Renesas R8C series User Manual

R8C/1A Group, R8C/1B Group 17. A/D Converter
Rev.1.30 Dec 08, 2006 Page 241 of 315
REJ09B0252-0130
17.5 Internal Equivalent Circuit of Analog Input Block
Figure 17.8 shows the Internal Equivalent Circuit of Analog Input Block.
Figure 17.8 Internal Equivalent Circuit of Analog Input Block
VCC
Parasitic diode
Chopper-type
amplifier
A/D successive
conversion register
Comparison
voltage
b1b2 b0
VCC VSS
AN8
VSS
i = 4
AN11
VREF
AVSS
Vref
Comparison reference voltage
(Vref) generator
SW1
SW2
AVCC
AMP
SW3
AVSS
VIN
SW4
SW2
SW1
Parasitic diode
ON resistor
approx. 2 k
Ω
Wiring resistor
approx. 0.2 k
Ω
ON resistor
approx. 0.6 k
Ω
ON resistor
approx. 2 k
Ω
Wiring resistor
approx. 0.2 k
Ω
i ladder-type
switches
A/D control register 0
ON resistor
approx. 0.6 k f
Analog input
voltage
Sampling
control signal
ON resistor
approx. 5 k
Ω
C = Approx.1.5 pF
A/D conversion
interrupt request
SW1 conducts only to 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 at left.
SW4 conducts only when A/D conversion is not in progress.
Control signal
for SW2
Control signal
for SW3
Sampling
Co mp aris on
Connect to
Connect to
Connect to
Connect to
NOTE:
1. Use this data only as a guideline for circuit design.
Mass production may cause some changes in device characteristics.
i ladder-type
wiring resistors
Resistor
ladder
Reference
control signal

Renesas R8C series Specifications

General

Brand	Renesas
Model	R8C series
Category	Computer Hardware
Language	English