MP4050 Datasheet by Monolithic Power Systems Inc.

I'I'IPSf
MP4050
Non-Isolated, High Brightness,
LED Driver
MP4050 Rev.1.02 www.MonolithicPower.com 1
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
The Future of Analog IC Technology
DESCRIPTION
The MP4050 is a constant current LED driver
integrated with an internal 500V MOSFET. It is
specifically designed for energy efficient and
low cost LED bulk replacement applications.
MP4050 is designed to drive high-brightness
LEDs from an 85VAC to 265VAC line. It is also
useable under DC input voltage. The accurate
output LED current is achieved by an averaging
internal current feedback loop. Constant LED
current is delivered quietly by switching the
internal MOSFET at a frequency regulated
above 22kHz.
MP4050 can be directly powered by the high
input voltage. An internal high voltage current
source regulates supply voltage without
external circuitry. MP4050 features various
protections like Thermal Shutdown (TSD), VCC
Under Voltage Lockout (UVLO), Open Lamp
Protection and Short Lamp Protection. All of
there features make MP4050 an ideal solution
for simple, off-line and non-isolated LED
applications.
MP4050 is available in the TSOT23-5 and
SOIC8 packages.
FEATURES
Constant Current LED Driver
500V/7.2 MOSFET integrated
Low Vcc Operating Current
Maximum frequency limit
Audible noise restrain
Internal High Voltage Current Source
Internal 200ns Leading Edge Blanking
Thermal Shutdown (auto restart with
Hysteresis)
VCC Under Voltage Lockout with Hysteresis
(UVLO)
Open Lamp Protection
Short Lamp Protection
APPLICATIONS
AC/DC or DC/DC LED driver application
General Illumination
Industrial Lighting
Automotive/Decorative LED Lighting
All MPS parts are lead-free, halogen free, and adhere to the RoHS
directive. For MPS green status, please visit MPS website under Qualit
y
Assurance.
“MPS” and “The Future of Analog IC Technology” are Registered
Trademarks of Monolithic Power Systems, Inc.
TYPICAL APPLICATION
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 2
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
ORDERING INFORMATION
Part Number Package Top Marking
MP4050GJ* TSOT23-5 AGN
MP4050GS** SOIC8 MP4050
*For Tape & Reel, add suffix –Z (e.g. MP4050GJ–Z);
** For Tape & Reel, add suffix –Z (e.g. MP4050GS–Z);
PACKAGE REFERENCE
TOP VIEW
VCC
PRO
GND
1
2
3
5
4
DRAIN
SOURCE
VCC
PRO
GND
SOURCE
N.C
DRAIN
N.C
N.C
1
2
3
4
8
7
6
5
TOP VIEW
TSOT23-5 SOIC8
ABSOLUTE MAXIMUM RATINGS (1)
Drain to SOURCE.........................-0.3V to 500V
VCC, SOURCE to GND… ……..-0.3V to 6.5V
PRO to GND ..................................-0.7V to 6.5V
Source Current on PRO ............................. 4mA
Continuous Power Dissipation (TA = +25°C) (2)
--TSOT23-5, TA=25C................................... 1W
--SOIC8, TA=25C......................................... 1W
Junction Temperature...............................150C
Lead Temperature ....................................260C
Storage Temperature............... -60C to +150C
ESD Capability Human Body Mode .......... 2.0kV
ESD Capability Machine Mode .................. 200V
Recommended Operating Conditions (3)
Operating Junction Temp. (TJ)..-40°C to +125°C
Operating VCC range .....................4.5V to 4.7V
Thermal Resistance (4) θJA θJC
TSOT23-5.............................. 100 ..... 55... C/W
SOIC8..................................... 96 ...... 45... 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-to-
ambient thermal resistance JA, and the ambient temperature
TA. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by PD (MAX) = (TJ
(MAX)-TA)/JA. Exceeding the maximum allowable powe
r
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.
