LC87F7NJ2A Datasheet, PDF (21/28 Pages) ON Semiconductor – 8-bit Microcontroller

LC87F7NJ2A
AD Converter Characteristics at VSS1 = VSS2 = VSS3 = 0V
<12bits AD Converter Mode at Ta =30 to +70C>
Parameter
Resolution
Absolute
accuracy
Conversion
time
Analog input
voltage range
Analog port
input current
Symbol
N
ET
tCAD
VAIN
IAINH
IAINL
Pin/Remarks
AN0(P80) to
AN7(P87),
AN8(P70),
AN9(P71),
AN10(XT1),
AN11(XT2)
Conditions
(Note 6-1)
• See Conversion time calculation
formulas.
(Note 6-2)
VAIN=VDD
VAIN=VSS
VDD [V]
2.5 to 3.6
2.5 to 3.6
3.0 to 3.6
2.7 to 3.6
2.5 to 3.6
2.5 to 3.6
2.5 to 3.6
min
64
128
256
VSS
1
Specification
typ
max
unit
12
bit
±16 LSB
115
230 s
460
VDD
V
1
A
<8bits AD Converter Mode at Ta =30 to +70C>
Parameter
Resolution
Absolute
accuracy
Conversion
time
Analog input
voltage range
Analog port
input current
Symbol
N
ET
TCAD
VAIN
IAINH
IAINL
Pin/Remarks
AN0(P80) to
AN7(P87),
AN8(P70),
AN9(P71),
AN10(XT1),
AN11(XT2)
Conditions
(Note 6-1)
• See Conversion time calculation
formulas.
(Note 6-2)
VAIN=VDD
VAIN=VSS
VDD [V]
2.5 to 3.6
2.5 to 3.6
3.0 to 3.6
2.7 to 3.6
2.5 to 3.6
2.5 to 3.6
2.5 to 3.6
min
39
79
157
VSS
1
Specification
typ
max
unit
8
bit
1.5 LSB
71
140 s
280
VDD
V
1
A
<Conversion time calculation formulas>
12bits AD Converter Mode: tCAD(Conversion time)=((52/(division ratio)) + 2)  (1/3) tCYC
8bits AD Converter Mode: tCAD(Conversion time)=((32/(division ratio)) + 2)  (1/3) tCYC
Note 6-1: The quantization error (±1/2LSB) must be excluded from the absolute accuracy. The absolute accuracy must
be measured in the microcontroller's state in which no I/O operations occur at the pins adjacent to the analog
input channel.
Note 6-2: The conversion time refers to the period from the time an instruction for starting a conversion process till the
time the conversion results register(s) are loaded with a complete digital conversion value corresponding to
the analog input value.
The conversion time is 2 times the normal-time conversion time when:
• The first AD conversion is performed in the 12-bit AD conversion mode after a system reset.
• The first AD conversion is performed after the AD conversion mode is switched from 8-bit to 12-bit
conversion mode.
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