MP3383
4-String, Max 400mA/String, Max 80V VOUT,
Step-Up WLED Controller
DESCRIPTION
FEATURES
The MP3383 is a step-up controller with four
LED current channels, designed to drive WLED
arrays for large LCD panel backlighting
applications. The MP3383 can expand the
number of LED channels with two or more ICs in
parallel sharing a single power source.
•
•
•
•
The MP3383 employs peak current control mode
with a fixed switching frequency (fSW) that is
configurable via an external setting resistor. The
MP3383 drives an external MOSFET to boost up
the output voltage (VOUT) from a 6V to 33V input
voltage (VIN) supply. It also regulates the current
in each LED string to the value set by an external
current-setting resistor.
The MP3383 applies four internal current
sources for current balancing. The current
matching achieves 1.8% regulation accuracy
among strings. The low regulation voltage on the
LED current sources reduces power loss.
The MP3383 supports direct pulse-width
modulation (PWM) dimming as well as analog
dimming using a PWM input. Full protection
features include over-current protection (OCP),
over-temperature protection (OTP), undervoltage
protection
(UVP),
over-voltage
protection (OVP), LED short and open protection,
and inductor and diode short protection.
•
•
•
•
•
•
•
•
•
•
4-String, Max 400mA/String WLED Driver
6V to 33V Input Voltage (VIN) Range
12V Gate Voltage (VGATE) (VIN > 13V)
80V Absolute Maximum Rating for Each
String
1.8% Current Matching Accuracy between
Each String
3% Current Accuracy
Direct PWM Dimming
Analog Dimming Mode with PWM Input
Cascading Capability with a Single Power
Source
LED Open and Short Protection
Configurable Recoverable Over-Voltage
Protection (OVP)
Over-Temperature Protection (OTP)
Short Inductor and Diode Protection
Available in SOIC-16 and TSSOP-16EP
Packages
APPLICATIONS
•
•
•
Desktop LCD Flat-Panel Displays
All-in-One PCs
2D and 3D LCD TVs
All MPS parts are lead-free, halogen-free, and adhere to the RoHS directive.
For MPS green status, please visit the MPS website under Quality
Assurance. “MPS,” the MPS logo, and “Simple, Easy Solutions” are
trademarks of Monolithic Power Systems, Inc. or its subsidiaries.
The MP3383 is available in SOIC-16 and
TSSOP-16EP packages.
MP3383 Rev. 1.0
5/2/2022
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1
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
TYPICAL APPLICATION
L1
D1
VIN
VOUT
C2
C1
GND
R5
R4
C4
8
R3
9
COMP
GND
OSC
OVP
EN
14
PWM
ADIM
R6
10
R1
3
7
MP3383
LED1
LED2
16
M1
LED3
LED4
ISET
1
String 4
15
ISENSE
VCC
11
String 3
12
GATE
String 2
C3
VIN
String 1
13
2
4
5
6
R2
MP3383 Rev. 1.0
5/2/2022
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2
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
ORDERING INFORMATION
Part Number*
MP3383GS*
MP3383GF**
Package
SOIC-16
TSSOP-16EP
Top Marking
See Below
See Below
MSL Rating
2
2a
* For Tape & Reel, add suffix -Z (e.g. MP3383GS-Z). Contact the factory for sample and production.
** For Tape & Reel, add suffix -Z (e.g. MP3383GF-Z).
TOP MARKING (MP3383GS)
TOP MARKING (MP3383GF)
MPS: MPS prefix
YY: Year code
WW: Week code
MP3383: Part number
LLLLLL: Lot number
MPS: MPS prefix
YY: Year code
WW: Week code
MP3383: Part number
LLLLLLLLL: Lot number
PACKAGE REFERENCE
TOP VIEW
LED1 1
16 PWM
LED4
1
16 LED3
LED2
2
15 COMP
ISET
2
15
GND
3
14 ADIM
OVP
3
14
LED3
4
13 VIN
OSC
4
13
LED4
5
12 VCC
EN
5
12
ISET
6
11
ISENSE
6
11 COMP
OVP
7
10 ISENSE
GATE
7
10 ADIM
OSC
8
EN
VCC
8
9
Exposed Pad
Connect to GND
9
TSSOP-16EP
MP3383 Rev. 1.0
5/2/2022
VIN
SOIC-16
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3
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
PIN FUNCTIONS
TSSOP-16EP SOIC-16
Pin #
Pin #
1
13
2
14
3
15
4
16
5
1
6
2
7
3
8
4
9
5
10
6
11
7
12
8
13
9
14
10
15
11
16
12
/
MP3383 Rev. 1.0
5/2/2022
Name
Description
LED string 1 current input. Connect the LED1 pin to the LED string 1
cathode.
