MB90550A/550B Series
46
5.
A/D Converter
(1)
Electrical Characteristics
(4.5 V
≤
AVRH
AVRL, V
CC
=
AV
CC
=
5.0 V
±
10%, V
SS
=
AV
SS
=
0.0 V, T
A
=
40
°
C to +85
°
C)
Value
*1:When F
CP
= 8 MHz, t
CMP
= 176
×
t
CP
. When F
CP
= 16 MHz, t
CMP
= 352
×
t
CP
.
*2: Equivalent to the time for conversion per channel if “t
SMP
= 64
×
t
CP
” or “t
CMP
= 352
×
t
CP
” is selected when F
CP
=
16 MHz.
*3: Specifies the power-supply current (Vcc = AVcc = AVRH = 5.0 V) when the A/D converter is inactive and the
CPU has been stopped.
Notes: The error becomes larger relatively as |AVRH-AVRL| becomes smaller.
Use the output impedance r
S
of the external circuit for analog input under the following condition:
External circuit output impedance r
S
= 10 k
Max.
If the output impedance of the external circuit is too high, the analog voltage sampling time may be
insufficient.
If you insert a DC-blocking capacitor between the external circuit and the input pin, select a capacitance
that is about several thousands times the sampling capacitance C
SH
in the chip to suppress the effect of
capacity potential division with C
SH.
Parameter
Symbol
Pin name
Unit
Remarks
Min.
Typ.
Max.
Resolution
—
—
—
10
—
±
5.0
±
2.5
±
1.9
AVRL
+
4.5LSB
AVRH
+
1.5LSB
bit
Total error
—
—
—
—
LSB
Non-linearity error
—
—
—
—
LSB
Differential linearity error
—
—
—
—
LSB
Zero transition voltage
V
OT
AN0 to AN7
AVRL
3.5LSB
AVRH
6.5LSB
AVRL
+
0.5LSB
AVRH
1.5LSB
V
1LSB=
(AVRH
AVRL)
/1024
Full-scale transition
voltage
V
FST
AN0 to AN7
V
Sampling period
t
SMP
—
64
—
4096
t
CP
Compare time
t
CMP
—
22
—
—
μ
s
*1
A/D Conversion time
t
CNV
—
26.3
—
—
μ
s
*2
Analog port input current
I
AIN
AN0 to AN7
—
—
10
μ
A
Analog input voltage
V
AIN
AN0 to AN7
AVRL
—
AVRH
V
Reference voltage
—
AVRH
AVRL
—
AV
CC
V
—
AVRL
0
—
AVRH
V
Power supply current
I
A
AV
CC
—
3.5
7.0
mA
I
AH
—
—
5
μ
A
*3
Reference voltage
supply current
I
R
AVRH
—
300
500
μ
A
I
RH
—
—
5
μ
A
*3
Offset between channels
—
AN0 to AN7
—
—
4
LSB