
17
GND
16
Dis
1
15
M
A1
14
V
MM1
13
E
1
12
M
B1
M
A1 12
GND
13
GND
14
GND
15
GND
16
GND
17
Dis
1 18
E
2 10
M
B2 11
Figure 4. Pin configuration.
Pin Description
PLCC
DIP
Symbol
Description
1-3, 9, 5, 6
GND
13-17 17, 18
28
4
5
6
7
8
10
11
12
18
19
20
21
8
9
10
11
12
13
14
15
16
19
20
21
M
A2
V
MM2
E
2
M
B2
M
B1
E
1
V
MM1
M
A1
Dis
1
Phase
1
V
R1
C
1
Ground and negative supply. Note: these pins are used thermally for heat-sinking. Make sure that all
ground pins are soldered onto a suitably large copper ground plane for efficient heat sinking.
Motor output A, channel 2. Motor current flows from M
A2
to M
B2
when Phase
2
is HIGH.
Motor supply voltage, channel 2, +10 to +40 V.V
MM1
and V
MM2
should be connected together.
Common emitter, channel 2. This pin connects to a sensing resistor R
S
to ground.
Motor output B, channel 2. Motor current flows from M
A2
to M
B2
when Phase
2
is HIGH.
Motor output B, channel 1. Motor current flows from M
A1
to M
B1
when Phase
1
is HIGH.
Common emitter, channel 1. This pin connects to a sensing resistor R
S
to ground.
Motor supply voltage, channel 1, +10 to +40 V. V
MM1
and V
MM2
should be connected together.
Motor output A, channel 1. Motor current flows from M
A1
to M
B1
when Phase
1
is HIGH.
Disable input (TTL level compatible) for channel 1. When HIGH, all four output transistors are turned off,
which results in a rapidly decreasing output current to zero.
Controls the direction of motor current at outputs M
A1
and M
B1
. Motor current flows from M
A1
to M
B1
when
Phase
1
is HIGH.
Ref. voltage, channel 1. Controls the threshold voltage for the comparator and hence the output current.
Comparator input channel 1. This input senses the instantaneous voltage across the sensing resistor,
filtered by an RC network. The threshold voltage for the comparator is V
CH1
= 0.18 • V
R1
[V], i.e. 450 mV
at V
R1
= 2.5 V.
Logic voltage supply, nominally +5 V.
Clock oscillator RC pin. Connect a 15 kohm resistor to V
CC
and a 3300 pF capacitor to ground to obtain
the nominal switching frequency of 26.5 kHz.
Comparator input channel 2. This input senses the instantaneous voltage across the sensing resistor,
filtered by an RC network. The threshold voltage for the comparator is V
CH2
= 0.18 • V
R2
[V], i.e. 450 mV at
V
R2
= 2.5 V.
Ref. voltage, channel 2. Controls the threshold voltage for the comparator and hence the output current.
Controls the direction of motor current at outputs M
A2
and M
B2
. Motor current flows from M
A2
to M
B2
when
Phase
2
is HIGH.
Disable input (TTL level compatible) for channel 2. When HIGH, all four output transistors are turned off,
which results in a rapidly decreasing output current to zero.
22
23
24
22
1
2
V
CC
RC
C
2
25
26
27
3
4
7
V
R2
Phase
2
Dis
2
4
ERICSSON [ ERICSSON ]
