Linear Technology Corporation has introduced the LT3800, a current mode, high voltage step-down controller with line and load regulation, along with fast transient response that operates without requiring an auxiliary DC/DC regulator for startup. An integrated regulator provides IC power directly from input supply. The LT3800 operates from 4V to 60V supplies and regulates output voltages ranging from 1.23V to 36V at load currents up to 10A. By driving N-channel MOSFETs synchronously with maximum gate-source "ON" voltage, this controller operates at 94% efficiency while converting 60V input to 12V at 36W output. Moreover, the LT3800 incorporates Burst Mode operation, which reduces no load quiescent current to less than 100uA, a feature required in automotive maintenance power supplies. The LT3800 has applications in 12V and 42V automotive, 48V telecom supplies, avionic and industrial control systems.
The LT3800 operates at a 200kHz fixed frequency. The device employs a reverse-current inhibit feature to increase efficiency during light loads. This feature disables the synchronous switch if inductor current approaches zero. Another feature of the LT3800 is its adaptive nonoverlap control. Nonoverlap control maintains a constant dead time, preventing shoot-through switch currents, independent of the type, size or operating conditions of the external mosfet switches.
The Features of LT3800 are Wide 4V to 60V Input Voltage Range; Output Voltages up to 36V; Adaptive Nonoverlap Circuitry Prevents Switch Shoot-Through; Reverse Inductor Current Inhibit for Discontinuous Operation Improves Efficiency with Light Loads; 100uA No Load Quiescent Current; 200kHz Operating Frequency.
The LT3800 is offered in a 16-pin thermally enhanced TSSOP and is rated for operation from -40ºC to 125ºC. 1,000-piece pricing starts at $3.10.
Linear Technology Corporation :
www.linear.com
