1.1MHz, 1A Switch PWM DC/DC Converter

OBSOLETE PRODUCT: Data Sheet For Reference Only. Contact Analog Devices for Potential Replacement.

The LT1949-1 is a fixed frequency step-up DC/DC converter with a 1A, 0.5Ω internal switch. Capable of generating 10V at 175mA from a 3.3V input, the LT1949-1 is ideal for generating bias voltages for large screen LCD panels. Constant frequency 1.1MHz operation results in a low noise output that is easy to filter and the 30V switch rating allows output voltage up to 28V using a single inductor. The high switching frequency allows the use of ceramic output capacitors. An external compensation pin gives the user flexibility in optimizing loop compensation, allowing small, low ESR ceramic capacitors to be used at the output. The 8-lead MSOP package ensures a low profile overall solution.

The LT1949-1 includes a low-battery detector that stays alive when the device goes into shutdown. Quiescent current in shutdown is 50µA, while operating current is 8mA.

Applications

* LCD Bias Supplies

* GPS Receivers

* Battery Backup

* Portable Electronic Equipment

* Diagnostic Medical Instrumentation

* 1A, 0.5 Ω, 30V Internal Switch

* 1.1MHz Fixed Frequency Operation

* Operates with VIN as Low as 1.5V

* Low-Battery Detector Stays Active in Shutdown