LED string 2 current input. Connect the LED2 pin to the LED string 2
LED2
cathode.
GND Ground.
LED string 3 current input. Connect the LED3 pin to the LED string 3
LED3
cathode.
LED string 4 current input. Connect the LED4 pin to the LED string 4
LED4
cathode.
LED current setting. Connect a current-setting resistor from the ISET pin to
ISET
GND to configure the current in each LED string.
Output over-voltage protection (OVP) setting. Connect a resistor divider
OVP
from the output to the OVP pin to configure the OVP threshold.
Switching frequency (fSW) setting. Connect a resistor between the OSC
OSC
pin and GND to set the step-up converter’s fSW.
Enable control input. A voltage exceeding 1.2V turns the part on; a voltage
EN
below 0.4V turns the part off. Do not float the EN pin.
Current-sense input. During normal operation, the ISENSE pin senses the
voltage across the external inductor current-sense resistor (RSENSE) for peak
ISENSE current control mode. ISENSE also limits the inductor current (IL) during each
switching cycle. For cascading applications, connect the slave IC’s ISENSE
to GND. Do not float ISENSE.
Step-up converter MOSFET driver output. The GATE pin drives the
GATE
external power N-channel MOSFET.
The internal 12V linear regulator output. The VCC pin provides the power
VCC supply for the external MOSFET gate driver and the internal control circuitry.
Bypass VCC to GND using a ceramic capacitor.
VIN
Supply input. The VIN pin must be bypassed locally.
Input signal for analog brightness control. The LED current amplitude is
determined by the duty cycle of the PWM signal applied to the ADIM pin. An
internal RC filter (10MΩ resistor and 100pF capacitor) is integrated into
ADIM
ADIM. A frequency exceeding 20kHz is recommended to achieve better
PWM signal filtering performance and ensure that the high-level ADIM
voltage (VADIM) exceeds 1.2V and the low-level VADIM is below 0.4V.
Step-up converter compensation. The COMP pin compensates for the
COMP regulation control loop. Connect a ceramic capacitor or a resistor combined
with a capacitor from COMP to GND.
Input signal for PWM brightness control. By applying a PWM signal on
this pin, the LED current is chopped, and the average current is equal to ISET
x DDIM, where ISET is the LED current value set by a resistor between the ISET
PWM
pin and GND, and DDIM is the PWM input signal’s duty cycle. Ensure that the
high-level voltage exceeds 1.2V and the low-level voltage is below 0.4V. If
the PWM pin is floating, weakly pull it to GND internally.
EP
Exposed pad. Connect the exposed pad to GND.
LED1
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4
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
θJA
θJC
ABSOLUTE MAXIMUM RATINGS (1)
Thermal Resistance (4)
VIN .................................................-0.3V to +37V
VCC, VGATE......................................-0.3V to +16V
VLED1 to VLED4 .................................-0.3V to +80V
All other pins ................................-0.3V to +6.5V
Continuous power dissipation (TA = 25°C) (2)
TSSOP-16EP ........................................... 2.78W
SOIC-16 ................................................... 1.56W
Junction temperature ................................150°C
Lead temperature .....................................260°C
Storage temperature ................ -60°C to +150°C
TSSOP-16EP ......................... 45 ...... 10 ... °C/W
SOIC-16…………………………..80……35....°C/W
ESD Ratings
Human body model (HBM) ........................ ±2kV
Charged device model (CDM) ................. ±750V
Recommended Operating Conditions (3)
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 can produce an excessive die temperature, which
may cause the regulator to 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, a 4-layer PCB.
5) Not tested in production. Guaranteed by characterization.
Supply voltage (VIN) ............................ 6V to 33V
Max LED current ................................. 400mA (5)
Operating junction temp ........... -40°C to +125°C
MP3383 Rev. 1.0
5/2/2022
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MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
ELECTRICAL CHARACTERISTICS
VIN = 15V, VEN = 5V, TA = 25°C, unless otherwise noted.
