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Linduino
1.3.0
Linear Technology Arduino-Compatible Demonstration Board
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LTC2656: Octal SPI 16-/12-Bit Rail-to-Rail DACs with 10ppm/C Max Reference. More...
LTC2656: Octal SPI 16-/12-Bit Rail-to-Rail DACs with 10ppm/C Max Reference.
The LTC2656 is a family of octal 16-/12-bit rail-to-rail DACs with a precision integrated reference. The DACs have built-in high performance, rail-to-rail, output buffers and are guaranteed monotonic. The LTC2656-L has a full-scale output of 2.5V with the integrated 10ppm/C reference and operates from a single 2.7V to 5.5V supply. The LTC2656-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 DAC full-scale output to two times the external reference voltage. These DACs communicate via a SPI/MICROWIRE compatible 4-wire serial interface which operates at clock rates up to 50MHz. The LTC2656 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. If PORSEL is tied to VCC, the DACs reset to mid-scale. SPI DATA FORMAT (MSB First): 24-Bit Load Sequence: Byte #1 Byte #2 Byte #3 Command MSB LSB LTC2656-16 : C3 C2 C1 C0 A3 A2 A1 A0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 LTC2656-12 : C3 C2 C1 C0 A3 A2 A1 A0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X 32-Bit Load Sequence: Byte #1 Byte #2 Byte #3 Byte #4 Command MSB LSB LTC2656-16 : X X X X X X X X C3 C2 C1 C0 A3 A2 A1 A0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 LTC2656-12 : X X X X X X X X C3 C2 C1 C0 A3 A2 A1 A0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X 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 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 = LTC2656_voltage_to_code(dac_voltage, LTC2656_lsb, LTC2656_offset); // Calculate DAC code from voltage, lsb, and offset LTC2656_write(LTC2656_CS, LTC2656_CMD_WRITE_UPDATE, LTC2656_DAC_A, dac_code << shift_count); // Set DAC A with DAC code
http://www.linear.com/product/LTC2656
http://www.linear.com/product/LTC2656#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:
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Header for LTC2656 Octal SPI 16-/12-Bit Rail-to-Rail DACs with 10ppm/C Max Reference
Definition in file LTC2656.h.
Go to the source code of this file.
Functions | |
void | LTC2656_write (uint8_t cs, uint8_t dac_command, uint8_t dac_address, uint16_t dac_code) |
Write the 16-bit dac_code to the LTC2656. More... | |
uint16_t | LTC2656_voltage_to_code (float dac_voltage, float LTC2656_lsb, int16_t LTC2656_offset) |
Calculate a LTC2656 DAC code given the desired output voltage and DAC address (0-7) More... | |
float | LTC2656_code_to_voltage (uint16_t dac_code, float LTC2656_lsb, int16_t LTC2656_offset) |
Calculate the LTC2656 DAC output voltage given the DAC code, offset, and LSB value. More... | |
void | LTC2656_calibrate (uint16_t dac_code1, uint16_t dac_code2, float voltage1, float voltage2, float *LTC2656_lsb, int16_t *LTC2656_offset) |
Calculate the LTC2656 offset and LSB voltage given two measured voltages and their corresponding codes. More... | |
Macros | |
#define | LTC2656_CS QUIKEVAL_CS |
Define the SPI CS pin. More... | |
LTC2656 Command Codes | |
OR'd together with the DAC address to form the command byte | |
#define | LTC2656_CMD_WRITE 0x00 |
Write to input register n. More... | |
#define | LTC2656_CMD_UPDATE 0x10 |
Update (power up) DAC register n. More... | |
#define | LTC2656_CMD_WRITE_UPDATE_ALL 0x20 |
Write to input register n, update (power up) all. More... | |
#define | LTC2656_CMD_WRITE_UPDATE 0x30 |
Write to input register n, update (power up) all. More... | |
#define | LTC2656_CMD_POWER_DOWN 0x40 |
Power down n. More... | |
#define | LTC2656_CMD_POWER_DOWN_ALL 0x50 |
Power down chip (all DACs and reference) More... | |
#define | LTC2656_CMD_INTERNAL_REFERENCE 0x60 |
Select internal reference (power up reference) More... | |
#define | LTC2656_CMD_EXTERNAL_REFERENCE 0x70 |
Select external reference (power down internal reference) More... | |
#define | LTC2656_CMD_NO_OPERATION 0xF0 |
No operation. More... | |
LTC2656 DAC Addresses | |
Which DAC to operate on | |
#define | LTC2656_DAC_A 0x00 |
#define | LTC2656_DAC_B 0x01 |
#define | LTC2656_DAC_C 0x02 |
#define | LTC2656_DAC_D 0x03 |
#define | LTC2656_DAC_E 0x04 |
#define | LTC2656_DAC_F 0x05 |
#define | LTC2656_DAC_G 0x06 |
#define | LTC2656_DAC_H 0x07 |
#define | LTC2656_DAC_ALL 0x0F |
void LTC2656_calibrate | ( | uint16_t | dac_code1, |
uint16_t | dac_code2, | ||
float | voltage1, | ||
float | voltage2, | ||
float * | LTC2656_lsb, | ||
int16_t * | LTC2656_offset | ||
) |
Calculate the LTC2656 offset and LSB voltage given two measured voltages and their corresponding codes.
dac_code1 | First DAC code |
dac_code2 | Second DAC code |
voltage1 | First voltage |
voltage2 | Second voltage |
LTC2656_lsb | Returns resulting LSB (volts) |
LTC2656_offset | Returns resulting Offset (volts) |
Definition at line 115 of file LTC2656.cpp.
float LTC2656_code_to_voltage | ( | uint16_t | dac_code, |
float | LTC2656_lsb, | ||
int16_t | LTC2656_offset | ||
) |
Calculate the LTC2656 DAC output voltage given the DAC code, offset, and LSB value.
dac_code | DAC code |
LTC2656_lsb | LSB value (volts) |
LTC2656_offset | Offset (volts) |
Definition at line 107 of file LTC2656.cpp.
uint16_t LTC2656_voltage_to_code | ( | float | dac_voltage, |
float | LTC2656_lsb, | ||
int16_t | LTC2656_offset | ||
) |
Calculate a LTC2656 DAC code given the desired output voltage and DAC address (0-7)
dac_voltage | Voltage to send to DAC |
LTC2656_lsb | LSB value (volts) |
LTC2656_offset | Offset (volts) |
Definition at line 94 of file LTC2656.cpp.
void LTC2656_write | ( | uint8_t | cs, |
uint8_t | dac_command, | ||
uint8_t | dac_address, | ||
uint16_t | dac_code | ||
) |
Write the 16-bit dac_code to the LTC2656.
cs | Chip Select Pin |
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 79 of file LTC2656.cpp.
#define LTC2656_CMD_EXTERNAL_REFERENCE 0x70 |
#define LTC2656_CMD_INTERNAL_REFERENCE 0x60 |
#define LTC2656_CMD_POWER_DOWN_ALL 0x50 |
#define LTC2656_CMD_UPDATE 0x10 |
#define LTC2656_CMD_WRITE_UPDATE 0x30 |
#define LTC2656_CMD_WRITE_UPDATE_ALL 0x20 |
#define LTC2656_CS QUIKEVAL_CS |