MP4050
Non-Isolated, High Brightness,
LED Driver
The Future of Analog IC Technology
DESCRIPTION
FEATURES
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.
Constant Current LED Driver
500V/7.2Ω 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 Quality
Assurance.
“MPS” and “The Future of Analog IC Technology” are Registered
Trademarks of Monolithic Power Systems, Inc.
TYPICAL APPLICATION
MP4050 Rev.1.03
9/19/2019
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1
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
ORDERING INFORMATION
Part Number
MP4050GJ*
MP4050GS**
Package
TSOT23-5
SOIC8
Top Marking
AGN
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
1
PRO
2
GND
3
TOP VIEW
5
4
DRAIN
SOURCE
TSOT23-5
VCC
1
8
N.C
PRO
2
7
DRAIN
GND
3
6
N.C
SOURCE
4
5
N.C
SOIC8
ABSOLUTE MAXIMUM RATINGS (1)
Thermal Resistance (4)
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
TSOT23-5 .............................. 100 ...... 55 ... C/W
SOIC8...................................... 96 ....... 45 ... C/W
Recommended Operating Conditions (3)
θJA
θJC
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.
Operating Junction Temp. (TJ)..-40°C to +125°C
Operating VCC range ..................... 4.5V to 4.7V
MP4050 Rev.1.03
9/19/2019
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2
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
ELECTRICAL CHARACTERISTICS
VCC = 4.7V, TA = 25C, unless otherwise noted.
Parameter
Symbol
Condition
Min
Typ
Max
Units
Internal regulator supply current
IRegulator
VCC=4.5V;VDrain=100V
4.5
5
6
mA
Leakage Current from Pin Drain
ILeak
14
20
μA
Start-up Current Source (Drain Pin)
VCC=6V;Vdarin=400V
Supply Voltage Management (VCC Pin)
VCC Increasing Level at which the
internal regulator stops
VCC Decreasing Level at which the
internal regulator Turns-On
VCC Hysteresis between regulator
ON/OFF
VCC Decreasing level at which the
IC stops working
VCC Hysteresis between regulator
OFF to VCC stop
VCC Decreasing Level at which the
protection Phase Ends
Internal IC Consumption
Internal IC Consumption, Latch off
Phase
Internal MOSFET (Drain Pin)
Break Down Voltage
On-State resistance
VCCOFF
4.45
4.65
4.85
V
VCCON
4.2
4.4
4.6
V
VCCOFF-ON
0.18
0.24
0.3
V
VCCSTOP
3.17
3.27
3.37
V
1.23
1.38
1.52
V
2.10
2.35
2.60
V
VCC=4.3V, Fs=33kHz,
D=84%
350
400
uA
VCC=5V
18
21
μA
7.2
10
Ω
0.45
0.49
V
VCCOFFSTOP
VCCPRO
ICC
ICCLATCH
VBRDSS
RON
500
ID=10mA, Tj=25℃
V
Current Sampling Management (Source Pin)
Peak Current Limit
VLimit
Leading edge blanking
TLEB
Feedback Threshold to turn on the
primary MOSFET
Minimum OFF time limitation
Maximum ON time limitation
MP4050 Rev.1.03
9/19/2019
0.42
200
ns
VFB
0.188
0.194
0.200
V
TOFF_MIN
TON_MAX
3.5
18
4.7
25
5.9
33
μs
μs
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3
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
ELECTRICAL CHARACTERISTICS (continued)
VCC = 4.7V, TA = 25C, unless otherwise noted.
Parameter
Symbol
Condition
Min
Typ
Max
Units
1.9
2.0
2.1
V
21
28
μs
0.39
0.43
V
Protection input (PRO Pin)
Threshold to trigger the OVP
Time Constraint on the OVP
Comparator
Threshold to trigger the UVP
Thermal Shutdown
Thermal shutdown threshold
Thermal shutdown recovery
hysteresis
MP4050 Rev.1.03
9/19/2019
VOVP
TOVP
VUVP
0.35
150
ºC
60
ºC
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4
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
TYPICAL CHARACTERISTICS
Internal Regulation
Currentt vs. Junction
Temperature
Leakage Current vs.
Junction Temperature
6 .5
640
19.0
620
18.0
600
VBRDSS (V)
5 .5
17.0
16.0
5.0
15.0
4 .5
4.0
3 .5
-50 -25
0
25
50
VCC Current In Latch
Phase vs. Junction
Temperature
560
14.0
540
13.0
520
12.0
-50 -25
75 100 125
580
0
25
50
500
-50 -25
75 100 125
VCC OFF Threshold vs.
