MC68HC16Z1CFC16 Freescale Semiconductor, MC68HC16Z1CFC16 Datasheet - Page 205

• Manufacturer Part Number: MC68HC16Z1CFC16
• Description: IC MPU 1K RAM 16MHZ 132-PQFP
• Manufacturer: Freescale Semiconductor
• Series: HC16r

Specifications of MC68HC16Z1CFC16

• Core Processor: CPU16
• Core Size: 16-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 16
• Program Memory Type: ROMless
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 132-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -

8.8.5 Analog Input Considerations
M68HC16 Z SERIES
USER’S MANUAL
The current out of the pin (I
equation:
where:
The current into (I
sitic bipolar transistor (1/K
One way to minimize the impact of stress conditions on the ADC is to apply voltage
limiting circuits such as diodes to supply and ground. However, leakage from such cir-
cuits and the potential influence on the sampled voltage to be converted must be con-
sidered. Refer to
Another method for minimizing the impact of stress conditions on the ADC is to stra-
tegically allocate ADC inputs so that the lower accuracy inputs are adjacent to the in-
puts most likely to see stress conditions.
Finally, suitable source impedances should be selected to meet design goals and min-
imize the effect of stress conditions.
The source impedance of the analog signal to be measured and any intermediate fil-
tering should be considered whether external multiplexing is used or not.
shows the connection of eight typical analog signal sources to one ADC analog input
pin through a separate multiplexer chip. Also, an example of an analog signal source
connected directly to a ADC analog input channel is displayed.
Figure 8-8 Voltage Limiting Diodes in a Negative Stress Circuit
V
V
APPENDIX A ELECTRICAL
R
channel)
STRESS
BE
STRESS
EXTERNAL VOLTAGE
= Parasitic bipolar base/emitter voltage (refer to V
Figure
= Adjustable voltage source
IN
= Source impedance (10K resistor in
) the neighboring pin is determined by the 1/K
Freescale Semiconductor, Inc.
For More Information On This Product,
ANALOG-TO-DIGITAL CONVERTER
8-8.
N
‹‹1).
OUT
Go to: www.freescale.com
) under negative stress is determined by the following
I
OUT
kR
=
CHARACTERISTICS)
VDD
VSS
------------------------------------------ -
V
STRESS
R
STRESS
R
–
V
BE
Figure 8-7
TO DEVICE
NEGCLAMP
N
(Gain) of the para-
on stressed
in
Figure 8-9
ADC NEG STRESS CONN
8-19