LM34919B_15 Datasheet, PDF (1/27 Pages) Texas Instruments – Ultra-Small 40-V 600-mA Constant On-Time Buck Switching Regulator

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LM34919B
LM34919B-Q1
SNVS623B – MAY 2010 – REVISED JULY 2013
LM34919B Ultra-Small 40-V 600-mA Constant On-Time
Buck Switching Regulator
Check for Samples: LM34919B, LM34919B-Q1
FEATURES
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•2 AEC-Q100 Grade 1 Qualified (-40°C to 125°C)
• Maximum Switching Frequency: 2.6 MHz
(V_IN=14V,V_o=3.3V)
• Input Voltage Range: 6V to 40V
• Integrated N-Channel Buck Switch
• Integrated Startup Regulator
• No loop compensation Required
• Ultra-Fast transient Response
• Operating frequency remains constant with
Load Current and Input Voltage
• Maximum Duty Cycle Limited During Startup
• Adjustable Output Voltage
• Valley Current Limit At 0.64A
• Precision Internal Reference
• Low Bias Current
• Highly Efficient Operation
• Thermal Shutdown
• 10-Pin DSBGA Package
TYPICAL APPLICATIONS
• Automotive Safety and Infotainment
• High Efficiency Point-Of-Load (POL) Regulator
• Non-Isolated Telecommunication Buck
Regulator
• Secondary High Voltage Post Regulator
DESCRIPTION
The LM34919B Step-Down Switching Regulator
features all of the functions needed to implement a
low cost, efficient, buck bias regulator capable of
supplying 0.6A to the load. This buck regulator
contains an N-Channel Buck Switch, and is available
in a 10-pin DSBGA package. The constant on-time
feedback 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 valley current limit
results in a smooth transition from constant voltage to
constant current mode when current limit is detected,
reducing the frequency and output voltage, without
the use of foldback. Additional features include: VCC
under-voltage lockout, thermal shutdown, gate drive
under-voltage lockout, and maximum duty cycle
limiter.
Basic Step-Down Regulator
6V - 40V
Input
C1
R_ON
VIN
VCC
LM34919B
BST
SHUTDOWN
RON/SD
SW
SS
ISEN
C6
FB
RTN
SGND
C3
C4
L1
D1
R1
R2
V_OUT
R3
C2
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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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