la6538t Sanyo Semiconductor Corporation, la6538t Datasheet - Page 4

• Manufacturer Part Number: la6538t
• Description: Single-phase Bipolar Linear Drive For Fan Motor
• Manufacturer: Sanyo Semiconductor Corporation

Sample Application Circuit
Note: 1. When the diode Di is used to prevent device destruction from reverse connection, the capacitor Cr must be
Block Diagram
2. The Hall element is biased at a constant voltage of approximately 2.1V from the HB pin. Thus the LA6538T
3. If the Hall bias is taken from V CC , bias the Hall device at 1/2 V CC as shown in the figure.
4. This pin must be left open if unused.
inserted to assure a path for regenerative currents. Similarly, if there are no nearby capacitors on the fan power
supply line, the capacitor Cr is also required to increase reliability.
provides a stable Hall output with excellent temperature characteristics. The resistor R1 adjusts the Hall output
amplitude.
The LA6538T implements linear drive by amplifying the Hall output and applying voltage control to the motor
coils. Startup characteristics and efficiency are improved by using a higher Hall device output. However, the
motor can be made to operate more quietly by adjusting the Hall device.
V CC
2.1 V RG
H
HB
GND
Devices on the
printed circuit board
IN +
IN -
*1
500Ω
Di
R1
*2
H
Cr
180kΩ
HB
IN --
IN +
LA6538T
GND
OUT1 OUT2
V CC
OUT1
OUT2
FG
ILA00207
180kΩ
*4
500Ω
R2
R2
ILA00209
V CC
H
*3
ILA00208
FG
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