LM5005 Datasheet, PDF (1/21 Pages) National Semiconductor (TI) – High Voltage 2.5 Amp Buck Regulator

September 2005
LM5005
High Voltage 2.5 Amp Buck Regulator
General Description
The LM5005 high voltage switching regulator features all of
the functions necessary to implement an efficient high volt-
age buck regulator using a minimum of external compo-
nents. This easy to use regulator includes a 75V N-Channel
buck switch with an output current capability of 2.5 Amps.
The regulator control method is based upon current mode
control utilizing an emulated current ramp. Current mode
control provides inherent line feed-forward, cycle-by-cycle
current limiting and ease of loop compensation. The use of
an emulated control ramp reduces noise sensitivity of the
pulse-width modulation circuit, allowing reliable control of
very small duty cycles necessary in high input voltage appli-
cations. The operating frequency is programmable from
50kHz to 500kHz. An oscillator synchronization pin allows
multiple LM5005 regulators to self-synchronize or to be syn-
chronized to an external clock. Additional protection features
include: current limit, thermal shutdown and remote shut-
down capability. The device is available in a power enhanced
TSSOP-20 package featuring an exposed die attach pad to
aid thermal dissipation.
Features
n Integrated 75V, 2.5A N-Channel Buck Switch
n Ultra-wide input voltage range from 7V to 75V
n Internal high voltage bias regulator
n Adjustable output voltage from 1.225V
n 1.5% feedback reference accuracy
n Current mode control with emulated inductor current
ramp
n Single resistor oscillator frequency setting
n Oscillator synchronization input
n Programmable soft-start
n Shutdown / Standby input
n Wide bandwidth error amplifier
n Thermal Shutdown
Package
n TSSOP-20EP (Exposed Pad)
Simplified Application Schematic
© 2005 National Semiconductor Corporation DS201619
20161901
www.national.com