R5F2L3AAANFP#U1 Renesas Electronics America, R5F2L3AAANFP#U1 Datasheet - Page 687

• Manufacturer Part Number: R5F2L3AAANFP#U1
• Description: MCU FLASH 96+4KB 100LQFP
• Manufacturer: Renesas Electronics America
• Series: R8C/Lx/3AAr

Specifications of R5F2L3AAANFP#U1

• Core Processor: R8C
• Core Size: 16/32-Bit
• Speed: 20MHz
• Connectivity: I²C, LIN, SIO, SSU, UART/USART
• Peripherals: LCD, POR, PWM, Voltage Detect, WDT
• Number Of I /o: 88
• Program Memory Size: 96KB (96K x 8)
• Program Memory Type: FLASH
• Ram Size: 10K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 20x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 100-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/L35A Group, R8C/L36A Group, R8C/L38A Group, R8C/L3AA Group,
R8C/L35B Group, R8C/L36B Group, R8C/L38B Group, R8C/L3AB Group
REJ09B0441-0100 Rev.1.00
Page 650 of 802
29.9
Figure 29.10
To carry out A/D conversion properly, charging the internal capacitor C shown in Figure 29.10 has to be completed
within a specified period of time. T (sampling time) as the specified time. Let output impedance of sensor
equivalent circuit be R0, internal resistance of microcomputer be R, precision (error) of the A/D converter be X,
and the resolution of A/D converter be Y (Y is 1024 in the 10-bit mode, and 256 in the 8-bit mode).
Figure 29.10 shows the Analog Input Pin and External Sensor Equivalent Circuit. When the difference between
VIN and VC becomes 0.1LSB, we find impedance R0 when voltage between pins VC changes from 0 to VIN-
(0.1/1024) VIN in time T. (0.1/1024) 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.
T = 0.75 s when AD = 20 MHz. Output impedance R0 for sufficiently charging capacitor C within time T is
determined as follows.
Thus, the allowable output impedance of the sensor equivalent circuit, making the precision (error) 0.1LSB or less,
is approximately 3.5 k . maximum.
Output Impedance of Sensor under A/D Conversion
VC is generally
And when t = T,
Hence,
T = 0.75 s, R = 10 k , C = 6.0 pF, X = 0.1, and Y = 1024. Hence,
R0
Analog Input Pin and External Sensor Equivalent Circuit
=
R0
–
-------------------------------------------------- -
6.0
=
–
0.75
VC
10
-------------------
C
Sensor equivalent
circuit
VC
Oct 30, 2009
–
–
e
T
12
VIN
=
ln
–
--------------------------
C R0
10
VIN 1 e
X
--- -
Y
=
--------------------------T
C R0
ln
6 –
–
VIN
1
----------- -
1024
R
0.1
1
+
+
R
R0
–
–
R
–
X
--- - VIN
Y
T
10
–
=
--------------------------
C R0
=
10
ln
X
--- -
Y
X
--- -
Y
3
1
=
+
3.5
MCU
VIN 1
R
C (6.0 pF)
R (10 k )
10
t
3
–
X
--- -
Y
VC
29. A/D Converter