MC9S12P32CFT Freescale Semiconductor, MC9S12P32CFT Datasheet - Page 513

• Manufacturer Part Number: MC9S12P32CFT
• Description: MCU 16BIT 32K FLASH 48-QFN
• Manufacturer: Freescale Semiconductor
• Series: HCS12r

Specifications of MC9S12P32CFT

• Core Processor: HCS12
• Core Size: 16-Bit
• Speed: 32MHz
• Connectivity: CAN, SCI, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.72 V ~ 5.5 V
• Data Converters: A/D 10x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 48-QFN Exposed Pad
• Processor Series: S12P
• Core: HCS12
• 3rd Party Development Tools: EWHCS12
• Development Tools By Supplier: KIT33812ECUEVME, DEMO9S12PFAME
• Package: 48QFN EP
• Family Name: HCS12
• Maximum Speed: 32 MHz
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 16 Bit
• Interface Type: CAN/SCI/SPI
• On-chip Adc: 10-chx12-bit
• Number Of Timers: 8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

A.2.2
Source resistance, source capacitance and current injection have an influence on the accuracy of the ATD.
A further factor is that PortAD pins that are configured as output drivers switching.
A.2.2.1
PortAD output drivers switching can adversely affect the ATD accuracy whilst converting the analog
voltage on other PortAD pins because the output drivers are supplied from the VDDA/VSSA ATD supply
pins. Although internal design measures are implemented to minimize the affect of output driver noise, it
is recommended to configure PortAD pins as outputs only for low frequency, low load outputs. The impact
on ATD accuracy is load dependent and not specified. The values specified are valid under condition that
no PortAD output drivers switch during conversion.
A.2.2.2
Due to the input pin leakage current as specified in
resistance there will be a voltage drop from the signal source to the ATD input. The maximum source
resistance R
leakage current. If device or operating conditions are less than worst case or leakage-induced error is
acceptable, larger values of source resistance of up to 10Kohm are allowed.
A.2.2.3
When sampling an additional internal capacitor is switched to the input. This can cause a voltage drop due
to charge sharing with the external and the pin capacitance. For a maximum sampling error of the input
voltage ≤ 1LSB (10-bit resilution), then the external filter capacitor, C
A.2.2.4
There are two cases to consider.
Freescale Semiconductor
1. A current is injected into the channel being converted. The channel being stressed has conversion
2. Current is injected into pins in the neighborhood of the channel being converted. A portion of this
values of $3FF (in 10-bit mode) for analog inputs greater than V
V
current is picked up by the channel (coupling ratio K), This additional current impacts the accuracy
of the conversion depending on the source resistance.
The additional input voltage error on the converted channel can be calculated as:
with I
RL
Factors Influencing Accuracy
S
unless the current is higher than specified as disruptive condition.
INJ
Port AD Output Drivers Switching
Source Resistance
Source Capacitance
Current Injection
specifies results in an error (10-bit resolution) of less than 1/2 LSB (2.5 mV) at the maximum
V
being the sum of the currents injected into the two pins adjacent to the converted channel.
ERR
= K * R
S
* I
INJ
S12P-Family Reference Manual, Rev. 1.13
Table A-6
and
Table A-7
f
≥ 1024 * (C
RH
in conjunction with the source
and $000 for values less than
INS
Electrical Characteristics
–C
INN
).
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