Parameters
General
Operating input voltage
Quiescent supply current
Shutdown supply current
Low-dropout (LDO) output
voltage
VCC under-voltage lockout
(UVLO) threshold
VCC UVLO hysteresis
threshold
Enable (EN) high threshold
EN low threshold
Step-Up Converter
Gate driver sourcing
impedance
Gate driver sinking
impedance
Switching frequency
OSC pin voltage
Maximum duty cycle
Cycle-by-cycle ISENSE
current limit
Latch-off ISENSE current limit
COMP source current limit
COMP sink current limit
COMP transconductance
Current Dimming
PWM input low threshold
PWM input high threshold
ADIM input low threshold
ADIM input high threshold
Current Regulation
ISET pin voltage
LEDx average current
Current matching
(6)
LEDx regulation voltage
MP3383 Rev. 1.0
5/2/2022
Symbol
Condition
Min
Typ
Max
Unit
3
33
4
1
V
mA
μA
VIN
IQ
IST
VIN = 15V, no switching
VEN = 0V, VIN = 15V
VCC
13V < VIN, 0 < ICC < 10mA
10.5
12
13.5
V
Rising edge
4.5
5
5.5
V
VCC_UVLO
6
500
VEN_HIGH
VEN_LOW
VEN rising
VEN falling
1.2
0.4
VCC = 12V,VGATE = 12V
VCC = 12V, IGATE = 10mA
fSW
VOSC
DMAX
V
V
4
Ω
3.4
Ω
ROSC = 100kΩ
ROSC = 100kΩ, fSW = 500kHz
ROSC = 100kΩ, fSW = 500kHz
450
0.75
89
500
0.8
Duty = 89%
160
200
mV
500
75
15
400
mV
μA
μA
μA/V
ICOMP_SOLI
ICOMP_SILI
GCOMP
1V < COMP < 2.7V
1V < COMP < 2.7V
ΔICOMP = ±10µA
VPWM_LO
VPWM_HI
VADIM_LO
VADIM_HI
VPWM falling
VPWM rising
VADIM falling
VADIM rising
VISET
ILED
mV
RISET = 13.33kΩ, analog and
PWM dimming duty cycle = 100%
RISET = 12kΩ, PWM dimming duty
cycle = 100%, analog dimming
duty cycle = 5%
RISET = 13.33kΩ, analog and
PWM dimming duty cycle =
100%, ILED = 90mA
RISET = 12kΩ, PWM dimming duty
cycle = 100%, analog dimming
duty cycle = 5%, ILED = 5mA
ILED = 100mA
ILED = 300mA
550
0.85
0.4
1.2
0.4
1.2
kHz
V
%
V
V
V
V
1.17
1.2
1.23
V
87
90
93
mA
5
6
7
mA
1.8
%
5.5
%
250
450
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mV
mV
6
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
ELECTRICAL CHARACTERISTICS (continued)
VIN = 15V, VEN = 5V, TA = 25°C, unless otherwise noted.
Parameters
Protections
Over-voltage protection (OVP)
threshold
OVP UVLO threshold
LEDx UVLO threshold
LEDx over-voltage (OV)
threshold
Thermal protection threshold (7)
Thermal protection hysteresis (7)
Symbol
Condition
VOVP_OV
VOVP_UVLO
VLEDx_UVLO
Typ
Max
Unit
1.85
2
2.15
V
Step-up converter fails
VLEDx_OV
TST
Min
50
100
14
Rising edge
18
mV
mV
22
150
25
V
°C
°C
Note:
6)
7)
Matching is defined as the difference between the maximum and minimum current divided by 2 times the average current.
Not tested in production. Guaranteed by characterization.
MP3383 Rev. 1.0
5/2/2022
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7
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 15V, VEN = 5V, 120mA/string, 4 strings, 14 LEDs in series, TA = 25°C, unless otherwise noted.
Analog Dimming
500
450
400
350
300
250
200
150
100
50
0
ILED (mA)
ILED (mA)
PWM Dimming
FPWM=200Hz
FPWM=20kHz
0
10 20 30 40 50 60 70 80 90 100
DUTY (%)
MP3383 Rev. 1.0
5/2/2022
500
450
400
350
300
250
200
150
100
50
0
FADIM=20kHz
0
10 20 30 40 50 60 70 80 90 100
DUTY (%)
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MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 15V, VEN = 5V, 120mA/string, 4 strings, 14 LEDs in series, TA = 25°C, unless otherwise noted.
