Linduino  1.3.0
Linear Technology Arduino-Compatible Demonstration Board

LTC1867: 16-bit 8-channel 200ksps ADC. More...

Detailed Description

LTC1867: 16-bit 8-channel 200ksps ADC.

The LTC1863/LTC1867 are pin-compatible, 8-channel 12-/16-bit A/D converters
with serial I/O, and an internal reference. The ADCs typically draw only 1.3mA
from a single 5V supply. The 8-channel input multiplexer can be configured for
either single-ended or differential inputs and unipolar or bipolar conversions
(or combinations thereof). The automatic nap and sleep modes benefit power
sensitive applications.

The LTC1867's DC performance is outstanding with a +/-2LSB INL specification and
no missing codes over temperature. The signal-to-noise ratio (SNR) for the
LTC1867 is typically 89dB, with the internal reference.

SPI DATA FORMAT (MSB First):

            Byte #1                           Byte #2
Data Out :  D15 D14 D13 D12 D11 D10 D9  D8    D7  D6  D5  D4  D3  D2  D1  D0
Data In  :  SD  OS  S1  S0  COM UNI SLP X     X   X   X   X   X   X   X   X

SD   : Single/Differential Bit
OS   : ODD/Sign Bit
Sx   : Address Select Bit
COM  : CH7/COM Configuration Bit
UNI  : Unipolar/Bipolar Bit
SLP  : Sleep Mode Bit
Dx   : Data Bits
X    : Don't care


Example Code:

Read Channel 0 in Single-Ended Unipolar mode when input is with respect to GND

    adc_command = LTC1867_CH0 | LTC1867_UNIPOLAR_MODE;  // Build ADC command for channel 0
    LTC1867_read(LTC1867_CS, adc_command, &adc_code);   // Throws out last reading
    LTC1867_read(LTC1867_CS, adc_command, &adc_code);   // Obtains the current reading and stores to adc_code variable

    // Convert adc_code to voltage
    adc_voltage = LTC1867_unipolar_code_to_voltage(adc_code, LTC1867_lsb, LTC1867_offset_unipolar_code);

http://www.linear.com/product/LTC1867

http://www.linear.com/product/LTC1867#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 LTC1867: 16-bit 8-channel 200ksps ADC

Definition in file LTC1867.h.

Go to the source code of this file.

Functions

void LTC1867_read (uint8_t cs, uint8_t adc_command, uint16_t *adc_code)
 Reads the ADC and returns 16-bit data. More...
 
float LTC1867_unipolar_code_to_voltage (uint16_t adc_code, float LTC1867_lsb, int32_t LTC1867_offset_unipolar_code)
 Calculates the LTC1867 input's unipolar voltage given the binary data and lsb weight. More...
 
float LTC1867_bipolar_code_to_voltage (uint16_t adc_code, float LTC1867_lsb, int32_t LTC1867_offset_bipolar_code)
 Calculates the LTC1867 input's bipolar voltage given the two's compliment data and lsb weight. More...
 
void LTC1867_cal_voltage (uint16_t zero_unipolar_code, uint16_t zero_bipolar_code, uint16_t fs_code, float zero_voltage, float fs_voltage, float *LTC1867_lsb, int32_t *LTC1867_offset_unipolar_code, int32_t *LTC1867_offset_bipolar_code)
 Calibrate the offset and LSB voltage given two measured offset codes, and a full-scale voltage with the corresponding code. More...
 

Macros

#define LTC1867_CS   QUIKEVAL_CS
 Define the SPI CS pin. More...
 