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 3
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
ELECTRICAL CHARACTERISTICS
VCC = 4.7V, TA = 25C, unless otherwise noted.
Parameter Symbol Condition Min Typ Max Units
Start-up Current Source (Drain Pin)
Internal regulator supply current IRegulator V
CC=4.5V;VDrain=100V 4.5 5 6 mA
Leakage Current from Pin Drain ILeak V
CC=6V;Vdarin=400V 14 20 A
Supply Voltage Management (VCC Pin)
VCC Increasing Level at which the
internal regulator stops VCCOFF 4.05 4.25 4.45 V
VCC Decreasing Level at which the
internal regulator Turns-On VCCON 3.85 4.05 4.25 V
VCC Hysteresis between regulator
ON/OFF VCCOFF-ON 0.14 0.20 0.26 V
VCC Decreasing level at which the
IC stops working VCCSTOP 3.17 3.27 3.37 V
VCC Hysteresis between regulator
OFF to VCC stop
VCCOFF-
STOP 1.23 1.38 1.52 V
VCC Decreasing Level at which the
protection Phase Ends VCCPRO 2.10 2.35 2.60 V
Internal IC Consumption ICC VCC=4.3V, Fs=33kHz,
D=84% 350 400 uA
Internal IC Consumption, Latch off
Phase ICCLATCH V
CC=5V 18 21 A
Internal MOSFET (Drain Pin)
Break Down Voltage VBRDSS 500 V
On-State resistance RON ID=10mA, Tj=25 7.2 10
Current Sampling Management (Source Pin)
Peak Current Limit VLimit 0.42 0.45 0.49 V
Leading edge blanking TLEB 200 ns
Feedback Threshold to turn on the
primary MOSFET VFB 0.188 0.194 0.200 V
Minimum OFF time limitation TOFF_MIN 3.5 4.7 5.9 s
Maximum ON time limitation TON_MAX 18 25 33 s
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 4
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
ELECTRICAL CHARACTERISTICS
(continued)
VCC = 4.7V, TA = 25C, unless otherwise noted.
Parameter Symbol Condition Min Typ Max Units
Protection input (PRO Pin)
Threshold to trigger the OVP VOVP 1.9 2.0 2.1 V
Time Constraint on the OVP
Comparator TOVP 21 28 s
Threshold to trigger the UVP VUVP 0.35 0.39 0.43 V
Thermal Shutdown
Thermal shutdown threshold 150 ºC
Thermal shutdown recovery
hysteresis 60 ºC
I'I'IP£' 'chATcH (HA) ILEAK (HA) TEMPERATURE (=0) TEMPERATURE (‘0 TE ATURE (“(3) MP4050 — NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER Q TEMP U "0) TEMPE TURE (‘0) TEMPERATURE (“C) go \ < g?”="" temperature="" temperature="" (‘0)="" temperature="" (“(2)="">
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 5
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
TYPICAL CHARACTERISTICS
VCC
OFF
(V)
Leakage Current vs.
Junction Temperature Break Down Voltage vs.
Junction Temperature
VCC OFF Threshold vs.
Junction Temperature VCC ON Threshold vs.
Junction Temperature
VCC Current In Latch
Phase vs. Junction
Temperature
VCC Protection Threshold
vs. Junction Temperature Feedback Reference vs.
Junction Temperature
VCC Stop Threshold vs.
