ST72325R6-AUTO STMicroelectronics, ST72325R6-AUTO Datasheet - Page 204

• Manufacturer Part Number: ST72325R6-AUTO
• Description: 8-bit Mcu For Automotive With 16 To 60 Kbyte Flash, Adc, Css, 5 Timers, Spi, Sci, I2c Interface
• Manufacturer: STMicroelectronics

Electrical characteristics
19.5.3
Figure 77. Typical application with a crystal or ceramic resonator
204/227
WHEN RESONATOR WITH
INTEGRATED CAPACITORS
Crystal and ceramic resonator oscillators
The ST7 internal clock can be supplied with four different crystal/ceramic resonator
oscillators. All the information given in this paragraph is based on characterization results
with specified typical external components. In the application, the resonator and the load
capacitors have to be placed as close as possible to the oscillator pins in order to minimize
output distortion and start-up stabilization time. Refer to the crystal/ceramic resonator
manufacturer for more details (such as frequency, package or accuracy).
Table 116. Crystal and ceramic resonator oscillators
1. The oscillator selection can be optimized in terms of supply current using a high quality resonator with
2. Data based on characterization results, not tested in production. The relatively low value of the RF resistor
3. For C
Symbol
f
C
C
OSC
R
small R
offers a good protection against issues resulting from use in a humid environment, due to the induced
leakage and the bias condition change. However, it is recommended to take this point into account if the
microcontroller is used in tough humidity conditions.
designed for high-frequency applications and selected to match the requirements of the crystal or
resonator. C
capacitance which is the series combination of C
included when sizing C
capacitance).
C
i
L1
L2
2
F
L2
L1
C
S
Oscillator frequency
Feedback resistor
Recommended load
capacitance versus
equivalent serial resistance of
the crystal or ceramic
resonator (R
OSC2 driving current
and C
L1
value. Refer to crystal/ceramic resonator manufacturer for more details.
L1
L2
and C
it is recommended to use high-quality ceramic capacitors in the 5pF to 25pF range (typ.)
Parameter
L2,
S
L1
)
RESONATOR
(3)
are usually the same size. The crystal manufacturer typically specifies a load
and C
(2)
(1)
OSC1
OSC2
L2
(10pF can be used as a rough estimate of the combined pin and board
R
R
R
R
V
DD
S
S
S
S
R
F
= 200Ω
= 200Ω
= 200Ω
= 100Ω
= 5V, V
L1
V
Ref
and C
DD
/2
Conditions
IN
L2
= V
. PCB and MCU pin capacitance must be
AMPLIFIER
i
2
LINEAR
-
-
SS
LP oscillator
MP oscillator
MS oscillator
HS oscillator
LP oscillator
MP oscillator
MS oscillator
HS oscillator
f
OSC
FEEDBACK
LOOP
Min Typ Max Unit
20
20
20
15
15
1
-
ST72325xxx-Auto
POWER DOWN
426
425
456
660
-
-
ST72XXX
LOGIC
16
40
60
50
35
35
-
MHz
kΩ
pF
µA