Internal Equivalent Circuit - Renesas M16C Series User Manual

M30240 Group

2.6.6 Internal Equivalent Circuit

Figure 2.98 shows the internal equivalent circuit of analog input.
Vcc
Vcc Vss
Parasitic
diode
ON resistor
approx. 2kΩ
AN0
SW1
Parasitic
diode
Vss
AN i
SW1
b2 b1 b0
A-D control register 0
V
REF
AVss
Control signal
for SW2
Control signal
for SW3
Warning: Use only as a standard for designing this data.
Figure 2.98: Internal equivalent circuit to analog input
Rev.1.00 Sep 24, 2003 Page 252 of 360
ON resistor
approx. 0.6kΩ
Wiring resistor
approx. 0.2kΩ
SW2
Sampling
control signal
i ladder-type
i ladder-type wiring
switches
resistors
(i = 10)
(i = 10)
Reference control
signal
SW2
Resistor
ON resistor
ladder
approx. 0.6kΩ
Comparison reference voltage (Vref) generator
Sampling
Comparison
Connect to
Connect to
Connect to
Connect to
Mass production may cause some changes in device characteristics.
AVcc
C = Approx. 3.0pF
Analog input voltage
V
IN
SW4
AVss
A-D successive conversion
Vref
Comparison voltage
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.
A-D Converter
AMP
ON resistor,
approx. 5kΩ
SW3
Chopper-type
amplifier
register
ADT/A-D conversion
interrupt request