ST72325S6B5(2007) View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST72325S6B5
(Rev.:2007)

8-bit MCU with 16 to 60K Flash/ROM, ADC, CSS, 5 timers, SPI, SCI, I2C interface

STMicroelectronics 

Figure 76. Typical Application with a Crystal or Ceramic Resonator

WHEN RESONATOR WITH

INTEGRATED CAPACITORS

CL1

OSC1

LINEAR

AMPLIFIER

fOSC

FEEDBACK

LOOP

POWER DOWN

LOGIC

RESONATOR

VDD/2 i2

RF Ref

CL2

OSC2

ST72XXX

Figure 77 Application with a Crystal or Ceramic Resonator for ROM (LQFP64 or any 48/60K ROM)

3. The relatively low value of the RF resistor, offers a good protection against issues resulting from use in a humid envi-

ronment, due to the induced leakage and the bias condition change. However, it is recommended to take this point into

account if the µC is used in tough humidity conditions.

3. For CL1 and CL2 it is recommended to use high-quality ceramic capacitors in the 5-pF to 25-pF range (typ.) designed

for high-frequency applications and selected to match the requirements of the crystal or resonator. CL1 and CL2, are usu-

ally the same size. The crystal manufacturer typically specifies a load capacitance which is the series combination of CL1

and CL2. PCB and MCU pin capacitance must be included when sizing CL1 and CL2 (10 pF can be used as a rough esti-

mate of the combined pin and board capacitance).

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