Internal Equivalent Circuit Of Analog Input - Renesas M16C Series User Manual

M30245 Group

2.9.12 Internal Equivalent Circuit of Analog Input

Figure 2.9.23 shows the internal equivalent circuit of analog input.
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P a r a s i t i c
d i o d e
A N 0
Parasitic
diode
V s s
AN i
V
REF
A V s s
Control signal
for SW2
C o n t r o l s i g n a l
f o r S W 3
Figure 2.9.23. Internal equivalent circuit to analog input
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
V c c
V c c V s s
O N r e s i s t o r
Ω
W i r i n g r e s i s t o r
a p p r o x . 2 k
a p p r o x . 0 . 2 k
S W 1
i l a d d e r - t y p e
s w i t c h e s
( i = 1 0 )
i l a d d e r - t y p e
O N r e s i s t o r
w i r i n g r e s i s t o r s
Ω
a p p r o x . 2 k
(i = 10)
O N r e s i s t o r
S W 1
a p p r o x . 0 . 2 k
b2 b1 b0
AD control register 0
R e s i s t o r
l a d d e r
Comparison reference voltage (Vref) generator
Sampling
Comparison
C o n n e c t t o
C o n n e c t t o
Connect to
Connect to
Warning: Use only as a standard for designing this data.
Mass production may cause some changes in device characteristics.
page 237 of 354
O N r e s i s t o r
Ω
a p p r o x . 0 . 6 k
Ω
Analog input voltage
V
I N
S W 2
S a m p l i n g
c o n t r o l s i g n a l
Ω
Reference control
signal
Vref
Comparison voltage
SW2'
ON resistor
Ω
approx. 0.6k
SW1 conducts only on the ports selected for analog input.
SW2 and SW3 are open when A/D conversion is not in
progress; their status varies as shown by the waveforms in
the diagrams on the left.
SW4 conducts only when A/D conversion is not in progress.
2. A/D Converter
AVcc
C = Approx. 3.0pF
AMP
ON resistor,
Ω
approx. 5k
S W 3
SW4
Chopper-type
A V s s
amplifier
A D s u c c e s s i v e c o n v e r s i o n
r e g i s t e r
A D T / A / D c o n v e r s i o n
i n t e r r u p t r e q u e s t