LTC1867 Single-Ended Channel Addresses, COM=GND
#define LTC1867_CH0   0x80
 
#define LTC1867_CH1   0xC0
 
#define LTC1867_CH2   0x90
 
#define LTC1867_CH3   0xD0
 
#define LTC1867_CH4   0xA0
 
#define LTC1867_CH5   0xE0
 
#define LTC1867_CH6   0xB0
 
#define LTC1867_CH7   0xF0
 
LTC1867 Differential Channel Addresses
#define LTC1867_P0_N1   0x00
 
#define LTC1867_P1_N0   0x40
 
#define LTC1867_P2_N3   0x10
 
#define LTC1867_P3_N2   0x50
 
#define LTC1867_P4_N5   0x20
 
#define LTC1867_P5_N4   0x60
 
#define LTC1867_P6_N7   0x30
 
#define LTC1867_P7_N6   0x70
 
LTC1867 Single-Ended Channel Addresses, COM=CH7
#define LTC1867_CH0_7COM   0x88
 
#define LTC1867_CH1_7COM   0xC8
 
#define LTC1867_CH2_7COM   0x98
 
#define LTC1867_CH3_7COM   0xD8
 
#define LTC1867_CH4_7COM   0xA8
 
#define LTC1867_CH5_7COM   0xE8
 
#define LTC1867_CH6_7COM   0xB8
 
LTC1867 Sleep / Unipolar/Bipolar config bits
#define LTC1867_SLEEP_MODE   0x02
 
#define LTC1867_EXIT_SLEEP_MODE   0x00
 
#define LTC1867_UNIPOLAR_MODE   0x04
 
#define LTC1867_BIPOLAR_MODE   0x00
 

Function Documentation

◆ LTC1867_bipolar_code_to_voltage()

float LTC1867_bipolar_code_to_voltage ( uint16_t  adc_code,
float  LTC1867_lsb,
int32_t  LTC1867_offset_bipolar_code 
)

Calculates the LTC1867 input's bipolar voltage given the two's compliment data and lsb weight.

Returns
Floating point voltage
Parameters
adc_codeRaw ADC code
LTC1867_lsbLSB value (volts)
LTC1867_offset_bipolar_codeOffset code

Definition at line 92 of file LTC1867.cpp.

◆ LTC1867_cal_voltage()

void LTC1867_cal_voltage ( uint16_t  zero_unipolar_code,
uint16_t  zero_bipolar_code,
uint16_t  fs_code,
float  zero_voltage,
float  fs_voltage,
float *  LTC1867_lsb,
int32_t *  LTC1867_offset_unipolar_code,
int32_t *  LTC1867_offset_bipolar_code 
)

Calibrate the offset and LSB voltage given two measured offset codes, and a full-scale voltage with the corresponding code.

Returns
Void
Parameters
zero_unipolar_codeCode from a unipolar zero reading
zero_bipolar_codeCode from a bipolar zero reading
fs_codefull-scale code
zero_voltageMeasured zero voltage
fs_voltageMeasured full-scale voltage
LTC1867_lsbReturn LSB value (volts)
LTC1867_offset_unipolar_codeReturn Unipolar Offset code, in floating point
LTC1867_offset_bipolar_codeReturn Bipolar Offset code, in floating point

Definition at line 105 of file LTC1867.cpp.

◆ LTC1867_read()

void LTC1867_read ( uint8_t  cs,
uint8_t  adc_command,
uint16_t *  adc_code 
)

Reads the ADC and returns 16-bit data.

Returns
void
Parameters
csChip Select Pin
adc_commandChannel address, config bits ORed together
adc_codeReturns code read from ADC (from previous conversion)

Definition at line 78 of file LTC1867.cpp.

◆ LTC1867_unipolar_code_to_voltage()

float LTC1867_unipolar_code_to_voltage ( uint16_t  adc_code,
float  LTC1867_lsb,
int32_t  LTC1867_offset_unipolar_code 
)

Calculates the LTC1867 input's unipolar voltage given the binary data and lsb weight.

Returns
Floating point voltage
Parameters
adc_codeRaw ADC code
LTC1867_lsbLSB value (volts)
LTC1867_offset_unipolar_codeOffset code

Definition at line 84 of file LTC1867.cpp.