Steady State
Start-Up through VIN
CH1: VSW
CH1: VSW
CH2: VOUT
CH2: VOUT
CH3: IL
CH3: IL
CH4: ILED
CH4: ILED
Shutdown through VIN
Start-Up through EN
CH1: VSW
CH1: VSW
CH2: VIN
CH2: VEN
CH3: IL
CH3: IL
CH4: ILED
CH4: ILED
Start-Up through PWM
Shutdown through EN
CH1: VSW
CH2: VEN
CH3: IL
CH4: ILED
MP3383 Rev. 1.0
5/2/2022
fPWM = 200Hz, DPWM = 50%
CH1: VSW
CH2: PWM
CH3: IL
CH4: ILED
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MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 15V, VEN = 5V, 120mA/string, 4 strings, 14 LEDs in series, TA = 25°C, unless otherwise noted.
Shutdown through PWM
Start-Up through ADIM
fPWM = 200Hz, DPWM = 50%
fADIM = 20kHz, DADIM = 50%
CH1: VSW
CH1: VSW
CH2: PWM
CH2: ADIM
CH3: IL
CH3: IL
CH4: ILED
CH4: ILED
Shutdown through ADIM
PWM Dimming
fADIM = 20kHz, DADIM = 50%
fPWM = 200Hz, DPWM = 50%
CH1: VSW
CH1: VSW
CH2: ADIM
CH2: PWM
CH3: IL
CH3: IL
CH4: ILED
CH4: ILED
PWM Dimming
Analog Dimming
fPWM = 200Hz, DPWM = 0.1%
fADIM = 20kHz, DADIM = 50%
CH1: VSW
CH1: VSW
CH2: PWM
CH2: ADIM
CH3: IL
CH4: ILED
CH3: IL
CH4: ILED
MP3383 Rev. 1.0
5/2/2022
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MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 15V, VEN = 5V, 120mA/string, 4 strings, 14 LEDs in series, TA = 25°C, unless otherwise noted.
Start-Up with One String Open
Start-Up with All Strings Open
CH1: VSW
CH1: VSW
CH2: VOUT
CH2: VOUT
CH3: IL
CH3: IL
CH4: ILED
CH4: ILED
Open One String during Normal
Operation
Open All Strings during Normal
Operation
CH1: VSW
CH1: VSW
CH2: VOUT
CH2: VOUT
CH3: IL
CH3: IL
CH4: ILED
CH4: ILED
Short One String during Normal
Operation
Start-Up with One-String Short
CH1: VSW
CH1: VSW
CH2: VLEDx
CH2:VLEDx
CH3: IL
CH3: IL
CH4: ILED
CH4: ILED
MP3383 Rev. 1.0
5/2/2022
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MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN = 15V, VEN = 5V, 120mA/string, 4 strings, 14 LEDs in series, TA = 25°C, unless otherwise noted.
Short Inductor during Normal
Operation
CH1: VSW
Short Diode during Normal
Operation
CH1: VSW
CH2: VOUT
CH2: VOUT
CH3: ISHORT
CH3: ISHORT+L
CH4: ILED
CH4: ILED
OTP and Recovery
CH1: VSW
CH2: VOUT
CH3: IL
CH4: ILED
MP3383 Rev. 1.0
5/2/2022
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12
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
FUNCTIONAL BLOCK DIAGRAM
VCC
Regulator
VIN
-
Control
Logic
+
PWM
Comparator
GATE
Current-Sense
Amplifier
ISENSE
-
GND
Over-Voltage
Protection
Oscillator
LEB
+
-
COMP
PWM
Stop
-
UP_CLAMP
Short-String
Protection
OVP
+
ILIMIT
-
OSC
+
LED_SHORT
+
Max
-
Min
Feedback
Control
EA
+
ADIM
+
VREF
VREF
-
LED1
ISET
Current Control
PWM
LED4
ILIMIT
EN
Enable
Control
OTP
LED_SHORT
LED_OPEN
Protection
Figure 1: Functional Block Diagram
MP3383 Rev. 1.0
5/2/2022
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13
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
OPERATION
The MP3383 is a configurable constantfrequency, peak current control mode, step-up
converter with 4-channel regulated current
sources to drive an array of up to four white LED
strings.
