MP4030
TRIAC-Dimmable, Primary-Side-Control
Offline LED Controller with Active PFC
The Future of Analog IC Technology
DESCRIPTION
The MP4030 is a TRIAC-dimmable, primary-sidecontrol, offline LED lighting controller with active
PFC. It can output an accurate LED current for
an isolated lighting application with a single-stage
converter. The proprietary real-current-control
method can accurately control the LED current
using primary-side information. It can significantly
simplify LED lighting system design by
eliminating secondary-side feedback components
and the optocoupler.
The MP4030 implements power-factor correction
and works in boundary-conduction mode to
reduce MOSFET switching losses.
The MP4030 has an integrated charging circuit at
the supply pin for fast start-up without a
perceptible delay.
The proprietary dimming contraol expands the
TRIAC-based dimming range.
The MP4030 has multiple protections that greatly
enhance system reliability and safety, and
include over-voltage protection, short-circuit
protection, programmable primary-side overcurrent protection, supply-pin under-voltage
lockout, and over-temperature protection.
FEATURES
Primary-Side-Control without Requiring a
Secondary-Side Feedback Circuit
Internal Charging Circuit at the Supply Pin for
Fast Start-Up
Accurate Line Regulation
High Power Factor
Flicker-Free, Phase-Controlled TRIAC
Dimming with Expanded Dimming Range.
Operates in Boundary Conduction Mode
Cycle-by-Cycle Current Limit
Programmable Primary-Side Over-Current
Protection
Over-Voltage Protection
Short-Circuit Protection
Over-Temperature Protection
Available in an 8-Pin SOIC Package
APPLICATIONS
Solid-State Lighting, including:
Industrial and Commercial Lighting
Residential Lighting
All MPS parts are lead-free and adhere to the RoHS directive. For MPS green
status, please visit MPS website under Products, Quality Assurance page.
“MPS” and “The Future of Analog IC Technology” are registered trademarks of
Monolithic Power Systems, Inc.
All fault protections feature auto-restart.
The MP4030 is available in an 8-pin SOIC
package.
MP4030 Rev.1.02
4/16/2013
www.MonolithicPower.com
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1
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
TYPICAL APPLICATION
N:1
TRIAC
Dimmer
EMI
Filter
Damper
&
Bleeder
MP4030
1
MP4030 Rev.1.02
4/16/2013
MULT
COMP
ZCD
GND
VCC
D
DP
S
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2
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
ORDERING INFORMATION
Part Number*
Package
SOIC8
MP4030GS
Top Marking
MP4030
* For Tape & Reel, add suffix –Z (e.g. MP4030GS–Z);
PACKAGE REFERENCE
TOP VIEW
MULT
1
8
COMP
ZCD
2
7
GND
VCC
3
6
D
DP
4
5
S
SOIC8
(4)
ABSOLUTE MAXIMUM RATINGS (1)
Thermal Resistance
VCC Pin Voltage ...........................-0.3V to +30V
Low-Side MOSFET Drain Voltage -0.7V to +30V
ZCD Pin Voltage ................................-8V to +7V
Other Analog Inputs and Outputs .....-0.3V to 7V
ZCD Pin Current ..........................-5mA to +5mA
Continuous Power Dissipation
(TA = +25°C) (2)
SOIC8 ........................................................ 1.3W
Junction Temperature ...............................150°C
Lead Temperature ....................................260°C
Storage Temperature............... -65°C to +150°C
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
operation conditions.
4) Measured on JESD51-7 4-layer board.
VCC Pin Voltage ...............................11V to 27V
Operating Junction Temp (TJ).. -40C to +125C
MP4030 Rev.1.02
4/16/2013
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3
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
ELECTRICAL CHARACTERISTICS
TA = +25°C, unless otherwise noted.
