mc145220 Freescale Semiconductor, Inc, mc145220 Datasheet - Page 12

• Manufacturer Part Number: mc145220
• Description: Dual Frequency Synthesizer
• Manufacturer: Freescale Semiconductor, Inc

Use of a capacitor causes undesirable current spikes to ap-
pear on the phase detector output when invoking the standby
mode.
POWER SUPPLY PINS
V+ and V+
Positive Supply Potentials (Pins 9 and 12)
a portion of the serial port. V+
portion of the serial port. Both V+ and V+
same voltage level and may range from 2.7 V to 5.5 V with
respect to the GND and GND
MC145220
12
Do not use a decoupling capacitor on the Rx or Rx
V+ supplies power to the main PLL, reference circuit, and
i
i
i
pins.
supplies power to PLL
i
must be at the
i
and a
i
pin.
GND and V+
tance capacitors mounted very close to the MC145220. Lead
lengths and printed circuit board traces to the capacitors
should be minimized. (The very fast switching speed of the
device can cause excessive current spikes on the power
leads if they are improperly bypassed.)
GND and GND
Grounds (Pins 6 and 15)
the ground for PLL
For optimum performance, V+ should be bypassed to
The GND pin is the ground for the main PLL and GND
i
bypassed to GND
i
i
.
i
using separate low–induc-
MOTOROLA
i
is