UC6226NIS-E310E2 (QFN40) Hardware Reference Design
5
2.3
TCXO
The CLK_I pin is used for connecting an external TCXO of 26 MHz. It is recommended to
use an external independent LDO to power the TCXO.
The basic parameter requirements for TCXO are as follows:
1.
Frequency and temperature:
26 MHz ± 0.5 ppm (-40 ° C ~ +85 ° C)
2.
Short-term frequency stability: <10 ppb
3.
Output voltage range:
-0.2 V ~ 1.05 V
4.
Output peak-to-peak voltage Vpp: 0.3 V ~ 1 V
Special attentions should be paid to the layout and routing of TCXO in addition to the
general rules:
1.
It is recommended to maintain copper void for the layer where TCXO is placed and
the adjacent layers, and keep the reference ground complete for other layers, so as
to reduce the impact of heat conduction on the performance of TCXO.
2.
Place the TCXO away from any heat source or interference source, with ground
shields for the surrounding circuits.
3.
Avoid placing any high-power or strong interference devices, signals, traces, etc.
around the TCXO. Keep a distance of more than 3 times the trace width between the
clock signal trace and other traces.
3
Recommended BOM
Component
Manufacturer
Order No.
LNA
MAXSCEND
MXDLN16GF
MAXIM
MAXT
SAW
TAI-SAW
TA0757A; TA1661A
TCXO
EPSON
X1G003841003400
KDS
1XXD26000MAA
