LTC2499: 24-Bit, 16-Channel Delta Sigma ADCs with Easy Drive Input Current Cancellation.
More...
LTC2499: 24-Bit, 16-Channel Delta Sigma ADCs with Easy Drive Input Current Cancellation.
The LTC2499 is a 16-channel (eight differential), 24-bit, No Latency DS TM
ADC with Easy Drive technology and a 2-wire, I2C interface. The patented
sampling scheme eliminates dynamic input current errors and the
shortcomings of on-chip buffering through automatic cancellation of
differential input current. This allows large external source impedances
and rail-to-rail input signals to be directly digitized while maintaining
exceptional DC accuracy.
I2C DATA FORMAT (MSB FIRST);
Data Out:
Byte #1 Byte #2
START SA6 SA5 SA4 SA3 SA2 SA1 SA0 R SACK SGN MSB D23 D22 D21 D20 D19 D18 MACK
Byte #3 Byte #4
D17 D16 D15 D14 D13 D12 D11 D10 MACK D9 D8 D7 D6 D5 D4 D3 D2
Byte #5
MACK D1 D0 SUB5 SUB4 SUB3 SUB2 SUB1 SUB0 MNACK STOP
Data In:
Byte #1 Byte #2
MSB
START SA6 SA5 SA4 SA3 SA2 SA1 SA0 W SACK C12 C11 C10 C9 C8 C7 C6 C5 SACK
Byte #3
C4 C3 C2 C1 C0 X X X SACK STOP
START : I2C Start
REPEAT Start : I2C Repeat Start
STOP : I2C Stop
SACK : I2C Slave Generated Acknowledge (Active Low)
MACK : I2C Master Generated Acknowledge (Active Low)
MNACK : I2C Master Generated Not Acknowledge
SAx : I2C Address
W : I2C Write (0)
R : I2C Read (1)
Cx : Command Code
Dx : Data Bits
X : Don't care
MSB : Most Significant Bit
Example Code:
Read Channel 0 in Single-Ended with 1X speed mode and rejection frequency of 50Hz
adc_command_high = LTC2499_CH0; // Build ADC command for channel 0
adc_command_low = LTC2499_R50 | LTC2499_SPEED_1X; // Set to 1X mode with 50hz rejection
ack |= LTC2499_read(i2c_address, adc_command_high, adc_command_low, &adc_code); // Throws out last reading
ack |= LTC2499_read(i2c_address, adc_command_high, adc_command_low, &adc_code); // Obtains the current reading and stores to adc_code variable
if(!ack)
adc_voltage = LTC2499_code_to_voltage(adc_code, LTC2499_vref); // Convert adc_code to voltage
http://www.linear.com/product/LTC2499
http://www.linear.com/product/LTC2499#demoboards
Copyright 2018(c) Analog Devices, Inc.
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
- Neither the name of Analog Devices, Inc. nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
- The use of this software may or may not infringe the patent rights of one or more patent holders. This license does not release you from the requirement that you obtain separate licenses from these patent holders to use this software.
- Use of the software either in source or binary form, must be run on or directly connected to an Analog Devices Inc. component.
THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Header for LTC2499: 24-Bit, 16-Channel Delta Sigma ADCs with Easy Drive Input Current Cancellation
Definition in file LTC2499.h.