SM5301BS Datasheet, PDF (13/15 Pages) Nippon Precision Circuits Inc – 3-channel Video Buffer with Built-in Wideband Filters with Filter Through Function

SM5301BS
TYPICAL APPLICATION CIRCUITS
ATSC Digital TV Application
Filter through
switch
RIN/YIN
GSR1
1.0µF
(*4)
Cut-off
control voltage
(*1)
+5V
(*3)
+
R/Y
220µF 75Ω
(*2)
(*2)
(*6)
GIN/UIN
(*1)
1.0µF
GSG1
(*4)
BIN/VIN
1.0µF
GSB1
(*4)
DISABLE
(*6)
(*1)
+
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) Connect a capacitor if an error occurs due to external noise for GSR1, GSG1, GSB1 pins. 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.
(*6) The tab (radiation fin) between 7 pin and 8 pin and between 21 pin and 22 pin should be connected to the
large ground plane as much as possible for radiation.
Input Capacitor and High Pass Filter 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 (typ))
SEIKO NPC CORPORATION —13