PIC18F2525-I/SO Microchip Technology, PIC18F2525-I/SO Datasheet - Page 230

• Manufacturer Part Number: PIC18F2525-I/SO
• Description: IC MCU FLASH 24KX16 28SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2525-I/SO

• Program Memory Type: FLASH
• Program Memory Size: 48KB (24K x 16)
• Package / Case: 28-SOIC (7.5mm Width)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 25
• Eeprom Size: 1K x 8
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 10x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3986 B
• Interface Type: SPI, I2C, EUSART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 25
• Number Of Timers: 1 x 8
• Operating Supply Voltage: 4.2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DM163022, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Package: 28SOIC W
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 40 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28SO-1 - SOCKET TRANSITION 28SOIC 300MILI3DB18F4620 - BOARD DAUGHTER ICEPIC3
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F2525/2620/4525/4620
19.1
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 19-3. The
source impedance (R
switch (R
required to charge the capacitor C
switch (R
(V
at the analog 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 19-1:
EQUATION 19-2:
EQUATION 19-3:
DS39626B-page 228
T
V
or
T
T
T
T
Temperature coefficient is only required for temperatures > 25 C. Below 25 C, T
T
T
ACQ
C
ACQ
AMP
COFF
C
ACQ
DD
Note:
HOLD
). The source impedance affects the offset voltage
=
=
A/D Acquisition Requirements
SS
=
=
=
=
=
SS
=
=
) impedance varies over the device voltage
When the conversion is started, the
holding capacitor is disconnected from the
input pin.
Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient
T
) impedance directly affect the time
AMP
T
0.2 s
(Temp – 25 C)(0.02 s/ C)
(85 C – 25 C)(0.02 s/ C)
1.2 s
-(C
-(25 pF) (1 k + 2 k + 2.5 k ) ln(0.0004883)
1.05 s
0.2 s + 1 s + 1.2 s
2.4 s
(V
-(C
AMP
+ T
REF
HOLD
HOLD
+ T
C
– (V
ACQUISITION TIME
A/D MINIMUM CHARGING TIME
CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME
S
+ T
)(R
C
)(R
) and the internal sampling
+ T
COFF
REF
IC
IC
+ R
COFF
/2048)) • (1 – e
+ R
HOLD
SS
SS
HOLD
+ R
+ R
) must be allowed
S
S
) ln(1/2047)
. The sampling
) ln(1/2048)
(-T
C
/C
HOLD
Preliminary
(R
IC
+ R
SS
+ R
S
To
Equation 19-1 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.
Example 19-3 shows the calculation of the minimum
required acquisition time T
based
assumptions:
C
Rs
Conversion Error
V
Temperature
))
DD
HOLD
)
calculate
on
COFF
the
= 0 ms.
the
=
=
=
=
following
minimum
 2004 Microchip Technology Inc.
25 pF
2.5 k
1/2 LSb
5V
85 C (system max.)
ACQ
Rss = 2 k
. This calculation is
application
acquisition
system
time,