xref: /linux/Documentation/iio/ad7625.rst (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1.. SPDX-License-Identifier: GPL-2.0-only
2
3====================
4AD7625 driver
5====================
6
7ADC driver for Analog Devices Inc. AD7625, AD7626, AD7960, and AD7961
8devices. The module name is ``ad7625``.
9
10Supported devices
11=================
12
13The following chips are supported by this driver:
14
15* `AD7625 <https://www.analog.com/AD7625>`_
16* `AD7626 <https://www.analog.com/AD7626>`_
17* `AD7960 <https://www.analog.com/AD7960>`_
18* `AD7961 <https://www.analog.com/AD7961>`_
19
20The driver requires use of the Pulsar LVDS HDL project:
21
22* `Pulsar LVDS HDL <http://analogdevicesinc.github.io/hdl/projects/pulsar_lvds/index.html>`_
23
24To trigger conversions and enable subsequent data transfer, the devices
25require coupled PWM signals with a phase offset.
26
27Supported features
28==================
29
30Conversion control modes
31------------------------
32
33The driver currently supports one of two possible LVDS conversion control methods.
34
35Echoed-Clock interface mode
36^^^^^^^^^^^^^^^^^^^^^^^^^^^
37
38.. code-block::
39
40                                                +----------------+
41                     +xxxxxxxxxxxxxxxxxxxxxxxxxx| CNV            |
42                     X                          |                |
43                     v                          |    HOST        |
44          +----------------------------+        |                |
45          |      CNV+/CNV-   DCO+/DCO- |xxxxxxx>| CLK_IN         |
46          |                            |        |                |
47          |                            |        |                |
48          |       AD7625         D+/D- |xxxxxxx>| DATA_IN        |
49          |                            |        |                |
50          |                            |        |                |
51          |                  CLK+/CLK- |<xxxxxxx| CLK & CLK_GATE |
52          +----------------------------+        |                |
53                                                +----------------+
54
55Reference voltage
56-----------------
57
58Three possible reference voltage sources are supported:
59
60- Internal reference (only available on AD7625 and AD7626)
61- External reference and internal buffer
62- External reference
63
64The source is determined by the device tree. If ``ref-supply`` is present, then
65the external reference is used. If ``refin-supply`` is present, then the internal
66buffer is used. If neither is present, then the internal reference is used.
67
68Unimplemented features
69----------------------
70
71- Self-clocked mode
72
73
74Device attributes
75=================
76
77The AD762x is a fully-differential ADC and has the following attributes:
78
79+---------------------------------------+--------------------------------------------------------------+
80| Attribute                             | Description                                                  |
81+=======================================+==============================================================+
82| ``scale``                             | Scale factor to convert raw value from buffered reads to mV. |
83+---------------------------------------+--------------------------------------------------------------+
84
85
86Device buffers
87==============
88
89This driver supports IIO triggered buffers.
90
91See :doc:`iio_devbuf` for more information.
92