Linduino  1.3.0
Linear Technology Arduino-Compatible Demonstration Board

LTC2418: 16-Channel 24-Bit No Latency Delta-Sigma ADC. More...

Detailed Description

LTC2418: 16-Channel 24-Bit No Latency Delta-Sigma ADC.

The LTC2414/LTC2418 are 8-/16-channel (4-/8-differential) micropower 24-bit
delta-sigma analog-to-digital converters. They operate from 2.7V to 5.5V and
include an integrated oscillator, 2ppm INL and 0.2ppm RMS noise. They use
delta-sigma technology and provide single cycle settling time for multiplexed
applications. Through a single pin, the LTC2414/LTC2418 can be configured for
better than 110dB differential mode rejection at 50Hz or 60Hz +/-2%, or they can
be driven by an external oscillator for a user-defined rejection frequency. The
internal oscillator requires no external frequency setting components.

SPI DATA FORMAT (MSB First):

            Byte #1                            Byte #2                           Byte #3                    Byte #4

Data Out :  !EOC DMY SIG D22 D21 D20 D19 D18   D17 D16 D15 D14 D13 D12 D11 D10   D9 D8 D7 D6 D5 D4 D3  D2   D1 D0 SGL OS S2 S1 S0 PAR
Data In  :  1    0   EN  SGL OS  S2  S1  S0    X   X   X   X   X   X   X   X     X  X  X  X  X  X   X  X    X  X  X   X  X  X  X  X

!EOC : End of Conversion Bit (Active Low)
DMY  : Dummy Bit (Always 0)
SIG  : Sign Bit (1-data positive, 0-data negative)
Dx   : Data Bits
EN   : Enable Bit (0-keep previous mode, 1-change mode)
SGL  : Enable Single-Ended Bit (0-differential, 1-single-ended)
OS   : ODD/Sign Bit
Sx   : Address Select Bit
PAR  : Parity Bit

Command Byte
1    0    EN   SGL  OS   S2   S1   S0   Comments
1    0    0    X    X    X    X    X    Keep Previous Mode
1    0    1    0    X    X    X    X    Differential Mode
1    0    1    1    X    X    X    X    Single-Ended Mode


Example Code:

Read Channel 0 in Single-Ended mode

    uint16_t miso_timeout = 1000;
    adc_command = LTC2418_CH0;                          // Build ADC command for channel 0

    if(LTC2418_EOC_timeout(LTC2418_CS, miso_timeout))    // Check for EOC
        return(1);
    LTC2418_read(LTC2418_CS, adc_command, &adc_code);   // Throws out last reading

    if(LTC2418_EOC_timeout(LTC2418_CS, miso_timeout))    // Check for EOC
        return(1);
    LTC2418_read(LTC2418_CS, adc_command, &adc_code);   // Obtains the current reading and stores to adc_code variable

    // Convert adc_code to voltage
    adc_voltage = LTC2418_code_to_voltage(adc_code, LTC2418_lsb , LTC2418_offset_code);

http://www.linear.com/product/LTC2418

http://www.linear.com/product/LTC2418#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 LTC2418: 16-Channel 24-Bit No Latency Delta-Sigma ADC

Definition in file LTC2418.h.

Go to the source code of this file.

Functions

int8_t LTC2418_EOC_timeout (uint8_t cs, uint16_t miso_timeout)
 Checks for EOC with a specified timeout. More...
 
void LTC2418_read (uint8_t cs, uint8_t adc_command, uint32_t *adc_code)
 Reads the LTC2418 result and programs the configuration for the next conversion. More...
 
float LTC2418_code_to_voltage (int32_t adc_code, float LTC2418_lsb, int32_t LTC2418_offset_code)
 Calculates the LTC2418 input bipolar voltage. More...
 
void LTC2418_cal_voltage (int32_t zero_code, int32_t fs_code, float zero_voltage, float fs_voltage, float *LTC2418_lsb, int32_t *LTC2418_offset_code)
 Calibrate the lsb. More...
 

