
59
MB90660A Series
5. Electrical Characteristics of A/D Converter
(AV
CC
= V
CC
= +2.7 V to +5.5 V, AV
SS
= V
SS
= 0.0 V, 2.7 V
≤
AVR, T
A
= –40
°
C to +85
°
C)
*1: V
CC
= 5.0 V
±
10% at 16 MHz machine clock
*2: V
CC
= 3.0 V
±
10% at 8 MHz machine clock
*3: Current when CPU is stopped and A/D converter is not operating (when V
CC
= AV
CC
= AVR = 5.0 V)
Notes: The relative error becomes larger as the reference voltage (AVR) becomes smaller.
Be sure to use the A/D converter only when output impedance of the external analog input circuit meets
the following conditions.
External circuit output impedance < approx. 7 k
If the output impedance of the external circuit is too high, there may not be enough time to sample the
analog voltage. (Sampling time = 3.75
μ
s @4 MHz (equivalent to internal 16 MHz when multiplying by 4))
For an external capacitor to be provided outside the chip, its capacity should desirably be thousands times
larger than of the capacity in the chip taking in consideration the influence of the capacity destribution of
the external and internal capacitors.
Parameter
Symbol
Pin name
Value
Typ.
10
—
—
—
+0.5
AVR – 1.5
—
—
0.1
—
—
3
—
200
—
—
Unit
Min.
—
—
—
—
–1.5
Max.
10
±
3.0
±
2.0
±
1.5
+2.5
Resolution
Total error
Linearity error
Differential linearity error
Zero transition voltage
Full-scale transition voltage
—
—
—
—
—
—
—
—
bit
LSB
LSB
LSB
LSB
LSB
μ
s
μ
s
μ
A
V
V
mA
μ
A
μ
A
μ
A
LSB
V
OT
V
FST
AN0 to AN7
AN0 to AN7
AVR – 4.5
6.125
*1
12.25
*2
—
0
3.5
—
—
—
—
—
AVR + 0.5
—
—
10
AVR
AV
CC
—
5
*3
—
5
*3
4
Conversion time
—
—
Analog port input voltage
Analog input voltage
Reference voltage
I
AIN
V
AIN
AN0 to AN7
AN0 to AN7
AVR
AV
CC
AV
CC
AVR
AVR
AN0 to AN7
—
Supply current
I
A
I
AH
I
R
I
RH
Reference voltage supply current
Variation between channels
—
Comparator
Analog input
R
ON1
R
ON2
R
ON3
C
1
C
0
R
ON1
= Approx. 1.5 k
(V
CC
= 5.0 V)
R
ON2
= Approx. 0.5 k
(V
CC
= 5.0 V)
R
ON3
= Approx. 0.5 k
(V
CC
= 5.0 V)
R
ON4
= Approx. 0.5 k
(V
CC
= 5.0 V)
C
0
= Approx. 60 pF
C
1
= Approx. 4 pF
R
ON4
Sample and hold circuit
Note: Use the values shown here as guidelines.
Figure Model of Analog Input Circuit