Semtech have crammed two 300 mA low-dropout regulators into a chip measuring just 1.6 × 1.2 mm and 0.6-mm thick. The two regulators have fixed outputs and the data sheet indicates the standard SC563 uses one regulator to give a 1.8 V output while the other provides 3.3 V (contact the manufacturer for other output options). The input supply range of 2.3 to 5.5 V and low dropout voltage of 180 mV makes it ideal to be powered by a single Li-ion cell.

The 8-pin SC563 has separate input, output and enable pins for each LDO channel. A quiescent current of 50 µA per channel optimizes battery life. The regulator also includes short-circuit, undervoltage lockout and thermal protection.

Key features of the SC563:
• Input voltage range 2.3 to 5.5 V
• Two 300 mA (max) outputs
• 180 mV (typ) dropout at 300 mA load
• 50 µA per channel quiescent current
• 100 nA shutdown current
• 100 µVRMS /V O/P noise
• Over temperature protection
• Short circuit protection
• Under-voltage lockout
• 100 ohm internal output discharge
• MLPD-UT8 package 1.6 mm x 1.2 mm x 0.6 mm

Pricing of the SC563 LDO regulator works out at $0.25 per unit for order quantities of 3000 units.