LM5008 Datasheet | National Semiconductor

LM5008 High Voltage (100V) Step Down Switching Regulator October 2004 LM5008 High Voltage (100V) Step Down Switching Regulator General Description The LM5008 Step Down Switching Regulator Features all of the functions needed to implement a low cost, efficient, Buck bias regulator. This high voltage regulator contains an 100 V N-Channel Buck Switch. The device is easy to implement and is provided in the MSOP-8 and the thermally enhanced LLP-8 packages. The regulator is based on a hysteretic control scheme using an ON time inversely proportional to VIN. This feature allows the operating frequency to remain relatively constant. The hysteretic control requires no loop pensation. An intelligent current limit is implemented with forced OFF time, which is inversely proportional to Vout. This scheme ensures short circuit protection while providing minimum foldback. Other protection Features include: Thermal Shutdown, VCC under-voltage lockout, Gate drive undervoltage lockout, and Max Duty Cycle limiter Features n n n n n n n n n n n n Integrated 100V, N-Channel buck switch Internal VCC regulator No loop pensation required Ultra-Fast transient response On time varies inversely with line voltage Operating frequency remains constant with varying line voltage and load current Adjustable output voltage Highly efficient operation Precision internal reference Low bias current Intelligent current limit protection Thermal shutdown Typical Applications n Non-Isolated Telemunication Buck Regulator n Secondary High Voltage Post Regulator n +42V Automotive Systems Package n MSOP - 8 n LLP - 8 (4mm x 4mm) Connection Diagram 8-Lead MSOP, LLP Ordering Information Order Number LM5008MM LM5008SD Package Type MSOP-8 LLP-8 NSC Package Drawing MUA08A SDC08A Supplied As 1000 Units on Tape and Reel 1000 Units on Tape and Reel © 2004 National Semiconductor Corporation DS200979 .national. Typical Application Circuit and Block Diagram FIGURE...