1 Features

• 1.9-A, 0.2-Ω Internal Switch (Typical)
• Operating Voltage as Low as 2.2 V
• 600 kHz to 1.25 MHz Adjustable Frequency Operation
• Switchers Made Simple® Software
• 8-Pin VSSOP Package

2 Applications

• 3.3 V to 5 V and 5 V to 12 V Conversion
• Distributed Power
• Set-Top Boxes
• DSL Modems
• Diagnostic Medical Instrumentation
• Boost Converters
• Flyback Converters
• SEPIC Converters

3 Description

The LM2698 device is a general purpose PWM boost converter. The 1.9-A, 18-V, 0.2-Ω internal switch enables the LM2698 to provide efficient power conversion to outputs ranging from 2.2 V to 17 V. It can operate with input voltages as low as 2.2 V and as high as 12 V. Current-mode architecture provides superior line and load regulation and simple frequency compensation over the device's 2.2 V to
12 V input voltage range. The LM2698 sets the standard in power density and is capable of supplying 12 V at 400 mA from a 5-V input. The LM2698 can also be used in flyback or SEPIC topologies.

The LM2698 SIMPLE SWITCHER® features a pin selectable switching frequency of either 600 kHz or 1.25 MHz. This promotes flexibility in component selection and filtering techniques. A shutdown pin is available to suspend the device and decrease the quiescent current to 5 µA. An external compensation pin gives the user flexibility in setting frequency compensation, which makes possible the use of small, low-ESR ceramic capacitors at the output. Switchers Made Simple® software is available to ensure a quick, easy, and assured design. The LM2698 is available in a low-profile, 8-pin VSSOP (DGK) package.

1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application Circuit