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LTC2664.h
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1 /*!
2 LTC2664: 4-Channel SPI 16-/12-Bit +/-10V Vout SoftSpan DACs with 10ppm/C Max Reference.
3
4 @verbatim
5
6 The LTC2664 is a family of 4-channel, 12/16-bit +/-10V digital-to-analog converters with integrated
7 precision references. They are guaranteed monotonic and have built-in rail-to-rail output buffers.
8 These SoftSpan DACs offer five output ranges up to +/-10V. The range of each channel is independently
9 programmable, or the part can be hardware-configured for operation in a fixed range.
10
11 The integrated 2.5V reference is buffered separately to each channel; an external reference can be used
12 for additional range options. The LTC2668 also includes toggle capability - alternating codes via the
13 software toggle command, or by providing a free-running clock to the TGP pin.
14
15 The SPI/Microwire-compatible 3-wire serial interface operates on logic levels as low as 1.71V, at clock
16 rates up to 50MHz.
17
18
19 SPI DATA FORMAT (MSB First):
20
21 24-Bit Load Sequence:
22
23 Byte #1 Byte #2 Byte #3
24 Command MSB LSB
25 LTC2664-16 : C3 C2 C1 C0 A3 A2 A1 A0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
26 LTC2664-12 : C3 C2 C1 C0 A3 A2 A1 A0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 X X X X
27
28 32-Bit Load Sequence:
29 Byte #1 Byte #2 Byte #3 Byte #4
30 Command MSB LSB
31 LTC2664-16 : 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
32 LTC2664-12 : 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
33
34 Cx : DAC Command Code
35 Ax : DAC Address (0 to F, corresponding to DAC 0 to DAC 15)
36 Dx : DAC Data Bits
37 X : Don't care
38
39 @endverbatim
40
41 http://www.linear.com/product/LTC2664
42
43 http://www.linear.com/product/LTC2664#demoboards
44
45
46 Copyright 2018(c) Analog Devices, Inc.
47
48 All rights reserved.
49
50 Redistribution and use in source and binary forms, with or without
51 modification, are permitted provided that the following conditions are met:
52 - Redistributions of source code must retain the above copyright
53 notice, this list of conditions and the following disclaimer.
54 - Redistributions in binary form must reproduce the above copyright
55 notice, this list of conditions and the following disclaimer in
56 the documentation and/or other materials provided with the
57 distribution.
58 - Neither the name of Analog Devices, Inc. nor the names of its
59 contributors may be used to endorse or promote products derived
60 from this software without specific prior written permission.
61 - The use of this software may or may not infringe the patent rights
62 of one or more patent holders. This license does not release you
63 from the requirement that you obtain separate licenses from these
64 patent holders to use this software.
65 - Use of the software either in source or binary form, must be run
66 on or directly connected to an Analog Devices Inc. component.
67
68 THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
69 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
70 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
71 IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
72 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
73 LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR
74 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
75 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
76 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
77 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
78 */
79
80 /*! @file
81 @ingroup LTC2664
82 Header for LTC2664: 4-Channel SPI 16-/12-Bit +/-10V Vout SoftSpan DACs with 10ppm/C Max Reference
83 */
84
85 #ifndef LTC2664_H
86 #define LTC2664_H
87
88 //! Define the SPI CS pin
89 #ifndef LTC2664_CS
90 #define LTC2664_CS QUIKEVAL_CS //! SPI Chip Select Pin
91 #endif
92
93 //! @name LTC2664 Command Codes
94 //! OR'd together with the DAC address to form the command byte
95 #define LTC2664_CMD_WRITE_N 0x00 //!< Write to input register n
96 #define LTC2664_CMD_UPDATE_N 0x10 //!< Update (power up) DAC register n
97 #define LTC2664_CMD_WRITE_N_UPDATE_ALL 0x20 //!< Write to input register n, update (power-up) all
98 #define LTC2664_CMD_WRITE_N_UPDATE_N 0x30 //!< Write to input register n, update (power-up)
99 #define LTC2664_CMD_POWER_DOWN_N 0x40 //!< Power down n
100 #define LTC2664_CMD_POWER_DOWN_ALL 0x50 //!< Power down chip (all DAC's, MUX and reference)
101
102 #define LTC2664_CMD_SPAN 0x60 //!< Write span to dac n
103 #define LTC2664_CMD_CONFIG 0x70 //!< Configure reference / toggle
104 #define LTC2664_CMD_WRITE_ALL 0x80 //!< Write to all input registers
105 #define LTC2664_CMD_UPDATE_ALL 0x90 //!< Update all DACs
106 #define LTC2664_CMD_WRITE_ALL_UPDATE_ALL 0xA0 //!< Write to all input reg, update all DACs
107 #define LTC2664_CMD_MUX 0xB0 //!< Select MUX channel (controlled by 5 LSbs in data word)
108 #define LTC2664_CMD_TOGGLE_SEL 0xC0 //!< Select which DACs can be toggled (via toggle pin or global toggle bit)
109 #define LTC2664_CMD_GLOBAL_TOGGLE 0xD0 //!< Software toggle control via global toggle bit
110 #define LTC2664_CMD_SPAN_ALL 0xE0 //!< Set span for all DACs
111 #define LTC2664_CMD_NO_OPERATION 0xF0 //!< No operation
112 //! @}
113
114 //! @name LTC2664 Span Codes
115 //! @{
116 //! Descriptions are valid for a 2.5V reference.
