LTC2376-20 - 20-Bit, 250ksps, Low Power SAR ADC with 0.5ppm INL - Linear Technology
LTC2376-20 - 20-Bit, 250ksps, Low Power SAR ADC with 0.5ppm INL
250ksps Throughput Rate
&0.5ppm INL (Typ)
Guaranteed 20-Bit No Missing Codes
Low Power: 5.3mW at 250ksps, 5.3&W at 250sps
104dB SNR (Typ) at fIN = 2kHz
&125dB THD (Typ) at fIN = 2kHz
Digital Gain Compression (DGC)
Guaranteed Operation to 85&C
2.5V Supply
Fully Differential Input Range &VREF
VREF Input Range from 2.5V to 5.1V
No Pipeline Delay, No Cycle Latency
1.8V to 5V I/O Voltages
SPI-Compatible Serial I/O with Daisy-Chain Mode
Internal Conversion Clock
16-Lead MSOP and 4mm & 3mm DFN Packages
Typical Application
Description
The LTC&2376-20 is a low noise, low power, high speed 20-bit successive approximation register (SAR) ADC. Operating from a 2.5V supply, the LTC2376-20 has a &VREF fully differential input range with VREF ranging from 2.5V to 5.1V. The LTC2376-20 consumes only 5.3mW and achieves &2ppm INL maximum, no missing codes at 20 bits with 104dB SNR.
The LTC2376-20 has a high speed SPI-compatible serial interface that supports 1.8V, 2.5V, 3.3V and 5V logic while also featuring a daisy-chain mode. The fast 250ksps throughput with no cycle latency makes the LTC2376-20 ideally suited for a wide variety of high speed applications. An internal oscillator sets the conversion time, easing external timing considerations. The LTC2376-20 automatically powers down between conversions, leading to reduced power dissipation that scales with the sampling rate.
The LTC2376-20 features a unique digital gain compression (DGC) function, which eliminates the driver amplifier&s negative supply while preserving the full resolution of the ADC. When enabled, the ADC performs a digital scaling function that maps zero-scale code from 0V to 0.1 & VREF and full-scale code from VREF to 0.9 & VREF. For a typical reference voltage of 5V, the full-scale input range is now 0.5V to 4.5V, which provides adequate headroom for powering the driving amplifier from a single 5.5V supply.
Applications
Medical Imaging
High Speed Data Acquisition
Portable or Compact Instrumentation
Industrial Process Control
Low Power Battery-Operated Instrumentation
People Who Viewed This Product Also Viewed
Product Notifications
Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products.
If you do not have a MyLinear account you may
Email Address
Forgot your password? Click . Need help? Email
with questions and comments.
Design Tools
Linduino is Linear Technology's Arduino compatible system for developing and distributing firmware libraries and example code for Linear Technology’s integrated circuits.
The code below can be downloaded or copied and pasted into your project. Please visit the
for demo board, manual and setup information.
This part is Family Supported: There is example code available for a part in this family. The code may require some changes to work with this specific part, however it still provides many good examples of how certain interactions should take place. The code below may rely on other drivers available in the .
Linear Technology DC1783A Demonstration Board.
237X_16/18: 16/18-Bit, 1Msps ADC.
Max SCK rate is 100MHz.
Set the terminal baud rate to 115200 and select the newline terminator.
Equipment required is a precision voltage source (null box) and a precision voltmeter (to monitor voltage source).
No external power supply is required.
Ensure JP1 is installed in the default position from the factory.
How to test:
The voltage source should be connected with positive and negative leads to the positive & negative ADC inputs. Ensure the differential voltage is within the
range of -VREF to +VREF. Swapping input voltages results in a reversed polarity reading.
How to calibrate:
Enter menu item number "3 - Calibrate" and follow the prompts.
Calibration is now stored in EEPROM. Upon startup the calibration values will be restored.
USER INPUT DATA FORMAT:
decimal : 1024
(leading 0 "zero")
@endverbatim
/product/LTC237X_20
/product/LTC237X_20#demoboards
REVISION HISTORY
$Revision: 1792 $
13:58:53 -0700 (Thu, 25 Jul 2013) $
Copyright (c) 2013, Linear Technology Corp.(LTC)
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. 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.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, 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.
The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of Linear Technology Corp.
The Linear Technology Linduino is not affiliated with the official Arduino team.
