The enable (EN) pin is active high and compatible with standard digital-signaling levels. Setting V_EN below 0.4 V turns the regulator off, and setting V_EN above 1.1 V turns the regulator on. Unlike many regulators, the enable circuitry has hysteresis and deglitching for use with relatively slowly ramping analog signals. This configuration allows the device to be enabled by connecting the output of another supply to the EN pin. The enable circuitry typically has 70 mV of hysteresis and a deglitch circuit to help avoid on-off cycling as a result of small glitches in the V_EN signal.

The enable threshold is typically 0.75 V and varies with temperature and process variations. Temperature variation is approximately –1.2 mV/°C; process variation accounts for most of the remaining variation to the 0.4-V and 1.1-V limits. If precise turn-on timing is required, a fast rise-time signal must be used.

If not used, EN can be connected to BIAS. Place the connection as close as possible to the bias capacitor.