ST72F321 STMICROELECTRONICS [STMicroelectronics], ST72F321 Datasheet - Page 167

• Manufacturer Part Number: ST72F321
• Description: 64/44-PIN 8-BIT MCU WITH 32 TO 60K FLASH/ROM, ADC, FIVE TIMERS, SPI, SCI, I2C INTERFACE
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

12.12 10-BIT ADC CHARACTERISTICS
Subject to general operating conditions for V
Notes:
1. 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.
2. Injecting negative current on any of the analog input pins significantly reduces the accuracy of any conversion being
performed on any analog input. Analog pins can be protected against negative injection by adding a Schottky diode (pin
to ground). Injecting negative current on digital input pins degrades ADC accuracy especially if performed on a pin close
to the analog input pins. Any positive injection current within the limits specified for I
does not affect the ADC accuracy.
Symbol
V
C
R
C
f
V
t
t
f
AREF
ADC
ADC
ADC
I
AIN
ADC
lkg
AIN
AIN
AIN
ADC clock frequency
Analog reference voltage
Conversion voltage range
Positive input leakage current for analog
input
Negative input leakage current on ro-
bust analog pins (ROM devices only)
External input impedance
External capacitor on analog input
Variation freq. of analog input signal
Internal sample and hold capacitor
Conversion time (Sample+Hold)
f
- No of sample capacitor loading cycles
- No. of Hold conversion cycles
CPU
=8MHz, SPEED=0 f
Parameter
ADC
1)
=2MHz
2
DD
0.7*V
-40°C≤T
Other T
V
on adjacent robust ana-
log pin
, f
IN
CPU
<
V
DD
Conditions
SS,
, and T
A
A
≤V
ranges
≤85°C range
| I
AREF
IN
|< 400µA
A
≤V
unless otherwise specified.
DD
V
Min
0.4
3.8
SSA
INJ(PIN)
and ΣI
Typ
12
7.5
5
11
4
INJ(PIN)
Figure 96
97
Figure
V
±250
Max
and
V
see
AREF
±1
2)3)4)
2
6
in
DD
Section 12.8
ST72321
167/189
1/f
Unit
MHz
nA
µA
µA
kΩ
pF
Hz
pF
µs
V
ADC