MC68HC705X32CFU Freescale Semiconductor, MC68HC705X32CFU Datasheet - Page 134

• Manufacturer Part Number: MC68HC705X32CFU
• Manufacturer: Freescale Semiconductor

Specifications of MC68HC705X32CFU

• Cpu Family: HC05
• Device Core Size: 8b
• Frequency (max): 4MHz
• Interface Type: SCI
• Program Memory Type: EPROM
• Program Memory Size: 32KB
• Total Internal Ram Size: 528Byte
• # I/os (max): 32
• Number Of Timers - General Purpose: 1
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 4.5V
• On-chip Adc: 8-chx8-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 64
• Package Type: PQFP
• Lead Free Status / Rohs Status: Supplier Unconfirmed

9
9.4
The A/D converter is not affected by WAIT mode and continues normal operation.
In order to reduce power consumption the A/D converter can be disconnected, under software
control using the ADON bit and the ADRC bit in the A/D status/control register at $0009, before
entering WAIT mode.
9.5
The external analog voltage value to be processed by the A/D converter is sampled on an internal
capacitor through a resistive path, provided by input-selection switches and a sampling aperture
time switch, as shown in
the analog value is stored on the capacitor and held until the end of conversion. During this hold
time, the analog input is disconnected from the internal A/D system and the external voltage
source sees a high impedance input.
The equivalent analog input during sampling is an RC low-pass filter with a minimum resistance
of 50 k
measured at room temperature.
and a capacitance of at least 10pF. It should be noted that these are typical values
A/D converter during WAIT mode
Port D analog input
Note:
Freescale Semiconductor, Inc.
Analog
input
pin
Figure
Figure 9-2 Electrical model of an A/D input pin
For More Information On This Product,
The analog switch is closed during the 12 cycle sample
time only.
ANALOG TO DIGITAL CONVERTER
9-2. Sampling time is limited to 12 bus clock cycles. After sampling,
Input protection device
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< 2pF
+ ~20V
- ~0.7V
junction
leakage
400 nA
50k
capacitance
DAC
10pF
V
RL
MC68HC05X16
Rev. 1