M30245FCGP#U1 Renesas Electronics America, M30245FCGP#U1 Datasheet - Page 177

• Manufacturer Part Number: M30245FCGP#U1
• Description: IC M16C/24 MCU FLSH 128K 100LQFP
• Manufacturer: Renesas Electronics America
• Series: M16C™ M16C/20r

Specifications of M30245FCGP#U1

• Core Processor: M16C/60
• Core Size: 16-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, SSI, UART/USART, USB
• Peripherals: DMA, PWM, WDT
• Number Of I /o: 82
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 10K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 100-LQFP
• Package: 100LQFP
• Family Name: R8C
• Maximum Speed: 16 MHz
• Operating Supply Voltage: 3.3 V
• Data Bus Width: 16 Bit
• Number Of Programmable I/os: 82
• Interface Type: USB/UART/I2C/SPI
• On-chip Adc: 8-chx10-bit
• Number Of Timers: 5
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

M30245 Group
Figure 1.128. A circuit equivalent to the A/D conversion terminal
Rev.2.00
REJ03B0005-0200
Output impedance of sensor at A/D conversion (Reference value).
•
Read the corresponding AD register after confirming A/D conversion is finished. (Check the A/D conversion interrupt
request bit.)
•
Use the undivided main clock as the internal CPU clock.
When f(X
To carry out A/D conversion properly, charging the internal capacitor C shown in Figure 1.126 has to be completed
within a specified period of time T. Let the output impedance of sensor equivalent circuit be R0, the microcomputer's
internal resistance be R, the precision (error) of the A/D converter be X, and the A/D converter’s resolution be Y (Y is
1024 in the 10-bit mode, and 256 in the 8-bit mode).
With the model shown in Figure 1.128 as an example, when the difference between V
we find impedance R0 when voltage between pins VC changes from 0 to V
means that A/D precision drop due to insufficient capacitor charge is held to 0.1LSB at time of A/D conversion in the
10-bit mode. Actual error however is the value of absolute precision added to 0.1LSB. When f(X
us in the A/D conversion mode with sample & hold. Output impedance R0 for sufficiently charging capacitor C within
time T is determined as follows.
Thus, the allowable output impedance of the sensor circuit capable of thoroughly driving the A/D converter turns out
to be approximately 3.0 kΩ. Table 1.62 and Table 1.63 show output impedance values based on the LSB values.
Using repeat mode, repeat sweep mode 0 or repeat sweep mode 1:
Using one-shot mode or single sweep mode:
Oct 16, 2006
in
) is faster than 10MHz, make the A/D frequency 10MHz or less by dividing.
page 175 of 264
Then R0 = -
If T = 0.3µs, R = 7.8kΩ, C = 3pF, X = 0.1, and Y = 1024
Sensor-equivalent circuit
And when t = T,
Therefore, R0 = -
3.0 x 10
Vc is generally = V
V
0.3 x 10
IN
-12
-6
In 0.1
R
0
e -
1024
-
Vc = V
C(R0+R)
C(R0+R)
C
IN
_
_
R (7.8k )
T
C (3.0pF)
{1 - e - C(R0+R) }
Internal circuit of microprocessor
T
T
In X
7.8 x 10
IN
Y
Ω
- X V
Y
- R
=
= In
3
IN
X
Y
= approximately 3.0 x 10
= V
t
X
Y
V
C
IN
(1 - X)
IN
-(0.1/1024) V
Y
IN
and VC becomes 0.1LSB,
IN
3
in time T. (0.1/1024)
in
) = 10 MHz, T = 0.3
A/D converter