LC87FBH08A_16 Datasheet, PDF (21/32 Pages) ON Semiconductor – 8-bit Microcontroller

LC87FBH08A
AD Converter Characteristics at VSS1 = VSS2 = 0V
<12bits AD Converter Mode at Ta = 40C to +85C >
Parameter
Symbol
Resolution
Absolute
accuracy
Conversion time
N
ET
TCAD
Pin/Remarks
AN0(P00) to
AN6(P06),
AN8(P70) to
AN10(P72)
Analog input
voltage range
Analog port
input current
VAIN
IAINH
IAINL
Conditions
(Note 6-1)
 See Conversion time calculation
formulas. (Note 6-2)
VDD[V]
1.8 to 5.5
2.7 to 5.5
1.8 to 5.5
2.7 to 5.5
2.2 to 5.5
1.8 to 5.5
1.8 to 5.5
VAIN=VDD
VAIN=VSS
1.8 to 5.5
1.8 to 5.5
min
32
134
400
VSS
1
Specification
typ
max
unit
12
bit
16
LSB
20
115
215
s
430
VDD
V
1
A
<8bits AD Converter Mode at Ta = 40C to +85C >
Parameter
Symbol
Resolution
Absolute
accuracy
Conversion time
N
ET
TCAD
Pin/Remarks
AN0(P00) to
AN6(P06),
AN8(P70) to
AN10(P72)
Conditions
(Note 6-1)
VDD[V]
1.8 to 5.5
1.8 to 5.5
 See Conversion time calculation
formulas. (Note 6-2)
2.7 to 5.5
2.2 to 5.5
min
20
80
Specification
typ
max
unit
8
bit
1.5 LSB
90
135
s
1.8 to 5.5
245
265
Analog input
voltage range
VAIN
1.8 to 5.5
VSS
VDD
V
Analog port
input current
IAINH
IAINL
VAIN=VDD
VAIN=VSS
1.8 to 5.5
1.8 to 5.5
1
1
A
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.
Conversion time calculation formulas:
12bits AD Converter Mode: TCAD(Conversion time) = ((52/(AD division ratio))+2)(1/3)tCYC
8bits AD Converter Mode: TCAD(Conversion time) = ((32/(AD division ratio))+2)(1/3)tCYC
External
oscillation
(FmCF)
CF-12MHz
CF-8MHz
CF-4MHz
Operating supply
voltage range
(VDD)
2.7V to 5.5V
2.7V to 5.5V
2.2V to 5.5V
2.7V to 5.5V
2.2V to 5.5V
1.8V to 5.5V
System division ratio
(SYSDIV)
1/1
1/1
1/1
1/1
1/1
1/1
Cycle time
(tCYC)
250ns
375ns
375ns
750ns
750ns
750ns
AD division
ratio
(ADDIV)
1/8
1/8
1/32
1/8
1/16
1/32
AD conversion time
(TCAD)
12bit AD
8bit AD
34.8s
21.5s
52.25s
32.25s
208.25s
128.25s
104.5s
64.5s
208.5s
128.5s
416.5s
256.5s
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