Can the LT6010 Shutdown pin be left open?

Hi KBarkley872:  If the SHDN pin is truly open and floating, then the LT6010 will remain "on".   

However, note that the SHDN input is an open base, so it will not take much input leakage from a higher supply (above Vee) to turn on the SHDN transistor and turn off the opamp.  So the SHDN pin should be guarded from positive leakage sources, or should be tied to Vee to preclude accidental turn-offs.  Note also that external EMI could forward / rectify the base emitter of the SHDN transistor, turning off the opamp. (See Figure 3 in the data sheet as well as the Simplified Schematic on page 13.)

Hi KBarkley872:  If the SHDN pin is truly open and floating, then the LT6010 will remain "on".   

However, note that the SHDN input is an open base, so it will not take much input leakage from a higher supply (above Vee) to turn on the SHDN transistor and turn off the opamp.  So the SHDN pin should be guarded from positive leakage sources, or should be tied to Vee to preclude accidental turn-offs.  Note also that external EMI could forward / rectify the base emitter of the SHDN transistor, turning off the opamp. (See Figure 3 in the data sheet as well as the Simplified Schematic on page 13.)

That's what I thought. For my next rev I am going to tie it to Vee just in case. I have seen some weird behavior, that in retrospect might have been the shutdown activating. Thanks!

I should add that I got a bit concerned when I realized that with my +/- 12 V supply, 500K to ground could shut the amp down.