MP3412
1.1A, 1MHz Synchronous Boost
WLED Driver with Output Disconnect
The Future of Analog IC Technology
DESCRIPTION
The MP3412 is a synchronous, fixed frequency,
high efficiency step-up WLED driver with true
output load disconnect function
in a low
profile
6-lead Thin-SOT23 package.
The MP3412 can startup from an input voltage as
low as 0.8V and provides in-rush current limiting
as well as output short circuit protection. The
open load protection is also integrated
A switching frequency of 1MHz minimizes overall
solution footprint by allowing the use of tiny, low
profile inductors and ceramic capacitors. Current
mode PWM control with internal compensation
reduces external parts, thereby saving critical
board space.
The device also features low shutdown current of
under 1µA. The true output disconnect feature
allows the output to be completely discharged in
shutdown. It also limits the inrush of current
during start-up, minimizing surge current seen by
the input supply.
The MP3412 is available in 6-pin thin SOT23
package.
FEATURES
Input Range: 0.8V to 4.4V
Output Range: 2.5V to 5.0V
0.8V Low Start-Up Voltage
Internal Power MOSFET and Synchronous
Rectifier
1MHz Fixed Switching Frequency
Current Mode Control with Internal
Compensation
Up to 96% Efficiency
<1µA Shutdown Current
Tiny External Components
True Output Load Disconnect
Inrush Current Limiting and Internal Soft-
Start
Open-Load Protection
Short-Circuit Protection
Available in TSOT23-6 Package
General LED Illuminations
Cellular Phones
Digital Cameras
Handheld Instruments
Wireless Handsets
GPS Receivers
APPLICATION
“Monolithic Power Systems”, “MPS”, and “The Future of Analog IC
Technology” are Registered Trademarks of Monolithic Power Systems, Inc.
TYPICAL APPLICATION
Efficiency
100
95
90
Boost Mode
LDO Mode
EFFICIENCY (%)
85
80
75
70
65
60
55
50
0
1
2
3
V
IN
(V)
I
o
=200mA
I
o
=80mA
4
5
MP3412 Rev. 0.9
9/7/2011
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
1
MP3412 - 1.1A, 1MHz SYNCHRONOUS BOOST WLED DRIVER WITH OUTPUT DISCONNECT
ORDERING INFORMATION
Part Number*
MP3412EJ
Package
TSOT23-6
Top Marking
7Q
Free Air Temperature (T
A
)
–20C to +85C
* For Tape & Reel, add suffix –Z (e.g. MP3412EJ–Z).
For RoHS Compliant Packaging, add suffix –LF (e.g. MP3412EJ–LF–Z)
PACKAGE REFERENCE
TOP VIEW
SW
1
2
3
6
5
4
IN
GND
OUT
FB
EN
ABSOLUTE MAXIMUM RATINGS
(1)
IN Pin ............................................. -0.3V to 4.6V
All other Pins .................................. -0.3V to 6.5V
Continuous Power Dissipation (T
A
= +25°C)
(2)
................................................................. 0.56W
Junction Temperature ...............................150C
Lead Temperature ....................................260C
Storage Temperature ............... -65C to +150C
Thermal Resistance
(4)
TSOT23-6 .............................. 220 .... 110 ..
C/W
Notes:
1) Exceeding these ratings may damage the device.
2) The maximum allowable power dissipation is a function of the
maximum junction temperature T
J
(MAX), the junction-to-
ambient thermal resistance
θ
JA
, and the ambient temperature
T
A
. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by P
D
(MAX)=(T
J
(MAX)-
T
A
)/θ
JA
. Exceeding the maximum allowable power dissipation
will cause excessive die temperature, and the regulator will go
into thermal shutdown. Internal thermal shutdown circuitry
protects the device from permanent damage.
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7, 4-layer PCB.
θ
JA
θ
JC
Recommended Operating Conditions
(3)
Input Supply Voltage V
IN
................. 0.8V to 4.4V
Output Voltage V
OUT
........................ 2.5V to 5.0V
Operating JuncT. TemP. (T
J
) ... -20C to +125C
MP3412 Rev. 0.9
9/7/2011
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
2
MP3412 - 1.1A, 1MHz SYNCHRONOUS BOOST WLED DRIVER WITH OUTPUT DISCONNECT
ELECTRICAL CHARACTERISTICS
V
IN
= V
EN
=1.2V, I
LED
= 200mA, T
A
= +25C, unless otherwise noted.