Junction Temperature
VCC
PRO
(V)
VCC
STOP
(V) I
REGULATOR
(mA)
Internal Regulation
Currentt vs. Junction
Temperature
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
20.0
-50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 125-50 -25 0 25 50 75 100 125
-50 -25 0 25 50 75 100 125
-50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 125
-50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 125
3.5
4.0
4.5
5.0
5.5
6.0
6.5
500
520
540
560
580
600
620
640
V
BRDSS
(V)
10.0
13.0
16.0
19.0
22.0
25.0
28.0
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.0
4.1
4.2
4.3
4.4
4.5
4.6
VCC
ON
(V)
2.9
3.0
3.1
3.2
3.3
3.4
3.5
2.0
2.1
2.2
2.3
2.4
2.5
2.6
0.189
0.191
0.193
0.195
0.197
0.199
VFB (V)
I'I'IPS' TONgMAX lus} TEMPERATURE (‘0) MP4050 — NON-ISOLATED HIGH BRIGHTNESS LED DRIVER 17? 3 z 2 3 ,_ TEMPERATURE ( TEMPERATURE ‘6) @URE (“0) TEMPERATURE (°C)
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 6
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
TYPICAL CHARACTERISTICS
(continued)
VUVP (V)
Under Voltage Protection
Reference vs. Junction
Temperature
Minimum OFF Time vs.
Junction Temperature
On-State Resistance vs.
Junction Temperature Peak Current Limit vs.
Junction Temperature
Minimum ON Time vs.
Junction Temperature
V
OVP
(V)
Over Voltage Protection
Reference vs. Junction
Temperature
-50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 125-50 -25 0 25 50 75 100 125
-50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 125
V
LIMIT
(V)
1.9
2.0
2.0
2.1
2.1
0.370
0.380
0.390
0.400
0.410
3.0
3.5
4.0
4.5
5.0
5.5
6.0
20.0
22.0
24.0
26.0
28.0
30.0
2.00
4.00
6.00
8.00
10.00
12.00
14.00
0.40
0.42
0.44
0.46
0.48
0.50
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 7
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
TYPICAL PERFORMANCE CHARACTERISTICS
Performance waveforms are tested on the evaluation board of the Design Example section.
VIN = 230Vac, VOUT = 40V, IOUT=115mA, L = 4.7mH, COUT=47uF, TA = 25°C, unless otherwise noted.
Input Power Shutdown SCP Entry
OVP Entry
SCP Recovery
Output Current RippleOVP Recovery
V
DS
100V/div.
I
L
100mA/div.
V
DS
100V/div.
I
L
100mA/div.
V
OUT
10V/div.
I
L
100mA/div.
V
DS
10V/div.
I
L
100mA/div.
V
OUT
10V/div.
I
L
100mA/div.
V
OUT
10V/div.
I
L
100mA/div.
Steady State
V
BULK
100V/div.
V
OUT
10V/div.
I
OUT
50mA/div.
I
OUT
20mA/div.
V
DS
100V/div.
I
L
100mA/div.
Turn On Delay Input Power Startup
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 8
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
TYPICAL PERFORMANCE CHARACTERISTICS
(continued)
Performance waveforms are tested on the evaluation board of the Design Example section.
VIN = 230Vac, VOUT = 40V, IOUT=115mA, L = 4.7mH, COUT=47uF, TA = 25°C, unless otherwise noted.
INPUT VOLTAGE (VAC)
Input Line Voltage to
Output Current Regulation
High/Low Temperature
Output Current Regulation
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-30 -10 10 30 50 70 90 -1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
75 115 155 195 235 275
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 9
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
PIN FUNCTIONS
Pin #
TSOT23-5 Pin #
SOIC8 Name Description
1 1 VCC Power supply for all the control circuits.
2 2 PRO
Open lamp protection if the voltage is higher than VOVP, Short Lamp
protection if the voltage is lower than VUVP.
3 3 GND Ground of the IC
4 4 SOURCE
Source of internal power MOSFET. Internal peak current limit is 0.45V
(typical value). Output current sample.
5 7 DRAIN Drain of internal power MOSFET. Input of high voltage current source.
5,6,8 N.C Not Connected.
