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Linduino
1.3.0
Linear Technology Arduino-Compatible Demonstration Board
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LTC2637: Octal 12-/10-/8-Bit I2C VOUT DACs with 10ppm/°C Reference. More...
LTC2637: Octal 12-/10-/8-Bit I2C VOUT DACs with 10ppm/°C Reference.
The LTC2637 is a family of octal I2C 16-/12-Bit Rail-to-Rail DACs with Integrated 10ppm/C Max Reference. The DACs have built-in high performance, rail-to-rail, output buffers and are guaranteed monotonic. The LTC2637-L has a full-scale output of 2.5V with the integrated reference and operates from a single 2.7V to 5.5V supply. The LTC2637-H has a full-scale output of 4.096V with the integrated reference and operates from a 4.5V to 5.5V supply. Each DAC can also operate with an external reference, which sets the full-scale output to 2 times the external reference voltage. The parts use a 2-wire I2C compatible serial interface. The LTC2637 operates in both the standard mode (maximum clock rate of 100kHz) and the fast mode (maximum clock rate of 400kHz). The LTC2637 incorporates a power-on reset circuit that is controlled by the PORSEL pin. If PORSEL is tied to GND the DACs reset to zero-scale at power-up. If PORSEL is tied to VCC, the DACs reset to mid-scale at power-up. I2C DATA FORMAT (MSB First): Byte #1 Byte #2 LTC2637-12 : START SA6 SA5 SA4 SA3 SA2 SA1 SA0 W SACK C3 C2 C1 C0 A3 A2 A1 A0 SACK LTC2637-10 : START SA6 SA5 SA4 SA3 SA2 SA1 SA0 W SACK C3 C2 C1 C0 A3 A2 A1 A0 SACK LTC2637- 8 : START SA6 SA5 SA4 SA3 SA2 SA1 SA0 W SACK C3 C2 C1 C0 A3 A2 A1 A0 SACK Byte #3 Byte #4 MSB LSB D11 D10 D9 D8 D7 D6 D5 D4 SACK D3 D2 D1 D0 X X X X SACK STOP D9 D8 D7 D6 D5 D4 D3 D2 SACK D1 D0 X X X X X X SACK STOP D7 D6 D5 D4 D3 D2 D1 D0 SACK X X X X X X X X SACK STOP START: I2C Start SAx : I2C Address W : I2C Write (0) SACK : I2C Slave Generated Acknowledge (Active Low) Cx : DAC Command Code Ax : DAC Address (0=DACA, 1=DACB, 2=DACC, 3=DACD, 4=DACE, 5=DACF, 6=DACG, 7=DACH, 0xFF=All DACs) Dx : DAC Data Bits X : Don't care STOP : I2C Stop Example Code: Set DAC A to to 2V for 12-bit DAC. shift_count = 4; // 16-bit DAC does not have to be shifted dac_voltage = 2.0; // Sets dac voltage variable to 2v dac_code = LTC2637_voltage_to_code(dac_voltage, LTC2637_lsb, LTC2637_offset); // Calculate DAC code from voltage, lsb, and offset ack = LTC2637_write(LTC2637_I2C_ADDRESS, LTC2637_CMD_WRITE_UPDATE, LTC2637_DAC_A, dac_code << shift_count); // Set DAC A with DAC code
http://www.linear.com/product/LTC2637
http://www.linear.com/product/LTC2635
http://www.linear.com/product/LTC2637#demoboards
http://www.linear.com/product/LTC2635#demoboards
Copyright 2018(c) Analog Devices, Inc.
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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 LTC2637 Octal 12-/10-/8-Bit I2C VOUT DACs with 10ppm/°C Reference
Definition in file LTC2637.h.
Go to the source code of this file.
