HMP8170CN Intersil Corporation, HMP8170CN Datasheet - Page 31

• Manufacturer Part Number: HMP8170CN
• Description: NTSC/PAL Video Encoder
• Manufacturer: Intersil Corporation

For proper operation, power supply decoupling is required. It
should be done using a 0.1 F ceramic capacitor in parallel
with a 0.01 F chip capacitor for each group of V
ground. These capacitors should be located as close to the
V
If a separate linear regulator is used to provide power to the
HMP817x power plane, the power-up sequence should be
designed to ensure latchup will not occur. A separate linear
regulator is recommended if the power supply noise on the
AA
and GND pins as possible, using short, wide traces.
GND
GND
VCC
VCC
31
HMP8170, HMP8171, HMP8172, HMP8173
FERRITE
FERRITE
FIGURE 26. EXAMPLE POWER AND GROUND PLANES
BEAD
BEAD
FIGURE 26B. COMMON GROUND PLANE
FIGURE 26A. V
AA
BULK AREA
BULK AREA
CAPACITOR
CAPACITOR
pins to
VAA
VAA
CC
8154/8156A
8154/8156A
AND V
817x
817x
VAA pins exceeds 200mV. About 10% of the noise (that is
less than 1MHz) on the VAA pins will couple onto the analog
outputs.
External Reference Voltage
If an external reference voltage is used, its circuitry should
receive power from the same plane as the HMP817x. The
external VREF must also be stable and well decoupled from
the power plane. An example VREF circuit using a band gap
reference diode is shown in Figure 27.
AA
PLANES
FILTERS
FILTERS
FILTERS
FILTERS
LP
LP
LP
LP
ANALOG
ANALOG
ANALOG
ANALOG
CONN.
CONN.
CONN.
CONN.
PCB
PCB
PCB
PCB