PIC16F684-ISL Microchip Technology Inc., PIC16F684-ISL Datasheet - Page 65
Manufacturer Part Number
Microchip Technology Inc.
Specifications of PIC16F684-ISL
CONVERTER (A/D) MODULE
The Analog-to-Digital converter (A/D) allows conver-
sion of an analog input signal to a 10-bit binary repre-
sentation of that signal. The PIC16F684 has eight
analog inputs, multiplexed into one sample and hold
A/D BLOCK DIAGRAM
A/D Configuration and Operation
There are three registers available to control the
functionality of the A/D module:
ANSEL (Register 9-1)
ADCON0 (Register 9-2)
ADCON1 (Register 9-3)
ANALOG PORT PINS
The ANS<7:0> bits (ANSEL<7:0>) and the TRIS bits
control the operation of the A/D port pins. Set the
corresponding TRIS bits to set the pin output driver to
its high-impedance state. Likewise, set the correspond-
ing ANSEL bit to disable the digital input buffer.
Analog voltages on any pin that is defined
as a digital input may cause the input
buffer to conduct excess current.
There are eight analog channels on the PIC16F684,
(ADCON0<4:2>) control which channel is connected to
the sample and hold circuit.
2004 Microchip Technology Inc.
circuit. The output of the sample and hold is connected
to the input of the converter. The converter generates a
binary result via successive approximation and stores
the result in a 10-bit register. The voltage reference
used in the conversion is software selectable to either
or a voltage applied by the V
shows the block diagram of the A/D on the PIC16F684.
VCFG = 0
VCFG = 1
There are two options for the voltage reference to the
A/D converter: either V
applied to V
controls the voltage reference selection. If VCFG is set,
then the voltage on the V
pin. Figure 9-1
is used, or an analog voltage
is used. The VCFG bit (ADCON0<6>)
pin is the reference;
is the reference.