LTC2499
LTC2499 16-channel (eight differential, 24-bit) ADC Linux Driver.
Supported Devices
Evaluation Boards
Source Code
Status
Files
Function |
File |
|---|---|
core driver |
|
Documentation |
Example device tree
Function |
File |
|---|---|
dts |
Driver testing
The driver exposes 16 single-ended voltage inputs and eight differential input pairs in both polarities. All channels are ADC inputs; there are no current channels or DAC outputs. The following is an example sysfs listing.
root@analog:/sys/bus/iio/devices/iio:device0# ls -l
total 0
-r--r--r-- 1 root root 4096 Sep 22 15:17 dev
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage0_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage0-voltage1_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage10_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage10-voltage11_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage11_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage11-voltage10_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage12_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage12-voltage13_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage13_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage13-voltage12_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage14_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage14-voltage15_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage15_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage15-voltage14_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage1_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage1-voltage0_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage2_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage2-voltage3_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage3_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage3-voltage2_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage4_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage4-voltage5_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage5_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage5-voltage4_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage6_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage6-voltage7_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage7_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage7-voltage6_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage8_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage8-voltage9_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage9_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage9-voltage8_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage_scale
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage-voltage_scale
-r--r--r-- 1 root root 4096 Sep 22 15:17 name
lrwxrwxrwx 1 root root 0 Sep 22 15:17 of_node -> ../../../../../../../firmware/devicetree/base/soc/i2c@7e804000/ltc2499@76
drwxr-xr-x 2 root root 0 Sep 22 15:17 power
lrwxrwxrwx 1 root root 0 Sep 22 15:17 subsystem -> ../../../../../../../bus/iio
-rw-r--r-- 1 root root 4096 Sep 22 15:17 uevent
Identify the device
root@analog:/sys/bus/iio/devices/iio:device0# cat name
ltc2499
Basic operation
Show raw measurement
Description: Raw ADC code for voltage input channel 0.
root@analog:/sys/bus/iio/devices/iio:device0# cat in_voltage0_raw
16777216
Show scale
Description: Multiply the raw code by in_voltage_scale to obtain
millivolts. The scale is VREF_mV / 2^(resolution + 1), with a resolution of 24
for LTC2499 and 16 for LTC2497.
root@analog:/sys/bus/iio/devices/iio:device0# cat in_voltage_scale
0.000074505