XE88LC01MI000 ETC1 [List of Unclassifed Manufacturers], XE88LC01MI000 Datasheet - Page 17

• Manufacturer Part Number: XE88LC01MI000
• Description: Sensing Machine 16 + 10 bit Data Acquisition Ultra Low-Power Microcontroller
• Manufacturer: ETC1 [List of Unclassifed Manufacturers]

7.5 Xtal clock
Table 7.1:
Note:
7.6 RC oscillator
Note:
17
Figure 7.1:
duty_clk32k
f_clk32k
symbol
st_x32k
fstab_1
nominal, for a crystal with CL=8.2 pF
and temperature between -40° and
relative frequency deviation from
duty cycle on the digital output
oscillator start-up time
nominal frequency
description
The Xtal Oscillator operates with an external crystal of 32’768 Hz.
Xtal oscillator specifications.
Board layout recommendations for safer crystal oscillation and lower current consumption:
Keep lines xtal_in and xtal_out short and insert a VSS line between them.
Connect package of the crystal to VSS.
No noisy or digital lines near xtal_in and xtal_out.
Insert guards at VSS where needed.
The RC Oscillator is always turned on at power-on reset and can be turned off after the option-
al Xtal oscillator has been started. The RC oscillator has two frequency ranges: sub-MHz
(100KHz to 1MHz) and above-MHz (1MHz to max MCU frequency). Inside a range, the fre-
quency can be tuned by software for coarse and fine adjustment.
No external component is required for the RC oscillator.
The RC oscillator can be in 3 modes. In mode 1(RC on), the RC oscillator and its bias are on.
In mode 2 (RC ready), the RC oscillator is off and the bias is on. In mode 3 (RC off), the RC
oscillator and the bias are off. RC ready mode is a compromise between power consumption
and start-up time.
+85°C
RC frequencies programming example for low range (typical values)
-100
min
30
32768
typ
50
1
max
+300
70
2
unit
ppm
Hz
%
s
not included:
crystal frequency tolerance and aging
crystal frequency - temperature dependence
Data Sheet XE88LC01
Data Acquisition Microcontroller
for full precision
comments
D0202-60