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 10
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
FUNCTION BLOCK DIAGRAM
Drain
VCC
Source
Start up unit
Power
Management
PRO
GND
Protection Unit
Driving Signal
Unit
Peak current
Limit
Minimum
Frequency
Control
Average current
Control
Figure 1: Functional Block Diagram
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 11
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
OPERATION
MP4050 is a non-isolated, cost-effective, high
efficiency converter designed to drive high-
brightness light emitting diodes (LEDs) from an
85Vac to 265 Vac line, or a DC input. As shown
in the typical application diagram, the regulator
is designed to operate with a minimum number
of external components. It incorporates the
following features:
Start-up and Under Voltage Lock-out (UVLO)
The IC is self supplied by the internal high
voltage regulator which is drawn from the Drain
pin. The IC starts switching and the internal
high voltage regulator turns off as soon as the
voltage on pin VCC reaches VCCOFF. When the
voltage on Pin VCC decreases below VCCON,
the internal high voltage regulator turns on
again to charge the external VCC capacitor. A
small capacitor such as several F capacitor is
enough to hold on the voltage of VCC and a
smaller capacitor also reduce component cost.
When the voltage on Pin VCC drops blow
VCCSTOP, the IC stops working, the internal high
voltage regulator recharges the Vcc capacitor.
When fault conditions happen, such as Short
Lamp Protection, Open Lamp Protection and
Over Temperature Protection (OTP), MP4050
stops working and a 18uA internal current source
discharges the Vcc capacitor. After the VCC drops
below VCCPRO, the internal high voltage regulator
recharges the VCC capacitor again. The restart
time can be calculated by the following equation,
restart Vcc Vcc
Vcc 2.37V 4.65V 2.37V
tC C
18 A 5mA

 
Figure 2 shows the typical waveform with VCC
under voltage lock out.
VCCOFF
VCCON
VCC
Internal
Voltage
Regulator
Driving
Signal
ON
OFF
VCCSTOP
Figure 2: VCC Under-Voltage Lock Out
(UVLO)
Constant Current Operation
MP4050 is a fully integrated regulator, the
internal feedback logic responds to the internal
sample and hold circuit to achieve constant
output current regulation. The voltage of the
internal sampling capacitor (VFB) is compared to
the internal reference 0.194V, when the
sampling capacitor voltage (VFB) falls below the
reference voltage, which indicates insufficient
output current, the integrated MOSFET is
turned ON. The ON period is determined by the
peak current limit. After the ON period elapses,
the integrated MOSFET is turned OFF. The
detail operation is shown as Figure 3.
MOS
Diode
IL
IPeak
IO
VO
VFB
0.194V
Figure 3: VFB vs IOUT
Thus by monitoring the internal sampling
capacitor voltage, the output current can be
regulated and the output current is determined
by the following equation:
O
0.194V
IR1
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 12
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
The peak current can be obtained as follow:
Peak
0.45V
IR1
R1 is the sense resistor.
Minimum Operating Frequency Limit
MP4050 incorporates minimum operating
frequency (22kHz) to eliminate the audible
noise when frequency is less than 20kHz.
When operating frequency is less than 22kHz,
the internal peak current regulator will decrease
the peak current value to keep the operating
frequency constant about 22kHz.
If the inductance value is too large to make the
operating frequency reach the minimum
operating frequency, the converter will enter the
CCM. And the converter works in DCM when
operating frequency is larger than 22kHz.
Minimum Off Time Limit
A minimum off time limit is implemented. During
the normal operation, the minimum off time limit
is 4.7us, and during the start up period, the
minimum off time limit is shortened gradually
from 18.8s, 9.4s to 4.7s (Shown as Figure
4). Each minimum off time keeps 128 switching
cycle. This soft start function enables safe start-
up.
18.4us 9.4us 4. 7us
Driver
128 switching cycle 128 switching cycle
Figure 4: tminoff at start-up
Thermal Shutdown (TSD)
To prevent MP4050 from any thermal damage,
MP4050 shuts down switching cycle when the
junction temperature exceeds 150C. As soon
as the junction temperature drops below 90C,
the power supply resumes operation. During
the thermal shutdown (TSD), the VCC is
discharged to VCCPRO, and then is re-charged
by the internal high voltage regulator.