Functions | |
int8_t | LTC2637_write (uint8_t i2c_address, uint8_t dac_command, uint8_t dac_address, uint16_t dac_code) |
Write a 16-bit dac_code to the LTC2637. More... | |
uint16_t | LTC2637_voltage_to_code (float dac_voltage, float LTC2637_lsb, int16_t LTC2637_offset) |
Calculate a LTC2637 DAC code given the desired output voltage and DAC address (0-3) More... | |
float | LTC2637_code_to_voltage (uint16_t dac_code, float LTC2637_lsb, int16_t LTC2637_offset) |
Calculate the LTC2637 DAC output voltage given the DAC code, offset, and LSB value. More... | |
void | LTC2637_calibrate (uint16_t dac_code1, uint16_t dac_code2, float voltage1, float voltage2, float *LTC2637_lsb, int16_t *LTC2637_offset) |
Calculate the LTC2637 offset and LSB voltages given two measured voltages and their corresponding codes. More... | |
Macros | |
I2C_Addresses | |
#define | LTC2637_I2C_ADDRESS 0x10 |
#define | LTC2637_I2C_GLOBAL_ADDRESS 0x73 |
LTC2637 Command Codes | |
OR'd together with the DAC address to form the command byte | |
#define | LTC2637_CMD_WRITE 0x00 |
#define | LTC2637_CMD_UPDATE 0x10 |
#define | LTC2637_CMD_WRITE_UPDATE 0x30 |
#define | LTC2637_CMD_POWER_DOWN 0x40 |
#define | LTC2637_CMD_POWER_DOWN_ALL 0x50 |
#define | LTC2637_CMD_INTERNAL_REFERENCE 0x60 |
#define | LTC2637_CMD_EXTERNAL_REFERENCE 0x70 |
#define | LTC2637_CMD_NO_OPERATION 0xF0 |
LTC2637 DAC Addresses | |
Which DAC to operate on | |
#define | LTC2637_DAC_A 0x00 |
#define | LTC2637_DAC_B 0x01 |
#define | LTC2637_DAC_C 0x02 |
#define | LTC2637_DAC_D 0x03 |
#define | LTC2637_DAC_E 0x04 |
#define | LTC2637_DAC_F 0x05 |
#define | LTC2637_DAC_G 0x06 |
#define | LTC2637_DAC_H 0x07 |
#define | LTC2637_DAC_ALL 0x0F |
void LTC2637_calibrate | ( | uint16_t | dac_code1, |
uint16_t | dac_code2, | ||
float | voltage1, | ||
float | voltage2, | ||
float * | LTC2637_lsb, | ||
int16_t * | LTC2637_offset | ||
) |
Calculate the LTC2637 offset and LSB voltages given two measured voltages and their corresponding codes.
dac_code1 | First DAC code |
dac_code2 | Second DAC code |
voltage1 | First voltage |
voltage2 | Second voltage |
LTC2637_lsb | Returns resulting LSB (volts) |
LTC2637_offset | Returns resulting Offset (volts) |
Definition at line 117 of file LTC2637.cpp.
float LTC2637_code_to_voltage | ( | uint16_t | dac_code, |
float | LTC2637_lsb, | ||
int16_t | LTC2637_offset | ||
) |
Calculate the LTC2637 DAC output voltage given the DAC code, offset, and LSB value.
dac_code | DAC code |
LTC2637_lsb | LSB value (volts) |
LTC2637_offset | Offset (volts) |
Definition at line 109 of file LTC2637.cpp.
uint16_t LTC2637_voltage_to_code | ( | float | dac_voltage, |
float | LTC2637_lsb, | ||
int16_t | LTC2637_offset | ||
) |
Calculate a LTC2637 DAC code given the desired output voltage and DAC address (0-3)
dac_voltage | Voltage to send to DAC |
LTC2637_lsb | LSB value (volts) |
LTC2637_offset | Offset (volts) |
Definition at line 96 of file LTC2637.cpp.
int8_t LTC2637_write | ( | uint8_t | i2c_address, |
uint8_t | dac_command, | ||
uint8_t | dac_address, | ||
uint16_t | dac_code | ||
) |
Write a 16-bit dac_code to the LTC2637.
i2c_address | I2C address of DAC |
dac_command | Command Nibble, left-justified, lower nibble set to zero |
dac_address | DAC Address Nibble, right justified, upper nibble set to zero |
dac_code | 16-bit DAC code |
Definition at line 87 of file LTC2637.cpp.