M62301SP/FP
2. 4-channel 12-bit A/D converter system
Separate power supplies to analog section and digital section, analog input voltage range mode wider up to V
DD
,
external reference voltage for integration.
To microcomputer
5 V power supply
8V
10 k 10 k
1
2
20
A1 19
A2 18
To microcomputer
control pin
To counter
To
RESET
C
INT
680 pF
3
4
5
6
7
8
A3 17
A4 16
15
V
DD
14
13
12
11
Input analog
voltage
2.5 V
M62301SP/FP
C
REF
4700 pF
To microcomputer
5 V power supply
50
µA
C
I
6800 pF
9
10
I
I
= 50
µA
R
I
24 k
Note:
C
REF
: To stabilize reference voltage, be sure to connect capacitance of approximately 4700 pF.
C
INT
: We suggest that this capacitance be connected to prevent malfunction due to noise.
Use C
I
that leaks as slight current as possible. To prevent leak to the circuit board, we recommend
providing guard ring (7), (9).
Because separate power supplies are provided for the analog are digital sections, the M62301 has two supply
voltage V
CC
and V
DD
, enabling a wide analog input voltage range V
IA
. The upper limit of the range is required to be
no more than the difference between V
CC
– 2.5 V as well as V
DD
, therefore, the analog input voltage range in this
application is 0 V to 5 V.
When the counter clock frequency is 8 MHz, resolution is;
6800 pF
×
1
8M
(5 + 0.13)
50
µA
≈
2
12
An A/D converter system with resolution of approximately 12 bits can be formed.
REJ03D0861-0300 Rev.3.00 Mar 25, 2008
Page 7 of 11
RENESAS [ RENESAS TECHNOLOGY CORP ]