Junction Temperature
4.7
4.5
22.0
4.6
4.4
16.0
4.5
4.4
4.3
13.0
10.0
-50 -25
3.5
VCCON (V)
25.0
VCCOFF (V)
4.6
19.0
0
25
50
VCC Stop Threshold vs.
Junction Temperature
2.6
2.5
3.3
2.4
VCCPRO (V)
3.4
3.2
3.1
2.9
-50 -25
MP4050 Rev.1.03
9/19/2019
0
25
50
0
25
50
75 100 125
50
75 100 125
4.3
4.2
VCC Protection Threshold
vs. Junction Temperature
0
25
50
75 100 125
Feedback Reference vs.
Junction Temperature
0.199
0.197
0.195
2.3
0.193
2.2
2.0
-50 -25
4.0
-50 -25
75 100 125
0.191
2.1
3.0
25
4.1
4.2
-50 -25
75 100 125
0
VCC ON Threshold vs.
Junction Temperature
4.8
28.0
VCCSTOP (V)
20.0
VFB (V)
IREGULATOR (mA)
6.0
Break Down Voltage vs.
Junction Temperature
0
25
50
75 100 125
0.189
-50 -25
0
25
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50
75 100 125
5
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
TYPICAL CHARACTERISTICS (continued)
Over Voltage Protection
Reference vs. Junction
Temperature
Under Voltage Protection
Reference vs. Junction
Temperature
2.1
0.410
2.1
0.400
Minimum OFF Time vs.
Junction Temperature
6 .0
VUVP (V)
VOVP (V)
5 .5
2.0
5 .0
0.390
4 .5
4 .0
0.380
2.0
3 .5
1.9
-50 -25
0
25
50
75 100 125
0.370
-50 -25
Minimum ON Time vs.
Junction Temperature
0
25
50
On-State Resistance vs.
Junction Temperature
VLIMIT (V)
10.00
8.00
6.00
22.0
MP4050 Rev.1.03
9/19/2019
25
50
75 100 125
2.00
-50 -25
75 100 125
0.46
0.44
0.42
4.00
0
50
0.48
26.0
24.0
25
0.50
12.00
28.0
0
Peak Current Limit vs.
Junction Temperature
14.00
30.0
20.0
-50 -25
3 .0
-50 -25
75 100 125
0
25
50
75 100 125
0.40
-50 -25
0
25
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50
75 100 125
6
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
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.
Steady State
VDS
100V/div.
Turn On Delay
Input Power Startup
VDS
100V/div.
VBULK
100V/div.
VOUT
10V/div.
IOUT
50mA/div.
IL
100mA/div.
Input Power Shutdown
VDS
100V/div.
IL
100mA/div.
SCP Entry
VOUT
10V/div.
IL
100mA/div.
VOUT
10V/div.
IL
100mA/div.
OVP Entry
IL
100mA/div.
OVP Recovery
VDS
10V/div.
VOUT
10V/div.
IL
100mA/div.
IL
100mA/div.
MP4050 Rev.1.03
9/19/2019
SCP Recovery
Output Current Ripple
IOUT
20mA/div.
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7
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
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.
High/Low Temperature
Input Line Voltage to
Output Current Regulation
Output Current Regulation
2
1
1.5
0.8
0.6
1
0.4
0.5
0.2
0
0
-0.5
-0.2
-0.4
-1
-0.6
-1.5
-2
-30 -10
-0.8
10
30
50
70
90
-1
75
115
155
195
235
275
INPUT VOLTAGE (VAC)
MP4050 Rev.1.03
9/19/2019
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8
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
PIN FUNCTIONS
Pin #
TSOT23-5
Pin #
SOIC8
Name
1
1
VCC
2
2
3
3
4
4
5
7
DRAIN
5,6,8
N.C
MP4050 Rev.1.03
9/19/2019
Description
Power supply for all the control circuits.
Open lamp protection if the voltage is higher than VOVP, Short Lamp
PRO
protection if the voltage is lower than VUVP.
GND
Ground of the IC
Source of internal power MOSFET. Internal peak current limit is 0.45V
SOURCE
(typical value). Output current sample.
Drain of internal power MOSFET. Input of high voltage current source.
Not Connected.
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9
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
FUNCTION BLOCK DIAGRAM
VCC
Power
Management
Start up unit
Drain
Driving Signal
Unit
PRO
Protection Unit
Average current
Control
Peak current
Limit
GND
Source
Minimum
Frequency
Control
Figure 1: Functional Block Diagram
MP4050 Rev.1.03
9/19/2019
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10
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
OPERATION
MP4050 is a non-isolated, cost-effective, high
efficiency converter designed to drive highbrightness 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 μF 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,
t restart
Vcc 2.37V
4.65V 2.37V
CVcc
CVcc
18A
5mA
Figure 2 shows the typical waveform with VCC
under voltage lock out.
