LM2832
High Frequency 2.0A Load - Step-Down DC-DC
Regulator
General Description
The LM2832 regulator is a monolithic, high frequency, PWM
step-down DC/DC converter in a 6 Pin LLP and a 8 Pin
eMSOP package. It provides all the active functions to pro-
vide local DC/DC conversion with fast transient response
and accurate regulation in the smallest possible PCB area.
With a minimum of external components, the LM2832 is
easy to use. The ability to drive 2.0A loads with an internal
150 m
PMOS switch using state-of-the-art 0.5 m BiCMOS
technology results in the best power density available. The
world-class control circuitry allows on-times as low as 30ns,
thus supporting exceptionally high frequency conversion
over the entire 3V to 5.5V input operating range down to the
minimum output voltage of 0.6V. Switching frequency is
internally set to 550 kHz, 1.6 MHz, or 3.0 MHz, allowing the
use of extremely small surface mount inductors and chip
capacitors. Even though the operating frequency is high,
efficiencies up to 93% are easy to achieve. External shut-
down is included, featuring an ultra-low stand-by current of
30 nA. The LM2832 utilizes current-mode control and inter-
nal compensation to provide high-performance regulation
over a wide range of operating conditions. Additional fea-
tures include internal soft-start circuitry to reduce inrush
current, pulse-by-pulse current limit, thermal shutdown, and
output over-voltage protection.
Features
n
Input voltage range of 3.0V to 5.5V
n
Output voltage range of 0.6V to 4.5V
n
2.0A output current
n
High Switching Frequencies
1.6MHz (LM2832X)
0.55MHz (LM2832Y)
3.0MHz (LM2832Z)
n
150m
PMOS switch
n
0.6V, 2% Internal Voltage Reference
n
Internal soft-start
n
Current mode, PWM operation
n
Thermal Shutdown
n
Over voltage protection
Applications
n
Local 5V to Vcore Step-Down Converters
n
Core Power in HDDs
n
Set-Top Boxes
n
USB Powered Devices
n
DSL Modems
Typical Application Circuit
20197564
20197581
August 2006
LM2832
High
Frequency
2.0A
Load
-
Step-Down
DC-DC
Regulator
2006 National Semiconductor Corporation
DS201975
www.national.com
Connection Diagrams
20197501
6-Pin LLP
20197502
8-Pin eMSOP
Ordering Information
Order Number
Frequency
Option
Package Type
NSC Package
Drawing
Top Mark
Supplied As
LM2832XMY
1.6MHz
eMSOP-8
MUY08A
SLBB
1000 units Tape and Reel
LM2832XMYX
3500 units Tape and Reel
LM2832XSD
LLP-6
SDE06A
L196B
1000 units Tape and Reel
LM2832XSDX
4500 units Tape and Reel
LM2832YMY
0.55MHz
eMSOP-8
MUY08A
SLCB
1000 units Tape and Reel
LM2832YMYX
3500 units Tape and Reel
LM2832YSD
LLP-6
SDE06A
L197B
1000 units Tape and Reel
LM2832YSDX
4500 units Tape and Reel
LM2832ZMY
3MHz
eMSOP-8
MUY08A
SLDB
1000 units Tape and Reel
LM2832ZMYX
3500 units Tape and Reel
LM2832ZSD
LLP-6
SDE06A
L198B
1000 units Tape and Reel
LM2832ZSDX
4500 units Tape and Reel
NOPB versions available as well
LM2832
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Pin Descriptions 8-Pin eMSOP
Pin
Name
Function
1
VIND
Power Input supply.
2
VINA
Control circuitry supply voltage. Connect VINA to VIND on PC board.
3, 5, 7
GND
Signal and power ground pin. Place the bottom resistor of the feedback network as close
as possible to this pin.
4
EN
Enable control input. Logic high enables operation. Do not allow this pin to float or be
greater
than VIN + 0.3V.
6
FB
Feedback pin. Connect to external resistor divider to set output voltage.
8
SW
Output switch. Connect to the inductor and catch diode.
DAP
Die Attach Pad
Connect to system ground for low thermal impedance, but it cannot be used as a primary
GND connection.
Pin Descriptions 6-Pin LLP
Pin
Name
Function
1
FB
Feedback pin. Connect to external resistor divider to set output voltage.
