ADUC824 Analog Devices, ADUC824 Datasheet - Page 32

• Manufacturer Part Number: ADUC824
• Description: Precision Analog Microcontroller: 1MIPS 8052 MCU + 8kB Flash + 16/24-Bit ADC + 12-Bit DAC
• Manufacturer: Analog Devices

Specifications of ADUC824

• Mcu Core: 8052
• Mcu Speed (mips): 1
• Sram (bytes): 256Bytes
• Gpio Pins: 34
• Adc # Channels: 4

ADuC824
Auxiliary ADC
The Auxiliary ADC is intended to convert supplementary inputs
such as those from a cold junction diode or thermistor. This ADC
is not buffered and has a fixed input range of 0 V to 2.5 V
TEMPERATURE
ON-CHIP
SENSOR
CONVERSION CYCLE. CHOPPING
ANALOG INPUT CHOPPING
THE INPUTS ARE ALTERNATELY
THE MULTIPLEXER IS CONTROLLED
AIN3
AIN4
AIN5
EXTERNAL SINGLE ENDED INPUTS
OR THE ON-CHIP TEMP. SENSOR.
ALLOWS SELECTION OF THREE
OFFSET AND OFFSET DRIFT
A DIFFERENTIAL MULTIPLEXER
VIA THE CHANNEL SELECTION
REVERSED THROUGH THE
YIELDS EXCELLENT ADC
ANALOG MULTIPLEXER
SEE PAGES 28 AND 33
PERFORMANCE
BITS IN ADC1CON
SEE PAGE 36
MUX
CHOP
REFIN(–) REFIN(+)
REFERENCE VOLTAGE IS SELECTED
THE EXTERNAL REFERENCE INPUT
DIFFERENTIAL REFERENCE
TO THE ADuC824 IS DIFFERENTIAL
AND FACILITATES RATIOMETRIC
VIA THE XREF1 BIT IN ADC1CON.
CIRCUITRY TESTS FOR OPEN OR
SHORTED REFERENCES INPUTS
OPERATION. THE EXTERNAL
STREAM (THE OUTPUT OF WHICH
THE MODULATOR PROVIDES A
REFERENCE DETECT
HIGH FREQUENCY 1-BIT DATA
REPRESENTS THE SAMPLED
THE DUTY CYCLE OF WHICH
IS ALSO CHOPPED) TO THE
ANALOG INPUT VOLTAGE
SEE PAGE 35
SIGMA DELTA
MODULATOR
DIGITAL FILTER,
SIGMA-DELTA
MODULATOR
SEE PAGE 35
SIGMA-DELTA A/D CONVERTER
PROGRAMMABLE
DIGITAL
FILTER
(assuming an external 2.5 V reference). The single-ended inputs
can be driven from AIN3, AIN4, or AIN5 pins or directly from
the on-chip temperature sensor voltage. A block diagram of the
Auxiliary ADC is shown in Figure 19.
CHOPPED TO REMOVE DRIFT
ARCHITECTURE ENSURES
SIGMA-DELTA ADC
SIGMA-DELTA ADC IS
16 BITS NO MISSING
CODES. THE ENTIRE
THE SIGMA-DELTA
QUANTIZATION NOISE INTRODUCED
BY THE MODULATOR. THE UPDATE
SEE PAGE 35
PROGRAMMABLE DIGITAL
RATE AND BANDWIDTH OF THIS
FILTER ARE PROGRAMMABLE
THE SINC 3 FILTER REMOVES
ERRORS
VIA THE SF SFR
SEE PAGE 35
CHOP
FILTER
AVERAGE
OUTPUT
AS PART OF THE CHOPPING
SUMMED AND AVERAGED
WITH ITS PREDECESSOR
IMPLEMENTATION EACH
TO NULL ADC CHANNEL
OUTPUT AVERAGE
DATA WORD OUTPUT
FROM THE FILTER IS
OFFSET ERRORS
SEE PAGE 36
DIGITAL FILTER IS SCALED BY
THE OUPUT WORD FROM THE
THE CONVERSION RESULT
SCALING
COEFFICIENTS BEFORE
OUTPUT
OUTPUT SCALING
BEING PROVIDED AS
THE CALIBRATION
SEE PAGE 37
RESULT WRITTEN
TO ADC1H/L SFRs
DIGTAL OUTPUT