PIC16F631 Datasheet, PDF (119/294 Pages) Microchip Technology – 20-Pin Flash-Based, 8-Bit CMOS Microcontrollers with nanoWatt Technology

PIC16F631/677/685/687/689/690
FIGURE 9-4:
ANALOG INPUT MODEL
Rs ^ANx
VDD
VT = 0.6V
RIC ≤ 1k
Sampling
Switch
SS _Rss
VA
CPIN
5 pF
VT = 0.6V
I LEAKAGE
± 500 nA
CHOLD = 10 pF
VSS/VREF-
Legend: CPIN
= Input Capacitance
VT
= Threshold Voltage
I LEAKAGE = Leakage current at the pin due to
various junctions
RIC
= Interconnect Resistance
SS
= Sampling Switch
CHOLD = Sample/Hold Capacitance
6V
5V
RSS
VDD 4V
3V
2V
5 6 7 8 9 10 11
Sampling Switch
(kΩ)
FIGURE 9-5:
ADC TRANSFER FUNCTION
3FFh
3FEh
3FDh
3FCh
3FBh
004h
003h
002h
001h
000h
VSS/VREF-
Full-Scale Range
1 LSB ideal
Zero-Scale
Transition
1 LSB ideal
Full-Scale
Transition
Analog Input Voltage
VDD/VREF+
© 2007 Microchip Technology Inc.
DS41262D-page 117