lb1836m Sanyo Semiconductor Corporation, lb1836m Datasheet - Page 4

• Manufacturer Part Number: lb1836m
• Description: Dual Low-voltage, Low-saturation, Bidirectional Motor Driver
• Manufacturer: Sanyo Semiconductor Corporation

Design Notes
Vcont pin
If large current flows on the power supply (V S ) line and the GND line, then in some applications and layouts,
misoperation due to line oscillation may result.
The modes during which large current flows are as follows :
• Motor surge current when the DC motor starts up or when it shifts rotation directions (forward ↔ reverse).
• Passthrough current generated within the IC when shifting rotation directions (forward ↔ reverse) or when shifting
The following points should be kept in mind regarding the pattern layout :
• Keep the wiring lines thick and short in order to reduce wiring inductance between the power supply (V S ) and GND.
• Insert a passthrough capacitor near the IC. (Maximum effect is obtained by inserting the passthrough capacitor
• If the CPU and the LB1836M are mounted on separate boards and the difference between the ground potential of each
As shown in the above diagram, the Vcont pin outputs the voltage of the band gap Zener V Z + V F (=1.93V).
In normal use, this pin is left open.
The drive current ID is varied by the Vcont voltage. However, because the band gap Zener is shared, it functions as a
bridge.
from forward/reverse rotation to braking, or vice versa.
between VS and the pin 7 GND at the closest distance possible.
board is large, install resistors of about 10kΩ in series between the CPU and the LB1836M inputs.
IN
V CC
Vcont
V Z
I D
M
OUT
OUT
LB1836M
I D =
V S
V Z
r (= constant)
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