MP3306
30V, 700kHz Synchronous Step-Up
White LED Driver
DESCRIPTION
FEATURES
The MP3306 is a step-up converter designed for
driving white LEDs from 3V to 12V power supply.
The MP3306 uses current mode, fixed frequency
architecture to regulate the LED current, which is
measured through an external high-side current
sense resistor. The low 202mV feedback voltage
and synchronous rectification reduces power loss
and improves efficiency.
The MP3306 is turned off if an over-voltage
condition is present due to an open circuit
condition. The output disconnect feature allows
the output to be completely discharged. The
MP3306 includes under-voltage lockout, current
limiting, output short protection and thermal
overload protection.
The MP3306 is available in small 12-pin QFN
(2mm x 2mm) package.
3V~12V Input Voltage
Analog Dimming and PWM Dimming
Output-to-Input Disconnect in Shutdown
Mode
Programmable Open Load Shutdown
Output Short Protection
Low 202mV Feedback Voltage with +/-3%
accuracy
UVLO, Thermal Shutdown
Available in 2mm x 2mm QFN12 Package
APPLICATIONS
Smart Phone, MID, PDA
Digital Still Cameras
Small LCD Displays
All MPS parts are lead-free, halogen free, and adhere to the RoHS directive. For
MPS green status, please visit MPS website under Quality Assurance. “MPS”
and “The Future of Analog IC Technology” are Registered Trademarks of
Monolithic Power Systems, Inc.
TYPICAL APPLICATION
MP3306 Rev.1.02
1/18/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
1
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
ORDERING INFORMATION
Part Number*
Package
Top Marking
MP3306EG
QFN12 (2x2mm)
3Y
* For Tape & Reel, add suffix –Z (e.g. MP3306EG–Z).
For RoHS Compliant packaging, add suffix –LF (e.g. MP3306EG–LF–Z)
PACKAGE REFERENCE
ABSOLUTE MAXIMUM RATINGS
(1)
VSW, VOUT, VFB....................................-0.5V to 35V
VBST................................. ..................... VSW +6V
VIN, VL, ............................................ -0.5V to 14V
VEN, VOVP, VPWMI, VPWMO, VCC ........... -0.3V to 6.5V
(2)
Continuous Power Dissipation (TA = +25°C)
………………………………………………....1.6W
Storage Temperature ............... -55C to +150C
Recommended Operating Conditions
(3)
IN Supply Voltage VIN ........................ 3V to 12V
Vsw ................................................ -0.5V to 30V
Operating Junct. Temp (TJ) ...... -40C to +125C
MP3306 Rev.1.02
1/18/2018
Thermal Resistance
(4)
θJA
θJC
QFN12 (2 x 2mm) ................... 80 ...... 16 ... 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 TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature
TA. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by PD (MAX) = (TJ
(MAX)-TA)/θJA. 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.
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
2
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
ELECTRICAL CHARACTERISTICS
VIN = VEN = 5V, TA = +25C, all voltages with respect to GND, unless otherwise noted.
Parameters
Symbol
Operating Input Voltage
Condition
Min
VIN
Typ
Max
Units
12
V
3.7
3.9
4.1
V
300
550
0.1
380
690
93
1
460
830
µA
µA
kHz
%
2.5
2.7
2.9
V
3
VCC Voltage
VVCC
VIN > 5.5V, VEN = 3V
Supply Current (Shutdown)
Supply Current (Quiescent)
Switching Frequency
Maximum Duty Cycle
Under Voltage Lockout
ISD
IQS
fSW
DMAX
VEN = 0V
VEN = 5V, VOUT - VFB = 0.5V
IN Under Voltage Lockout
UVLO
VIN Rising
VFB = VOUT
Under Voltage Lockout Hysteresis
Protection
OVP Threshold
(5)
SW Current Limit
Thermal Shutdown
130
VOVP-TH
1.18
Duty Cycle = 60%
(5)
1.22
1.8
mV
1.26
V
A
C
150
Enable
EN OFF Threshold
EN ON Threshold
Dimming
VENLO
VENHI
PWMI Low Threshold
PWMI High Threshold
PWMI Input Frequency
VPWMI-LO
VPWMI-HI
FPWMI
Minimum PWMO Dimming
Threshold
Maximum PWMO Dimming
Threshold
Feedback
FB Voltage
FB Input Bias Current
Disconnect Switch
On-Resistance
Output Switch
High-Side NMOS On-Resistance
Low-Side NMOS On-Resistance
(5)
(5)
0.6
VPMWI Falling
VPMWI Rising
0.8
0.1
1.1
V
V
1.2
50
V
V
kHz
VPWMO-MIN VFB = VOUT
25
mV
VPWMO-MAX VOUT-VFB = 0.2V
850
mV
VFB
IFB
(5)
VEN Falling
VEN Rising
VEN = 3V
VEN = 3V
196
3
202
7
208
11
mV
µA
RND-ON
0.5
Ω
RNH-ON
0.6
Ω
RNL-ON
0.6
Ω
Notes:
5) Guaranteed by design
MP3306 Rev.1.02
1/18/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
3
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
PIN FUNCTIONS
Pin #
1
2
3
4
5
6
7
Name Pin Function
IN
Input Supply Pin. It provides the power for internal driver and logic circuit. Must be locally
bypassed.