However, the Linduino is only possible because of the Arduino team's commitment
to the open-source community.
Please, visit http://www.arduino.cc and
http://store.arduino.cc , and consider a purchase that will help fund their
ongoing work.
@ingroup LTC237X
#include "Linduino.h"
#include "LT_SPI.h"
#include "UserInterface.h"
#include "LT_I2C.h"
#include "QuikEval_EEPROM.h"
#include "LTC237X.h"
// Function Declaration
void print_title();
// Print the title block
void print_prompt();
// Prompt the user for an input command
void print_user_command(uint8_t menu);
// Display selected differential channels
void menu_1_read_input();
void menu_2_select_gain_compression();
void menu_3_select_bits();
// Global variables
static uint8_t LTC237X_gain_compression = 0;
//!< Default set for no gain compression
float vref = 5;
static uint8_t LTC237X_bits = 18;
//!< Default set for 18 bits
static float LTC237X_lsb = (float) 2*vref/pow(2,LTC237X_bits);
//!< Code weight in volts per LSB - no gain compression
static int32_t LTC237X_offset_code = 0;
//!> (32 - LTC237X_bits);
if(LTC237X_bits == 16)
display_code = display_code & 0
display_code = display_code & 0x3
Serial.print(F("Received Code: 0x"));
Serial.println(display_code, HEX);
// Convert the received code to voltage
adc_voltage = LTC237X_code_to_voltage(adc_code, vref);
Serial.print(F("Equivalent voltage: "));
Serial.print(adc_voltage, 4);
Serial.println(F("V"));
//! Select gain compression
//! @return void
void menu_2_select_gain_compression()
uint8_t user_
Serial.println();
if(LTC237X_gain_compression == 0)
Serial.print(F("No gain compression enabled"));
Serial.print(F("Gain compression enabled"));
Serial.println(F("\n0=No Gain Compression, 1=Gain Compression"));
Serial.print(F("Enter a Command, based upon the position of jumper JP6: "));
user_command = read_int();
// Read user input
Serial.println(user_command);
// Prints the user command to com port
switch (user_command)
LTC237X_gain_compression = 0;
LTC237X_gain_compression = 1;
Serial.println("Invalid Option");
//! Select number of bits
//! @return void
void menu_3_select_bits()
uint8_t user_
Serial.println();
if(LTC237X_bits == 16)
Serial.print(F("16 bits selected"));
Serial.print(F("18 bits selected"));
Serial.println(F("\n16 = 237X-16,
18 = 237X-18"));
Serial.print(F("Enter a Command, based upon the resolution of the part under test: "));
user_command = read_int();
// Read user input
Serial.println(user_command);
// Prints the user command to com port
switch (user_command)
LTC237X_bits = 16;
LTC237X_bits = 18;
Serial.println("Invalid Option");
//! Prints the title block when program first starts.
void print_title()
Serial.println();
Serial.println(F("*****************************************************************"));
Serial.println(F("* DC1783A Demonstration Program
Serial.println(F("*
Serial.println(F("* This program demonstrates how to receive data
Serial.println(F("* from the LTC237X-16/18 ADC.
Serial.println(F("*
Serial.println(F("* Set the baud rate to 115200 and select the newline terminator.*"));
Serial.println(F("*
Serial.println(F("*****************************************************************"));
//! Prints main menu.
void print_prompt()
Serial.println(F("*************************"));
Serial.println(F("1-Read ADC Input"));
Serial.println(F("2-Select No Gain Compression / Gain Compression (default is no compression)"));
Serial.println(F("3-Select Number of bits (default is 18 bits)\n"));
Serial.print(F("Enter a command:"));
Linear Technology DC1925A Demonstration Board with SPI interface.
LTC-Bit, 250Ksps ADC
LTC-Bit, 500Ksps ADC
LTC-Bit, 1Msps ADC
Max SCK rate is 100MHz.
Set the terminal baud rate to 115200 and select the newline terminator.
Equipment required is a precision voltage source (null box) and a precision voltmeter (to monitor voltage source).
No external power supply is required.
Ensure JP1 is installed in the default position from the factory.
How to test:
The voltage source should be connected with positive and negative leads to the positive & negative ADC inputs. Ensure the differential voltage is within the
range of -VREF to +VREF. Swapping input voltages results in a reversed polarity reading.
