PIC12F675-I/SN Microchip Technology, PIC12F675-I/SN Datasheet - Page 47

• Manufacturer Part Number: PIC12F675-I/SN
• Description: IC MCU CMOS FLSH-BASE 8BIT 8SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 12Fr

Specifications of PIC12F675-I/SN

• Program Memory Type: FLASH
• Program Memory Size: 1.75KB (1K x 14)
• Package / Case: 8-SOIC (3.9mm Width)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Peripherals: POR, WDT
• Number Of I /o: 5
• Eeprom Size: 128 x 8
• Ram Size: 64 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC12F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 64 B
• Interface Type: RS- 232/USB
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 6
• Number Of Timers: 2
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 53270-913
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163014, DM164120-4
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 4-ch x 10-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Connectivity: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

7.2
For the A/D converter to meet its specified accuracy,
the charge holding capacitor (C
to fully charge to the input channel voltage level. The
analog input model is shown in Figure 7-3. The source
impedance (R
impedance directly affect the time required to charge
the capacitor C
impedance varies over the device voltage (V
Figure 7-3. The maximum recommended imped-
ance for analog sources is 10 kΩ. As the impedance
is decreased, the acquisition time may be decreased.
EQUATION 7-1:
FIGURE 7-3:
 2003 Microchip Technology Inc.
T
T
T
ACQ
C
ACQ
Note 1: The reference voltage (V
A/D Acquisition Requirements
2: The charge holding capacitor (C
3: The maximum recommended impedance for analog sources is 10 kΩ. This is required to meet the pin
=
=
=
=
=
=
=
=
leakage specification.
Amplifier Settling Time +
Hold Capacitor Charging Time +
Temperature Coefficient
T
2µs + T
C
- 120pF (1kΩ + 7kΩ + 10kΩ) In(0.0004885)
16.47µs
2µs + 16.47µs + [(50°C -25°C)(0.05µs/°C)
19.72µs
S
AMP
HOLD
) and the internal sampling switch (R
Legend C
HOLD
+ T
C
(R
VA
. The sampling switch (R
C
+ [(Temperature -25°C)(0.05µs/°C)]
ACQUISITION TIME
ANALOG INPUT MODEL
IC
+ T
V
I
R
SS
C
R
+ R
LEAKAGE
T
PIN
IC
HOLD
S
COFF
SS
ANx
+ R
C
5 pF
HOLD
PIN
= input capacitance
= threshold voltage
= leakage current at the pin due to
= interconnect resistance
= sampling switch
= sample/hold capacitance (from DAC)
S
) In(1/2047)
various junctions
) must be allowed
REF
) has no effect on the equation, since it cancels itself out.
HOLD
V
DD
DD
), see
V
V
) is not discharged after each conversion.
T
T
SS
SS
= 0.6V
= 0.6V
)
)
I
± 500 nA
LEAKAGE
After the analog input channel is selected (changed),
this acquisition must be done before the conversion
can be started.
To
Equation 7-1 may be used. This equation assumes
that 1/2 LSb error is used (1024 steps for the A/D).
The 1/2 LSb error is the maximum error allowed for
the A/D to meet its specified resolution.
To calculate the minimum acquisition time, T
the
(DS33023).
R
IC
≤ 1K
calculate
PICmicro™
V
SS R
Sampling
Switch
DD
6V
5V
4V
3V
2V
PIC12F629/675
SS
the
Mid-Range
Sampling Switch
5 6 7 8 9 10 11
V
minimum
SS
C
= DAC capacitance
= 120 pF
(kΩ)
HOLD
Reference
acquisition
DS41190C-page 45
ACQ
Manual
time,
, see