xe8805a Semtech Corporation, xe8805a Datasheet - Page 46

• Manufacturer Part Number: xe8805a
• Description: Xe8805a Sensing Machine With 16 + 10 Bit Zoomingadc? And Buffered Dac, Low-power Microcontroller Based Sensor Interface Ic
• Manufacturer: Semtech Corporation

7.5.1.3
Note 1: this is the frequency tolerance when all trimming codes are 0.
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 DFLL (digital frequency locked loop) which uses the crystal oscillator as a reference frequency.
© Semtech 2006
symbol
f
RcFreqFine
RC_su
PSRR @ DC
∆f/∆T
RCmin
1E+08
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
Figure 7-2. RC oscillator nominal frequency tuning.
RcFreqRange='1'
RcFreqRange='0'
Table 7-7. RC oscillator specifications
0001
min
40
TBD
TBD
typ
1.4
0.1
80
30
3
7-5
0011
max
120
2.0
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)
XE8805/05A
1111
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