LM2670SX-3.3/NOPB

The LM2670 series of regulators are monolithic integrated circuits which provide all of the active functions for a step-down (buck) switching regulator capable of driving up to 3-A loads with excellent line and load regulation characteristics. High efficiency (√>90%) is obtained through the use of a low ON-resistance DMOS power switch. The series consists of fixed output voltages of 3.3-V, 5-V, and 12-V output version. The SIMPLE SWITCHER concept provides for a complete design using a minimum number of external components. The switching clock frequency can be provided by an internal fixed frequency oscillator (260 kHz) or from an externally provided clock in the range of 280 kHz to 400 kHz which allows the use of physically smaller sized components. A family of standard inductors for use with the LM2670 are available from several manufacturers to greatly simplify the design process. The external sync clock provides direct and precise control of the output ripple frequency for consistent filtering or frequency spectrum positioning. The LM2670 series also has built-in thermal shutdown, current limiting and an ON/OFF control input that can power down the regulator to a low 50-μA quiescent current standby condition. The output voltage is ensured to a ±2% tolerance.

Applications

• Simple-to-Design, High Efficiency (>90%) Step Down Switching Regulators
• Efficient System Preregulator for Linear Voltage Regulators
• Battery Chargers
• Communications and Radio Equipment Regulator With Synchronized Clock Frequency

Key features

• Efficiency Up to 94%
• Simple and Easy to Design With (Using Off-the Shelf External Components)
• 150-mΩ DMOS Output Switch
• 3.3-V, 5-V, 12-V Fixed Output and Adjustable (1.2 V to 37 V) Versions
• 50-μA Standby Current When Switched OFF
• ±2% Maximum Output Tolerance Over Full Line and Load Conditions
• Wide Input Voltage Range: 8 V to 40 V
• External Sync Clock Capability (280 kHz to 400 kHz)
• 260-kHz Fixed Frequency Internal Oscillator
• -40 to 125°C Operating Junction Temperature Range