Low-saturation, current-controlled
bidirectional motor driver
Overview
The LB1843V is a low-saturation bidirectional motor driver
with output current limitation and detection functions. This
design is ideal for controlling the loading motor in a video
camera.
Features
.
Output current limiter and detector built in
.
Low-saturation voltage bidirectional bridge circuit built in:
V
O
sat = 0.40 V typ. at 400 mA
.
Practically no current drain (0.1 A or less) in standby mode
.
Input-linked reference voltage built in
.
Thermal shutdown circuit built in
.
Requires little space, since few external components are
needed and the IC is contained in a small SSOP-20 package
Package Dimensions
unit : mm
3179A-SSOP20
[LB1843V]
SANYO : SSOP20
Specifications
Absolute Maximum Ratings
at Ta = 25C
Parameter
Symbol
Conditions
Ratings
Unit
Maximum supply voltage
V
CC
max
10.5
V
Maximum output current
Im max
800
mA
Applied input voltage
V
IN
0.3 to +10
V
Allowable power dissipation
Pd max
With board ( 50
35
1.6 mm
3
)
800
mW
Operating temperature
Topr
20 to +80
C
Storage temperature
Tstg
40 to +150
C
Allowable Operating Ranges
at Ta = 25C
Parameter
Symbol
Conditions
Ratings
Unit
Supply voltage
V
CC
3.0 to 9.0
V
V
M
voltage
V
M
2.2 to V
CC
V
High-level input voltage
V
IH
3.0 to 9.0
V
Low-level input voltage
V
IL
0.3 to +0.7
V
LIR input voltage
V
LIR
0.5 to V
CC
1.0
V
Output current limitation
I
limit
50 to 350
mA
Ordering number: EN 4385B
Monolithic Digital IC
LB1843V
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
O3096HA(II) No.4385-1/6
Electrical Characteristics
at Ta = 25C, V
CC
= 7.2 V
Parameter
Symbol
Conditions
min
typ
max
Unit
Supply current
I
CC
0
During standby
0.1
10
A
I
CC
1
During bidirectional operation, no load
9
13
mA
I
CC
2
During braking
12
18
mA
Output saturation voltage
Vsat1
I
O
= 200 mA (upper side + lower side)
0.20
0.30
V
Vsat2
I
O
= 400 mA (upper side + lower side)
0.40
0.60
V
Reference voltage
Vref
I
V
ref = 1 mA
1.85
2.0
2.15
V
Set output current
I
limit
Resistance between V
CC
and V
M
= 1
,
when LIR = 2 V
165
185
205
mA
Input current
I
IN
V
IN
= 5 V
90
150
A
RD saturation voltage
V
RD
sat
I
O
= 1 mA
0.3
V
Output current limit is determined by the following equation (R
f
is the sensing resistance between V
CC
and V
M
):
I
limit
= V
LIR
/10R
f
(A)
The input range for V
LIR
is 0.5 to V
CC
1.0 (V)
Pd max Ta
Specified board (50
35
1.6 mm
3
glass epoxy)
Allowable
power
dissipation,
Pd
max
m
W
Ambient temperature, Ta C
LB1843V
No.4385-2/6
Block Diagram and Sample Application Ciruit
Pin Assignment
Thermal
shut down
Decoder
Limit detection
VCC = 3 to 10.5 V
R
f
= 0.47 to 2
0.001 F
to 0.01 F
Top view
Notes:
.
Connect both V
M
pins
(motor power supply/sensing pins).
.
Connect both P-GND pins
(motor power supply GND pins).
.
Connect S-GND (control power
supply GND pin) to the
microcontroller's GND.
LB1843V
No.4385-3/6
Truth Table
Input
Output
Mode
IN1
IN2
OUT1
OUT2
L
L
off
off
Standby
H
L
H
L
Forward
L
H
L
H
Reverse
H
H
L
L
Brake
Output Current Limitation and Detector Output
DEL
OUT output
RD
H
Limit
L
Non-limit
Off
L
Saturated
Off
Sample Application Timing Chart
Sample application timing chart
1 Connect a DC motor (R
L
= R
) between OUT1 and OUT2, and with the RD pin pulled up, input a forward rotation signal
(IN1 = high, IN2 = low).
