ST72334J4TC View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST72334J4TC

8-bit MCU for automotive with single voltage Flash/ROM memory, ADC, 16-bit timers, SPI, SCI interfaces

STMicroelectronics 

ST72334xx-Auto, ST72314xx-Auto, ST72124Jx-Auto

CLOCK AND TIMING CHARACTERISTICS (Cont’d)

15.5.3 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 are based

on characterization results with specified typical

external components. In the application, the reso-

nator 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 stabiliza-

tion time. Refer to the crystal/ceramic resonator

manufacturer for more details (frequency, pack-

age, accuracy...).

Symbol

Parameter

Conditions

Min

fOSC

Oscillator Frequency 3)

LP: Low power oscillator

1

MP: Medium power oscillator

>2

MS: Medium speed oscillator

>4

HS: High speed oscillator

>8

RF

Feedback resistor

20

CL1

CL2

Recommended load capacitance ver-

sus equivalent serial resistance of the

crystal or ceramic resonator (RS)

RS=200Ω

RS=200Ω

RS=200Ω

RS=100Ω

LP oscillator 38

MP oscillator 32

MS oscillator 18

HS oscillator 15

i2

OSC2 driving current

VDD=5V

VIN=VSS

LP oscillator 40

MP oscillator 110

MS oscillator 180

HS oscillator 400

Max

2

4

8

16

40

56

46

26

21

100

190

360

700

Unit

MHz

kΩ

pF

µA

15.5.3.1 Typical Crystal Resonators

Option

Byte

Config.

Reference

Freq.

Characteristic 1)

LP

S-200-30-30/50

2MHz ∆fOSC=[±30ppm25°C,±30ppm∆Ta], Typ. RS=200Ω

MP

SS3-400-30-30/30

4MHz ∆fOSC=[±30ppm25°C,±30ppm∆Ta], Typ. RS=60Ω

MS

SS3-800-30-30/30

8MHz ∆fOSC=[±30ppm25°C,±30ppm∆Ta], Typ. RS=25Ω

HS

SS3-1600-30-30/30 16MHz ∆fOSC=[±30ppm25°C,±30ppm∆Ta], Typ. RS=15Ω

Figure 67. Application with a Crystal Resonator

CL1 CL2 tSU(osc)

[pF] [pF] [ms] 2)

33 34 10~15

33 34 7~10

33 34 2.5~3

33 34 1~1.5

i2

CL1

OSC1

fOSC

RESONATOR

RF

CL2

OSC2

ST72XXX

Notes:

1. Resonator characteristics given by the crystal manufacturer.

2. tSU(OSC) is the typical oscillator start-up time measured between VDD=2.8V and the fetch of the first instruction (with a

quick VDD ramp-up from 0 to 5V (<50µs).

3. The oscillator selection can be optimized in terms of supply current using a high quality resonator with small RS value.

Refer to crystal manufacturer for more details.

118/150

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