Texas Instruments Evaluation Board for the LM20333 LM20333EVAL/NOPB LM20333EVAL/NOPB 数据表
产品代码
LM20333EVAL/NOPB
User's Guide
SNVA325B – May 2008 – Revised May 2013
AN-1791 LM20333 Evaluation Board
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Introduction
This evaluation board provides a solution to examine the full featured LM20333 buck switching regulator
that is capable of driving up to 3A of load current. This device features a clock synchronization input that
allows the switching frequency to be synchronized to an external clock source. The flexibility to
synchronize the switching frequency from 250 kHz to 1.5 MHz allows the size of the power stage
components to be reduced while still allowing for high efficiency. The LM20333 is capable of down
converting from an input voltage between 4.5V and 36V. Fault protection features include cycle-by-cycle
current limit, output power good, and output over-voltage protection. The dual function soft-start/tracking
pin can be used to control the startup response of the LM20333, and the precision enable pin can be used
to easily sequence the LM20333 in applications with sequencing requirements.
that is capable of driving up to 3A of load current. This device features a clock synchronization input that
allows the switching frequency to be synchronized to an external clock source. The flexibility to
synchronize the switching frequency from 250 kHz to 1.5 MHz allows the size of the power stage
components to be reduced while still allowing for high efficiency. The LM20333 is capable of down
converting from an input voltage between 4.5V and 36V. Fault protection features include cycle-by-cycle
current limit, output power good, and output over-voltage protection. The dual function soft-start/tracking
pin can be used to control the startup response of the LM20333, and the precision enable pin can be used
to easily sequence the LM20333 in applications with sequencing requirements.
The LM20333 evaluation board has been optimized to work from 4.5V to 25V achieving a balance
between overall solution size with the efficiency of the regulator. The evaluation board measures just
under 2” x 2” on a four layer PCB, and exhibits a thermal characteristic of 27 °C/W with no air flow. The
power stage and compensation components of the LM20333 evaluation board have been optimized for an
input voltage of 12V, but for testing purposes, the input can be varied across the entire operating range.
The output voltage of the evaluation board is nominally 3.3V, but this voltage can be easily changed by
replacing one of the feedback resistors (R5 or R6).
between overall solution size with the efficiency of the regulator. The evaluation board measures just
under 2” x 2” on a four layer PCB, and exhibits a thermal characteristic of 27 °C/W with no air flow. The
power stage and compensation components of the LM20333 evaluation board have been optimized for an
input voltage of 12V, but for testing purposes, the input can be varied across the entire operating range.
The output voltage of the evaluation board is nominally 3.3V, but this voltage can be easily changed by
replacing one of the feedback resistors (R5 or R6).
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SNVA325B – May 2008 – Revised May 2013
AN-1791 LM20333 Evaluation Board
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