The CAT6218 is a 300 mA CMOS low dropout regulator that provides fast response time during load current and line voltage changes.
The quick-start feature allows the use of an external bypass capacitor to reduce the overall output noise without affecting the turn-on time of just 150 µs.
With zero shutdown current and low ground current of 55 µA typical, the CAT6218 is ideal for battery-operated devices with supply voltages from 2.3 V to 5.5 V. An internal under voltage lockout circuit disables the output at supply voltages under 2.1 V typical.
The CAT6218 offers 1% initial accuracy and low dropout voltage, 180 mV typical at 300 mA. Stable operation is provided with a small value ceramic capacitor, reducing required board space and component cost.
Other features include fold-back current current limit and thermal protection.
The device is available in the low profile (1 mm max height) 5-lead thin SOT23 package.

• Guaranteed 300 mA output current
• Low dropout voltage of 180 mV typical at 300 mA
• Stable with 1 µF ceramic output capacitor
• External 10 nF bypass capacitor for low noise
• Quick-start feature
• No-load ground current of 55 µA typical
• Full-load ground current of 80 µA typical
• ±1.0% initial accuracy (V
• ≥ 2.0V)
• ±2.0% accuracy over temperature (V
• ≥ 2.0V)
• “Zero” current shutdown mode
• Fold-back current limit and undervoltage lockout
• Thermal protection
• Thin SOT23-5 package