Because the output is used in the saturated state at startup, set the DEL input to low.
2 The DC motor starts up, and the startup current (I
ST
= V
M
/R) flows to the motor.
3 The DC motor rotates in the normal state. At this point, set the DEL input to high.
4 If the DC motor locks, the motor current I
M
increases to the point of I
limit
(= V
LIR
/(10R
f
)), the output current limiter operates
to limit the output current. At the same time, RD is output low from the set current detection circuit.
LB1843V
No.4385-4/6
Reference voltage (Vref)
The Vref output is linked to the input; if either IN1 or IN2 is high, the reference voltage is output.
Output current limiter
The schematic for the output current limiter is shown below.
The output set current is set according to the reference voltage V
LIR
applied to the LIR pin. When V
LIR
is applied, 1/10 of that
voltage is generated at both ends of R
S
in the diagram; this voltage is input on the positive (+) side of the current setting
amplifier.
The motor current I
M
generates voltage equal to (I
M
R
f
) at both ends of the external resistor R
f
. This voltage is input to the
negative () side of the same amplifier, and the differential amplifier functions and the output transistors are driven so that these
inputs become equal.
The set current value in this instance is determined by the following equation:
I
limit
= V
LIR
/(10R
f
) [A]
Set current detector
(1) When DEL = high
If the motor current I
M
has not reached the set current I
limit
, the input voltage on the negative () side of the amplifier is
greater than the input voltage on the positive (+) side. As a result, the drive current increases and the output PNP transistors
reach the saturation state. If this state is detected, the detection signal is sent to the set current detector, and the RD output
goes high.
If the motor current I
M
reaches the set current I
limit
, the output PNP transistor enters the controlled state, and the RD output
goes low.
(2) When DEL = low
Because the operation of the current setting amplifier is cancelled when a low signal is input to the DEL pin, the output PNP
transistors reach the saturation state and the RD output goes high, just as in the case described above.
The following table summarizes the states described above.
DEL
OUT
RD
H
limit
L
Non-limit (saturated)
H
L
Saturated
H
Output Current Limiter and Set Current Detector Block Diagram
Set current
detector
LB1843V
No.4385-5/6
No products described or contained herein are intended for use in surgical implants, life-support systems,
aerospace equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and the like,
the failure of which may directly or indirectly cause injury, death or property loss.
Anyone purchasing any products described or contained herein for an above-mentioned use shall:
1
Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and
distributors and all their officers and employees, jointly and severally, against any and all claims and litigation
and all damages, cost and expenses associated with such use:
2
Not impose any responsibility for any fault or negligence which may be cited in any such claim or litigation on
SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of their officers and employees
jointly or severally.
Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guaranteed for
volume production. SANYO believes information herein is accurate and reliable, but no guarantees are made or
implied regarding its use or any infringements of intellectual property rights or other rights of third parties.
This catalog provides information as of October, 1996. Specifications and information herein are subject to change without notice.
I
CC
V
CC
Current
drain,
I
CC
m
A
Rf = 0.5
, no load
Brake
Bidirec-
tional
Supply voltage, V
CC
V
I
IN
V
IN
Input
current,
I
IN
A
Input voltage, V
IN
V
I
limit
V
LIR
Set
output
current,
I
limit
m
A
V
LIR
V
I
limit
V
CC
Set
output
current,
I
limit
m
A
Supply voltage, V
CC
V
V
O
(sat) I
O
Output
saturation
voltage,
V
O
(sat)
V
Output current, I
O
mA
V
O
(sat) Ta
Output
saturation
voltage,
V
O
(sat)
V
Ambient temperature, Ta C
LB1843V
No.4385-6/6
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