![](http://datasheet.mmic.net.cn/30000/M30102F3TFP_datasheet_2358625/M30102F3TFP_112.png)
Under
development
Tentative Specifications REV.E1
Specifications in this manual are tentative and subject to change.
Mitsubishi microcomputers
M30100/M30102 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
A-D Converter
111
A-D Converter
The A-D converter consists of one 10-bit successive approximation A-D converter circuit with a capacitive
coupling amplifier. Pins P00 to P07, P10 to P13, P40 and P41 also function as the analog signal input pins.
The direction registers of these pins for A-D conversion must therefore be set to input. The Vref connect bit
(bit 5 at address 00D716) can be used to isolate the resistance ladder of the A-D converter from the refer-
ence voltage input pin (VREF) when the A-D converter is not used. Doing so stops any current flowing into
the resistance ladder from VREF, reducing the power dissipation. When using the A-D converter, start A-D
conversion only after connecting to VREF.
The result of A-D conversion is stored in the A-D registers. When set to 10-bit precision, the low 8 bits are
stored in the even addresses and the high 2 bits in the odd addresses. When set to 8-bit precision, the low
8 bits are stored in the even addresses.
Table 1.16.1 shows the performance of the A-D converter. Figure 1.16.1 shows the block diagram of the A-
D converter, and Figures 1.16.2 and 1.16.3 show the A-D converter-related registers.
Table 1.16.1. Performance of A-D converter
Item
Performance
Method of A-D conversion Successive approximation (capacitive coupling amplifier)
Analog input voltage (Note 1) 0V to VCC
Operating clock
φAD (Note 2) VCC = 5V
fAD, divide-by-2 of fAD, divide-by-4 of fAD, fAD=f(XIN)
VCC = 3V
divide-by-2 of fAD, divide-by-4 of fAD, fAD=f(XIN)
Resolution
8-bit or 10-bit (selectable)
Absolute precision
VCC = 5V
Without sample and hold function
±3LSB
With sample and hold function (8-bit resolution)
±2LSB
With sample and hold function (10-bit resolution)
AN0 to AN11 input :
±3LSB
ANEX0 and ANEX1 input (including mode in which external
operation amp is connected) :
±7LSB
VCC = 3V
Without sample and hold function (8-bit resolution)
±2LSB
Operating modes
One-shot mode and repeat mode (Note 3)
Analog input pins
12 pins (AN0 to AN11) + 2 pins (ANEX0 to ANEX1)
A-D conversion start condition Software trigger
A-D conversion starts when the A-D conversion start flag changes to “1”
Conversion speed per pin Without sample and hold function
8-bit resolution: 49
φAD cycles, 10-bit resolution: 59 φAD cycles
With sample and hold function
8-bit resolution: 28
φAD cycles, 10-bit resolution: 33 φAD cycles
Note 1: Does not depend on use of sample and hold function.
Note 2: Divide fAD if (XIN) exceeds 10MHz, and make
φAD equal to or lower than 10MHz. Also if Vcc is less
than 4.2V or an external RC circuit is used for the main clock, divide fAD and make
φAD equal to or
lower than fAD/2.
Without sample and hold function, set the
φAD frequency to 250kHz min.
With the sample and hold function, set the
φAD frequency to 1MHz min.
Note 3: In repeat mode, only 8-bit mode can be used.