Open Lamp Protection
If the PRO pin voltage (VPRO) is higher than VOVP
when MOSFET turns off, MP4050 stops
working and a re-start cycle begins. Open lamp
protection is hiccup mode. MP4050 monitors
the PRO pin voltage continuously and the VCC
voltage discharges and charges repeatedly.
MP4050 resumes work until the fault
disappears.
Short Lamp Protection
If the PRO pin voltage (VPRO) is lower than VUVP
when MOSFET turns off, MP4050 stops
working and a re-start cycle begins. Short lamp
protection is hiccup mode. MP4050 monitors
the PRO pin voltage continuously and the VCC
voltage discharges and charges repeatedly.
MP4050 resumes work until the fault
disappears.
Leading Edge Blanking
There are parasitic capacitances in the circuit
which can cause high current spike during the
turn-on of the internal MOSFET. In order to
avoid the premature termination of the
switching pulse, an internal Leading Edge
Blanking (LEB) unit is employed. During the
blanking time, the current comparator is
disabled and blocked from turning off the
internal MOSFET. Figure 5 shows the leading
edge blanking.
TLEB
VLimit
t
Figure 5: Leading Edge Blanking (LED)
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 13
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
APPLICATION INFORMATION
Component Selection
Input Capacitor
The input capacitor is used to supply the DC
input voltage for the converter. Figure 6 shows
the typical DC bus voltage waveform of full
bridge rectifier.
Vin
t
DC input voltage
VDC(max)
AC input voltage
VDC(min)
0
VAC
Figure 6: Input voltage waveform
When the full-bridge rectifier is used, the input
capacitor is usually set as 2F/W for the
universal input condition. And when small
power output, the half-bridge rectifier could also
be used with a bigger capacitor.
Very low DC input voltage could cause thermal
problem in LED application in Buck topology
application. The minimum DC voltage is limited
by the maximum duty cycle of MP4050 as
following expression:
OON_MAX OFF_MIN
DC(min)
ON _ MAX
V(t t )
Vt

Inductor
MP4050 has a minimum off time limit and
maximum on time limit. Both time limits affect
the inductance value. The maximum inductance
value and minimum inductance value can be
obtained as follows:
DC(min) O ON _ MAX
mMAX
Peak
(V V ) t
LL I


OOFF_MIN
mMIN
Peak
Vt
LL I

If the inductance value is too large, the
converter enters CCM when the frequency
reaches the minimum operating frequency. In
such case, the reverse recovery of freewheeling
diode results more power loss. Normally, it’s
better to make the converter operate in DCM.
The following expression shows the limit of the
minimum operating frequency.
O
m
2
SMIN Peak
DC(min) O O
2I
L11
f( )I
VVV

Freewheeling Diode
The diode should have a maximum reverse
voltage rating which is greater than the
maximum input voltage. The current rating of
diode is determined by the output current which
should be larger than 1.5~2 times output
current.
Slow diodes cause excessive leading edge
current spikes during start-up which is not
acceptable. Long reverse recovery time of
freewheeling diode can also affect the efficiency
and the circuit operation. So ultrafast diode
(Trr<75ns) such as WUGC10JH or EGC10GH
are recommended.
Output Capacitor
The output capacitor is required to filter the
inductance current and maintain the DC output
voltage.
The output current ripple is reduced by using a
bigger output capacitor. A low ESR capacitor is
necessary in low temperature application.
