SM5304AV

SEIKO NPC CORPORATION —7

Gain Control Function and Enable Function

When setting GSEL pin to open, in order to prevent incorrect operation by the external noise, it recommends connecting a capacitor between GSEL pin

and GND pin.

Equivalent circuit

The equivalent circuit of GSEL pin and ENABLE pin is shown in figure. GSEL pin is connected only to pull-

down resistor in the state of disable.

ENABLE pin

GSEL pin

Gain setting

HIGH

(Enable)

LOW

6dB

Open

0dB

HIGH

12dB

LOW

(Disable)

LOW

High impedance output

Open

HIGH

ENABLE

3-level

decoder

GSEL