CMPWR101

• Automatic detection of VCC input supply
• Glitch-free output during supply transitions
• Built-in hysteresis during supply selection
• 250mA output maximum load current
• Fully integrated VAUX switch
• Overload current protection
• Short circuit current protection
• Operates from either VCC or VAUX
• 8-pin SOIC package
• RoHS compliant (lead-free) finishing

The California Micro Devices&prime SmartOR™ CMPWR101 is a low dropout regulator that delivers up to 250mA of load current at a fixed 3.3V output. An internal threshold level (typically 4.1V) is used to prevent the regulator from being operated below dropout voltage. The device continuously monitors the input supply and will automatically disable the regulator when VCC falls below the threshold level. When the regulator is disabled, a low impedance, fully integrated switch is enabled which allows the output to be directly powered from an auxiliary 3.3V supply.

When VCC is restored to a level above the select threshold, CMPWR101 low impedance switch is disabled and the regulator is once again enabled.

All the necessary control circuitry CMPWR101 needed to provide a smooth and automatic transition between the supplies has been incorporated. This allows VCC to be dynamically switched without loss of output voltage.

An output logic signal, DRIVE, is active LOW whenever the internal regulator is disabled.

The CMPWR101 is housed in a 8-pin SOIC package and is available with RoHS compliant lead-free finishing.