If the output voltage ripple is limited, the
ceramic, tantalum or low ESR electrolytic
capacitors are recommends to use. The output
voltage ripple can be estimated by:
CCM _ Ripple ESR
SO
i
ViR
8f C

CCM
2
OPeakO
DCM _ Ripple Peak ESR
SO Peak
II I
V()IR
fC I
 
DCM
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 14
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
Sense Resistor
The sense resistor needs to choose properly for
better output current regulation. The right
resistor guarantees stable output current
regulation in high temperature and low
temperature conditions. The sense resistor
should have 1% tolerance. It is even better to
parallel two 1% tolerance resistors to decrease
the resistance value error further. Sense
resistor with ±400PPM/ temperature
coefficient can be used for better output current
regulation in high temperature and low
temperature.
Feedback Resistor
Feedback resistor is used to detect the fault
operation mode such as open lamp or short
lamp conditions. Figure 7 shows the feedback
resistors connection.
MP4050 VCC
PRO
GND L
R2 R3
Figure 7: Feedback resistor connection
MP4050 is integrated with open lamp protection
and the over voltage protection point can be
designed as following function.
OVP PRO D
R2 R3
VV(1 )V
R2
 
VD is the freewheeling diode forward voltage
drop.
The upper feedback resistor (R3) is suggested
to be larger than 100k to avoid the efficiency
reduction in application. And the 1% tolerance
type is recommended to use as feedback
resistor to achieve accurate protection such
over voltage protection when open lamp.
The feedback resistor R2 could be sized down
to SMD 0603 package. Considering the
dielectric withstanding voltage, R3 is
recommended to have a minimum size of SMD
1206 package.
Dummy Load
Dummy load is recommended to regulate the
output voltage low than over voltage protection
point when open lamp condition. The dummy
load is used to consume the power transferred
to output capacitor when hiccup mode without
any power consumption.
Normally less than 1mA dummy load is
suggested which not deteriorate the system
efficiency and also guarantees the normal open
lamp protection.
PRO Decoupling Capacitor
One decoupling cap is recommended to parallel
between the PRO pin and GND pin. The
floating GND pin is sensitive to the voltage
noise spike in high side Buck solution. One
ceramic capacitor is suggested to use as
decoupling capacitor to decouple the voltage
noise for more stable operation.
Around 30pF PRO decoupling capacitor could
be used in SOIC8 package application and as
for smaller package TSOT23-5, no less than
100pF decoupling capacitor is recommended.
Figure 8 shows the PRO pin decoupling
capacitor connection.
MP4050 VCC
PRO
GND L
R2 R3
CPRO
Figure 8: Decoupling capacitor
PRO Time Constant
MP4050 detects the PRO pin voltage to judge
the fault condition when internal MOSEFET
turns off. Long rise time of the PRO pin voltage
affects MP4050 normal output voltage sample
which can not judge the open lamp immediately.
The PRO pin time constant (τ) should satisfy
the following expression to guarantee the
normal open lamp protection.
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 15
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
PRO
R2 R3
C1s
R2 R3
  
Output Power V-I Curve
The thermal performance limits the output
power of MP4050 in very small size LED
application. Different output voltage and output
current specification bring about different
maximum output power delivered form the
MP4050 device.
Figure 9 and Figure 10 separately show the
reference V-I curve in universal input voltage
and high voltage input under following assumed
conditions:
1. Buck topology.
2. Ambient temperature 90 .
3. Around 30kHz working frequency.
4. No PF required where input capacitor >9uF.
5. Not trigger the thermal shutdown and leave
one LED margin.
I
OUT
(mA)
V
OUT
(V)
MP4050 V-I Curve
Universal Input
85VAC~265VAC
100
125
150
175
200
225
250
275
300
325
350
375
400
0 5 101520253035 4045505560657075
SOIC8_85VAC
SOIC8_265VAC
TSOT23-5_85VAC
TSOT23-5_265VAC
Figure 9: Universal input V-I curve
(85VAC~265VAC)
I
OUT
(mA)
V
OUT
(V)
MP4050 V-I Curve High
Voltage Input
265VAC
0
50
100
150
200
250
300
350
400
0 20 40 60 80 100120140160180200220
TSOT23-5
SOIC8
Figure 10: High voltage input V-I curve
(200VAC~265VAC)
Power Factor
MP4050 is mainly used for non-isolated, space
constrained and cost sensitive LED driver
solution. As for the PF>0.5 when 120VAC input
required, MP4050 is also the best choose. The
input capacitance is reduced to achieve the
highest possible power factor as PF>0.7 when
120VAC and PF>0.5 when 230VAC if the
output current regulation is not strict.
