The LM5009 is a step-down DC-DC switching regulator that implements all the functions required for a cost-effective, high-efficiency, step-down bias power converter.

Depending on the input and output voltage, the switching frequency can exceed 600kHz. The high voltage regulator can consist of a 100V N-channel buck switch and an internal start-up regulator. The output voltage can be set from 2.5V to 85V.

LM5009MMX/NOPB

Regulator operation is based on a control scheme using an on-time that is inversely proportional to Vin. No loop compensation is required, resulting in ultra-fast transient response. This feature allows the operating frequency to remain relatively constant as the load and input voltage vary.

The LM5009 operates in discontinuous conduction mode at light load currents and in continuous conduction mode at heavy load currents. It contains an internal high voltage startup regulator. The input pin (VIN) can be connected directly to line voltages up to 95V, with transient capability to 100V. The regulator is internally current limited at 9.5mA. Upon power-up, the regulator sources current into the external capacitor at VCC (C3). When the voltage on the VCC pin reaches the under-voltage lockout threshold of 6.3V, the buck switch is enabled.

Smart current limiting is implemented with a forced off-time that is inversely proportional to Vout. Ensures short-circuit protection and provides minimal foldback.

The packages are VSSOP-8 and thermally enhanced WSON-8 packages

The device efficiently steps down higher voltages and is well suited for the 48V telecom and 24V automotive power bus ranges.

FEATURE

•  Newer product: LM5163 100-V, 0.5-A synchronous buck DC/DC converter

•  Integrated N-channel MOSFET

•  150-mA output current capability

•  Ultra-fast transient response

•  No loop compensation is required

•  VIN feedforward provides constant operatingfrequency

•  Switching frequency can exceed 600 kHz

•  Highly efficient operation

•  2% accurate 2.5-V feedback from–40°C to +125°C

•  Internal start-up regulator

•  Intelligent current limit protection

•  External shutdown control

•  Thermal shutdown

•  8-pin VSSOP and thermally enhanced 8-pinWSON packages

APPLICATION:

•  Heat sink eliminator for classic linear regulator applications

•  12V, 24V, 36V, and 48V rectified AC systems

•  Non-isolated AC mains charge-coupled supplies

•  LED current source