Linduino  1.3.0
Linear Technology Arduino-Compatible Demonstration Board

LTC2308: 16-bit 8-channel 100ksps ADC. More...

Detailed Description

LTC2308: 16-bit 8-channel 100ksps ADC.

The LTC2308 is an 8-channel 12-bit A/D converter with
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 LTC2308's DC performance is outstanding with a +/-2LSB INL specification and
no missing codes over temperature. The signal-to-noise ratio (SNR) for the
LTC2308 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  UNI GAIN NAP SLP   X   X   X   X   X   X   X   X

SD   : Single/Differential Bit
OS   : ODD/Sign Bit
Sx   : Address Select Bit
UNI  : Unipolar/Bipolar Bit
GAIN : Input Span Bit
NAP  : Nap Mode 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 = LTC2308_CH0 | LTC2308_UNIPOLAR_MODE | LTC2308_LOW_GAIN_MODE | LTC2308_NORMAL_MODE;     // Single-ended, CH0, unipolar, low gain, normal mode.
    LTC2308_read(LTC2308_CS, adc_command, &adc_code);   // Throws out last reading
    LTC2308_read(LTC2308_CS, adc_command, &adc_code);   // Obtains the current reading and stores to adc_code variable

    // Convert adc_code to voltage
    adc_voltage = LTC2308_unipolar_code_to_voltage(adc_code, LTC2308_lsb, LTC2308_offset_unipolar_code);

http://www.linear.com/product/LTC2308

http://www.linear.com/product/LTC2308#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 LTC2308: 16-bit 8-channel 100ksps ADC

Definition in file LTC2308.h.

Go to the source code of this file.

Functions

void LTC2308_read (uint8_t cs, uint8_t adc_command, uint16_t *adc_code)
 Reads the ADC and returns 16-bit data. More...
 
float LTC2308_code_to_voltage (uint16_t adc_code, float vref, uint8_t uni_bipolar)
 Calculates the LTC2308 input's unipolar voltage given the binary data and lsb weight. More...
 

Macros

#define LTC2308_CS   QUIKEVAL_CS
 Define the SPI CS pin. More...
 
LTC2308 Single-Ended Channel Addresses
#define LTC2308_CH0   0x80
 
#define LTC2308_CH1   0xC0
 
#define LTC2308_CH2   0x90
 
#define LTC2308_CH3   0xD0
 
#define LTC2308_CH4   0xA0
 
#define LTC2308_CH5   0xE0
 
#define LTC2308_CH6   0xB0
 
#define LTC2308_CH7   0xF0
 
LTC2308 Differential Channel Addresses
#define LTC2308_P0_N1   0x00
 
#define LTC2308_P1_N0   0x40
 
#define LTC2308_P2_N3   0x10
 
#define LTC2308_P3_N2   0x50
 
#define LTC2308_P4_N5   0x20
 
#define LTC2308_P5_N4   0x60
 
#define LTC2308_P6_N7   0x30
 
#define LTC2308_P7_N6   0x70
 
LTC2308 Uni/GAIN config bits
#define LTC2308_UNIPOLAR_MODE   0x08
 
#define LTC2308_BIPOLAR_MODE   0x00
 
#define LTC2308_SINGLE_ENDED_MODE   0x80
 
#define LTC2308_DIFFERENTIAL_MODE   0x00
 
LTC2308 Sleep/Nap config bits
#define LTC2308_SLEEP_MODE   0x01
 
#define LTC2308_NORMAL_MODE   0x00
 
#define LTC2308_NAP_MODE   0x02
 

Function Documentation

◆ LTC2308_code_to_voltage()

float LTC2308_code_to_voltage ( uint16_t  adc_code,
float  vref,
uint8_t  uni_bipolar 
)

Calculates the LTC2308 input's unipolar voltage given the binary data and lsb weight.

Returns
Floating point voltage
Parameters
adc_codeRaw ADC code

Definition at line 84 of file LTC2308.cpp.

◆ LTC2308_read()

void LTC2308_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 77 of file LTC2308.cpp.

Macro Definition Documentation

◆ LTC2308_BIPOLAR_MODE

#define LTC2308_BIPOLAR_MODE   0x00

Definition at line 134 of file LTC2308.h.

◆ LTC2308_CH0

#define LTC2308_CH0   0x80

Definition at line 104 of file LTC2308.h.

◆ LTC2308_CH1

#define LTC2308_CH1   0xC0

Definition at line 105 of file LTC2308.h.

◆ LTC2308_CH2

#define LTC2308_CH2   0x90

Definition at line 106 of file LTC2308.h.

◆ LTC2308_CH3

#define LTC2308_CH3   0xD0

Definition at line 107 of file LTC2308.h.

◆ LTC2308_CH4

#define LTC2308_CH4   0xA0

Definition at line 108 of file LTC2308.h.

◆ LTC2308_CH5

#define LTC2308_CH5   0xE0

Definition at line 109 of file LTC2308.h.

◆ LTC2308_CH6

#define LTC2308_CH6   0xB0

Definition at line 110 of file LTC2308.h.

◆ LTC2308_CH7

#define LTC2308_CH7   0xF0

Definition at line 111 of file LTC2308.h.

◆ LTC2308_CS

#define LTC2308_CS   QUIKEVAL_CS

Define the SPI CS pin.

Definition at line 98 of file LTC2308.h.

◆ LTC2308_DIFFERENTIAL_MODE

#define LTC2308_DIFFERENTIAL_MODE   0x00

Definition at line 137 of file LTC2308.h.

◆ LTC2308_NAP_MODE

#define LTC2308_NAP_MODE   0x02

Definition at line 146 of file LTC2308.h.

◆ LTC2308_NORMAL_MODE

#define LTC2308_NORMAL_MODE   0x00

Definition at line 144 of file LTC2308.h.

◆ LTC2308_P0_N1

#define LTC2308_P0_N1   0x00

Definition at line 117 of file LTC2308.h.

◆ LTC2308_P1_N0

#define LTC2308_P1_N0   0x40

Definition at line 118 of file LTC2308.h.

◆ LTC2308_P2_N3

#define LTC2308_P2_N3   0x10

Definition at line 120 of file LTC2308.h.

◆ LTC2308_P3_N2

#define LTC2308_P3_N2   0x50

Definition at line 121 of file LTC2308.h.

◆ LTC2308_P4_N5

#define LTC2308_P4_N5   0x20

Definition at line 123 of file LTC2308.h.

◆ LTC2308_P5_N4

#define LTC2308_P5_N4   0x60

Definition at line 124 of file LTC2308.h.

◆ LTC2308_P6_N7

#define LTC2308_P6_N7   0x30

Definition at line 126 of file LTC2308.h.

◆ LTC2308_P7_N6

#define LTC2308_P7_N6   0x70

Definition at line 127 of file LTC2308.h.

◆ LTC2308_SINGLE_ENDED_MODE

#define LTC2308_SINGLE_ENDED_MODE   0x80

Definition at line 136 of file LTC2308.h.

◆ LTC2308_SLEEP_MODE

#define LTC2308_SLEEP_MODE   0x01

Definition at line 143 of file LTC2308.h.

◆ LTC2308_UNIPOLAR_MODE

#define LTC2308_UNIPOLAR_MODE   0x08

Definition at line 133 of file LTC2308.h.