/*! LTC2604: Quad 16-Bit Rail-to-Rail DACs in 16-Lead SSOP @verbatim The LTC2604/LTC2614/LTC2624 are quad 16-,14- and 12-bit 2.5V to 5.5V rail-to-rail voltage output DACs in 16-lead narrow SSOP packages. These parts have separate reference inputs for each DAC. They have built-in high performance output buffers and are guaranteed monotonic. These parts establish advanced performance standards for output drive, crosstalk and load regulation in single-supply, voltage output multiples. SPI DATA FORMAT (MSB First): 24-Bit Load Sequence: Byte #1 Byte #2 Byte #3 Command MSB LSB LTC2604-16 : C3 C2 C1 C0 A3 A2 A1 A0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 LTC2604-14 : C3 C2 C1 C0 A3 A2 A1 A0 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X LTC2604-12 : 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 LTC2604-16 : 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 LTC2604-14 : X X X X X X X X C3 C2 C1 C0 A3 A2 A1 A0 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X LTC2604-12 : 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, 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 = LTC2604_voltage_to_code(dac_voltage, LTC2604_lsb, LTC2604_offset); // Calculate DAC code from voltage, lsb, and offset LTC2604_write(LTC2604_CS, LTC2604_CMD_WRITE_UPDATE, LTC2604_DAC_A, dac_code << shift_count); // Set DAC A with DAC code @endverbatim http://www.linear.com/product/LTC2604 http://www.linear.com/product/LTC2604#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. */ /*! @file @ingroup LTC2604 Header for LTC2604: Quad 16-Bit Rail-to-Rail DACs in 16-Lead SSOP */ #ifndef LTC2604_H #define LTC2604_H #include //! Define the SPI CS pin #ifndef LTC2604_CS #define LTC2604_CS QUIKEVAL_CS #endif //! @name LTC2604 Command Codes //!@{ //! OR'd together with the DAC address to form the command byte #define LTC2604_CMD_WRITE 0x00 //!< Write to input register n #define LTC2604_CMD_UPDATE 0x10 //!< Update (power up) DAC register n #define LTC2604_CMD_WRITE_UPDATE_ALL 0x20 //!< Write to input register n, update (power up) all #define LTC2604_CMD_WRITE_UPDATE 0x30 //!< Write to input register n, update (power up) all #define LTC2604_CMD_POWER_DOWN 0x40 //!< Power down n #define LTC2604_CMD_NO_OPERATION 0xF0 //!< No operation //!@} /*! | DAC Addresses | Value | | :--------------------------: | :------: | | LTC2605_DAC_A | 0x00 | | LTC2605_DAC_B | 0x01 | | LTC2605_DAC_C | 0x02 | | LTC2605_DAC_D | 0x03 | | LTC2605_DAC_ALL | 0x0F | */ /*! @name Dac Addresses @{*/ // Which DAC to operate on #define LTC2604_DAC_A 0x00 #define LTC2604_DAC_B 0x01 #define LTC2604_DAC_C 0x02 #define LTC2604_DAC_D 0x03 #define LTC2604_DAC_ALL 0x0F // //! Write the 16-bit dac_code to the LTC2604 //! @return Void void LTC2604_write(uint8_t cs, //!< Chip Select Pin uint8_t dac_command, //!< Command Nibble, left-justified, lower nibble set to zero uint8_t dac_address, //!< DAC Address Nibble, right justified, upper nibble set to zero uint16_t dac_code //!< 16-bit DAC code ); //! Calculate a LTC2604 DAC code given the desired output voltage and DAC address (0-3) //! @return The 16-bit code to send to the DAC uint16_t LTC2604_voltage_to_code(float dac_voltage, //!< Voltage to send to DAC float LTC2604_lsb, //!< LSB value (volts) int16_t LTC2604_offset //!< Offset (volts) ); //! Calculate the LTC2604 DAC output voltage given the DAC code, offset, and LSB value //! @return Calculated voltage float LTC2604_code_to_voltage(uint16_t dac_code, //!< DAC code float LTC2604_lsb, //!< LSB value (volts) int16_t LTC2604_offset //!< Offset (volts) ); #endif //LTC2604_H