Si501/2/3/4
LVCMOS CMEMS® Programmable Oscillator Series
Applications Circuits
VDD
VDD
VDD
VDD
RUP
VDD
VDD
CLK
FS/OE
~50K
1
2
4
3
RUP
0.1uF
FS/OE
RDOWN
VDD
CLK
4
3
1
2
Si501/2
0.1uF
Z0 = 50
Si503
CLK
GND
RS
Z0 = 50
CLK
GND
RS
Si501/2 Apps Circuit w/ Optional Series Resistor
Notes:
Si503 Apps Circuit w/ Configurable Options
1. Dotted line boxes show optional components depending on configuration options. See data sheet for additional information and for
applications using a microcontroller. Data sheet is available at www.silabs.com/cmems.
2. Recommended series termination resistor (RS) = 24.9 for Z0 = 50 .
Si502 FS/OE States and Resistor Values
Si503 FS States and Resistor Values
FS/OE State
Strong High
Weak High
Low
RUP
0 ≤ RUP ≤ 1 k
20 k ≤ RUP ≤ 200 k
—
Clock Output
Frequency 1
Frequency 2
Hi-Z
FS/OE State
Strong High
Weak High
Weak Low
Low
RUP
0 ≤ RUP ≤ 1 k
20 k ≤ RUP ≤ 200 k
No pop
RDOWN
No pop
No pop
Clock Output
Frequency 1
Frequency 2
Frequency 3
Frequency 4
20 k ≤ RDOWN ≤ 200 k
0 ≤ RDOWN ≤ 1 k
No pop
Notes for both FS/OE tables above:
1. If the internal pull-up resistor order option is NOT selected, an MCU internal pull-up resistor or an external pull-up resistor should be used.
See data sheet for more information.
2. The parallel combination of all pull-up resistors on the FS/OE pin including the optional internal pull-up resistor must be > 20 k to select
Weak High.
3. If the Si50x internal pull-up resistor is enabled with no other external OE connections, the OE state will be detected as “Weak High”,
selecting Frequency 2 by default.
4
Revision 0.72
www.silabs.com/cmems
SILICON [ SILICON ]
