SM5301AS

NIPPON PRECISION CIRCUITS INC.—10

TYPICAL APPLICATION CIRCUITS

ATSC Digital TV Application

(*1) Pins without an input signal, set by NUXSEL, should be left open or tied to GND.

(*2) Connect 4

× 0.1µF capacitor between the supply pins close to the IC.

(*3) Connect a 47

µF capacitor between the supply pins close to the IC.

(*4) GS

×1 are 3-level pins. Connect a capacitor if an error occurs due to external noise. Also, if open-circuit,

the internal impedance and external capacitance (C) form an RC network. When power is applied, the

open-circuit potential rises with time constant

τ = C × 10k (sec).

(*5) Printed circuit board supply wiring

I

If the supply is used for other digital circuits, there is a possibility that noise will be introduced. Accord-

ingly, these circuits should be connected to the application’s analog supply.

I

Ground-plane wiring should be performed, as much as possible, to provide low GND line impedance.

I

If ground-plane wiring up to the GND pins is difficult, the ground plane should be as close to the IC as

possible with a separate wire to each GND pin.

Input Capacitor and Cutoff Frequency

forms a highpass filter (HPF) with the internal impedance.

The HPF cutoff frequency is given by the following equation.

(C: input capacitance, R: signal input impedance = 9.3k

Ω)

Cut-off

control voltage

+5V

(*2)

(*3)

1.0

µF

1.0

µF

(*1)

(*4)

GSB1

DISABLE

(*1)

(*2)

220

µF

B/V

+

75

Ω

220

µF

R/Y

+

75

Ω

(*4)

GSG1

(*4)

GSR1

1.0

µF

SYNC

(*1)

(*2)

(*2)

220

µF

G/U

+

75

Ω

fc =

1

2

πCR