DF2437FV Renesas Electronics America, DF2437FV Datasheet - Page 584

• Manufacturer Part Number: DF2437FV
• Description: IC H8S/2437 MCU FLASH 128QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2400r

Specifications of DF2437FV

• Core Processor: H8S/2600
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: I²C, SCI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 85
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 16K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 128-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

18.7
18.7.1
Operation of the A/D converter can be disabled or enabled using the module stop control register.
The initial setting is for operation of the A/D converter to be halted. Register access is enabled by
clearing module stop mode. For details, refer to section 22, Power-Down Modes.
18.7.2
This LSI’s analog input is designed so that conversion accuracy is guaranteed for an input signal
for which the signal source impedance is 5 kΩ or less. This specification is provided to enable the
input capacitance of the A/D converter’s sample-and-hold circuit to be charged within the
sampling time; if the sensor output impedance exceeds 5 kΩ, charging may be insufficient and it
may not be possible to guarantee the A/D conversion accuracy. However, if a large capacitance is
provided externally for conversion in single mode, the input load will essentially comprise only
the internal input resistance of 10 kΩ, and the signal source impedance is ignored. However, since
a low-pass filter effect is obtained in this case, it may not be possible to follow an analog signal
with a large differential coefficient (e.g., 5 mV/μs or greater) (see figure 18.6). When converting a
high-speed analog signal or performing conversion in scan mode, a low-impedance buffer should
be inserted.
Rev.2.00 May. 28, 2009 Page 544 of 732
REJ09B0059-0200
Sensor input
Usage Notes
Module Stop Mode Setting
Permissible Signal Source Impedance
Sensor output
impedance
Up to 10 kΩ
Low-pass
filter
C to 0.1 μF
Figure 18.6 Example of Analog Input Circuit
This LSI
Cin =
15 pF
Equivalent circuit of A/D converter
10 kΩ
20 pF