SM5301 Datasheet, PDF (10/12 Pages) Nippon Precision Circuits Inc – 3-channel Video Buffer with Built-in Wideband Filters

SM5301AS
TYPICAL APPLICATION CIRCUITS
ATSC Digital TV Application
SYNC
RIN/YIN
GSR1
1.0µF
(*4)
Cut-off
control voltage
(*1)
+5V
(*3)
+
R/Y
220µF 75Ω
(*2)
(*2)
GIN/UIN
(*1)
(*1)
1.0µF
GSG1
(*4)
BIN/VIN
1.0µF
GSB1
(*4)
DISABLE
+
220µF 75Ω
(*2)
(*2)
+
220µF 75Ω
G/U
B/V
(*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 47µF 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
The capacitor connected to pins R_INA/Y_INA, R_INB/Y_INB, G_INA/U_INB, G_INB/U_INB, B_INA/V_INA, and B_INB/V_INB
forms a highpass filter (HPF) with the internal impedance.
The HPF cutoff frequency is given by the following equation.
fc = ¹
2πCR
(C: input capacitance, R: signal input impedance = 9.3kΩ)
NIPPON PRECISION CIRCUITS INC.—10