Below part of an email trail between myself and TI support before they suggest I post on E2E which is not what I wanted but here goes:-"I understand RS provide support but recently I find it useless - they simply attempt to interpret data sheets and have no real knowledge of the products they offer and more important are not aware of limitations of some parts - this is not helped when companies like Vishay and TI buy lines from others and then 're-badge' the data as I think is the case with the problem I have
A colleague placed the LME49724 in circuit making layout changes to replace an AD part that oscillated with usual precautions applied - We did not expect the EN input to draw enough current to pull down a 3.3V 0.5A supply line - I then built the circuit x2 as a simple unbalanced to balanced x1 gain amplifier and with a single 9V supply current limited at 100mA the EN pin draws over 55mA in this arrangement !
The circuit modified with 10kR resistors in place of 1kR all round works as expected but takes more than 25mA with the EN pin left open - when EN voltage is increased the current rises sharply above 1V
So apart from the numerous meaningless graphs relating to noise and distortion the data sheet shows the wrong quiescent current and operation of the EN line - Do you think RS can help ??"The answer was that RS are not a distributor for TI ???The demo board circuit shows a link to connect EN to VEE only - The data sheet voltages would suggest EN can be driven by most logic outputs ref VEE but this does not appear to be the case unless using an open collector/drain etc. but then the data sheet also says EN must not be left floating?At about 1V above VEE the EN input current becomes excessive - connecting EN to VCC as shown in many of the sample layouts and demo circuits for modelling would appear to be a mistake - Also the Quiescent current in all the circuits we have built (not modelled) is about 25mA not 10mA typical 15mA max as stated on the data sheetHas anyone else experienced the same problem ?