ASM3P2811A/B
ASM3P2812A/B
ASM3P2814A/B
November 2006
rev 1.5
Block Diagram
VDD
D_C SRS FRS
Modulation
PLL
XIN
Crystal
Frequency
Divider
Oscillator
Output
Divider
Phase
Loop
Filter
VCO
Detector
XOUT
Feedback
Divide
ModOUT
VSS
Pin Configuration
XIN
VSS
D_C
SRS
1
8
XOUT
2
3
4
VDD
P2811A/B
P2812A/B
P2814A/B
7
6
5
FRS
ModOUT
Pin Description
Pin#
Pin Name
Type
Description
Crystal connection or external frequency input. This pin has dual functions. It can
be connected to either an external crystal or an external reference clock.
1
2
3
XIN
I
P
I
VSS
Ground to entire chip.
Digital logic input used to select Down (LOW) or Center (HIGH) spread options.
(Refer Output Frequency Deviation and Spread Option Selection Table).
This pin has an internal pull-up resistor.
Spread range select. Digital logic input used to select frequency deviation
(Refer Output Frequency Deviation and Spread Option Selection Table).
This pin has an internal pull-up resistor.
D_C
4
5
6
7
8
SRS
ModOUT
FRS
I
O
I
Spread spectrum clock output
Frequency range select. Digital logic input used to select Input frequency range
(Refer Input/Output Frequency Range Selection Table).
This pin has an internal pull-up resistor.
VDD
P
O
Power supply for the entire chip.
Crystal connection. Output connection for an external crystal. If using an external
reference, this pin must be left unconnected.
XOUT
Low Power EMI Reduction IC
2 of 11
Notice: The information in this document is subject to change without notice.