ST72260G1B6/XXX View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

ST72260G1B6/XXX

8-BIT MCU WITH FLASH OR ROM MEMORY, ADC, TWO 16-BIT TIMERS, I2C, SPI, SCI INTERFACES

STMicroelectronics 

ST72260G, ST72262G, ST72264G

13.12 10-BIT ADC CHARACTERISTICS

TA = -40°C to 85°C, unless otherwise specified

Symbol

Parameter

Conditions

fADC

VAIN

CADC

tCONV

ADC clock frequency

Conversion voltage range

Internal sample and hold capacitor

Conversion time

fADC=4MHz

RAIN

CAIN

fAIN

External input impedance

External capacitor on analog input

Variation frequency of analog input

signal

Min

0.41)

VSS

Typ

6

28

112

Max

4

VDD

see

Figure

105 and

Figure

1062)3)4)

Unit

MHz

V

pF

µs

1/fADC

kΩ

pF

Hz

Figure 105. RAIN max. vs fADC with CAIN=0pF3)

Figure 106. Recommended CAIN/RAIN values4)

45

40

35

30

25

20

15

10

5

0

0

4 MHz

2 MHz

1 MHz

10

30

70

CPARASITIC (pF)

1000

100

10

1

0.1

0.01

Cain 10 nF

Cain 22 nF

Cain 47 nF

0.1

1

10

fAIN(KHz)

Figure 107. Analog Input equivalent circuit

VDD

ST72XXX

VAIN

RAIN

AINx

CAIN

VT

0.6V

2kΩ(max) 10-Bit A/D

Conversion

VT

0.6V

IL

±1µA

CADC

6pF

Notes:

1. Data based on design simulation.

2. Any added external serial resistor will downgrade the ADC accuracy (especially for resistance greater than 10kΩ). Data

based on characterization results, not tested in production.

3. CPARASITIC represents the capacitance of the PCB (dependent on soldering and PCB layout quality) plus the pad ca-

pacitance (3pF). A high CPARASITIC value will downgrade conversion accuracy. To remedy this, fADC should be reduced.

4. This graph shows that depending on the input signal variation (fAIN), CAIN can be increased for stabilization time and

decreased to allow the use of a larger serial resistor (RAIN). It is valid for all fADC frequencies ≤ 4MHz.

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