PIC18F6493T-I/PT Microchip Technology, PIC18F6493T-I/PT Datasheet - Page 36

• Manufacturer Part Number: PIC18F6493T-I/PT
• Description: PIC18F With 128-segment LCD Driver And 12-bit ADC, 16KB Flash, 768B RAM, CCP, MS
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F6493T-I/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, LCD, POR, PWM, WDT
• Number Of I /o: 50
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 12x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TFQFP
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: AUSART, EUSART, I2C, MSSP, SPI
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 50
• Number Of Timers: 4
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DV164136, DM163030
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 12 bit, 12 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: PIC18F6493T-I/PTTR

PIC18F6393/6493/8393/8493
2.1
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 2-3. The source
impedance (R
impedance directly affect the time required to charge
the capacitor, C
impedance varies over the device voltage (V
source impedance affects the offset voltage at the ana-
log input (due to pin leakage current). The maximum
recommended impedance for analog sources is
2.5 k. After the analog input channel is selected
(changed), the channel must be sampled for at least
the minimum acquisition time before starting a
conversion.
EQUATION 2-1:
EQUATION 2-2:
EQUATION 2-3:
DS39896C-page 36
T
V
or
T
T
T
T
Temperature coefficient is only required for temperatures > 25C. Below 25C, T
T
T
ACQ
Note:
C
ACQ
AMP
COFF
C
ACQ
HOLD
= Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient
= T
=
= (V
= T
= 0.2 µs
= (Temp – 25C)(0.02 µs/C)
= -(C
= 0.2 µs + 1.56 s + 1.2 µs
A/D Acquisition Requirements
(85C – 25C)(0.02 µs/C)
1.2 µs
-(25 pF) (1 k + 4 k + 2.5 k) ln(0.0002441) µs
1.56 µs
2.96 µs
AMP
(C
When the conversion is started, the
holding capacitor is disconnected from the
input pin.
AMP
S
REF
HOLD
HOLD
) and the internal sampling switch (R
+ T
+ T
HOLD
– (V
C
)(R
)(R
C
+ T
+ T
REF
IC
IC
. The sampling switch (R
A/D ACQUISITION TIME
A/D MINIMUM CHARGING TIME
CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME
COFF
+ R
+ R
COFF
/4096)) • (1 – e
SS
SS
+ R
+ R
HOLD
S
S
) ln(1/4096)
) ln(1/4096) µs
) must be allowed
(-T
C
/C
HOLD
DD
(R
). The
IC
SS
SS
+ R
)
)
SS
+ R
S
))
)
To calculate the minimum acquisition time, Equation 2-1
may be used. This equation assumes that 1/2 LSb error
is used (4096 steps for the 12-bit A/D). The 1/2 LSb error
is the maximum error allowed for the A/D to meet its
specified resolution.
Equation 2-3 shows the calculation of the minimum
required acquisition time, T
based
assumptions:
C
Rs
Conversion Error
V
Temperature
HOLD
DD
on
COFF
the
= 0 µs.
=
=

=
=
following
 2010 Microchip Technology Inc.
25 pF
2.5 k
1/2 LSb
3V  Rss = 4 k
85C (system max.)
ACQ
. This calculation is
application
system