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W180
Document #: 38-07156 Rev. *B
Page 2 of 10
Pin Definitions
Pin Name
Pin No.
Pin
Type
Pin Description
CLKOUT
5
O
Output Modulated Frequency: Frequency modulated copy of the unmodulated
input clock (SSON# asserted).
CLKIN or X1
1
I
Crystal Connection or External Reference Frequency Input: This pin has dual
functions. It may either be connected to an external crystal, or to an external reference
clock.
NC or X2
2
I
Crystal Connection: Input connection for an external crystal. If using an external
reference, this pin must be left unconnected.
SSON#
8 (-02, -03 52, 53)
I
Spread Spectrum Control (Active LOW): Asserting this signal (active LOW) turns
the internal modulation waveform on. This pin has an internal pull-down resistor.
FS1:2
7, 8 (-01, 51)
I
Frequency Selection Bit(s) 1 and 2: These pins select the frequency range of
operation. Refer to Table 2. These pins have internal pull-up resistors.
SS%
4
I
Modulation Width Selection: When Spread Spectrum feature is turned on, this pin
is used to select the amount of variation and peak EMI reduction that is desired on
the output signal. Internal pull-up resistor.
VDD
6
P
Power Connection: Connected to 3.3V or 5V power supply.
GND
3
G
Ground Connection: This should be connected to the common ground plane.