aduc7023bcpz62irl Analog Devices, Inc., aduc7023bcpz62irl Datasheet - Page 34

• Manufacturer Part Number: aduc7023bcpz62irl
• Description: Precision Analog Microcontroller, 12-bit Analog I/o, Arm7tdmi Mcu With Enhanced Irq Handler
• Manufacturer: Analog Devices, Inc.

ADuC7023
For system gain error correction, the ADC channel input stage
must be tied to V
loop must be implemented to modify the value in ADCGN
until the ADCDAT reads Code 4094 to Code 4095. If the
ADCDAT value is less than 4094, ADCGN should be
incremented until ADCDAT reads Code 4094 to Code 4095.
Similar to the offset calibration, the gain calibration resolution
is 0.25 LSB with a range of ±3% of V
TEMPERATURE SENSOR
The ADuC7023 provides a voltage output from an on-chip
band gap reference that is proportional to absolute temperature.
This voltage output can also be routed through the front-end
ADC multiplexer (effectively an additional ADC channel
input), facilitating an internal temperature sensor channel,
measuring die temperature.
An ADC temperature sensor conversion differs from a standard
ADC voltage. The ADC performance specifications do not
apply to the temperature sensor.
Chopping of the internal amplifier should be enabled using the
TSCON register. To enable this mode, the user must set Bit 0 of
TSCON. The user must also take two consecutive ADC readings
and average them in this mode.
The ADCCON register must be configured to 0x37A3.
For maximum result accuracy, a calibrated temperature
reference is used. The TEMPREF register contains a voltage
calibration coefficient that is required to be applied to the ADC
result. The format of the calibration coefficient is described in
the TEMPREF register description.
To calculate die temperature use the following formula:
where:
T is the temperature result.
T
V
conversions.
V
TEMPREF register.
K is the gain of the ADC in temperature sensor mode as
determined by characterization data, K = 0.2683°C/mV.
TSCON Register
Name:
Address:
Default value:
Access:
REF
ADC
TREF
T − T
is the production test temperature.
is the average ADC result from two consecutive
is the calibration coefficient calculated from the
REF
= (V
REF
ADC
TSCON
0xFFFF0544
0x00
Read/write
. A continuous software ADC conversion
− V
TREF
) × K
REF
.
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TSCON MMR Bit Designations
Bit
7 to 1
0
TEMPREF Register
Name:
Address:
Default value:
Access:
TEMPREF MMR Bit Designations
Bit
15 to 9
8
7 to 0
BAND GAP REFERENCE
The ADuC7023 provides an on-chip band gap reference of
2.5 V, which can be used for the ADC and DAC. This internal
reference also appears on the V
reference, a 0.47 μF capacitor must be connected from the external
V
ADC conversions. This reference can also be connected to an
external pin (V
the system. An external buffer is required because of the low drive
capability of the V
an external reference input on the V
REF
pin to AGND to ensure stability and fast response during
Description
Reserved.
Temperature reference voltage sign.
ADC calibration voltage measured typically at 25°C.
Characterization data determined that 2292 decimal is
the typical ADC code from a temperature sensor
conversion at typically 25°C. The TEMPREF register
contains the deviation of each part from 2292 in sign
magnitude format.
To calculate the V
perform the following calculation:
where:
TEMPREF[8] = 1
Or
where:
TEMPREF[8] = 0.
Finally,
Description
Reserved.
Temperature sensor chop enable bit.
This bit is set to 1 to enable chopping of the internal
amplifier to the ADC.
This bit is cleared to disable chopping.
This bit is cleared by default.
V
negative, subtract TEMPREF from 2292
C
to 2292
V
REF
TREF
TREF
TREF
) and used as a reference for other circuits in
REF
= 2292 − TEMPREF[7:0]//If TEMPREF sign
= TEMPREF[7:0] + 2292//Positive TEMPREF add
= (C
TEMPREF
0xFFFF0548
0x0000
Read/write
output. A programmable option also allows
TREF
× V
TREF
REF
REF
from the TEMPREF register,
)/4096
pin. When using the internal
REF
pin.