117 //! These can also be interpreted as 0 to 2*Vref, 0 to 4*Vref, etc.
118 //! when an external reference other than 2.5V is used.
119 #define LTC2664_SPAN_0_TO_5V 0x0000
120 #define LTC2664_SPAN_0_TO_10V 0x0001
121 #define LTC2664_SPAN_PLUS_MINUS_5V 0x0002
122 #define LTC2664_SPAN_PLUS_MINUS_10V 0x0003
123 #define LTC2664_SPAN_PLUS_MINUS_2V5 0x0004
124 //! @}
125
126 //! @name LTC2664 Minimums and Maximums for each Span
127 //! @{
128 //! Lookup tables for minimum and maximum outputs for a given span
129 const float LTC2664_MIN_OUTPUT[5] = {0.0, 0.0, -5.0, -10.0, -2.5};
130 const float LTC2664_MAX_OUTPUT[5] = {5.0, 10.0, 5.0, 10.0, 2.5};
131 //! @}
132
133 //! @name LTC2664 Configuration options
134 //! @{
135 //! Used in conjunction with LTC2664_CMD_CONFIG command
136 #define LTC2664_REF_DISABLE 0x0001 //! Disable internal reference to save power when using an ext. ref.
137 #define LTC2664_THERMAL_SHUTDOWN 0x0002 //! Disable thermal shutdown (NOT recommended)
138 //! @}
139
140 //! @name LTC2664 MUX enable
141 //! @{
142 //! Used in conjunction with LTC2664_CMD_MUX command
143 #define LTC2664_MUX_DISABLE 0x0000 //! Disable MUX
144 #define LTC2664_MUX_ENABLE 0x0010 //! Enable MUX, OR with MUX channel to be monitored
145 //! @}
146
147 //! @name LTC2664 Global Toggle
148 //! @{
149 //! Used in conjunction with LTC2664_CMD_GLOBAL_TOGGLE command, affects DACs whose
150 //! Toggle Select bits have been set to 1
151 #define LTC2664_TOGGLE_REG_A 0x0000 //! Update DAC with register A
152 #define LTC2664_TOGGLE_REG_B 0x0010 //! Update DAC with register B
153 //! @}
154
155 //! Write the 16-bit dac_code to the LTC2664
156 //! @return Zero if readback (SDO) data matches the value previously sent, One if mismatched (indicating data error somewhere)
157 int8_t LTC2664_write(uint8_t cs, uint8_t dac_command, uint8_t dac_address, uint16_t dac_code);
158
159 //! Calculate a LTC2664 DAC code given the desired output voltage and DAC address (0-3)
160 //! @return The 16 bit code to send to the DAC
161 uint16_t LTC2664_voltage_to_code(float dac_voltage, float min_output, float max_output);
162
163 //! Calculate the LTC2664 DAC output voltage given the DAC code, offset, and LSB
164 //! @return the output voltage
165 float LTC2664_code_to_voltage(uint16_t dac_code, float min_output, float max_output);
166
167 #endif // LTC2664_H
LTC2664_MIN_OUTPUT
const float LTC2664_MIN_OUTPUT[5]
Definition: LTC2664.h:129
LTC2664_write
int8_t LTC2664_write(uint8_t cs, uint8_t dac_command, uint8_t dac_address, uint16_t dac_code)
Write the 16-bit dac_code to the LTC2664.
Definition: LTC2664.cpp:70
LTC2664_code_to_voltage
float LTC2664_code_to_voltage(uint16_t dac_code, float min_output, float max_output)
Calculate the LTC2664 DAC output voltage given the DAC code, offset, and LSB.
Definition: LTC2664.cpp:123
LTC2664_voltage_to_code
uint16_t LTC2664_voltage_to_code(float dac_voltage, float min_output, float max_output)
Calculate a LTC2664 DAC code given the desired output voltage and DAC address (0-3) ...
Definition: LTC2664.cpp:109
LTC2664_MAX_OUTPUT
const float LTC2664_MAX_OUTPUT[5]
Definition: LTC2664.h:130