Parameter
Supply Voltage
Symbol
Operating Range
VCC
VCC Upper Level: Internal
Charging Circuit Stops and IC
Turns On
VCC Lower Level: Internal
Charging Circuit Triggers
VCC Re-charge and IC turns off
Level in Fault Condition
Supply Current
VCC Charging Current from D
Quiescent Current
Quiescent Current at Fault
Operating Current
Condition
Min
After turn on
10
Typ
Max
Units
27
V
VCCH
9.5
10
10.5
V
VCCL
8.55
9
9.45
V
Fault condition
6.55
7
7.45
V
VD=16V, VCC=5V
12.5
15
17.5
mA
800
1000
µA
220
300
µA
1
2
mA
3
V
VCCEN
ID_Charge
IQ
IQ_Fault
Icc
No switching, VCC=15V
Fault condition, IC
latch,VCC=15V
fs =70kHz, VCC=15V
180
Multiplier
Linear Operation Range
VMULT
(5)
Gain
K
VCOMP from 1.9V to 4.9V
0
VCOMP=2V, VMULT=0.5V
0.84
1.06
1.26
1/V
VCOMP=2V, VMULT=1.5V
0.9
1.08
1.23
1/V
VCOMP=2V, VMULT=3V
0.93
1.1
1.25
1/V
TRIAC Dimming OFF Detection
Threshold
TRIAC Dimming ON Detection
Threshold
VMUL_OFF
0.13
0.15
0.17
V
VMUL_ON
0.32
0.35
0.38
V
TRIAC Dimming OFF Line-Cycle
Blanking Ratio
DOFF_LEB
Dimming Pull-Down MOSFET
Turn-ON Threshold
VMULT_DP_ON
Dimming Pull down MOSFET
Turn-OFF Delay Time
tDP_OFF_Delay
25%
starts at the rising edge
of VMULT=VMULT_ON
0.22
0.25
0.28
V
150
200
250
µs
0.386
0.4
0.414
V
Error Amplifier
Reference Voltage
VREF
Transconductance
GEA
Guaranteed by design
250
µA/V
COMP Lower Clamp Voltage
VCOMPL
Max. Source Current
ICOMP+
57
µA
Max. Sink Current without
Dimmer
Sink Current at TRIAC Dimming
Off
ICOMP-
-300
µA
Short-Circuit Detect Threshold
MP4030 Rev.1.02
4/16/2013
1.85
1.9
1.95
V
ISink_Dim
63
70
77
µA
VCOMP_SCP
4.85
5
5.15
V
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4
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
ELECTRICAL CHARACTERISTICS (continued)
TA = +25°C, unless otherwise noted.
Parameter
Symbol
Condition
Min
Typ
Max
Units
Current Sense Comparator
Leading Edge Blanking Time
tLEB
575
685
795
ns
Current Sense Upper Clamp
Voltage
VS_Clamp_H
2.2
2. 3
2.4
V
Current Sense Lower Clamp
Voltage
VS_Clamp_L
0.08
0.1
0.12
V
0.32
0.35
0.37
V
520
550
580
mV
1.8
2.5
3.1
µs
5.2
5.5
5.8
V
1.5
2
2.5
µs
0.81
0.9
0.99
V
575
685
795
ns
Zero-Current Detector
Zero-Current–Detect Threshold
VZCD_T
Zero-Current–Detect Hystestic
VZCD_HY
Zero-Current–Detect LEB
tZCD_LEB
Over-Voltage Threshold
VZCD_OVP
OVP Detect LEB
tOVP_LEB
Over-Current Threshold
VZCD_OCP
OCP Blanking Time
tLEB_OCP
Minimum Off Time
tOFF_MIN
4.2
5.6
7
µs
Tstart
90
115
140
µs
Falling Edge
Starts at Gate Turn Off
Starts at Gate Turn Off
Starts at Gate Turn On
Starter
Start Timer Period
Internal Main MOSFET
Breakdown Voltage
BVDSS_Main VGS=0
30
Drain-Source On-Resistor
RDS(ON) _Main ID=100mA
200
V
250
300
mΩ
Internal Dimming Pull Down MOSFET
Breakdown Voltage
BVDSS_DP
Drain-Source On-Resistor
RDS(ON) _DP ID=50mA
VGS=0
30
22
V
26
30
Ω
Notes:
5) The multiplier output is given by: Vs=K•VMULT• (VCOMP-1.5)
MP4030 Rev.1.02
4/16/2013
www.MonolithicPower.com
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© 2013 MPS. All Rights Reserved.