USER INPUT DATA FORMAT:
decimal : 1024
(leading 0 "zero")
@endverbatim
/product/LTC2376-20
/product/LTC2377-20
/product/LTC2378-20
/product/LTC2376-20#demoboards
/product/LTC2377-20#demoboards
/product/LTC2378-20#demoboards
REVISION HISTORY
$Revision: 1792 $
13:58:53 -0700 (Thu, 25 Jul 2013) $
Copyright (c) 2013, Linear Technology Corp.(LTC)
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. 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.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, 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.
The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of Linear Technology Corp.
The Linear Technology Linduino is not affiliated with the official Arduino team.
However, the Linduino is only possible because of the Arduino team's commitment
to the open-source community.
Please, visit http://www.arduino.cc and
http://store.arduino.cc , and consider a purchase that will help fund their
ongoing work.
@ingroup LTC2378
#include "Linduino.h"
#include "LT_SPI.h"
#include "UserInterface.h"
#include "LT_I2C.h"
#include "QuikEval_EEPROM.h"
#include "LTC2378.h"
// Function Declaration
void print_title();
// Print the title block
void print_prompt();
// Prompt the user for an input command
void print_user_command(uint8_t menu);
// Display selected differential channels
void menu_1_read_input();
void menu_2_select_gain_compression();
// Global variables
static uint8_t LTC2378_dgc = 0;
//!< Default set for no gain compression
static uint8_t LTC2378_bits = 20;
//!> (32 - LTC2378_bits);
//shift to the right
display_code = display_code & 0xFFFFF;
//mask off 20 bits
Serial.print(F("
Received Code: b"));
Serial.println(display_code, BIN);
adc_voltage = LTC2378_code_to_voltage(adc_code, LTC2378_dgc, LTC2378_vref);
// Convert the received code to voltage
Serial.print(F("
Equivalent voltage: "));
Serial.print(adc_voltage, 4);
Serial.println(F("V"));
//! Select gain compression
//! @return void
void menu_2_select_gain_compression()
uint8_t user_
Serial.println(F("
0 = No Gain Compression"));
Serial.println(F("
1 = Gain Compression"));
Serial.print(F("
Enter a Command, based upon the position of jumper JP6: "));
user_command = read_int();
// Read user input
Serial.println(user_command);
// Prints the user command to com port
switch (user_command)
Serial.println(F("
No Gain compression"));
LTC2378_dgc = 0;
Serial.println(F("
Gain compression"));
LTC2378_dgc = 1;
Serial.println("
Invalid Option");
//! Prints the title block when program first starts.
void print_title()
Serial.println();
Serial.println(F("*****************************************************************"));
Serial.println(F("* DC1925A Demonstration Program
Serial.println(F("*
Serial.println(F("* This program demonstrates how to receive data
Serial.println(F("* from the following ADCs:
Serial.println(F("*
LTC2376-20
Serial.println(F("*
LTC2377-20
Serial.println(F("*
LTC2378-20
Serial.println(F("*
Serial.println(F("* Set the baud rate to 115200 and select the newline terminator.*"));
Serial.println(F("*
Serial.println(F("*****************************************************************"));
//! Prints main menu.
void print_prompt()
Serial.println(F("*************************"));
Serial.println(F("1-Read ADC Input"));
Serial.println(F("2-Select No Gain Compression / Gain Compression (default is no compression)"));
Serial.print(F("Enter a command:"));
LTC237X: 16/18/20-Bit 1Msps ADC
The LTC237X_16/18/20 are pin-compatible, 16/18/20-bit A/D converters with
serial I/O, and an internal reference. The ADCs typically draw only TBDmA from a
single 5V supply. The automatic nap and sleep modes benefit power sensitive applications.
The LTC237X_16/18/20's DC performance is outstanding with a +/-2LSB INL specification and
no missing codes over temperature. The signal-to-noise ratio (SNR) for the LTC237X is typically TBDdB, with the internal reference.
@endverbatim
/product/LTC237X
/product/LTC237X#demoboards
REVISION HISTORY
$Revision: 1785 $
08:47:24 -0700 (Thu, 25 Jul 2013) $
Copyright (c) 2013, Linear Technology Corp.(LTC)
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. 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.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, 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.
The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of Linear Technology Corp.
The Linear Technology Linduino is not affiliated with the official Arduino team.