Internal 12V Regulator
The MP3383 includes an internal linear regulator
(VCC). When the input voltage (VIN) exceeds
13V, VCC outputs a 12V power supply to the
external MOSFET gate driver and the internal
control circuitry. The VCC voltage (VCC) drops to
0V when the chip shuts down. The MP3383
features under-voltage lockout (UVLO). The chip
is disabled until VCC exceeds the UVLO
threshold.
The
UVLO
hysteresis
is
approximately 500mV.
System Start-Up
When enabled, the MP3383 checks the topology
connection first by monitoring the over-voltage
protection (OVP) pin. This determines whether a
Schottky diode is connected or the boost output
is shorted to GND. An OVP voltage (VOVP)
exceeding 50mV allows the chip to switch
normally. Otherwise, switching is disabled. The
MP3383 also checks other safety limits after
passing the OVP test, including UVLO, overtemperature protection (OTP), and over-current
protection (OCP). If all protection tests pass, the
chip then begins boosting the step-up converter
with an internal soft start (SS).
To prevent a large inrush current, the enable
(EN) signal should occur after the establishment
of VIN and the pulse-width modulation (PWM)
dimming signal during the start-up sequence.
Step-Up Converter
At the beginning of each switching cycle, the
internal clock turns on the external MOSFET.
During normal operation, the minimum turn-on
time of the external MOSFET is around 150ns.
Adding a stabilizing ramp to the current-sense
amplifier’s output prevents subharmonic
oscillations for duty cycles greater than 50%,
which is then fed into the PWM comparator.
When the summed voltage reaches the error
amplifier (EA)’s output voltage (VCOMP), the
external MOSFET turns off.
MP3383 Rev. 1.0
5/2/2022
VCOMP is an amplified signal of the difference
between the reference voltage (VREF) and the
feedback voltage (VFB). The converter
automatically chooses the lowest active LEDx
pin voltage (VLEDx) to provide a sufficient bus
voltage to power all LED strings.
If VFB drops below VREF, the EA’s output voltage
(VCOMP) increases. This results in more current
flowing through the MOSFET, increasing the
power delivered to the output and forming a
closed loop that regulates the output voltage
(VOUT).
Under light-load operation, especially if VOUT ≈
VIN, the converter runs in pulse-skipping mode.
In this mode, the MOSFET turns on for a
minimum on time and then the converter
discharges the power to the load for the
remaining period. The external MOSFET
remains off until VOUT must be boosted again.
Dimming Control
The MP3383 provides two dimming methods:
PWM dimming and analog dimming.
For PWM dimming, apply a PWM signal to the
PWM pin. The LED current (ILED) is chopped by
this PWM signal, and the average ILED is equal to
ISET x DDIM, where DDIM is the PWM dimming
signal’s duty cycle, and ISET is the full-scale ILED
set by the ISET resistance (RISET).
For analog dimming, apply a PWM signal to the
ADIM pin. An internal RC filter (10MΩ resistor
and 100pF capacitor) is integrated to ADIM. This
PWM signal is filtered to the DC voltage by the
internal RC filter. The ILED amplitude is equal to
ISET x DDIM, where DDIM is the PWM dimming
signal’s duty cycle, and ISET is the full-scale ILED
set by RISET. A 20kHz or greater PWM signal is
recommended for improved filtering.
Operating Switching Frequency (fSW)
The MP3383’s switching frequency (fSW) is set
through an external resistor on the OSC pin. This
helps optimize both the size of the external
components and system efficiency.
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14
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
Open-String Protection
Open-string protection is achieved through
detecting VOVP and LEDx voltage (VLEDx, where
“LEDx” can be LED1, LED2, LED3, and LED4).
If one or more strings are open, then the
respective LEDx pins are pulled to ground and
the IC continues charging VOUT until it reaches
the OVP threshold. If the OVP threshold is
triggered, then the chip stops switching and
marks off the strings for which VLEDx is below
100mV. Once marked, the remaining LED
strings force VOUT back to normal regulation. The
string with the largest voltage drop determines
the output regulation value.
The MP3383 always attempts to light at least
one string. If all strings are open, the MP3383
shuts down the step-up converter. The open
strings remain in this marked-off state until the
chip resets.