2
GND
Signal and power ground pin. Place the bottom resistor of the feedback network as
close as possible to this pin.
3
SW
Output switch. Connect to the inductor and catch diode.
4
VIND
Power Input supply.
5
VINA
Control circuitry supply voltage. Connect VINA to VIND on PC board.
6
EN
Enable control input. Logic high enables operation. Do not allow this pin to float or be
greater than VINA + 0.3V.
DAP
Die Attach Pad
Connect to system ground for low thermal impedance, but it cannot be used as a
primary GND connection.
LM2832
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Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
VIN
-0.5V to 7V
FB Voltage
-0.5V to 3V
EN Voltage
-0.5V to 7V
SW Voltage
-0.5V to 7V
ESD Susceptibility
2kV
Junction Temperature (Note 2)
150C
Storage Temperature
-65C to +150C
Soldering Information
Infrared or Convection Reflow
(15 sec)
220C
Operating Ratings
VIN
3V to 5.5V
Junction Temperature
-40C to +125C
Electrical Characteristics
VIN = 5V unless otherwise indicated under the Conditions column. Limits in
standard type are for T
J
= 25C only; limits in boldface type apply over the junction temperature (T
J
) range of -40C to
+125C. Minimum and Maximum limits are guaranteed through test, design, or statistical correlation. Typical values represent
the most likely parametric norm at T
J
= 25C, and are provided for reference purposes only.
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
FB
Feedback Voltage
LLP-6 Package
0.588
0.600
0.612
V
eMSOP-8 Package
0.584
0.600
0.616
V
FB
/V
IN
Feedback Voltage Line Regulation
V
IN
= 3V to 5V
0.02
%/V
I
B
Feedback Input Bias Current
0.1
100
nA
UVLO
Undervoltage Lockout
V
IN
Rising
2.73
2.90
V
V
IN
Falling
1.85
2.3
UVLO Hysteresis
0.43
V
F
SW
Switching Frequency
LM2832-X
1.2
1.6
1.95
MHz
LM2832-Y
0.4
0.55
0.7
LM2832-Z
2.25
3.0
3.75
D
MAX
Maximum Duty Cycle
LM2832-X
86
94
%
LM2832-Y
90
96
LM2832-Z
82
90
D
MIN
Minimum Duty Cycle
LM2832-X
5
%
LM2832-Y
2
LM2832-Z
7
R
DS(ON)
Switch On Resistance
LLP-6 Package
150
m
eMSOP-8 Package
155
240
I
CL
Switch Current Limit
V
IN
= 3.3V
2.4
3.25
A
V
EN_TH
Shutdown Threshold Voltage
0.4
V
Enable Threshold Voltage
1.8
I
SW
Switch Leakage
100
nA
I
EN
Enable Pin Current
Sink/Source
100
nA
I
Q
Quiescent Current (switching)
LM2832X V
FB
= 0.55
3.3
5
mA
LM2831Y V
FB
= 0.55
2.8
4.5
LM2832Z V
FB
= 0.55
4.3
6.5
Quiescent Current (shutdown)
All Options V
EN
= 0V
30
nA
LM2832
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Electrical Characteristics
VIN = 5V unless otherwise indicated under the Conditions column. Limits in
standard type are for T
J
= 25C only; limits in boldface type apply over the junction temperature (T
J
) range of -40C to
+125C. Minimum and Maximum limits are guaranteed through test, design, or statistical correlation. Typical values represent
the most likely parametric norm at T
J
= 25C, and are provided for reference purposes only. (Continued)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
JA
Junction to Ambient
0 LFPM Air Flow (Note 3)
LLP-6 and eMSOP-8
Packages
80
C/W
JC
Junction to Case (Note 3)
LLP-6 and eMSOP-8
Packages
18
C/W
T
SD
Thermal Shutdown Temperature
165
C
Note 1: Absolute maximum ratings indicate limits beyond which damage to the device may occur. Operating Range indicates conditions for which the device is
intended to be functional, but does not guarantee specfic performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.
Note 2: Thermal shutdown will occur if the junction temperature exceeds the maximum junction temperature of the device.
Note 3: Applies for packages soldered directly onto a 3" x 3" PC board with 2oz. copper on 4 layers in still air.
LM2832
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