AD7280AWBSTZ Analog Devices Inc, AD7280AWBSTZ Datasheet - Page 38

• Manufacturer Part Number: AD7280AWBSTZ
• Description: IC BATT MON LI-ION AUTO 48LQFP
• Manufacturer: Analog Devices Inc
• Series: -r

Specifications of AD7280AWBSTZ

• Function: Battery Monitor, Over/Under Voltage Protection
• Battery Chemistry: Lithium-Ion (Li-Ion)
• Voltage - Supply: 8 V ~ 30 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 48-LQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

AD7280A
EXAMPLES OF INTERFACING WITH THE AD7280A
The AD7280A supports a number of read options. The user can
read back the results from
•
•
•
In each case, the user must first write to the read register on the
selected parts to configure that part to supply the correct data
on the outputs. When reading back an individual register, the
address of that register should be written to the read register of
the selected part. When reading back conversion results from
any or all parts in the chain, an address of 0x00 should be written
to the read register of the selected parts.
When the address written to the read register is 0x00, the
conversion results selected for readback are controlled by
setting Bits[D13:D12] of the control register (see Table 14).
These bits allow the user to select one of four different read-
back options:
•
•
•
•
To read back an individual register from a single AD7280A in
the daisy chain, follow these steps:
1.
2.
Note that it is more efficient in terms of 32-bit write cycles to
first switch off the read operation on all AD7280As in the daisy
chain. This is achieved with a single write cycle, using Bit D12
in the write command to address all parts in the chain. The user
can then address the individual part and set Bits[D13:D12] of
the control register to turn on the read operation for that part.
All conversions completed on all parts in the chain
Individual registers on all parts in the chain
Individual registers on selected parts in the chain
Read back 12 conversion results: six voltage and six
auxiliary.
Read back nine conversion results: six voltage and three
auxiliary.
Read back six conversion results: six voltage results only.
Switch off the read operation on this part.
On all other parts in the chain, set Bits[D13:D12] of the
control register to 11 to select the no-read operation on
those parts.
On the targeted part, set Bits[D13:D12] of the control
register to turn on the read operation.
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CONVERT AND READBACK ROUTINE
When conversion data from any or all of the AD7280As in a
daisy chain is read back, the conversion results returned from
the AD7280A are the last completed set of conversions on that
part. It is recommended that the user also set Bits[D15:D14] of
the control register to select the number of conversions to be
completed on each part and initiate the conversions through
either the CNVST pin or the rising edge of CS as part of the
read operation. In this way, the user can implement a simple
convert and readback routine with the most efficient number
of 32-bit write and read operations.
A general example of this routine, which converts and reads
back from all parts in the AD7280A daisy chain, is as follows:
1.
2.
3.
4.
5.
EXAMPLES
The following examples of conversion and/or readback routines
can be used in an application that implements a chain of AD7280A
devices to monitor the voltage and/or auxiliary ADC inputs of
the AD7280A on a stack of lithium ion batteries.
Write 0x00 to the read register on all parts in the daisy
chain. Note that 0x00 is the default value of this register
on power-up and following a software reset operation.
Write to the control register on all parts. Set Bits[D15:D14]
to select the required conversions. Set Bits[D13:D12] to
select the required conversion results for readback.
Initiate the conversions through either the falling edge of
CNVST or the rising edge of CS (set Bit D11 of the control
register to select the conversion start format).
Allow sufficient time for each conversion to be completed
plus t
ADC Inputs section.
Apply a CS low pulse that frames 32 SCLKs for each
conversion result to be read back.
WAIT
. See the Converting Cell Voltages and Auxiliary