Macro Definition Documentation

◆ LTC1867_BIPOLAR_MODE

#define LTC1867_BIPOLAR_MODE   0x00

Definition at line 148 of file LTC1867.h.

◆ LTC1867_CH0

#define LTC1867_CH0   0x80

Definition at line 104 of file LTC1867.h.

◆ LTC1867_CH0_7COM

#define LTC1867_CH0_7COM   0x88

Definition at line 133 of file LTC1867.h.

◆ LTC1867_CH1

#define LTC1867_CH1   0xC0

Definition at line 105 of file LTC1867.h.

◆ LTC1867_CH1_7COM

#define LTC1867_CH1_7COM   0xC8

Definition at line 134 of file LTC1867.h.

◆ LTC1867_CH2

#define LTC1867_CH2   0x90

Definition at line 106 of file LTC1867.h.

◆ LTC1867_CH2_7COM

#define LTC1867_CH2_7COM   0x98

Definition at line 135 of file LTC1867.h.

◆ LTC1867_CH3

#define LTC1867_CH3   0xD0

Definition at line 107 of file LTC1867.h.

◆ LTC1867_CH3_7COM

#define LTC1867_CH3_7COM   0xD8

Definition at line 136 of file LTC1867.h.

◆ LTC1867_CH4

#define LTC1867_CH4   0xA0

Definition at line 108 of file LTC1867.h.

◆ LTC1867_CH4_7COM

#define LTC1867_CH4_7COM   0xA8

Definition at line 137 of file LTC1867.h.

◆ LTC1867_CH5

#define LTC1867_CH5   0xE0

Definition at line 109 of file LTC1867.h.

◆ LTC1867_CH5_7COM

#define LTC1867_CH5_7COM   0xE8

Definition at line 138 of file LTC1867.h.

◆ LTC1867_CH6

#define LTC1867_CH6   0xB0

Definition at line 110 of file LTC1867.h.

◆ LTC1867_CH6_7COM

#define LTC1867_CH6_7COM   0xB8

Definition at line 139 of file LTC1867.h.

◆ LTC1867_CH7

#define LTC1867_CH7   0xF0

Definition at line 111 of file LTC1867.h.

◆ LTC1867_CS

#define LTC1867_CS   QUIKEVAL_CS

Define the SPI CS pin.

Definition at line 98 of file LTC1867.h.

◆ LTC1867_EXIT_SLEEP_MODE

#define LTC1867_EXIT_SLEEP_MODE   0x00

Definition at line 146 of file LTC1867.h.

◆ LTC1867_P0_N1

#define LTC1867_P0_N1   0x00

Definition at line 117 of file LTC1867.h.

◆ LTC1867_P1_N0

#define LTC1867_P1_N0   0x40

Definition at line 118 of file LTC1867.h.

◆ LTC1867_P2_N3

#define LTC1867_P2_N3   0x10

Definition at line 120 of file LTC1867.h.

◆ LTC1867_P3_N2

#define LTC1867_P3_N2   0x50

Definition at line 121 of file LTC1867.h.

◆ LTC1867_P4_N5

#define LTC1867_P4_N5   0x20

Definition at line 123 of file LTC1867.h.

◆ LTC1867_P5_N4

#define LTC1867_P5_N4   0x60

Definition at line 124 of file LTC1867.h.

◆ LTC1867_P6_N7

#define LTC1867_P6_N7   0x30

Definition at line 126 of file LTC1867.h.

◆ LTC1867_P7_N6

#define LTC1867_P7_N6   0x70

Definition at line 127 of file LTC1867.h.

◆ LTC1867_SLEEP_MODE

#define LTC1867_SLEEP_MODE   0x02

Definition at line 145 of file LTC1867.h.

◆ LTC1867_UNIPOLAR_MODE

#define LTC1867_UNIPOLAR_MODE   0x04

Definition at line 147 of file LTC1867.h.