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I am looking at the datasheet of LT3083EQ#PBF. I am wondering what is VCONTROL actually doing. Can it be used as enable pin ? I mean can VCONTROL = 0 turn down the output voltage to 0 V ?
VCONTROL pin in LT3083EQ#PBF
- Thread starter engr_david_ee
- Start date
No, it can’t.
As far as I can tell from the datasheet, the behavior of the regulator in the absence of VCONTROL is undefined. But, since this appears in the applications section, it can probably be safely assumed they do not support that configuration.
It would certainly seem most reasonable to use their application note for a shutdown/enable functionality. The cost of two MOSFETs seems very low. Not that operates by tying SET to 0V, not VCONTROL.
As far as I can tell from the datasheet, the behavior of the regulator in the absence of VCONTROL is undefined. But, since this appears in the applications section, it can probably be safely assumed they do not support that configuration.
VControl provides the base bias drive to the output transistor (emitter follower). For true LDO operation at higher output currents VControl needs to be ~1.3 - 1.6v above the output voltage @ around 50mA whereas Vin can be as low as 500mV above Vout @ 3A
Reducing VControl to 0 will turn the output down, but won't guarantee no leakage current. The circuit shown above guarantees no output leakage at 0v, by reducing base drive to 0mA and shorting output.
Reducing VControl to 0 will turn the output down, but won't guarantee no leakage current. The circuit shown above guarantees no output leakage at 0v, by reducing base drive to 0mA and shorting output.