Surge
Select the appropriate input capacitance to
obtain a good surge performance. With the
input capacitor C2 (4.7uF) and C3 (4.7uF) as
Figure 13, the board can pass 1kV differential
input line 1.2/50us surge test (IEC61000-4-5). It
is recommended to increase the input capacitor
value to suppress above 1kV surge test. As for
high PF required application with lower input
capacitor value giving a greater voltage rise, a
Metal Oxide Varistor (MOV) is typically required
to pass the above 1kV or greater surge test.
Table 1 shows input capacitor value required
for pass the differential surge test.
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 16
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
Table 1: Recommended input capacitance
Surge
voltage 500V 1000V 1500V 2000V
C2 3.3F 4.7F 4.7F
C3 3.3F 4.7F 10F
Show in
Figure11
The demo board can pass the 2000V
differential surge test by adopting below circuit
setup.
(1) Add a MOV RV1(TVR14431)
(2) Add a fuse F1 (SS-5-2A)
1mH/0.1AL1
4.7
400V
C3
4.7
400V
C2
10/1WFR1
L
N
MB6S
600V/0.5A
BD1
TVR14431
RV1
F1 250V/2A
85~265VAC
Figure11: 2kV surge solution
Layout Guide
PCB layout is very important to achieve reliable
operation, good EMI and good thermal
performance especially in very small size LED
application. The following describe some layout
recommendations.
1. The loop formed between the MP4050,
inductor, freewheeling diode and output
capacitor should be kept as small as
possible for better EMI.
2. Put the AC input far away from the switching
nodes to minimize the noise coupling that
may bypass the input filter.
3. The VCC pin and PRO pin capacitor should
be located physically close to the IC and
GND.
4. Put the feedback resistor next to the PRO
pin as possible and minimize the feedback
sampling loop to minimize the noise coupling
route.
5. In the buck topology, since the MP4050
SOURCE pin is switching nodes, the copper
area connected to SOURCE should be
minimize to minimize EMI with the thermal
constraints of the design.
6. Since MP4050 DRAIN pin is static node
connecting to DC input, the copper area
connected to DRAIN could be maximized to
improve the heat sinking.
Figure 12 shows a sample layout.
Top Layer
Bottom Layer
Figure 12: PCB Layout
Design Example
Below is a design example following the
application guidelines based on these
specifications:
Table 2: Design Example
VIN 85Vac~265Vac
VOUT 40V
IOUT 115mA
Figure 13 shows the detailed application
schematic. This circuit is used for the typical
performance and circuit waveforms. For more
device applications, please refer to the related
evaluation board datasheets.
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 17
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
TYPICAL APPLICATION CIRCUITS
Figure 13 shows a typical application example of a 40V, 115mA non-isolated buck topology power
supply using MP4050.
N
10 Ω/1W
FR1
L
WUGC10JH
600V/1A
D1 47 uF/50 V
C4
1mHL1
4.7 uF/400 V
C3
4.7 uF/400 V
C2 40V/115mA
3.3 Ω/1%/ 1206
R3
10KR5
2. 2uF/ 10VC1
LED+
LED -
3.3Ω/1%/ 1206R4
VCC 1
PRO 2
GND 3
SOURCE
4
DRAIN
5
U1 MP4050
MB6S
600V/0.5A
BD 1
9. 31K /1%/ 0603
R1
200 K/1 %/1206
R2
4.7mHL2
200 K
R6
85 VAC ~ 265 VAC
100 pF /50 V
R5
Figure 13: Typical Buck Converter Application
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 18
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
FLOW CHART
Start
VCC >VCC
OFF
Internal High Voltage
Regulator ON
YN
Soft Start
Monitor VCC
Y
OTP Monitor
Vcc Decrease
to VCCPRO
Shut Down
Internal High Voltage
Regulator VCC <VCCON
Y
N
OTP
Logic High?
