Datasheet

UVLO
VIN
VCC
SW Pin
Inductor
Current
SS Pin
t2
V
OUT
7.0V
2.5V
t1
LM5010A
LM5010A-Q1
www.ti.com SNVS376E –OCTOBER 2005–REVISED FEBRUARY 2013
FUNCTIONAL DESCRIPTION
Figure 7. Startup Sequence
The LM5010A Step Down Switching Regulator features all the functions needed to implement a low cost,
efficient buck DC-DC converter capable of supplying in excess of 1A to the load. This high voltage regulator
integrates an 80V N-Channel buck switch, with an easy to implement constant on-time controller. It is available in
the thermally enhanced WSON-10 and HTSSOP-14 packages. The regulator compares the feedback voltage to
a 2.5V reference to control the buck switch, and provides a switch on-time which varies inversely with VIN. This
feature results in the operating frequency remaining relatively constant with load and input voltage variations.
The switching frequency can range from less than 100 kHz to 1.0 MHz. The regulator requires no loop
compensation resulting in very fast load transient response. The valley current limit circuit holds the buck switch
off until the free-wheeling inductor current falls below the current limit threshold, nominally set at 1.25A.
The LM5010A can be applied in numerous applications to efficiently step down higher DC voltages. This
regulator is well suited for 48V telecom applications, as well as the 42V automotive power bus. Features include:
Thermal shutdown, VCC under-voltage lock-out, gate drive under-voltage lock-out, and maximum duty cycle limit.
Copyright © 2005–2013, Texas Instruments Incorporated Submit Documentation Feedback 7
Product Folder Links: LM5010A LM5010A-Q1