1 Features
1• 22-V DMOS FET Switch
• 1.6-MHz (X Option), 0.6-MHz (Y Option) Switching
Frequency
• Low R DS(ON) DMOS FET
• Switch Current Up to 1.8 A
• Wide Input Voltage Range (2.7 V to 14 V)
• Low Shutdown Current (<1 μA)
• 5-Lead SOT-23 Package
• Uses Tiny Capacitors and Inductors
• Cycle-by-Cycle Current Limiting
• Internally Compensated

2 Applications
• White LED Current Sources
• PDAs and Palm-Top Computers
• Digital Cameras
• Portable Phones and Games
• Local Boost Regulators

3 Description
The LM2731 switching regulators are current-mode
boost converters operating at fixed frequencies of 1.6 MHz (X option) and 600 kHz (Y option).
The use of SOT-23 package, made possible by the
minimal power loss of the internal 1.8-A switch, and
use of small inductors and capacitors result in the
highest power density of the industry. The 22-V
internal switch makes these solutions perfect for
boosting to voltages up to 20 V.
These parts have a logic-level shutdown pin that can
reduce quiescent current and extend battery life.
Protection is provided through cycle-by-cycle current
limiting and thermal shutdown. Internal compensation
simplifies design and reduces component count.