MV1001SC

28

5.3.2

Example of dimming circuit in high-side drive configuration

For dimming using a high-side drive configuration, a signal must be applied to the REF pin with the GND of the IC

(S.GND) as a reference, distinct from the circuit GND. Figure 25 shows an example of a high-side drive dimming circuit

the formulas given below.

To ensure the IC operates in the minimum dimming region when Q201 is turned on, set the value of resistors R203 +

(typical).

is applied to the REF pin. Adjust the capacitance levels of C201 and C202 to 1 uF or less while checking dimming

characteristics.

Figure 25 Example of dimming circuit in high-side drive configuration





202

R

201

R

R202

V

H

_

V

DD

REF











204

R

203

R

ref

_

I

L

_











L

_

V

Don

1

H

_

V

Don

V

REF

REF

REF











CAT.No.1A0102-1E