LM5088QMH-1 Datasheet, PDF (1/36 Pages) Texas Instruments – LM5088, LM5088-Q1 Wide Input Range Non-Synchronous Buck Controller

LM5088, LM5088-Q1
www.ti.com
SNVS600H – DECEMBER 2008 – REVISED MARCH 2013
LM5088, LM5088-Q1 Wide Input Range Non-Synchronous Buck Controller
Check for Samples: LM5088, LM5088-Q1
FEATURES
1
•2 LM5088-Q1 is an Automotive Grade Product
that is AEC-Q100 Grade 1 Qualified (-40°C to
+125°C Operating Junction Temperature)
• Emulated Current Mode Control
• Drives External High-Side N-channel MOSFET
• Ultra-Wide Input Voltage Range from 4.5V to
75V
• Low I_Q Shutdown and Standby Modes
• High Duty Cycle Ratio Feature for Reduced
Dropout Voltage
• Spread Spectrum EMI Reduction (LM5088-1)
• Hiccup Timer for Overload Protection
(LM5088-2)
• Adjustable Output Voltage from 1.205V with
1.5% Feedback Reference Accuracy
• Wide Bandwidth Error Amplifier
• Single Resistor Oscillator Frequency Setting
• Oscillator Synchronization Capability
• Programmable Soft-Start
• High Voltage, Low Dropout Bias Regulator
• Thermal Shutdown Protection
DESCRIPTION
The LM5088 high voltage non-synchronous buck
controller features all the necessary functions to
implement an efficient high voltage buck converter
using a minimum number of external components.
The LM5088 can be configured to operate over an
ultra-wide input voltage range of 4.5V to 75V. This
easy to use controller includes a level shifted gate
driver capable of controlling an external N-channel
buck switch. The control method is based upon peak
current mode control utilizing an emulated current
ramp. 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/low output voltage
applications. The LM5088 switching frequency is
programmable from 50 kHz to 1 MHz.
The LM5088 is available in two versions: The
LM5088-1 provides a +/-5% frequency dithering
function to reduce the conducted and radiated EMI,
while the LM5088-2 provides a versatile restart timer
for overload protection. Additional features include a
low dropout bias regulator, tri-level enable input to
control shutdown and standby modes, soft-start and
oscillator synchronization capability. The device is
available in a thermally enhanced HTSSOP-16 pin
package.
PACKAGE
• HTSSOP-16
Simplified Application Schematic
VIN (4.5V-75V)
RUV2
CIN
RUV1
CDITHER/RESTART
CVCC
RRAMP
CRAMP
CSS
EN
VIN _BOOT
HG
DITH/RES
SW
VCC
CS
LM5088
RAMP
CSG
SS
OUT
RT/SYNC
RRT
GND
FB
COMP
CBOOT
Q
L
D
COUT1
Rs
RCOMP ^CCOMP
VOUT
RFB2
COUT2 _RFB1
CHF
1
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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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