Linduino  1.3.0
Linear Technology Arduino-Compatible Demonstration Board

LTC2473: 16-Bit, Delta Sigma ADC with I2C interface. More...

Detailed Description

LTC2473: 16-Bit, Delta Sigma ADC with I2C interface.

The LTC2471/LTC2473 are small, 16-bit analog-to-digital converters with an
integrated precision reference and a selectable 208sps or 833sps output
rate. They use a single 2.7V to 5.5V supply and communicate through an I2C
Interface. The LTC2471 is single-ended with a 0V to VREF input range and
the LTC2473 is differential with a +-VREF input range. Both ADC's include
a 1.25V integrated reference with 2ppm/C drift performance and 0.1% initial
accuracy. They include an integrated oscillator and perform conversions with
no latency for multiplexed applications. The LTC2471/LTC2473 include a
proprietary input sampling scheme that reduces the average input current
several orders of magnitude when compared to conventional delta sigma
converters.

I2C DATA FORMAT (MSB FIRST);

Data Out:
Byte #1                                                   Byte #2
                                                          MSB
START  SA6 SA5 SA4 SA3 SA2 SA1 SA0 W SACK   REPEAT START  D15 D14 D13 D12 D11 D10 D9 D8 MACK

Byte #3
LSB
D7 D6 D5 D4 D3 D2 D1 D0 MNACK STOP

Data In:
Byte #1                                     Byte #2
START  SA6 SA5 SA4 SA3 SA2 SA1 SA0 W SACK   C3 C2 C1 C0 X 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

Example Code:

Read LTC2473:
    uint8_t acknowledge;
    int32_t adc_code = 0;
    uint16_t timeout = 300; // timeout in microseconds
    float adc_voltage;
    acknowledge = LTC2473_read(i2c_address, &adc_code, timeout);

    // Convert adc_code to voltage
    adc_voltage = LTC2473_code_to_voltage(adc_code, LTC2473_lsb, LTC2473_offset_code);

http://www.linear.com/product/LTC2473

http://www.linear.com/product/LTC2473#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 LTC2473: 16-Bit, Delta Sigma ADC with I2C interface

Definition in file LTC2473.h.

Go to the source code of this file.

Functions

uint8_t LTC2473_read (uint8_t i2c_address, int32_t *adc_code, uint16_t timeout)
 Reads from LTC2473. More...
 
uint8_t LTC2473_write (uint8_t i2c_address, uint8_t adc_command)
 Writes to the LTC2473. More...
 
float LTC2473_code_to_voltage (int32_t adc_code, float vref)
 Calculates the voltage corresponding to an ADC code, given the reference (in volts) More...
 

Macros

I2C_Addresses
#define LTC2473_I2C_ADDRESS   0x14
 I2C address of the LTC2473. More...
 
Mode Configuration
#define LTC2473_ENABLE_PROGRAMMING   0x80
 
#define LTC2473_SPS_208   0x00
 
#define LTC2473_SPS_833   0x20
 
#define LTC2473_SLEEP   0x10
 

Function Documentation

◆ LTC2473_code_to_voltage()

float LTC2473_code_to_voltage ( int32_t  adc_code,
float  vref 
)

Calculates the voltage corresponding to an ADC code, given the reference (in volts)

Returns
Returns voltage calculated from ADC code.
Parameters
adc_codeCode read from adc
vrefVRef (in volts)

Definition at line 94 of file LTC2473.cpp.

◆ LTC2473_read()

uint8_t LTC2473_read ( uint8_t  i2c_address,
int32_t *  adc_code,
uint16_t  timeout 
)

Reads from LTC2473.

Returns
1 if no acknowledge, 0 if acknowledge
Parameters
i2c_addressI2C address (7-bit format) for part
adc_code2 byte conversion code read from LTC2473
timeoutThe timeout in (microseconds)

Definition at line 77 of file LTC2473.cpp.

◆ LTC2473_write()

uint8_t LTC2473_write ( uint8_t  i2c_address,
uint8_t  adc_command 
)

Writes to the LTC2473.

Returns
1 if no acknowledge, 0 if acknowledge
Parameters
i2c_addressI2C address (7-bit format) for part
adc_commandCommand byte written to LTC2473

Definition at line 85 of file LTC2473.cpp.

Macro Definition Documentation

◆ LTC2473_ENABLE_PROGRAMMING

#define LTC2473_ENABLE_PROGRAMMING   0x80

Definition at line 125 of file LTC2473.h.

◆ LTC2473_I2C_ADDRESS

#define LTC2473_I2C_ADDRESS   0x14

I2C address of the LTC2473.

Configured by tying the ADR0 pin high or low. See datasheet for details. Uncomment LTC2473_I2C_ADDRESS to match demo board configuration.

Definition at line 116 of file LTC2473.h.

◆ LTC2473_SLEEP

#define LTC2473_SLEEP   0x10

Definition at line 128 of file LTC2473.h.

◆ LTC2473_SPS_208

#define LTC2473_SPS_208   0x00

Definition at line 126 of file LTC2473.h.

◆ LTC2473_SPS_833

#define LTC2473_SPS_833   0x20

Definition at line 127 of file LTC2473.h.