The Internal Linear Regulator Output. VCC provides power supply for the internal MOSFET
switch gate driver and the internal control circuitry .Bypass VCC to GND with a ceramic
capacitor.
EN Control Input. A voltage greater than 1.1V turns the part on and less than 0.6V turns the
EN
part off.
Apply a PWM signal on this pin for brightness control. This signal is uniformed and filtered at
PWMI PWMO pin with an internal 100kΩ resistance. With a capacitor at PWMO pin, the duty cycle
from 0% to 100% at PWMI pin is converted to 0V to 1.2V DC voltage at PWMO pin.
PWM Filter Output. Connect a capacitor from PWMO to GND. The voltage on this pin range
0V to 1.2V linearly controls the feedback voltage from 0V to 0.2V.
PWMO
To use PWM dimming, connect the PWM input signal to PWMI pin.
To use analog dimming, connect the analog input voltage to PWMO pin.
Over Voltage Protection Pin. Use one external resistor voltage divider to program OVP
OVP threshold. When the OVP pin voltage reaches the shutdown threshold 1.22V, the IC will be
turned off and latch up until EN is toggled again.
Feedback Input. The MP3306 regulates the voltage across the current sense resistor
FB
between FB and VOUT. Connect a current sense resistor from VOUT to the LED string.
Connect the anode of the LED string to FB. The regulation voltage is 202mV.
VCC
8
GND
9
SW
10
OUT
11
BST
12
L
MP3306 Rev.1.02
1/18/2018
Ground.
Power Switch Node. SW is the drain of the internal low side MOSFET switch. Connect the
power inductor to SW.
The OUTPUT terminal. Connect the output cap on this pin, the output capacitor must be
ceramic type and be placed as short as possible between OUT pin and GND pin.
Bootstrap. A capacitor is connected between SW and BST pins to form a floating supply to
drive the high side MOSFET.
Power input pin. L is the source of internal disconnection MOSFET. Connect the inductor to
this pin.
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
4
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
TYPICAL PERFORMANCE CHARACTERISTICS
VIN=5V, VEN=5V, 8 LEDs in series, 20mA, unless otherwise noted.
MP3306 Rev.1.02
1/18/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
5
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
FUNCTION DIAGRAM
L
M1
IN
12
1
10
OUT
11
BST
9
SW
8
GND
6
OVP
OTP
EN
3
PWMI
4
VCC
2
Enable
Dimming
Control
Level
Shift
Regulator
Regulator
UVLO
Soft-Start
M3
OSC
700kHz
RAMP
Compensation
PWMO 5
CONTROL
LOGIC
M2
Reference
RSENSE
FB 7
ERROR
AMPLIFIER
PWM
COMPARATOR
CURRENT
SENSE
AMPLIFIER
1.22V
Figure 1—Functional Block Diagram
MP3306 Rev.1.02
1/18/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
6
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
OPERATION
The MP3306 uses a constant frequency, peak
current mode step up regulator architecture to
regulate the current flowing through series string of
white LEDs. The operation of the MP3306 can be
understood by referring to the block diagram of
Figure 1.
At the start of each oscillator cycle the low side FET
(M2) is turned on through the control circuitry. To
prevent sub-harmonic oscillations at duty cycles
greater than 50 percent, a stabilizing ramp is added
to the output of the current sense amplifier and the
result is fed into the positive input of the PWM
comparator. When this voltage equals the output
voltage of the error amplifier the power FET is
turned off. Then the inductor current flows into the
output capacitor and LED load through internal high
side N-channel MOSFET (M3), which forces the
inductor current to decrease.
thus increasing the power charged in inductor and
delivered to the output.