Short-String Protection
The MP3383 monitors VLEDx to determine
whether a short-string fault has occurred. If one
or more strings are short, then the respective
LEDx pins tolerate high-voltage stress. If VLEDx
exceeds the protection threshold for 16 switching
cycles (128 switching cycles, optionally), shortstring protection is triggered, and the fault string
is marked off and disabled. Once a string is
marked off, it disconnects from the VOUT loop
until VIN or EN restarts.
To prevent mistriggering a short LED protection
when the LED string is open, the short LED
MP3383 Rev. 1.0
5/2/2022
protection function is disabled when VLEDx for all
used LED channels exceeds 2.1V.
For applications where VOUT > 90V, use an
external MOSFET to carry the huge voltage
when the whole LED string is shorted.
Cycle-by-Cycle Current Limit
To prevent the external components from
exceeding their respective current stress ratings,
the IC employs cycle-by-cycle current-limit
protection. When the current-sense voltage
across the sense resistor (connected between
ISENSE and GND) reaches the cycle-by-cycle
current-limit threshold, the external MOSFET
turns off until the next clock cycle begins.
Short Inductor and Diode Protection
When the external inductor or diode is shorted,
the IC provides protection by detecting the
current flowing through the power MOSFET. If
the current-sense voltage across the sense
resistor (connected between ISENSE and GND)
exceeds the latch-off current limit threshold and
lasts for five switching cycles, the IC stops
switching and latches off.
Thermal Shutdown
The MP3383 monitors the silicon die
temperature to prevent the IC from operating at
exceedingly high temperatures. If the die
temperature exceeds the threshold (TST), the IC
shuts down. Once the die temperature drops
below the lower threshold, the IC restarts and
resumes normal operation. The hysteresis value
is typically 25°C.
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15
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
APPLICATION INFORMATION
Selecting the Switching Frequency (fSW)
The step-up converter’s fSW is recommended to
be between 100kHz and 900kHz for most
applications. A resistor on OSC sets the internal
fSW for the step-up converter. fSW can be
estimated using Equation (1):
fSW (kHz) =
50000
ROSC ( kΩ )
(1)
The required inductance (L) can be calculated
using Equation (3):
L
η VOUT D (1− D)2
2 fSW ILOAD
The duty cycle (D) can be calculated using
Equation (4):
D = 1−
For ROSC is 100kΩ, fSW is set to 500kHz.
Setting the LED Current
The current in each LED string can be set
through the current-setting resistor on ISET,
which can be calculated using Equation (2):
ISET(mA) =
1200
RISET ( kΩ )
(2)
For RISET is 12kΩ, ILED is set to 100mA. Do not
leave ISET floating.
Selecting the Input Capacitor
The input capacitor (CIN) reduces the surge
current drawn from the input supply and the
switching noise from the device. CIN impedance
at fSW should be below the input source
impedance to prevent the high-frequency
switching current from passing through to the
input. Ceramic capacitors with X5R or X7R
dielectrics are recommended for their low ESR
and small temperature coefficients. For most
applications, use a 4.7μF ceramic capacitor in
parallel with a 220µF electrolytic capacitor.
Selecting the Inductor and Current-Sensing
Resistor
A larger-value inductor results in reduced ripple
current and a lower peak inductor current
(IL(PEAK)), which reduces stress on the N-channel
MOSFET. However, a larger-value inductor has
a larger physical size, higher series resistance,
and lower saturation current. Choose an inductor
that does not saturate under the worst-case load
conditions. Select the minimum inductance (L)
that ensures the boost converter works in
continuous conduction mode (CCM) with high
efficiency and good EMI performance.
VIN
VOUT
(4)
Where ILOAD is the LED load current, and η is the
efficiency.
The switching current is used for peak current
control mode. To avoid reaching the current limit,
the voltage across the sensing resistor (RSENSE)
must be below 80% of the current limit voltage
(VSENSE) in the worst-case scenario. RSENSE can
be calculated using Equation (5):
RSENSE =
0.8 VSENSE
IL(PEAK)
(5)
The peak inductor current (IL(PEAK)) can be
calculated using Equation (6):
IL(PEAK) =
VOUT ILOAD VIN (VOUT − VIN )
+
η VIN
2 L fSW VOUT
(6)
Selecting the Power MOSFET
The MP3383 is capable of driving a wide variety
of N-channel power MOSFETs. The critical
MOSFET selection parameters include the
maximum drain-to-source voltage (VDS(MAX)),
maximum current (ID(MAX)), on resistance
(RDS(ON)), gate source charge (QGS), gate drain
charge (QGD), and total gate charge (QG).
