hello.
I purchased an MPM3695-10 to output variable voltage between 1.2 and 3.3V.
As a result of the test, only 1~1.3V is output normally, and the desired value is not output in other ranges.
So I purchased EVKT-MPM3695-25-A, and although the datasheet says 0.5~5.5V, the output is only 0.6~2V.
How do I output 3V from MPM3695-10 and MPM3695-25?
(In Virtual Bench Pro 3.0, if you set VOUT_COMMAND to 3,
In MPM3695-25, a warning message appears: “The value must be in the range 0.597 ~ 2.006, and step is 0.002.” In MPM3695-10, a warning message appears: “The value must be in the range 0.4 ~ 1.344, and step is 0.002.”
In MPM3695-25, VO_MIN = 0.5 / VOUT_SCALE_LOOP(0.335), VO_MAX = 0.672 / VOUT_SCALE_LOOP(0.335), so a 1.492 ~ 2.006V warning message should appear, and in MPM3695-10, VO_MIN = 0.5 / VOUT_SCALE_LOOP(0.5 ), VO_MAX = 0.67/ Since it is VOUT_SCALE_LOOP(0.5), shouldn’t a 1 to 1.34V warning message appear?)
The MPM3695 uses MCOT control which requires both resistor configuration and register configuration to set the output.
I don’t think your Vo_max and Vout_scale values are correct. The default Vout for the EVB is 1.8V so it looks like it might not have overwritten the register’s original default when you programmed it.
I have a follow up questions to help narrow down the reason why it isn’t setting the voltage.
What are your R1 and R2 values?
When you programmed did you program the MTP or I2C registers?
Also, there is a updated version of the GUI Virtual Bench Pro 4.0, however I don’t think this is cause the Vout problem.
When using EVKT-MPM3695-25-A, I did not change the resistance (R1 = 2k, R2 = 1k), and in the case of MPM3695-10, I used 2k resistance each, referring to “TYPICAL APPLICATION CIRCUITS” in the datasheet.
When using Virtual Bench Pro, in the case of EVKT-MPM3695-25-A, VOUT_MAX started at 6V, VOUT_COMMAND started at 1.8V, and VOUT_SCALE started at 0.335, and only VOUT_COMMAND was changed for testing. However, only 0.6 ~ 2V can be tested, and if 3V is input, a warning message appears and input is not possible. (In the case of Pro 4.0, less than 1.4V is not input.)
When programming with MCU, MTP was left untouched and VOUT_COMMAND (0x21) was changed using I2C, and the output value was about 0.6 ~ 2V, the same as in Virtual Bench pro 3.0. From 2.1V, the output value becomes strange.
Please refer to the Application Information Section of the MPM3695-25 Data Sheet, specifically the section on Output Voltage Setting. Your chosen resistor values do not align with the equations and I believe that is the primary reason the output voltage is not correct when you set the Vout_command. Since 3V out is a non- standard value, you will have to change both R1 and R2 on your board, then update the registers accordingly with their corresponding values.