5
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
PIN FUNCTIONS
Pin #
Name
1
MULT
2
ZCD
3
VCC
4
DP
5
S
6
D
7
GND
8
COMP
MP4030 Rev.1.02
4/16/2013
Pin Function
One of the Internal Multiplier Input. Connect to the tap of resistor divider from the rectified
voltage of the AC line. The half-wave sinusoid signal to this pin provides a reference signal
for the internal current control loop. The MULT pin also detects the TRIAC dimming phase.
Zero-Current Detection. A negative going edge triggers the internal MOSFET’s turn-on
signal. Connect to the tap of a resistor divider from the auxiliary winding to GND. The ZCD
pin can also detect over-voltage and over-current conditions. Over-voltage occurs if VZCD
exceeds the over-voltage-protection (OVP) threshold after a 2µs blanking time when the
internal MOSFET turns off. Over-current occurs if VZCD exceeds 0.9V during the gate-on
interval after the leading edge blanking time
Supply Voltage. Supplies power for both the control signal and the internal MOSFET’s gate
driver. Connect to an external bulk capacitor—typically 22µF with a 100pF ceramic
capacitor to reduce noise.
Dimming Pull-Down. Drain of the internal dimming pull-down MOSFET. Connect a resistor
from this pin to the D pin to pull down the rectified input voltage during the TRIAC dimming
OFF interval.
Internal Low-Side main MOSFET Source. Connect a resistor from this pin to GND to sense
the internal MOSFET current. An internal comparator compares the resulting voltage to the
internal sinusoid shaped current reference signal to determine when the MOSFET turns off.
If the voltage exceeds the current-limit threshold of 2.3V after the leading edge blanking
time during the turn-on interval, the gate signal turns off.
Internal Low-Side main MOSFET Drain. This pin also internally connects to VCC via a diode
and a JFET to form an internal charging circuit for VCC. Connect to the source of the highside MOSFET.
Ground. Current return of the control signal and the gate drive signal.
Loop Compensation. Connects to a compensation network to stabilize the LED driver and
accurately control the LED driver current. The COMP pin can also monitor for short-circuit
conditions: if the COMP voltage rises above 5V, the short-circuit protection triggers.
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6
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
TYPICAL PERFORMANCE CHARACTERISTICS
VIN =120VAC, 7 LEDs in series, IO=350mA, VO=22V, Lm=1.6mH, NP:NS:NAUX =82:16:19, TRIAC
dimmable.
MP4030 Rev.1.02
4/16/2013
www.MonolithicPower.com
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7
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN =120VAC, 7 LEDs in series, IO=350mA, VO=22V, Lm=1.6mH, NP:NS:NAUX =82:16:19, TRIAC
dimmable.
Performance Data
Vin (VAC)
108V
120V
132V
Pin (W)
9.58W
9.54W
9.47W
PF
0.993
0.99
0.982
THD
7.00%
9.50%
11.60%
Io (A)
0.36A
0.364A
0.364A
Vo (V)
21.62V
21.65V
21.64V
Efficiency
81.20%
82.60%
83.10%
MP4030 Rev.1.02
4/16/2013
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8
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN =230VAC, 10 LEDs in series, IO=530mA, VO=30V, Lm=2.15mH, NP:NS:NAUX =145:29:19, TRIAC
dimmable, with ripple suppressor, refer to Figure 20.
MP4030 Rev.1.02
4/16/2013
www.MonolithicPower.com
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9
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VIN =230VAC, 10 LEDs in series, IO=530mA, VO=30V, Lm=2.15mH, NP:NS:NAUX =145:29:19, TRIAC
dimmable, with ripple suppressor, refer to Figure 20.