Parameters
Minimum Startup Voltage
Maximum Input Voltage
Output Voltage Range
Supply Current (Quiescent)
Supply Current (Shutdown)
Operation Frequency
Maximum Duty Cycle
Feedback Voltage
EN Low Threshold
EN High Threshold
EN Input Current
NMOS On Resistance
(5)
Synchronous Switch On
Resistance
(5)
NMOS Current Limit
(5)
Over Voltage Protection
Threshold
Soft-Start Time
Thermal Shutdown
(5)
Notes:
5) Guaranteed by design.
Symbol
V
ST MIN
V
IN MAX
V
OUT
I
O
I
SD
f
SW
D
MAX
V
FB
V
EN LOW
V
EN HIGH
I
EN
R
NMOS
ON
Condition
V
OUT
=0V
Min
0.62
2.5
Typ
0.72
Max
0.82
4.4
5
600
1
Units
V
V
V
µA
µA
MHz
%
mV
V
V
nA
nA
mΩ
mΩ
A
A
V
EN
=V
IN
=1.2V, V
FB
=0.3V,
Measured on OUT pin
V
EN
=V
OUT
=0V, V
IN
=3.3V
Measured on IN pin
0.90
87
190
0.4
380
1.05
200
1.20
210
0.62
V
EN
Falling
V
EN
Rising
V
EN
=6V
V
EN
=0V
16
0
336
405
R
PMOS_ON
I
LIMIT
V
OVP
T
SS
V
OUT
=2V, Start-up period
V
OUT
=3.3V
V
SW
Rising
Open loop
4.8
0.5
1.1
5.1
200
150
5.5
V
µs
C
MP3412 Rev. 0.9
9/7/2011
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
3
MP3412 - 1.1A, 1MHz SYNCHRONOUS BOOST WLED DRIVER WITH OUTPUT DISCONNECT
PIN FUNCTIONS
Pin #
1
2
3
4
5
6
Name
SW
GND
FB
EN
OUT
IN
Pin Function
Power Switch Output.
SW is the connection node of the internal NMOS switch and
synchronous switch.
Connect the power inductor to SW.
Ground.
Feedback Input to the Error Amplifier. Connect the anode of LED to this pin. The feedback
reference voltage is 0.2V
Enable Control Input.
Step-up Converter Output.
OUT is the drain of the Internal Synchronous Rectifier MOSFET.
Connect the LED anode to this pin.
OUT pin is completely disconnected from IN pin when
EN is low due to the output disconnect feature.
Battery Supply Input.
Must be locally bypassed
MP3412 Rev. 0.9
9/7/2011
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
4
MP3412 - 1.1A, 1MHz SYNCHRONOUS BOOST WLED DRIVER WITH OUTPUT DISCONNECT
TYPICAL PERFORMANCE CHARACTERISTICS
V
IN
= V
EN
= 1.8V, I
LED
= 200mA, One WLED, unless otherwise noted.
V
IN
vs. Efficiency
100
WLED CURRENT(mA)
PWM Dimming Duty vs.
WLED Current
250
f
PWM
=200Hz
95
90
EFFICIENCY (%)
Boost Mode
LDO Mode
200
150
100
50
0
0
85
80
75
70
65
60
55
50
0
1
2
3
V
IN
(V)
I
o
=200mA
I
o
=80mA
4
5
20
40
60
80
100
PWM DIMMING DUTY (%)
Steady State (Boost Mode)
V
IN
=V
EN
=0.8V, I
LED
=80mA
Steady State (Boost Mode)
V
IN
=V
EN
=1.8V, I
LED
=200mA
Steady State (LDO Mode)
V
IN
=V
EN
=4.4V, I
LED
=200mA
V
SW
2V/div.
V
OUT
/AC
100mV/div.
V
SW
2V/div.
V
OUT
/AC
100mV/div.
V
SW
2V/div.
V
OUT
/AC
50mV/div.
I
INDUCTOR
200mA/div.
V
FB
50mV/div.
1us/div.
I
INDUCTOR
200mA/div.
V
FB
50mV/div.
1us/div.
I
INDUCTOR
100mA/div.
V
FB
50mV/div.
1us/div.
Enable Startup
V
IN
=V
EN
=0.8V, I
LED
=80mA
Enable Startup
V
IN
=V
EN
=1.8V, I
LED
=200mA
Enable Shutdown
V
IN
=V
EN
=1.8V, I
LED
=200mA
V
SW
2V/div.
V
EN
1V/div.
V
OUT
2V/div.
I
LED
50mA/div.
V
SW
2V/div.
V
EN
2V/div.
V
OUT
2V/div.
I
LED
100mA/div.
V
SW
2V/div.
V
EN
2V/div.
V
OUT
2V/div.
I
LED
100mA/div.
100us/div.
40us/div.
20us/div.
MP3412 Rev. 0.9
9/7/2011
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
5
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