xe8802 Semtech Corporation, xe8802 Datasheet - Page 53

• Manufacturer Part Number: xe8802
• Description: Data Acquisition Soc With 16+10 Bit Zoomingadc? Embedded Risc Controller And Lcd Driver
• Manufacturer: Semtech Corporation

Figure 7-2. RC oscillator nominal frequency tuning.
7.5.3
Table 7-8. RC oscillator specifications
Note 1: this is the frequency tolerance when all trimming codes are 0. The frequency at start-up is about twice as
high.
Note 2: frequency shift as a function of VBAT with normal regulator function.
Note 3: frequency shift as a function of VBAT while the regulator is short-circuited to VBAT.
The tolerances on the minimal frequency and the drift with supply or temperature can be cancelled using the
software or hardware DFLL (digital frequency locked loop) which uses the crystal oscillator as a reference
frequency.
© Semtech 2006
sym
f
RcFreqFine
RC_su
PSRR @ DC
∆f/∆T
RCmin
1E+07
1E+06
1E+05
1E+04
RC oscillator specifications
description
Lowest RC frequency
fine tuning step
startup time
Supply voltage
dependence
Temperature
dependence
RcFreqFine(5:0)
0000
RcFreqRange='1'
RcFreqRange='0'
0001
XE8802 Sensing Machine Data Acquisition MCU
min
25
TBD
TBD
typ
1.4
0.1
40
30
3
7-6
0011
with ZoomingADC™ and LCD driver
max
2.0
55
50
5
unit
kHz
%
us
us
%/V
%/V
%/°C
0111
Comments
Note 1
BiasRc=0
BiasRc=1
Note 2
Note 3
RcFreqCoarse(3:0)
RcFreqFine(5:0)
1111
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