ST72321AR6-Auto STMicroelectronics, ST72321AR6-Auto Datasheet - Page 196

• Manufacturer Part Number: ST72321AR6-Auto
• Description: 8-bit MCU for automotive with 32 Kbyte Flash, 10-bit ADC, timers, SPI, SCI and I2C interfaces
• Manufacturer: STMicroelectronics

Specifications of ST72321AR6-Auto

• Hdflash Endurance: 100 cycles, data retention 20 years
• Clock Sources: crystal/ceramic resonator oscillators, internal RC oscillator and bypass for external clock
• 4 Power Saving Modes: Halt, Active Halt, Wait and Slow

Electrical characteristics
19.5.3
Figure 79. Typical application with a crystal or ceramic resonator)
196/243
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).
i
2
L1
L2
F
C
L2
L1
S
Oscillator frequency
Feedback resistor
Recommended load
capacitance versus
equivalent serial resistance
of the crystal or ceramic
resonator (R
OSC2 driving current
and C
value. Refer to crystal/ceramic resonator manufacturer for more details.
C
L1
L1
L2
and C
it is recommended to use high-quality ceramic capacitors in the 5pF to 25pF range (typ.)
Parameter
L2,
S
RESONATOR
L1
)
(3)
are usually the same size. The crystal manufacturer typically specifies a load
and C
(2)
(1)
L2
Doc ID 13829 Rev 1
(10pF can be used as a rough estimate of the combined pin and board
OSC1
OSC2
LP: Low power oscillator
MP: Medium power oscillator
MS: Medium speed oscillator
HS: High speed oscillator
R
R
R
R
V
DD
S
S
S
S
= 200
= 200
= 200
= 100
= 5V, V
L1
and C
Conditions
IN
R
L2
F
= V
. PCB and MCU pin capacitance must be
-
SS
LP oscillator
MP oscillator
MS oscillator
HS oscillator
LP oscillator
MP oscillator
MS oscillator
HS oscillator
i
2
Min Typ Max Unit
>2
>4
>8
20
22
22
18
15
1
-
ST72321xx-Auto
160
310
610
80
-
-
-
ST72XXX
f
OSC
150
250
460
910
16
40
56
46
33
33
2
4
8
MHz
k
µA
pF