LT3092 is used to excite the ICP vibration sensor. The current output current is set at 150uA. According to the manual, the minimum output current is 0.5mA.Will it damage the chip?If this is not appropriate, what is the recommended constant current source for the output current of about 100uA?
This is the description in the manual:
Note 3: Minimum load current is equivalent to the quiescent current of
The part Since all quiescent and drive current is delivered to the output
Of the part, the minimum load current is the minimum current required to
Device will not regulate with current output set to lower than 0.5mA as indicated on the datasheet.
*Page 8 of the datasheet,
PIN FUNCTIONSOUT (Pins 1, 2/Pin 2/Pins 2, 3, 4): Output. This is the power output of the device. The minimum current source value to which the LT3092 can be set is 0.5mA or the device will not regulate.
In fact, output is 150uA and the test is normal, but it is not clear for a long time
The 0.5mA value is a parameter which is dependent on production effects, hence it will be smaller but from characterization results it will never be higher. To obtain a reliable current smaller than 500uA you have to use two LT3092 in series (sink and source configuration) and configure them for I1 and I1+150uA. The 150uA will then be available between them. I would suggest to choose I1 for 1mA or so
Thank you. In parallel or in series?How?Are there any diagrams?
The answer to your first question was in my initial statement.
The answer to your 2nd question is here:
According to Kirchhoff law the sum of all currents into a single node equals to zero. So if you have two elements, one sources a current X into the node and the other one sinks a current X-deltaX from that node -> There has to be a third line/element where the current deltaX is available from that node, otherwise it won’t work.
The answer to question 3: Should not be required if you follow and understand answer 2. It's really that easy.