The recommended bias supply voltage range for LM5112 is from 3.5 V to 14 V. The lower end of this range is governed by the internal UVLO protection feature of the V_CC supply circuit. The upper end of this range is driven by the 14 V maximum recommended operating voltage rating of the V_CC supply. It is recommended to keep proper margin to allow for transient voltage spikes. The dedicated input ground pin (IN_REF) allows split output supply operation. For such applications, ensure V_EE is not connected to IN_REF.

The UVLO protection feature also involves a hysteresis function. This means that once the device is operating in normal mode, if the V_CC voltage drops, the device continues to operate in normal mode as long as the voltage drop does not exceed the hysteresis specification, V_CCH. If the voltage drop is greater than the hysteresis specification, the device shuts down. Therefore, while operating at or near the 3.5 V range, the voltage ripple on the auxiliary power supply output must be smaller than the hysteresis specification of LM5112 to avoid triggering device-shutdown.

A low-ESR or low-ESL capacitor must be connected close to the IC and between the V_CC and V_EE pins to support high peak currents being drawn from V_CC during turnon of the MOSFET. Also, if input pin (IN or INB) is not being used, it must be connected to V_CC or IN_REF, respectively, to avoid spurious output signals.