MB90420G/425G Series
76
5.
A/D Conversion Block
(1) Electrical Characteristics
(VCC
= AVCC = 5.0 V±10%, VSS = AVSS = 0.0 V, TA = 40 °C to +105 °C)
*1 : At FCP
= 16 MHz, tSMP = 32 × tCP = 2.000 (s) .
*2 : At FCP
= 16 MHz, tCMP = 66 × tCP = 4.125 (s) .
*3 : Equivalent to conversion time per channel at FCP
= 16 MHz, and selection of tSMP = 32 × tCP and tCMP = 32 × tCP.
*4 : Defined as supply current (when VCC
= AVCC = AVRH = 5.0 V) with A/D converter not operating, and CPU in
stop mode.
Notes :
The relative error increases as AVRH is reduced.
The output impedance (rs) on the external analog input circuit should be used as follows.
External circuit output impedance rs
= 5 k max.
If the output impedance on the external circuit is too great, the analog voltage sampling time may be
insufficient.
If DC inhibitor capacitance is placed between the external circuit and input pin, then a capacitance value
several thousand times the value of the chip internal sampling capacitance (CSH) should be selected in
order to suppress the effects of voltage division with CSH.
Parameter
Symbol
Pin name
Value
Unit
Remarks
Min
Typ
Max
Resolution
10
bit
Total error
±5.0
LSB
Non-linear error
±2.5
LSB
Differential linear error
±1.9
LSB
Zero transition voltage
VOT
AN0 to AN7
AVSS
3.5 LSB
AVSS
+ 0.5 LSB
AVSS
+ 4.5 LSB
V
1 LSB
=
(AVRH
AVSS)
/ 1024
Full scale transition
voltage
VFST
AN0 to AN7
AVRH
6.5 LSB
AVRH
1.5 LSB
AVRH
+ 1.5 LSB
V
Sampling time
tSMP
2.000
s*1
Compare time
tCMP
4.125
s*2
A/D conversion time
tCNV
6.125
s*3
Analog port
input current
IAIN
AN0 to AN7
10
AVAVSS = VAIN = VAVCC
Analog input current
VAIN
AN0 to AN7
0
AVRH
V
Reference voltage
AVR
+
AVRH
3.0
AVCC
V
Power supply current
IA
AVCC
2.3
6.0
mA
IAH
5
A*4
Reference voltage feed
current
IR
AVRH
200
400
600
AVAVRH = 5.0 V
IRH
AVRH
5
A*4
Inter-channel variation
—
AN0 to AN7
4LSB