Macros

#define LTC2418_CS   QUIKEVAL_CS
 Define the SPI CS pin. More...
 
LTC2418 Single-Ended configuration bytes

Address bytes with enable sequence prepended

#define LTC2418_CH0   0xB0
 
#define LTC2418_CH1   0xB8
 
#define LTC2418_CH2   0xB1
 
#define LTC2418_CH3   0xB9
 
#define LTC2418_CH4   0xB2
 
#define LTC2418_CH5   0xBA
 
#define LTC2418_CH6   0xB3
 
#define LTC2418_CH7   0xBB
 
#define LTC2418_CH8   0xB4
 
#define LTC2418_CH9   0xBC
 
#define LTC2418_CH10   0xB5
 
#define LTC2418_CH11   0xBD
 
#define LTC2418_CH12   0xB6
 
#define LTC2418_CH13   0xBE
 
#define LTC2418_CH14   0xB7
 
#define LTC2418_CH15   0xBF
 
LTC2418 Differential configuration bytes

Address bytes with enable sequence prepended

#define LTC2418_P0_N1   0xA0
 
#define LTC2418_P1_N0   0xA8
 
#define LTC2418_P2_N3   0xA1
 
#define LTC2418_P3_N2   0xA9
 
#define LTC2418_P4_N5   0xA2
 
#define LTC2418_P5_N4   0xAA
 
#define LTC2418_P6_N7   0xA3
 
#define LTC2418_P7_N6   0xAB
 
#define LTC2418_P8_N9   0xA4
 
#define LTC2418_P9_N8   0xAC
 
#define LTC2418_P10_N11   0xA5
 
#define LTC2418_P11_N10   0xAD
 
#define LTC2418_P12_N13   0xA6
 
#define LTC2418_P13_N12   0xAE
 
#define LTC2418_P14_N15   0xA7
 
#define LTC2418_P15_N14   0xAF
 

Function Documentation

◆ LTC2418_cal_voltage()

void LTC2418_cal_voltage ( int32_t  zero_code,
int32_t  fs_code,
float  zero_voltage,
float  fs_voltage,
float *  LTC2418_lsb,
int32_t *  LTC2418_offset_code 
)

Calibrate the lsb.

Returns
Void
Parameters
zero_codeOffset (Code)
fs_codeCode measured with full-scale input applied
zero_voltageMeasured zero voltage
fs_voltageMeasured full-scale voltage
LTC2418_lsbReturns LSB value (volts)
LTC2418_offset_codeReturns Offset (Code)

Definition at line 117 of file LTC2418.cpp.

◆ LTC2418_code_to_voltage()

float LTC2418_code_to_voltage ( int32_t  adc_code,
float  LTC2418_lsb,
int32_t  LTC2418_offset_code 
)

Calculates the LTC2418 input bipolar voltage.

Returns
Calculated voltage
Parameters
adc_codeRaw ADC code
LTC2418_lsbLSB value (volts)
LTC2418_offset_codeOffset (Code)

Definition at line 107 of file LTC2418.cpp.

◆ LTC2418_EOC_timeout()

int8_t LTC2418_EOC_timeout ( uint8_t  cs,
uint16_t  miso_timeout 
)

Checks for EOC with a specified timeout.

Returns
0=successful, 1=unsuccessful (exceeded timeout)
Parameters
csChip Select pin
miso_timeoutTimeout (ms)

Definition at line 73 of file LTC2418.cpp.

◆ LTC2418_read()

void LTC2418_read ( uint8_t  cs,
uint8_t  adc_command,
uint32_t *  adc_code 
)

Reads the LTC2418 result and programs the configuration for the next conversion.

Returns
void
Parameters
csChip Select pin
adc_commandCommand byte
adc_codeReturns raw 32-bit code read from ADC

Definition at line 92 of file LTC2418.cpp.

Macro Definition Documentation

◆ LTC2418_CH0

#define LTC2418_CH0   0xB0

Definition at line 116 of file LTC2418.h.

◆ LTC2418_CH1

#define LTC2418_CH1   0xB8

Definition at line 117 of file LTC2418.h.