MP4030 Rev.1.02
4/16/2013
www.MonolithicPower.com
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10
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
FUNCTION DIAGRAM
N:1
TRIAC
Dimmer
Damper
&
Bleeder
EMI
Filter
F
MULT
TRIAC
Phase
Detector
D
PWM /
PFC
Gate
Driver
Control
Multiplier
Current control
COMP
Current
Sense
S
Current
LImit
Real Current
Calculation
Gate
control
Latch off
and
counting
UVLO/
EN
VCC
Power Supply
DP
Protection
OVP
OCP
OTP
GND
Zero Current
Detection
ZCD
Zero current detection
Figure 1: Functional Block Diagram
MP4030 Rev.1.02
4/16/2013
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11
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
OPERATION
The MP4030 is a TRIAC-dimmable, primary-sidecontrol, offline LED controller designed for highperformance LED lighting. The MP4030 can
accurately control the LED current using the realcurrent-control method based on primary-side
information. It can also achieve a high power
factor to eliminate noise pollution on the AC line.
The integrated VCC charging circuit can achieve
fast start-up without any perceptible delay. The
MP4030 is suitable for TRIAC-based dimming
with an extended dimming range.
Boundary-Conduction Mode
During the external MOSFET ON time (tON), the
rectified input voltage applied across the primaryside inductor (Lm) increases the primary current
increases linearly from zero to the peak value
(IPK). When the external MOSFET turns off, the
energy stored in the inductor forces the
secondary side diode to turn on, and the inductor
current decreases linearly from the peak value to
zero. When the current decreases to zero, the
parasitic resonance caused by the inductor and
the combined parasitic capacitances decreases
the MOSFET drain-source voltage that is also
reflected on the auxiliary winding (see Figure 2).
The zero-current detector generates the external
MOSFET turn-on signal when the ZCD voltage
falls below 0.35V after a blanking time and
ensures the MOSFET turns on at a relatively low
voltage (see Figure 3).
VDS
VAC Line + N V OUT
Turn ON
VAC Line
Auxiliary Winding
+
Vcc
RZCD1
ZCD
0.35V
RZCD2
CZCD
Figure 3: Zero-Current Detector
As a result, there are virtually no primary switch
turn-on losses and no secondary-diode reverserecovery losses. This ensures high efficiency and
low EMI noise.
Real-Current-Control
The proprietary real-current-control method
allows the MP4030 to control the secondary-side
LED current based on primary-side information.
The output LED mean current can be calculated
approximately as:
IO
N VFB
2 RS
Where:
N is the turn ratio of the primary side to the
secondary side,
VFB is the feedback reference voltage
(typically 0.4), and
RS is the sense resistor between the
MOSFET source and GND.
Power-Factor Correction
IP
Inductor
current
IS /N
t ON
t OFF
VZCD
0
Figure 2: Boundary-Conduction Mode
MP4030 Rev.1.02
4/16/2013
The MULT pin connects to the tap of a resistor
divider from the rectified instantaneous line
voltage. The multiplier output also has a
sinusoidal shape. This signal provides the
reference for the current comparator against the
primary-side–inductor current, which shapes the
primary-peak current into a sinusoid with the
same phase as the input line voltage. This
achieves a high power factor.
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12
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
Multiplier Output
Vcc
Auxiliary Winding Takes Charge
And Regulates the VCC
Fault happens
Inductor Current
10V
9V
7V
Internal
Charging Circuit
Figure 4: Power-Factor Correction
The multiplier’s maximum output voltage to the
current comparator is clamped to 2.3V to limit the
cycle-by-cycle current. The multiplier’s minimum
output voltage is clamped to 0.1 to ensure a turnon signal during the TRIAC dimming OFF interval,
which pulls down the rectifier input voltage and
accurately detects the dimming phase.
VCC Timing Sequence
Initially, VCC is charged through the internal
charging circuit from the AC line. When VCC
reaches 10V, the internal charging circuit stops
charging, the control logic initializes and the
internal main MOSFET begins to switch. Then
the auxiliary winding takes over the power supply.
However, the initial auxiliary-winding positive
voltage may not be large enough to charge VCC,
causing VCC to drop. Instead, if the VCC drops
below the 9V threshold, the internal charging
circuit triggers and charges VCC to 10V again.
This cycle repeats until the auxiliary winding
voltage is high enough to power VCC.
If any fault occurs during this time, the switching
and the internal charging circuit will stop and
latch, and VCC drops. When VCC decreases to 7V,
the internal charging circuit re-charges for autorestart.