Ideally, the off-state voltage across the MOSFET
is equal to VOUT. Considering the voltage spike
when the MOSFET turns off, VDS(MAX) should be
1.5 times greater than VOUT.
The maximum current flowing through the power
MOSFET occurs at the minimum VIN and
maximum output power (POUT). The maximum
RMS current through the MOSFET (IRMS(MAX))
can be calculated using Equation (7):
IRMS(MAX) = IIN(MAX) DMAX
MP3383 Rev. 1.0
5/2/2022
(3)
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(7)
16
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
The maximum duty cycle (DMAX) can be
calculated using Equation (8):
DMAX
VOUT − VIN(MIN)
(8)
VOUT
The MOSFET’s current rating should be 1.5
times greater than IRMS(MAX).
The MOSFET’s RDS(ON) determines the
conduction loss (PCOND), which can be calculated
using Equation (9):
PCOND = IRMS 2 RDS(ON) k
Where k is
coefficient.
the
MOSFET’s
(9)
temperature
The switching loss is related to QGD and QGS,
which determine the commutation time. QGS is
the charge between the threshold voltage and
the plateau voltage when a driver charges the
gate, which can be read in the VGS vs. QG chart
of the MOSFET datasheet. QGD is the charge
during the plateau voltage. These two
parameters are required to estimate the turn-on
and turn-off losses (PSW), which can be
calculated using Equation (10):
PSW =
QGS RG
VDS IIN fSW +
VDR − VTH
QGD RG
VDS IIN fSW
VDR − VPLT
(10)
Where VDR is the drive voltage, VTH is the
threshold voltage, VPLT is the plateau voltage,
VDS is the drain-to-source voltage, and RG is the
gate resistance.
RG is recommended to be between 10Ω and 20Ω.
Note that calculating the switching loss is the
most difficult part of loss estimation. Equation
(10) provides a simplified equation. For more
accurate estimates, the calculations become
significantly more complex.
The total gate charge (QG) is used to calculate
the gate drive loss (PDR). PDR can be calculated
using Equation (11):
PDR = Q G VDR f SW
MP3383 Rev. 1.0
5/2/2022
Selecting the Output Capacitor
The output capacitor (COUT) keeps the VOUT ripple
small and ensures feedback loop stability. COUT
impedance must be low at fSW. Ceramic
capacitors
with
X7R
dielectrics
are
recommended for their low ESR characteristics.
A 4.7μF ceramic capacitor in parallel with a 22μF
to 47μF electrolytic capacitor is sufficient for
most applications.
Setting the Over-Voltage Protection (OVP)
Open-string protection is achieved by detecting
VOVP. In some cases, an LED string open fault
results in VFB always being 0V. The MP3383
continues boosting VOUT higher and higher. If
VOUT reaches the configured OVP threshold,
OVP is triggered.
To ensure that the chip functions properly, an
appropriate VOVP is required. The recommended
VOVP is about 1.1 to 1.2 times greater than VOUT
for normal operation. VOVP is set by an external
resistor on OVP, and can be calculated using
Equation (12):
VOVP = 2(V) (1 +
RHIGH
)
RLOW
(12)
Where RHIGH and RLOW are the voltage divider
resistors between VOUT and GND.
Expanding LED Channels
The MP3383 can expand the number of LED
channels by using two or three ICs in parallel. To
connect two ICs for a total of eight LED strings,
connect the VCC pins of the master IC and the
slave IC together to power the slave IC’s internal
logic circuitry. Connect the COMP pins of the
slave IC and the master IC together to regulate
the voltage of all eight LED strings. The slave
IC’s MOSFET driving signal is not used. The
boost converter can be driven by the master IC
only. Do not leave the slave IC’s ISENSE pin
floating; connect it to ground. Apply the EN and
DIM signals to both ICs.
