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Linduino
1.3.0
Linear Technology Arduino-Compatible Demonstration Board
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LTC2657: Octal I2C 16-/12-Bit Rail-to-Rail DACs with 10ppm/C Max Reference. More...
LTC2657: Octal I2C 16-/12-Bit Rail-to-Rail DACs with 10ppm/C Max Reference.
The LTC2657 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 LTC2657-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 LTC2657-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 LTC2657 operates in both the standard mode (maximum clock rate of 100kHz) and the fast mode (maximum clock rate of 400kHz). The LTC2657 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 LTC2657-16 : START SA6 SA5 SA4 SA3 SA2 SA1 SA0 W SACK C3 C2 C1 C0 A3 A2 A1 A0 SACK LTC2657-12 : 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 D15 D14 D13 D12 D11 D10 D9 D8 SACK D7 D6 D5 D4 D3 D2 D1 D0 SACK STOP D11 D10 D9 D8 D7 D6 D5 D4 SACK D3 D2 D1 D0 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 16-bit DAC. shift_count = 0; // 16-bit DAC does not have to be shifted dac_voltage = 2.0; // Sets dac voltage variable to 2v dac_code = LTC2657_voltage_to_code(dac_voltage, LTC2657_lsb, LTC2657_offset); // Calculate DAC code from voltage, lsb, and offset ack = LTC2657_write(LTC2657_I2C_ADDRESS, LTC2657_CMD_WRITE_UPDATE, LTC2657_DAC_A, dac_code); // Set DAC A with DAC code
http://www.linear.com/product/LTC2657
http://www.linear.com/product/LTC2657#demoboards
Copyright 2018(c) Analog Devices, Inc.
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Header for LTC2657 Octal I2C 16-/12-Bit Rail-to-Rail DACs with 10ppm/C Max Reference
Definition in file LTC2657.h.
Go to the source code of this file.
Functions | |
int8_t | LTC2657_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 LTC2657. More... | |
uint16_t | LTC2657_voltage_to_code (float dac_voltage, float LTC2657_lsb, int16_t LTC2657_offset) |
Calculate a LTC2657 DAC code given the desired output voltage and DAC address (0-3) More... | |
float | LTC2657_code_to_voltage (uint16_t dac_code, float LTC2657_lsb, int16_t LTC2657_offset) |
Calculate the LTC2657 DAC output voltage given the DAC code, offset, and LSB value. More... | |
void | LTC2657_calibrate (uint16_t dac_code1, uint16_t dac_code2, float voltage1, float voltage2, float *LTC2657_lsb, int16_t *LTC2657_offset) |
Calculate the LTC2657 offset and LSB voltages given two measured voltages and their corresponding codes. More... | |
Macros | |
I2C_Addresses | |
#define | LTC2657_I2C_ADDRESS 0x10 |
#define | LTC2657_I2C_GLOBAL_ADDRESS 0x73 |
LTC2657 Command Codes | |
OR'd together with the DAC address to form the command byte | |
#define | LTC2657_CMD_WRITE 0x00 |
#define | LTC2657_CMD_UPDATE 0x10 |
#define | LTC2657_CMD_WRITE_UPDATE 0x30 |
#define | LTC2657_CMD_POWER_DOWN 0x40 |
#define | LTC2657_CMD_POWER_DOWN_ALL 0x50 |
#define | LTC2657_CMD_INTERNAL_REFERENCE 0x60 |
#define | LTC2657_CMD_EXTERNAL_REFERENCE 0x70 |
#define | LTC2657_CMD_NO_OPERATION 0xF0 |
LTC2657 DAC Addresses | |
Which DAC to operate on | |
#define | LTC2657_DAC_A 0x00 |
#define | LTC2657_DAC_B 0x01 |
#define | LTC2657_DAC_C 0x02 |
#define | LTC2657_DAC_D 0x03 |
#define | LTC2657_DAC_E 0x04 |
#define | LTC2657_DAC_F 0x05 |
#define | LTC2657_DAC_G 0x06 |
#define | LTC2657_DAC_H 0x07 |
#define | LTC2657_DAC_ALL 0x0F |
void LTC2657_calibrate | ( | uint16_t | dac_code1, |
uint16_t | dac_code2, | ||
float | voltage1, | ||
float | voltage2, | ||
float * | LTC2657_lsb, | ||
int16_t * | LTC2657_offset | ||
) |
Calculate the LTC2657 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 |
LTC2657_lsb | Returns resulting LSB (volts) |
LTC2657_offset | Returns resulting Offset (volts) |
Definition at line 112 of file LTC2657.cpp.
float LTC2657_code_to_voltage | ( | uint16_t | dac_code, |
float | LTC2657_lsb, | ||
int16_t | LTC2657_offset | ||
) |
Calculate the LTC2657 DAC output voltage given the DAC code, offset, and LSB value.
dac_code | DAC code |
LTC2657_lsb | LSB value (volts) |
LTC2657_offset | Offset (volts) |
Definition at line 104 of file LTC2657.cpp.
uint16_t LTC2657_voltage_to_code | ( | float | dac_voltage, |
float | LTC2657_lsb, | ||
int16_t | LTC2657_offset | ||
) |
Calculate a LTC2657 DAC code given the desired output voltage and DAC address (0-3)
dac_voltage | Voltage to send to DAC |
LTC2657_lsb | LSB value (volts) |
LTC2657_offset | Offset (volts) |
Definition at line 91 of file LTC2657.cpp.
int8_t LTC2657_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 LTC2657.
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 82 of file LTC2657.cpp.