SM5301BS NPC [Nippon Precision Circuits Inc], SM5301BS Datasheet - Page 13

• Manufacturer Part Number: SM5301BS
• Description: 3-channel Video Buffer with Built-in Wideband Filters with Filter Through Function
• Manufacturer: NPC [Nippon Precision Circuits Inc]

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 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-
(*5) Printed circuit board supply wiring
(*6) The tab (radiation fin) between 7 pin and 8 pin and between 21 pin and 22 pin should be connected to the
Input Capacitor and High Pass Filter Cutoff Frequency
The capacitor connected to pins R
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 = 9.3kΩ (typ))
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).
I
I
I
large ground plane as much as possible for radiation.
Filter through
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.
Ground-plane wiring should be performed, as much as possible, to provide low GND line impedance.
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.
DISABLE
fc =
G
R
B
switch
GSG1
GSR1
IN
GSB1
IN
IN
/U
/Y
/V
IN
IN
IN
2πCR
1.0µF
1.0µF
1.0µF
1
(*4)
(*4)
(*4)
(*1)
(*1)
INA
control voltage
/Y
Cut-off
INA
, R
(*1)
INB
SM5301BS
/Y
(*6)
(*6)
INB
, G
INA
/U
(*2)
(*2)
INB
, G
INB
(*3)
(*2)
/U
(*2)
INB
SEIKO NPC CORPORATION —13
, B
+5V
220µF
220µF
220µF
+
+
+
INA
/V
75Ω
75Ω
75Ω
INA
, and B
INB
R/Y
G/U
B/V
/V
INB