LM5008_14 Datasheet, PDF (1/21 Pages) Texas Instruments – High Voltage (100V) Step Down Switching Regulator

LM5008
www.ti.com
SNVS280F – MAY 2004 – REVISED APRIL 2011
LM5008 High Voltage (100V) Step Down Switching Regulator
Check for Samples: LM5008
FEATURES
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•2 Integrated 100V, N-Channel buck switch
• Internal V_CC regulator
• No loop compensation 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
• Non-Isolated Telecommunication Buck
Regulator
• Secondary High Voltage Post Regulator
• +42V Automotive Systems
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 V_IN. This feature allows the
operating frequency to remain relatively constant. The hysteretic control requires no loop compensation. 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, V_CC under-voltage lockout, Gate drive under-voltage lockout, and Max Duty Cycle limiter
Package
• MSOP - 8
• LLP - 8 (4mm x 4mm)
Connection Diagram
1
SW
2
BST
3
R_CL
4
RTN
8
V_IN
7
V_CC
6
RON/SD
5
FB
Figure 1. 8-Lead MSOP, LLP
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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