MP3306 provides the analog and PWM dimming
solution, the internal resistor and external capacitor
one PWMO pin filters the PWM dimming signal on
PWMI pin to DC level that program the internal
reference to accomplish the analog dimming
function. When floating the PWMO pin, PWM
dimming function works.
Open Load protection shuts off the MP3306 if the
output voltage goes too high. In some cases an
LED may fail, this results in the feedback voltage
always being zero. The part then runs at maximum
duty cycle boosting the output voltage up. If the
output ever exceeds the programmable OVP
threshold, the MP3306 will shut down. The part
does not switch again until the EN pin or VIN is
toggled.
The voltage at the output of the error amplifier is an
amplified version of the difference between the
200mV reference voltage and the feedback voltage.
In this way the LED current is regulated accurately.
During Shutdown mode when EN is low, the IC
keeps the internal high-side N-channel MOSFET
(M1) off to disconnect the output from input.
If the feedback voltage starts to drop, the output of
the error amplifier increases. This result in more
current flowing through the high side power FET,
MP3306 has cycle by cycle current limit to protect
the load and IC from over current. And the internal
MOSFET (M1) limits the input current to prevent
system damage when short VOUT condition occurs.
MP3306 Rev.1.02
1/18/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
7
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
APPLICATION INFORMATION
Figure 2—3V~12V Input, Typical Application Driving 8 WLEDs in series
Figure 2 shows a typical application circuit that
can drive up to 8 white LEDs with 20mA. A
0.22~2.2µF output capacitor is sufficient for most
applications. The inductor with low DC inductor
resistance (DCR) will improve efficiency. Two
4.7μF ceramic capacitors provide sufficient input
decoupling.
Setting the LED Current
The LED current is controlled by the current
setting resistor, R1. The current through the
LEDs is given by: ILED = 202mV/R1.
Table 1 shows the selection of resistors for a
given LED current.
Table 1—ILED vs. R1 RSET
Selecting the Inductor
The inductor forces a higher output voltage
driven from a lower input voltage. A larger
inductor value results in less ripple current, a
lower peak inductor current, and reduces stress
on the internal N-Channel MOSFET. However,
larger-value inductor has a larger physical
footprint, higher series resistance, and lower
saturation current.
Choose an inductor that does not saturate under
the worst-case load conditions. Calculate the
required inductance value using the following
equations:
L
η VOUT D (1 D)2
2 fSW ILOAD
D 1
VIN
VOUT
Where VIN and VOUT are the input and output
voltages, fSW is the switching frequency, ILOAD is
the LED load current, and η is the efficiency.
MP3306 Rev.1.02
1/18/2018
ILED (mA)
1
5
10
20
60
180
200
R1 (Ω)
200
40
20
10
3.33
1.11
1
The internal ramped compensation voltage
added to the current sense amplifier reduces the
maximum output current as the duty cycle
increases. As more LEDs are added, the output
voltage rises but the maximum current delivered
to the load falls as well. Figure 3 shows the
current limit curve, and the max LED current is
gotten as the formula.
ILOAD(max) (IPK
VIN D
) (1 D) 0.8
2 L fSW
Where, IPK is the peak current corresponding duty
cycle from current limit curve, the L is inductor,
the 0.8 means the margin coefficient.
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
8
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
Layout Considerations
Careful attention must be paid to the PCB board
layout and components placement. Proper layout
of the high frequency switching path is critical to
prevent noise and electromagnetic interference
problems. The loop of MP3306’s internal low side
MOSFET, synchronous MOSFET, and output
capacitor is flowing with high frequency ripple
current, it must be minimized. So the output
capacitor should be placed to IC as close as
possible.
Figure 3—Current Limit Curve
Analog and PWM Dimming
MP3306 provides 2 types of dimming solutions,
analog dimming and PWM dimming.
For analog, connect an external capacitor on
PWMO pin to form the low pass filter with internal
resistor R, the PWM dimming signal on PWMI pin
is filtered to DC signal to set the internal
reference to accomplish the analog dimming. The
time constant should be ten times greater than a
PWM waveform cycle:
RC 10 TPWM
For PWM dimming, floating PWMO pin and apply
the PWM dimming signal on PWMI pin.