Y
N
UVLO, OTP, Short Lamp Protection, Open Lamp Protection
All protections are auto restart
Shut off the
Swit ching
Pulse
N
Y
VFB <0.194V VCS >V
Limit
Turn ON the
MOSFET
Y
VCC <VCC
STOP
Y
Y
N
Monitor Internal VFB Monitor Source VCS
Turn OFF the
MOSFET
N
Y
VPRO<VUVP VPRO >VOV P
Turn OFF the
MOSFET
Y
Monitor VPRO Monitor VPRO
N N
Figure 14: Control Flow Chart
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 19
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
VCCOFF
Driver
Internal Regulator
Supply Current
Fault
Condition
Open Lamp Fault
Occurs Here
Unplug
from main input
Short Lamp Fault
Occurs Here OTP Fault
Occurs Here
VCC Start up Normal
Operation
Drive
Pluses
On
Off
Open lamp
Blanking time
when start up
18uA Discharge
Current
VCCON
VCC PRO
VCC STOP
Plug
from main Input
Figure 15: Evolution of the signal in presence of a Fault
I'I'IPS'
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
MP4050 Rev.1.02 www.MonolithicPower.com 20
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
PACKAGE INFORMATION
TSOT23-5
0.30
0.50
SEATING PLANE
0.95 BSC
0.70
0.90 1.00 MAX
0.00
0.10
TOP VIEW
FRONT VIEW SIDE VIEW
RECOMMENDED LAND PATTERN
2.80
3.00
1.50
1.70 2.60
3.00
13
45
0.09
0.20
NOTE:
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH,
PROTRUSION OR GATE BURR.
3) PACKAGE WIDTH 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-193, VARIATION AA.
6) DRAWING IS NOT TO SCALE.
0.30
0.50
0o-8o
0.25 BSC
GAUGE PLANE
2.60
TYP
1.20
TYP
0.95
BSC
0.60
TYP
SEE DETAIL "A"
DETAIL A
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
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.
MP4050 Rev.1.02 www.MonolithicPower.com 21
1/18/2016 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2016 MPS. All Rights Reserved.
SOIC8
0.016(0.41)
0.050(1.27)
0o-8o
DETAIL "A"
0.010(0.25)
0.020(0.50) x 45o
SEE DETAIL "A"
0.0075(0.19)
0.0098(0.25)
0.150(3.80)
0.157(4.00)
PIN 1 ID
0.050(1.27)
BSC
0.013(0.33)
0.020(0.51)
SEATING PLANE
0.004(0.10)
0.010(0.25)
0.189(4.80)
0.197(5.00)
0.053(1.35)
0.069(1.75)
TOP VIEW
FRONT VIEW
0.228(5.80)
0.244(6.20)
SIDE VIEW
14
85
RECOMMENDED LAND PATTERN
0.213(5.40)
0.063(1.60)
0.050(1.27)
0.024(0.61)
NOTE:
1) CONTROL DIMENSION IS IN INCHES. DIMENSION IN
BRACKET IS IN MILLIMETERS.
2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH,
PROTRUSIONS OR GATE BURRS.
3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH
OR PROTRUSIONS.
4) LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING)
SHALL BE 0.004" INCHES MAX.
5) DRAWING CONFORMS TO JEDEC MS-012, VARIATION AA.
6) DRAWING IS NOT TO SCALE.
0.010(0.25) BSC
GAUGE PLANE