LT3071_15 Datasheet, PDF (1/30 Pages) Linear Technology – 5A, Low Noise, Programmable Output, 85mV Dropout Linear Regulator with Analog Margining

LT3071
5A, Low Noise,
Programmable Output, 85mV
Dropout Linear Regulator
with Analog Margining
FEATURES
nn _{Output Current: 5A}
nn _{Dropout Voltage: 85mV Typical}
nn _{Digitally Programmable VOUT : 0.8V to 1.8V}
nn _{Analog Output Margining: ±10% Range}
nn _{Low Output Noise: 25µVRMS (10Hz to 100kHz)}
nn _{Parallel Multiple Devices for 10A or More}
nn _{Precision Current Limit: ±20%}
nn _{Output Current Monitor: IMON = IOUT/2500}
nn _{±1% Accuracy Over Line, Load and Temperature}
nn _{Stable with Low ESR Ceramic Output Capacitors}
(15µF Minimum)
nn _{High Frequency PSRR: 30dB at 1MHz}
nn _{Enable Function Turns Output On/Off}
nn _{VIOC Pin Controls Buck Converter to Maintain Low}
Power Dissipation and Optimize Efficiency
nn _{PWRGD/UVLO/Thermal Shutdown Flag}
nn _{Current Limit with Foldback Protection}
nn _{Thermal Shutdown}
nn _{28-Lead (4mm × 5mm × 0.75mm) QFN Package}
APPLICATIONS
nn _{FPGA and DSP Supplies}
nn _{ASIC and Microprocessor Supplies}
nn _{Servers and Storage Devices}
nn _{Post Buck Regulation and Supply Isolation}
DESCRIPTION
The LT^®3071 is a low voltage, UltraFast™ transient re-
sponse linear regulator. The device supplies up to 5A of
output current with a typical dropout voltage of 85mV.
A 0.01µF reference bypass capacitor decreases output
voltage noise to 25µV_RMS. The LT3071’s high bandwidth
permits the use of low ESR ceramic capacitors, saving
bulk capacitance and cost. The LT3071’s features make
it ideal for high performance FPGAs, microprocessors or
sensitive communication supply applications.
Output voltage is digitally selectable in 50mV increments
over a 0.8V to 1.8V range. An analog margining function
allows the user to adjust system output voltage over a
continuous ±10% range. The IC incorporates a unique
tracking function to control a buck regulator powering
the LT3071’s input. This tracking function drives the buck
regulator to maintain the LT3071’s input voltage to V_OUT
+ 300mV, minimizing power dissipation.
Internal protection includes UVLO, reverse-current protec-
tion, precision current limiting with power foldback and
thermal shutdown. The LT3071 regulator is available in a
thermally enhanced 28-lead, 4mm × 5mm QFN package.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. UltraFast and VLDO are trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Patents pending.
TYPICAL APPLICATION
0.9V, 5A Regulator
V_BIAS
2.2V TO 3.6V
V_IN
1.2V
2.2µF
330µF
50k
BIAS
IN
PWRGD
EN
SENSE
V_O0 LT3071 OUT
V_O1
V_O2
NC
1nF
MARGA
VIOC
I_MON
REF/BYP
GND
PWRGD
2.2µF*
4.7µF*
V_OUT
0.9V
10µF* 5A
*X5R OR X7R CAPACITORS
0.01µF
1k
V_MON
2V AT 5A
FULL SCALE
3071 TA01a
Dropout Voltage
150
V_IN = V_OUT(NOMINAL)
120
90
V_OUT = 1.8V
V_BIAS = 3.3V
60
V_OUT = 0.8V
V_BIAS = 2.5V
30
0
0
1
2
3
4
5
OUTPUT CURRENT (A)
3071 TA01b
For more information www.linear.com/LT3071
3071fc
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