LM2831_15 Datasheet, PDF (1/38 Pages) Texas Instruments – LM2831 High-Frequency 1.5-A Load — Step-Down DC-DC Regulator

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LM2831
SNVS422D – AUGUST 2006 – REVISED SEPTEMBER 2015
LM2831 High-Frequency 1.5-A Load — Step-Down DC-DC Regulator
1 Features
•1 Space-Saving SOT-23 Package
• Input Voltage Range of 3 V to 5.5 V
• Output Voltage Range of 0.6 V to 4.5 V
• 1.5-A Output Current
• High Switching Frequencie
– 1.6 MHz (LM2831X)
– 0.55 MHz (LM2831Y)
– 3 MHz (LM2831Z)
• 130-mΩ PMOS Switch
• 0.6-V, 2% Internal Voltage Reference
• Internal Soft Start
• Current Mode, PWM Operation
• Thermal Shutdown
• Overvoltage Protection
2 Applications
• Local 5 V to Vcore Step-Down Converters
• Core Power in HDDs
• Set-Top Boxes
• USB Powered Devices
• DSL Modems
3 Description
The LM2831 regulator is a monolithic, high-
frequency, PWM step-down DC-DC converter in a 5-
pin SOT-23 and a 6-Pin WSON package. The
LM2831 provides all the active functions to provide
local DC-DC conversion with fast transient response
and accurate regulation in the smallest possible PCB
area. With a minimum of external components, the
LM2831 is easy to use. The ability to drive 1.5-A
loads with an internal 130-mΩ PMOS switch using
state-of-the-art 0.5-µm BiCMOS technology results in
the best power density available. The world-class
control circuitry allows on-times as low as 30 ns, thus
supporting exceptionally high frequency conversion
over the entire 3 V to 5.5 V input operating range,
down to the minimum output voltage of 0.6 V.
Switching frequency is internally set to 550 kHz, 1.6
MHz, or 3 MHz, allowing the use of extremely small
surface mount inductors and chip capacitors. Even
though the operating frequency is high, efficiencies of
up to 93% are easy to achieve. External shutdown is
included, featuring an ultra-low standby current of 30
nA. The LM2831 utilizes current-mode control and
internal compensation to provide high-performance
regulation over a wide range of operating conditions.
Additional features include internal soft-start circuitry
to reduce inrush current, pulse-by-pulse current limit,
thermal shutdown, and output overvoltage protection.
R3
VIN = 5V
C1
Typical Application Circuit
EN
FB
LM2831 ^GND
VIN
SW
L1
VO = 3.3V @ 1.5A
R1
D1
C2
C3
R2
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LM2831
WSON (6)
SOT-23 (5)
3.00 mm × 3.00 mm
1.60 mm × 2.90 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Efficiency vs Load
100
"X"
90
80
70
60
50
0.1
1
LOAD (A)
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.