LC87FBG08A

No.A2046-19/30

AD Converter Characteristics

at VSS1 = 0V

<12bits AD Converter Mode/Ta = -40

°C to +85°C >

Parameter

Symbol

Pin/Remarks

Conditions

Specification

VDD[V]

min

typ

max

unit

Resolution

N

AN0(P00) to

AN6(P06),

AN8(P70)

1.8 to 5.5

12

bit

Absolute

accuracy

ET

(Note 6-1)

2.7 to 5.5

±16

LSB

1.8 to 5.5

±20

Conversion time

TCAD

• See Conversion time calculation

formulas. (Note 6-2)

2.7 to 5.5

32

115

μs

2.2 to 5.5

134

215

1.8 to 5.5

400

430

Analog input

voltage range

VAIN

1.8 to 5.5

VSS

VDD

V

Analog port

input current

IAINH

VAIN=VDD

1.8 to 5.5

1

μA

IAINL

VAIN=VSS

1.8 to 5.5

-1

<8bits AD Converter Mode/Ta = -40

°C to +85°C >

Parameter

Symbol

Pin/Remarks

Conditions

Specification

VDD[V]

min

typ

max

unit

Resolution

N

AN0(P00) to

AN6(P06),

AN8(P70)

1.8 to 5.5

8

bit

Absolute

accuracy

ET

(Note 6-1)

1.8 to 5.5

±1.5

LSB

Conversion time

TCAD

• See Conversion time calculation

formulas. (Note 6-2)

2.7 to 5.5

20

90

μs

2.2 to 5.5

80

135

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

VAIN=VDD

1.8 to 5.5

1

μA

IAINL

VAIN=VSS

1.8 to 5.5

-1

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)

Operating supply

voltage range

(VDD)

System division ratio

(SYSDIV)

Cycle time

(tCYC)

AD division

ratio

(ADDIV)

AD conversion time

(TCAD)

12bit AD

8bit AD

CF-12MHz

2.7V to 5.5V

1/1

250ns

1/8

34.8

μs

21.5

μs

CF-8MHz

2.7V to 5.5V

1/1

375ns

1/8

52.25

μs

32.25

μs

2.2V to 5.5V

1/1

375ns

1/32

208.25

μs

128.25

μs

CF-4MHz

2.7V to 5.5V

1/1

750ns

1/8

104.5

μs

64.5

μs

2.2V to 5.5V

1/1

750ns

1/16

208.5

μs

128.5

μs

1.8V to 5.5V

1/1

750ns

1/32

416.5

μs

256.5

μs

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.