VCC
VCC OFF
Internal
Voltage
Regulator
VCC ON
ON
OFF
Driving
Signal
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
IPeak
IL
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:
IO
MP4050 Rev.1.03
9/19/2019
VCC STOP
0.194V
R1
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11
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
The peak current can be obtained as follow:
IPeak
0.45V
R1
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 18.8μs, 9.4μs to 4.7μs (Shown as Figure
4). Each minimum off time keeps 128 switching
cycle. This soft start function enables safe startup.
Driver
≥9.4us
≥18.4us
≥4.7us
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.
VLimit
128 switching cycle
128 switching cycle
TLEB
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.
MP4050 Rev.1.03
9/19/2019
t
Figure 5: Leading Edge Blanking (LED)
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12
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
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
VDC(min)
AC input voltage
t
0
Figure 6: Input voltage waveform
When the full-bridge rectifier is used, the input
capacitor is usually set as 2μF/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:
VDC(min)
VO (t ON _ MAX t OFF _ MIN )
t ON _ MAX
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:
Lm LMAX
(VDC(min) VO ) t ON _ MAX
Lm LMIN
Lm
2 IO
fSMIN (
1
VDC(min) VO
1
) IPeak 2
VO
Freewheeling Diode
VDC(max)
DC input voltage
VAC
better to make the converter operate in DCM.
The following expression shows the limit of the
minimum operating frequency.
IPeak
VO t OFF _ MIN
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
(Trr9uF.
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.
5. Not trigger the thermal shutdown and leave
one LED margin.
MP4050 V-I Curve
Universal Input
400
375
IOUT (mA)
350
325
300
275
85VAC~265VAC
SOIC8_85VAC
SOIC8_265VAC
TSOT23-5_85VAC
TSOT23-5_265VAC
250
225
200
175
150
125
100
0 5 1015202530354045505560657075
VOUT (V)
Figure 9: Universal input V-I curve
(85VAC~265VAC)
MP4050 Rev.1.03
9/19/2019
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.
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15
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
Table 1: Recommended input capacitance
Surge
voltage
500V
1000V
1500V
2000V
C2
3.3μF
4.7μF
4.7μF
C3
3.3μF
4.7μF
10μF
Show in
Figure11
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.
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)
L
L1 1mH/0.1A
F1 250V/2A FR1 10/1W
85~265VAC
BD1
MB6S
600V/0.5A
RV1
C2
4.7
400V
TVR14431
C3
4.7
400V
Top Layer
N
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.
Design Example
2. Put the AC input far away from the switching
nodes to minimize the noise coupling that
may bypass the input filter.
Below is a design example following the
application guidelines based on these
specifications:
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.
MP4050 Rev.1.03
9/19/2019
Bottom Layer
Figure 12: PCB Layout
Table 2: Design Example
85Vac~265Vac
VIN
40V
VOUT
115mA
IOUT
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.
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2019 MPS. All Rights Reserved.
16
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
TYPICAL APPLICATION CIRCUITS
Figure 13 shows a typical application example of a 40V, 115mA non-isolated buck topology power
supply using MP4050.
L1 1mH
U1
5
MP4050
DRAIN
PRO
R5 10K
BD 1
MB6S
600V/0.5A
L
VCC
4
SOURCE
GND
1
2
R5
100pF /50V
3
FR1 10Ω/1W
C2
85VAC~265VAC
N
4.7uF/400 V
C1 2. 2uF/ 10V
R1
9. 31K/1%/ 0603
R2
200 K/1%/1206
C3
4.7uF/400 V
LED+ 40V/115mA
R3 3.3Ω/1%/ 1206
L2 4.7mH
R4 3.3Ω/1%/ 1206
D1
C4
47uF/50V
R6
200K
WUGC10JH
600V/1A
LED -
Figure 13: Typical Buck Converter Application
MP4050 Rev.1.03
9/19/2019
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2019 MPS. All Rights Reserved.
17
MP4050 – NON-ISOLATED, HIGH BRIGHTNESS, LED DRIVER
FLOW CHART
Start
Vcc Decrease
to VCCPRO
Internal High Voltage
Regulator ON
Shut Down
Internal High Voltage
Regulator
Y
Y
N
VCC >VCCOFF
Shut off the
Switching
Pulse
Y
Y
VCC
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