Setting Over Voltage Protection Threshold
Open Load protection will shut off the MP3306 if
the output voltage goes too high. In some cases
an LED may fail, this will result in the feedback
voltage always being zero. The part boots the
output voltage higher and higher. If the output
voltage ever exceeds the programmed OVP
threshold as the formula,
VOVP =1.22 (1 R2/R3)
The MP3306 will shut down. The part will not
switch again until the power is recycled.
MP3306 Rev.1.02
1/18/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
9
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
TYPICAL APPLICATION CIRCUIT
L1
15μH
C3
10nF
2.7V~8.4V
VIN
IN
C1
1μF
L
R4
100kΩ
GND
EN
SW
BST
OUT
R1
10Ω
MP3306
EN
20mA
PWMI
R3
10kΩ
LED4
VCC
R2
130kΩ
LED1
FB
OFF ON
C4
1μF
C2
0.22μF
GND
PWMO
OVP
Figure 4— 4 LEDs in Series 20mA
L1
15μH
C3
10nF
2.7V~8.4V
VIN
C1
1μF
GND
IN
L
R4
100kΩ
EN
SW
BST
OUT
MP3306
EN
FB
OFF ON
VCC
PWMO
C2
0.22μF
R2
130kΩ
LED1
20mA
PWMI
C4
1μF
R1
10Ω
LED4
R3
10kΩ
GND
OVP
Figure 5— 4 LEDs in Series 20mA
MP3306 Rev.1.02
1/18/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
10
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
L1
15μH
C3
10nF
2.7V~8.4V
L
VIN
SW
IN
BST
OUT
C1
1μF
GND
R1
10Ω
C2
0.22μF
MP3306
EN
EN
LED1
FB
OFF ON
20mA
DIM
PWMI
100Hz~50kHz
C4
1μF
R3
10kΩ
LED6
VCC
R2
205kΩ
GND
OVP
PWMO
C5
1uF
Figure 6— 6 LEDs in Series with PWM Dimming
L1
15μH
C3
10nF
5V~10V
VIN
IN
C1
1μF
L
R4
100kΩ
GND
EN
SW
BST
OUT
C2
0.22μF
MP3306
EN
FB
OFF ON
VCC
PWMO
R2
95.3kΩ
LED1
20mA
PWMI
C4
1μF
R1
10Ω
LED3
R3
10kΩ
GND
OVP
Figure 7— 3 LEDs in Series 20mA with 5~10V Input Voltage
MP3306 Rev.1.02
1/18/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
11
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
L1
15uH
14V
VIN
C3
10nF
R4
2kΩ
C1
1uF
GND
L
R5
8kΩ
SW
IN
BST
OUT
C6
0.33uF
R1
10Ω
C2
0.22uF
MP3306
EN
EN
FB
OFF ON
LED1
20mA
DIM
PWMI
LED8
100Hz~50kHz
VCC
C4
1uF
PWMO
R2
232kΩ
R3
10kΩ
GND
OVP
C5
1uF
Figure 8— The application when Vin>12V
MP3306 Rev.1.02
1/18/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
12
MP3306-30V 700kHz SYNCHRONOUS STEP-UP WHITE LED DRIVER
PACKAGE INFORMATION
QFN12 (2x2mm)
1.90
2.10
0.35
0.45
0.30
0.40
PIN 1 ID
MARKING
11
0.20
0.30
1.90
2.10
PIN 1 ID
INDEX AREA
PIN 1 ID
0.10X45º TYP.
12
10
1
7
4
0.50
BSC
6
TOP VIEW
5
BOTTOM VIEW
0.80
1.00
0.20 REF
0.00
0.05
SIDE VIEW
NOTE:
1.90
0.70
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) EXPOSED PADDLE SIZE DOES NOT INCLUDE MOLD FLASH.
3) LEAD COPLANARITY SHALL BE 0.10 MILLIMETER MAX.
4) JEDEC REFERENCE IS MO-220, VARIATION VCCD.
5) DRAWING IS NOT TO SCALE.
0.25
1.90
0.50
RECOMMENDED LAND PATTERN
NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third
party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not
assume any legal responsibility for any said applications.
MP3306 Rev.1.02
1/18/2018
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2018 MPS. All Rights Reserved.
13
工商网监
湘ICP备2023018690号