◆ LTC2418_CH10

#define LTC2418_CH10   0xB5

Definition at line 126 of file LTC2418.h.

◆ LTC2418_CH11

#define LTC2418_CH11   0xBD

Definition at line 127 of file LTC2418.h.

◆ LTC2418_CH12

#define LTC2418_CH12   0xB6

Definition at line 128 of file LTC2418.h.

◆ LTC2418_CH13

#define LTC2418_CH13   0xBE

Definition at line 129 of file LTC2418.h.

◆ LTC2418_CH14

#define LTC2418_CH14   0xB7

Definition at line 130 of file LTC2418.h.

◆ LTC2418_CH15

#define LTC2418_CH15   0xBF

Definition at line 131 of file LTC2418.h.

◆ LTC2418_CH2

#define LTC2418_CH2   0xB1

Definition at line 118 of file LTC2418.h.

◆ LTC2418_CH3

#define LTC2418_CH3   0xB9

Definition at line 119 of file LTC2418.h.

◆ LTC2418_CH4

#define LTC2418_CH4   0xB2

Definition at line 120 of file LTC2418.h.

◆ LTC2418_CH5

#define LTC2418_CH5   0xBA

Definition at line 121 of file LTC2418.h.

◆ LTC2418_CH6

#define LTC2418_CH6   0xB3

Definition at line 122 of file LTC2418.h.

◆ LTC2418_CH7

#define LTC2418_CH7   0xBB

Definition at line 123 of file LTC2418.h.

◆ LTC2418_CH8

#define LTC2418_CH8   0xB4

Definition at line 124 of file LTC2418.h.

◆ LTC2418_CH9

#define LTC2418_CH9   0xBC

Definition at line 125 of file LTC2418.h.

◆ LTC2418_CS

#define LTC2418_CS   QUIKEVAL_CS

Define the SPI CS pin.

Definition at line 110 of file LTC2418.h.

◆ LTC2418_P0_N1

#define LTC2418_P0_N1   0xA0

Definition at line 137 of file LTC2418.h.

◆ LTC2418_P10_N11

#define LTC2418_P10_N11   0xA5

Definition at line 152 of file LTC2418.h.

◆ LTC2418_P11_N10

#define LTC2418_P11_N10   0xAD

Definition at line 153 of file LTC2418.h.

◆ LTC2418_P12_N13

#define LTC2418_P12_N13   0xA6

Definition at line 155 of file LTC2418.h.

◆ LTC2418_P13_N12

#define LTC2418_P13_N12   0xAE

Definition at line 156 of file LTC2418.h.

◆ LTC2418_P14_N15

#define LTC2418_P14_N15   0xA7

Definition at line 158 of file LTC2418.h.

◆ LTC2418_P15_N14

#define LTC2418_P15_N14   0xAF

Definition at line 159 of file LTC2418.h.

◆ LTC2418_P1_N0

#define LTC2418_P1_N0   0xA8

Definition at line 138 of file LTC2418.h.

◆ LTC2418_P2_N3

#define LTC2418_P2_N3   0xA1

Definition at line 140 of file LTC2418.h.

◆ LTC2418_P3_N2

#define LTC2418_P3_N2   0xA9

Definition at line 141 of file LTC2418.h.

◆ LTC2418_P4_N5

#define LTC2418_P4_N5   0xA2

Definition at line 143 of file LTC2418.h.

◆ LTC2418_P5_N4

#define LTC2418_P5_N4   0xAA

Definition at line 144 of file LTC2418.h.

◆ LTC2418_P6_N7

#define LTC2418_P6_N7   0xA3

Definition at line 146 of file LTC2418.h.

◆ LTC2418_P7_N6

#define LTC2418_P7_N6   0xAB

Definition at line 147 of file LTC2418.h.

◆ LTC2418_P8_N9

#define LTC2418_P8_N9   0xA4

Definition at line 149 of file LTC2418.h.

◆ LTC2418_P9_N8

#define LTC2418_P9_N8   0xAC

Definition at line 150 of file LTC2418.h.