ST6208C/ST6209C/ST6210C/ST6220C
CLOCK AND TIMING CHARACTERISTICS (Cont’d)
10.5.4 RC Oscillator
The ST6 internal clock can be supplied with an external RC oscillator. Depending on the RNET value, the
accuracy of the frequency is about 20%, so it may not be suitable for some applications.
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
MHz
kΩ
R
R
R
R
R
=22 kΩ
7.2
5.1
3.2
1.8
0.9
8.6
5.7
3.4
1.9
0.95
10
6.5
3.8
2
NET
=47 kΩ
NET
NET
NET
NET
=100 kΩ
=220 kΩ
=470 kΩ
1.1
1)
f
RC oscillator frequency
OSC
R
R
R
R
R
=22 kΩ
=47 kΩ
=100 kΩ
=220 kΩ
=470 kΩ
3.7
2.8
1.8
1
4.3
3
1.9
1.1
0.55
4.9
3.3
2
1.2
0.6
NET
NET
NET
NET
NET
0.5
2)
R
RC Oscillator external resistor
see Figure 52 & Figure 53
22
870
NET
Notes:
1. Data based on characterization results, not tested in production. These measurements were done with the OSCin pin
unconnected (only soldered on the PCB).
2. R
must have a positive temperature coefficient (ppm/°C), carbon resistors should therefore not be used.
NET
Figure 51. Typical Application with RC Oscillator
V
V
DD
DD
EXTERNAL RC
OSC
OUT
MIRROR
CURRENT
R
NET
V
DD
f
OSC
OSC
NC
IN
C
~9pF DISCHARGE
EX
ST62XX
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STMICROELECTRONICS [ ST ]