(11)
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17
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
PCB Layout Guidelines
Efficient PCB layout is critical for stable
operation and reducing EMI noise. For the best
results, follow the guidelines below and refer to
Figure 2:
1. Ensure that the loop between the external
MOSFET, output diode, and ceramic COUT is
as small and short as possible since it carries
a high-frequency pulse current.
2. Separate the power ground (PGND) and
signal ground (GND) to reduce noise
affection.
Figure 2: Recommended PCB Layout
3. Connect PGND and GND together. All logic
signals refer to the signal ground.
4. Place ceramic capacitors as close to VIN and
VCC as possible.
MP3383 Rev. 1.0
5/2/2022
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18
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
TYPICAL APPLICATION CIRCUIT
0Ω
R4
10Ω
1
U1
C10
0.47μF
AGND
C12
AGND
EN
1
R9
R22
R11
2kΩ
R12
200kΩ
100kΩ
AGND
ADIM
1
R21
C13
NC
2kΩ
9
VIN
8
VCC
470nF 270Ω 11
R17
C14
10kΩ
NC
4
GATE
7
ISENSE
6
COMP
MP3383
OSC
R5 R6
0.05Ω
1
NC
R8
0Ω PGND
AGND
NC
OVP
3
R13
2kΩ
13
10
ADIM
LED2
14
2
ISET
LED3
16
12
PWM
LED4
1
2
1
22μF/100V
316kΩ
C8
C9 PGND
R7
10kΩ 100pF
2.2μF/100V
C11
15
PGND
LED+
C4
NC
GND
LED1
R3
C7
PGND
EN
5
NC
2
C6
PGND
R1
M1
R2
NC
PGND
2.2μF/100V
3
1
1
1
2
NC
220μF/35V
C1
B290
2
33μH/5A
C5
GND
1
1
C3
FDD861 02LZ/AM4490N
2
2
L1
1
2
2
2
1
4.7μF/50V
1
F1
1
D1
TO-252 or SO8
C2
VIN
AGND
R14 0Ω
R15 0Ω
1
1
1
1
LED1
LED2
LED3
LED4
R16 0Ω
R18 0Ω
R10
100kΩ
PWM-DIM
1
R20
R19
AGND
100kΩ
2kΩ
Figure 3: Typical Application Circuit (8)
Note:
8)
Some components are adjustable based on real cases.
MP3383 Rev. 1.0
5/2/2022
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19
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
PACKAGE INFORMATION
PACKAGE OUTLINE DRAWING FOR 16-TSSOP w/ EXPOSED PADDLE
MF-PO-D-0036
revision 3.0
TSSOP-16EP
PIN 1 ID
TOP VIEW
RECOMMENDED LAND PATTERN
SEE DETAIL "A"
FRONT VIEW
SIDE VIEW
DETAIL "A"
NOTE:
BOTTOM VIEW
MP3383 Rev. 1.0
5/2/2022
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) PACKAGE LENGTH DOES NOT INCLUDE MOLD
FLASH, PROTRUSION OR GATE BURR.
3) PACKAGE WITDH DOES NOT INCLUDE INTERLEAD
FLASH OR PROTRUSION.
4) LEAD COPLANARITY (BOTTOM OF LEADS AFTER
FORMING) SHALL BE 0.10 MILLIMETERS MAX.
5) DRAWING CONFORMS TO JEDEC MO-153,
VARIATION ABT.
6) DRAWING IS NOT TO SCALE.
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20
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
PACKAGE INFORMATION (continued)
SOIC-16
MP3383 Rev. 1.0
5/2/2022
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21
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
CARRIER INFORMATION
1
Pin1
1
1
1
ABCD
ABCD
ABCD
ABCD
Feed Direction
Part Number
MP3383GS-Z
MP3383GF-Z
MP3383 Rev. 1.0
5/2/2022
Package
Description
SOIC-16
TSSOP-16EP
Quantity/
Reel
2500
2500
Quantity/
Tube
50
96
Reel
Diameter
13in
13in
Carrier Tape
Width
16mm
16mm
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Carrier Tape
Pitch
8mm
8mm
22
MP3383 – 4-STRING, MAX 80V VOUT, STEP-UP WLED CONTROLLER
REVISION HISTORY
Revision #
1.0
Revision Date
5/2/2022
Description
Initial Release
Pages Updated
-
Notice: The information in this document is subject to change without notice. Please contact MPS for current specifications.
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.
MP3383 Rev. 1.0
5/2/2022
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