However, the Linduino is only possible because of the Arduino team's commitment
to the open-source community.
Please, visit http://www.arduino.cc and
http://store.arduino.cc , and consider a purchase that will help fund their
ongoing work.
//! @defgroup LTC237X: 16/18/20-Bit 1Msps ADC
@ingroup LTC237X
Library for LTC237X: 16/18/20-Bit 1Msps ADC
#include "Linduino.h"
#include "LT_SPI.h"
#include "LTC237X.h"
// Reads from a SPI LTC237X-XX device that has no configuration word and a 20 bit output word.
void LTC237X_read(uint8_t cs, int32_t *ptr_adc_code)
LT_union_int16_2
// LTC237X data and command
command.LT_uint16 = 0;
// Set to zero, not necessary but avoids
// random data in scope shots.
//Form a four byte object to hold four bytes of data
LT_union_int32_4 //instantiate the union
data.LT_byte[3] = 0;
data.LT_byte[2] = 0;
data.LT_byte[1] = 0;
data.LT_byte[0] = 0;
spi_transfer_block(cs,command.LT_byte,data.LT_byte,4);
*ptr_adc_code = data.LT_int32;
// Calculates the voltage corresponding to an adc code, given the reference voltage (in volts)
float LTC237X_code_to_voltage(int32_t adc_code, float vref)
voltage = (float)adc_
voltage = voltage / (pow(2,31)-1);
//! 2) This calculates the input as a fraction of the reference voltage (dimensionless)
voltage = voltage *
//! 3) Multiply fraction by Vref to get the actual voltage at the input (in volts)
return(voltage);
LTC237X: 16/18/20-bit 1Msps ADC
The LTC237X_16/18/20 are pin-compatible, 16/18/20-bit A/D converters
with serial I/O, and an internal reference. The ADCs typically draw only TBDmA
from a single 5V supply. The automatic nap and sleep modes benefit power sensitive applications.
The LTC237X_16/18/20's DC performance is outstanding with a +/-TBDLSB INL specification and
no missing codes over temperature. The signal-to-noise ratio (SNR) for the LTC237X is typically TBDdB, with the internal reference.
Example Code:
Read ADC input.
adc_command = LTC237X_CH0 | LTC237X_UNIPOLAR_MODE | LTC237X_LOW_GAIN_MODE | LTC237X_NORMAL_MODE;
// Single-ended, CH0, unipolar, low gain, normal mode.
LTC237X_read(LTC237X_CS, adc_command, &adc_code);
// Throws out last reading
LTC237X_read(LTC237X_CS, adc_command, &adc_code);
// Obtains the current reading and stores to adc_code variable
// Convert adc_code to voltage
adc_voltage = LTC237X_unipolar_code_to_voltage(adc_code, LTC237X_lsb, LTC237X_offset_unipolar_code);
@endverbatim
/product/LTC237X
/product/LTC237X#demoboards
REVISION HISTORY
$Revision: 1807 $
13:06:06 -0700 (Mon, 29 Jul 2013) $
Copyright (c) 2013, Linear Technology Corp.(LTC)
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. 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.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, 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.
The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of Linear Technology Corp.
The Linear Technology Linduino is not affiliated with the official Arduino team.
However, the Linduino is only possible because of the Arduino team's commitment
to the open-source community.
Please, visit http://www.arduino.cc and
http://store.arduino.cc , and consider a purchase that will help fund their
ongoing work.
@ingroup LTC237X_
Header for LTC237X: 16/18/20-bit 1Msps ADC
#ifndef LTC237X_H
#define LTC237X_H
//! Define the SPI CS pin
#ifndef LTC237X_CS
#define LTC237X_CS QUIKEVAL_CS
//! @name LTC237X Channel Address
// Channel Address
#define LTC237X_ADDRESS
//! Reads the LTC237X and returns 32-bit data
//! @return void
void LTC237X_read(uint8_t cs,
//!< Chip Select Pin
int32_t *ptr_adc_code
//!< Returns code read from ADC (from previous conversion)
//! Calculates the LTC237X input voltage given the binary data and lsb weight.
//! @return Floating point voltage
float LTC237X_code_to_voltage(int32_t adc_code,
//!< Raw ADC code
float vref
//!< Reference voltage
Documentation
Design Note
Reliability Data
Product Selector Card
Software and Simulation}