aduc7030 Analog Devices, Inc., aduc7030 Datasheet - Page 50

• Manufacturer Part Number: aduc7030
• Description: Integrated Precision Battery Sensor For Automotive
• Manufacturer: Analog Devices, Inc.

ADuC7030/ADuC7033
VOLTAGE/TEMPERATURE CHANNEL ADC (V/T-
ADC)
This voltage/temperature channel ADC (V/T-ADC) is intended
to convert additional battery parameters such as voltage and
temperature. The input to this channel can be multiplexed from
one of three input sources, namely external voltage, external
temperature sensor circuit and on-chip temperature sensor.
As with the Current Channel ADC described previously, the
V/T-ADC employs an identical sigma-delta conversion
technique, including a modified Sinc3 low-pass filter to give a
valid 16-Bit data conversion result at programmable output
rates from 4Hz to 8 KHz. An external RC filter network is not
required as this is implemented internally in the voltage
channel.
VTEMP
VBAT
DIVIDE BY 24, INPUT
DIFFERENTIAL
ATTENUATOR
ATTENUATOR
45R
2R
1R
BUF
BUF
INTERNAL
TEMP
IMPEDANCE INPUT STAGE
THE BUFFER AMPLIFIERS
FOR THE ANALOG INPUT.
BUFFER AMPLIFIERS
PRESENTS A HIGH
REFERENCE IS ROUTED TO
EXTERNAL REFERENCE ON
THE ADC BY DEFAULT. AN
THE VREF PIN CAN ALSO
PRECISION REFERENCE
THE INTERNAL 5ppm/°C
MUX
BE SELECTED.
CHOP
Figure 16. Voltage/ Temperature ADC, Top Level Overview
REFERENCE
PROGRAMMABLE CHOPPING
THROUGH THE CONVERSION
INTERNAL
ALTERNATELY REVERSED
VREF
MODULATOR
THE INPUTS ARE
ANALOG INPUT
-û
-û A/D CONVERTER
CYCLE.
Rev. PrE | Page 50 of 150
PROGRAMMABLE
QUANTIZATION NOISE INTRODUCED
DIGITAL FILTER
BY THE MODULATOR. THE UPDATE
FILTER ARE PROGRAMMABLE VIA
RATE AND BANDWIDTH OF THIS
SCALED BY THE CALIBRATION
COEFFICIENTS BEFORE BEING
THE SINC
THE OUTPUT WORD FROM
THE DIGITAL FILTER IS
CONVERSION RESULT.
PROVIDED AS THE
THE ADCFLT MMR.
OUTPUT SCALING
PROGRAMMABLE
CYCLE OF WHICH REPRESENTS
THE DIGITAL FILTER, THE DUTY
THE MODULATOR PROVIDES A
THE SAMPLED ANALOG INPUT
DIGITAL FILTER
HIGH FREQUENCY 1-BIT DATA
WHICH IS ALSO CHOPPED) TO
STREAM (THE OUTPUT OF
3
FILTER REMOVES
The external battery voltage (VBAT) is routed to the ADC input
via an on-chip high voltage, (divide by 24) resistive attenuator.
This must be enabled/disabled via HVCFG1[7].
The battery temperature can be derived via the on chip
temperature sensor or an external temperature sensor input.
The time to a first valid (fully settled) result after an input
channel switch on the voltage/temperature channel is three
ADC conversion cycles with chop mode turned off.
This ADC is again buffered but unlike the current channel has a
fixed input range of 0V to V
on VBAT (assuming an internal 1.2V reference). A top level
overview of this ADC signal chain is shown in Figure 16.
-û MODULATOR
VOLTAGE.
COEFFICIENT
COEFFICIENT
OFFSET
GAIN
CHOP
Preliminary Technical Data
INTERRUPT ONCE A VOLTAGE
ADC INTERRUPT GENERATOR
CONVERSION IS COMPLETED.
AVERAGE
FORMAT
OUTPUT
RESULT
OUTPUT
NO MISSING CODES.
ADC
GENERATES AN ADC
ENSURES 16 BITS
ARCHITECTURE
OR TEMPERATURE
-û ADC
THE -û
REF
INTERRUPT
on VTEMP+ and 0V to 28.8V
TO VOLTAGE OR
TEMPERATURE
DATA MMR
ADC
THE FILTER IS SUMMED AND
AS PART OF THE CHOPPING
DATA-WORD OUTPUT FROM
IMPLEMENTATION, EACH
AVERAGED WITH ITS
OUTPUT AVERAGE
PREDECESSOR.