SBOS070D October 1997 – December 2019 OPA548
PRODUCTION DATA.
A unique feature of the OPA548 is its output disable capability. This function not only conserves power during idle periods (quiescent current drops to approximately 6 mA), but also allows multiplexing in low frequency (f < 20 kHz), multichannel applications. Signals greater than 20 kHz may cause leakage current to increase in devices that are shutdown. Figure 33 shows the two OPA548s in a switched amplifier configuration. The ON/OFF state of the two amplifiers is controlled by the voltage on the E/S pin.
To disable the output, the E/S pin is pulled LOW, no greater than 0.8 V more than the negative rail. Typically the output is shutdown in 1 μs. Figure 23 provides an example of how to implement this function using a single supply. Figure 24 gives a circuit for dual-supply applications. To return the output to an enabled state, the E/S pin should be disconnected (open) or pulled to at least (V–) + 2.4 V. It should be noted that pulling the E/S pin HIGH (output enabled) does not disable internal thermal shutdown.