LM5009A_14 Datasheet, PDF (1/22 Pages) Texas Instruments – 100V, 150 mA Constant On-Time Buck Switching Regulator

LM5009A
www.ti.com
SNVS608F – JUNE 2009 – REVISED APRIL 2011
LM5009A 100V, 150 mA Constant On-Time Buck Switching Regulator
Check for Samples: LM5009A
FEATURES
1
•2 Operating input voltage range: 6V to 95V
• Integrated 100V, N-Channel buck switch
• Internal start-up regulator
• No loop compensation required
• Ultra-Fast transient response
• On time varies inversely with input voltage
• Operating frequency remains constant with
varying line voltage and load current
• Adjustable output voltage from 2.5V
• Highly efficient operation
• Precision internal reference
• Low bias current
• Intelligent current limit
• Thermal shutdown
TYPICAL APPLICATIONS
• Non-Isolated Telecommunication Buck
Regulator
• Secondary High Voltage Post Regulator
• +42V Automotive Systems
DESCRIPTION
The LM5009A is a functional variant of the LM5009 COT Buck Switching Regulator. The functional differences of
the LM5009A are: The minimum input operating voltage is 6 volts, the on-time equation is slightly different, and
the requirement for a minimum load current is removed.
The LM5009A 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 control scheme using an ON time inversely proportional to V_IN. This feature allows the operating
frequency to remain relatively constant. The control scheme 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 control while providing minimum foldback. Other features include: Thermal Shutdown, V_CC under-voltage
lockout, Gate drive under-voltage lockout, Max Duty Cycle limiter, and a pre-charge switch.
Package
• MSOP - 8
• LLP - 8 (4mm x 4mm)
Typical Application, Basic Step-Down Regulator
6V - 95V
Input
V_IN
C1
R_T
GND
SHUTDOWN
R_CL
VIN
LM5009A
RT/SD
RCL
VCC
BST
SW
RTN
FB
C3
C4
L1
D1
R_FB2
R_FB1
V_OUT
R3
C2
GND
1
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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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