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Linear Technology Arduino-Compatible Demonstration Board

LTC2461: 16-Bit I2C Delta Sigma ADCs with 10ppm/C Max Precision Reference. More...

Detailed Description

LTC2461: 16-Bit I2C Delta Sigma ADCs with 10ppm/C Max Precision Reference.

LTC2463: Differential, 16-Bit I2C Delta Sigma ADCs with 10ppm/C Max Precision Reference. LTC2453: Differential, 16-Bit Delta Sigma ADC With I2C Interface.

The LTC2461/LTC2463 are ultra tiny, 16-Bit analog-todigital converters with an
integrated precision reference. They use a single 2.7V to 5.5V supply and
communicate through an I2C Interface. The LTC2461 is single-ended with a 0V to
1.25V input range and the LTC2463 is differential with a 1.25V input range. Both
ADCs include a 1.25V integrated reference with 2ppm/C drift performance and 0.1%
initial accuracy. The converters are available in a 12-pin 3mm x 3mm DFN package
or an MSOP-12 package. They include an integrated oscillator and perform
conversions with no latency for multiplexed applications. The LTC2461/LTC2463
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):

       Byte #1                             Byte #2                              Byte #3

START  SA6 SA5 SA4 SA3 SA2 SA1 SA0 W SACK  EN1 EN2 SPD SLP X   X   X  X   SACK  STOP

START  SA6 SA5 SA4 SA3 SA2 SA1 SA0 R SACK  D15 D14 D13 D12 D11 D10 D9 D8  MACK  D7 D6  D5  D4  D3  D2  D1  D0 MNACK STOP

SACK  : Slave Acknowledge
MACK  : Master Acknowledge
MNACK : Master Not Acknowledge
Sx    : Address Select Bit
EN1   : Enable 1 : to program, EN1 = High, EN2 = Low
EN2   : Enable 2
SPD   : Speed Bit- 0 for 60Hz, 1 for 30Hz
SLP   : Sleep Mode Bit
X     : Don't care
Dx    : Data Bits


Example Code:

Read ADC in 60Hz Speed Mode

    ack |= LTC2461_read(LTC2461_I2C_ADDRESS, LTC2461_60HZ_SPEED_MODE, &adc_code_60Hz);  // Throws out last reading
    ack |= LTC2461_read(LTC2461_I2C_ADDRESS, LTC2461_60HZ_SPEED_MODE, &adc_code_60Hz);  // Obtains the current reading and
                                                                                        // stores to adc_code_60Hz variable

    // Convert adc_code_60Hz to voltage
    adc_voltage_60Hz = LTC2461_code_to_voltage(adc_code_60Hz, LTC2461_lsb, LTC2461_offset_code);

http://www.linear.com/product/LTC2461 http://www.linear.com/product/LTC2463 http://www.linear.com/product/LTC2453

http://www.linear.com/product/LTC2461#demoboards http://www.linear.com/product/LTC2463#demoboards http://www.linear.com/product/LTC2453#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 LTC2461: 16-Bit I2C Delta Sigma ADCs with 10ppm/C Max Precision Reference

Definition in file LTC2461.h.

Go to the source code of this file.

Functions

int8_t LTC2461_read (uint8_t i2c_address, uint8_t adc_command, uint16_t *adc_code)
 Reads the ADC and returns 16-bit data. More...
 
int8_t LTC2461_command (uint8_t i2c_address, uint8_t adc_command)
 Write a 16-bit command to the ADC. More...
 
float LTC2461_code_to_voltage (uint16_t adc_code, float LTC2461_lsb, int32_t LTC2461_offset_code)
 Calculates the LTC2309 input unipolar voltage. More...
 
void LTC2461_cal_voltage (uint16_t zero_code, uint16_t fs_code, float zero_voltage, float fs_voltage, float *LTC2461_lsb, int32_t *LTC2461_offset_code)
 Calibrate the lsb. More...
 

Macros

I2C addresses

Un-comment the address corresponding to the LTC2309's address

#define LTC2461_I2C_ADDRESS   0x14
 
Modes
#define LTC2461_30HZ_SPEED_MODE   0xA0
 
#define LTC2461_60HZ_SPEED_MODE   0x80
 
#define LTC2461_SLEEP_MODE   0x90
 

Function Documentation

◆ LTC2461_cal_voltage()

void LTC2461_cal_voltage ( uint16_t  zero_code,
uint16_t  fs_code,
float  zero_voltage,
float  fs_voltage,
float *  LTC2461_lsb,
int32_t *  LTC2461_offset_code 
)

Calibrate the lsb.

Returns
Void
Parameters
zero_codeCode from zero reading
fs_codeFull-scale code
zero_voltageMeasured zero voltage
fs_voltageMeasured full-scale voltage
LTC2461_lsbReturn LSB value (volts)
LTC2461_offset_codeReturn Offset code

Definition at line 111 of file LTC2461.cpp.

◆ LTC2461_code_to_voltage()

float LTC2461_code_to_voltage ( uint16_t  adc_code,
float  LTC2461_lsb,
int32_t  LTC2461_offset_code 
)

Calculates the LTC2309 input unipolar voltage.

Returns
Floating point voltage
Parameters
adc_codeRaw ADC code
LTC2461_lsbLSB value (volts)
LTC2461_offset_codeOffset code

Definition at line 103 of file LTC2461.cpp.

◆ LTC2461_command()

int8_t LTC2461_command ( uint8_t  i2c_address,
uint8_t  adc_command 
)

Write a 16-bit command to the ADC.

Derived from 2655.

Returns
Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC2461.
adc_commandADC command to be written to the LTC2461.

Definition at line 93 of file LTC2461.cpp.

◆ LTC2461_read()

int8_t LTC2461_read ( uint8_t  i2c_address,
uint8_t  adc_command,
uint16_t *  adc_code 
)

Reads the ADC and returns 16-bit data.

Returns
Returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
Parameters
i2c_addressI2C address of the LTC2461.
adc_commandADC command to be written to the LTC2461.
adc_codeReturns code read from ADC.

Definition at line 82 of file LTC2461.cpp.

Macro Definition Documentation

◆ LTC2461_30HZ_SPEED_MODE

#define LTC2461_30HZ_SPEED_MODE   0xA0

Definition at line 122 of file LTC2461.h.

◆ LTC2461_60HZ_SPEED_MODE

#define LTC2461_60HZ_SPEED_MODE   0x80

Definition at line 123 of file LTC2461.h.

◆ LTC2461_I2C_ADDRESS

#define LTC2461_I2C_ADDRESS   0x14

Definition at line 115 of file LTC2461.h.

◆ LTC2461_SLEEP_MODE

#define LTC2461_SLEEP_MODE   0x90

Definition at line 124 of file LTC2461.h.