M37542F8FP Renesas Electronics America, M37542F8FP Datasheet - Page 72

• Manufacturer Part Number: M37542F8FP
• Description: IC 740 MCU FLASH 32K 36SSOP
• Manufacturer: Renesas Electronics America
• Series: 740/38000r

Specifications of M37542F8FP

• Core Processor: 740
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SIO, UART/USART
• Peripherals: POR, WDT
• Number Of I /o: 29
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 36-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

7542 Group
2. Connection of bypass capacitor across V
Connect an approximately 0.1 µ F bypass capacitor across the V
line and the V
• Connect a bypass capacitor across the V
• Connect a bypass capacitor across the V
• Use lines with a larger diameter than other signal lines for V
• Connect the power source wiring via a bypass capacitor to the
Fig. 91 Bypass capacitor across the V
Rev.3.03
REJ03B0006-0303
at equal length.
with the shortest possible wiring.
line and V
V
SS
pin and the V
CC
N.G.
CC
Jul 11, 2008
line.
V
V
line as follows:
CC
SS
CC
pin.
Page 70 of 117
SS
SS
SS
SS
line and the V
O.K.
V
V
pin and the V
pin and the V
line and V
CC
SS
CC
CC
CC
CC
line
line
pin
pin
SS
SS
3. Wiring to analog input pins
• Connect an approximately 100 Ω to 1 kΩ resistor to an analog
• Connect an approximately 1000 pF capacitor across the Vss pin
<Reason>
Signals which is input in an analog input pin (such as an A/D con-
verter/comparator input pin) are usually output signals from
sensor. The sensor which detects a change of event is installed far
from the printed circuit board with a microcomputer, the wiring to
an analog input pin is longer necessarily. This long wiring func-
tions as an antenna which feeds noise into the microcomputer,
which causes noise to an analog input pin.
Fig. 92 Analog signal line and a resistor and a capacitor
• The analog input pin is connected to the capacitor of a voltage
signal line which is connected to an analog input pin in series.
Besides, connect the resistor to the microcomputer as close as
possible.
and the analog input pin. Besides, connect the capacitor to the
Vss pin as close as possible. Also, connect the capacitor across
the analog input pin and the Vss pin at equal length.
comparator. Accordingly, sufficient accuracy may not be ob-
tained by the charge/discharge current at the time of A/D
conversion when the analog signal source of high-impedance is
connected to an analog input pin. In order to obtain the A/D con-
version result stabilized more, please lower the impedance of an
analog signal source, or add the smoothing capacitor to an ana-
log input pin.
Thermistor
Noise
Note : The resistor is used for dividing
N.G.
resistance with a thermistor.
(Note)
O.K.
Microcomputer
V
Analog
input pin
SS