LM34910_14 Datasheet, PDF (1/17 Pages) Texas Instruments – High Voltage (40V, 1.25A) Step Down Switching Regulator

LM34910
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SNVS297A – OCTOBER 2004 – REVISED FEBRUARY 2005
LM34910 High Voltage (40V, 1.25A) Step Down Switching Regulator
Check for Samples: LM34910
FEATURES
1
•2 Integrated 40V, N-Channel Buck Switch
• Integrated Start-Up Regulator
• Input Voltage Range: 8V to 36V
• No Loop Compensation Required
• Ultra-Fast Transient Response
• Operating Frequency Remains Constant with
Load Current and Input Voltage
• Maximum Duty Cycle Limited During Start-Up
• Adjustable Output Voltage
• Valley Current Limit At 1.25A
• Precision Internal Reference
• Low Bias Current
• Highly Efficient Operation
• Thermal Shutdown
TYPICAL APPLICATIONS
• High Efficiency Point-Of-Load (POL) Regulator
• Non-Isolated Telecommunication Buck
Regulator
• Secondary High Voltage Post Regulator
DESCRIPTION
The LM34910 Step Down Switching Regulator
features all of the functions needed to implement a
low cost, efficient, buck bias regulator capable of
supplying 1.25A to the load. This buck regulator
contains a 40V N-Channel Buck Switch, and is
available in the thermally enhanced WSON package.
The hysteretic regulation scheme requires no loop
compensation, results in fast load transient response,
and simplifies circuit implementation. The operating
frequency remains constant with line and load
variations due to the inverse relationship between the
input voltage and the on-time. The current limit
detection is set at 1.25A. Additional features include:
VCC under-voltage lockout, thermal shutdown, gate
drive under-voltage lockout, and maximum duty cycle
limiter.
Package
• WSON (4 mm x 4 mm)
• Exposed Thermal Pad For Improved Heat
Dissipation
Connection Diagram
SW
1
BST
2
ISEN
3
SGND
4
RTN
5
10
VIN
9
VCC
8
RON/SD
7
SS
6
FB
Figure 1. 10-Lead WSON
See DPR0010A Package
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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.
Copyright © 2004–2005, Texas Instruments Incorporated