PIC16F874-20/L Microchip Technology, PIC16F874-20/L Datasheet - Page 429

• Manufacturer Part Number: PIC16F874-20/L
• Description: IC MCU FLASH 4KX14 EE 44PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F874-20/L

• Core Size: 8-Bit
• Program Memory Size: 7KB (4K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 44-PLCC
• Controller Family/series: PIC16F
• No. Of I/o's: 33
• Eeprom Memory Size: 128Byte
• Ram Memory Size: 192Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 192 B
• Interface Type: MSSP, PSP, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163022, DV164120
• Minimum Operating Temperature: 0 C
• On-chip Adc: 10 bit, 8 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164309 - MODULE SKT FOR PM3 44PLCC444-1001 - DEMO BOARD FOR PICMICRO MCUDVA16XL441 - ADAPTER DEVICE ICE 44PLCC309-1040 - ADAPTER 44-PLCC ZIF TO 40-DIP309-1039 - ADAPTER 44-PLCC TO 40-DIPDV007003 - PROGRAMMER UNIVERSAL PROMATE II
• Lead Free Status / Rohs Status: Details

1997 Microchip Technology Inc.
Legend C
V
AIN
Rs
V
I
R
SS
C
LEAKAGE
T
PIN
IC
HOLD
ANx
C
5 pF
Now to get an idea what happens to the acquisition time when the source impedance is a mini-
mal value ( R
the source impedance made a minimal value ( R
Example 23-2:
Figure 23-3: Analog Input Model
PIN
T
Temperature coefficient is only required for temperatures > 25 C.
T
T
T
ACQ
ACQ
C
ACQ
= input capacitance
= threshold voltage
= leakage current at the pin due to
= interconnect resistance
= sampling switch
= sample/hold capacitance (from DAC)
Note 1: The reference voltage (V
Note 2: The charge holding capacitor (C
Note 3: The maximum recommended impedance for analog sources is 10 k . This is
Note 4: After a conversion has completed, a 2.0T
=
various junctions
=
=
=
Section 23. 10-bit A/D Converter
out.
required to meet the pin leakage specification.
can begin again. During this time the holding capacitor is not connected to the
selected A/D input channel.
S
T
2 s + Tc + [(Temp - 25 C)(0.05 s/ C)]
-C
-120 pF (1 k + 7 k + 50 ) ln(0.0004885)
-120 pF (8050 ) ln(0.0004885)
-0.966 s (-7.6241)
7.36 s
2 s + 16.47 s + [(50 C - 25 C)(0.05 s/ C)]
9.36 s + 1.25 s
10.61 s
= 50
AMP
V
HOLD
DD
Calculating the Minimum Required Acquisition Time (Case 2)
V
+ T
V
).
T
T
(R
Example 23-2
= 0.6V
= 0.6V
C
IC
+ T
+ R
Preliminary
COFF
SS
+ R
I leakage
100 nA
REF
shows the same conditions as in
S
R
) ln(1/2047)
IC
) has no effect on the equation, since it cancels itself
HOLD
1k
S
V
) is not discharged after each conversion.
= 50 ).
SS
DD
Sampling
Switch
AD
6V
5V
4V
3V
2V
R
delay must complete before acquisition
SS
Sampling Switch
5 6 7 8 9 10 11
V
SS
C
( k )
HOLD
Example 23-1
= 120 pF
DS31023A-page 23-7
with only
23