Gate
Switching Pulses
Figure 5: VCC Timing Sequence
Auto Start
The MP4030 includes an auto starter that starts
timing when the MOSFET turns off. If ZCD fails
to send a turn-on signal after 122µs, the starter
will automatically sends a turn-on signal to avoid
unnecessary Ic shutdowns if ZCD fails.
Minimum OFF Time
The MP4030 operates with a variable switching
frequency; the frequency changes with the
instantaneous input-line voltage. To limit the
maximum frequency and get good EMI
performance, the MP4030 employs an internal
minimum OFF-time limiter of 5.6µs, as shown in
Figure 6.
ZCD
GATE
5.6us
Figure 6: Minimum OFF time
MP4030 Rev.1.02
4/16/2013
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13
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
Leading-Edge Blanking
In order to avoid premature switching-pulse
termination due to the parasitic capacitances
discharging when the MOSFET turns on, an
internal leading-edge blanking (LEB) unit
between the S pin and the current-comparator
input blocks the path from the S pin to the current
comparator input during the blanking time. Figure
7 shows the leading-edge blanking.
Auxiliary Winding
+
Vcc
1
ZCD
OVP
signal
Latch
2
VS
Blanking
TLEB=685nS
Figure 8: OVP Sampling Circuit
To avoid switch-on spikes mis-triggering OVP,
OVP sampling has a tOVPS blanking period of
around 2µs, as shown in Figure 9.
t
VZCD
Sampling Here
Figure 7: Leading-Edge Blanking
Output Over-Voltage Protection (OVP)
Output over-voltage protection (OVP) prevents
component damage from over-voltage conditions.
The auxiliary winding voltage’s positive plateau is
proportional to the output voltage, and the OVP
monitors this auxiliary winding voltage instead of
directly monitoring the output voltage as shown in
Figure 8. Once the ZCD pin voltage exceeds
5.5V, the OVP signal triggers and latches, the
gate driver turns off, and the IC enters quiescent
mode. When the VCC drops below the UVLO
threshold, the IC shuts down and the system
restarts. The output OVP set point can be
calculated as:
VOUT_OVP
NAUX
R ZCD2
5.5V
NSEC R ZCD1 R ZCD2
Where:
VOUT_OVP is the output OVP threshold,
0V
T OVPS
Figure 9: ZCD Voltage and OVP Sampling
Output Short-Circuit Protection (SCP)
In the event of an output short-circuit, the COMP
voltage rises. When the voltage reaches 5V, the
IC will shut down and restart until VCC drops
below UVLO.
Primary Over-Current Protection (OCP)
The ZCD pin has an internally-integrated
comparator for primary OCP. When the gate is
on, the comparator is enabled. Over-current
occurs when VZCD exceeds 0.9V after a blanking
time. Then the IC shuts down and restarts until
VCC dropping below UVLO. Figure 10 shows ZCD
OCP.
NAUX is the number of auxiliary winding turns, and
NSEC is the number of secondary winding turns
MP4030 Rev.1.02
4/16/2013
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14
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
Ip
Latch
ZCD
OCP
signal
R1
LEB
RS
0.9V
R2
Gate
Figure 10: ZCD Over-Current Protection Circuit
Thermal Shutdown
To prevent internal temperatures from exceeding
150°C and causing lethal thermal damage, the
MP4030 shuts down the switching cycle and
latched until VCC dropping below UVLO and
restarts again.
The MP4030 detects the dimming turn-on cycle
through the MULT pin, which is fed into the
control loop to adjust the internal reference
voltage. When the MULT voltage exceeds 0.35V,
the device treats this signal as a dimmer turn-on
signal. When the MULT voltage falls below 0.15V,
the system treats this as a dimmer turn-off signal.
The MP4030 has a 25% line-cycle–detection
blanking time with each line cycle, The real
phase detector output adds this time, as shown
in Figure 12. That means if the turn-on cycle
exceeds 75% of the line cycle, the output
remains at the same maximum current. It
improves the line regulation during the maximum
TRIAC turn-on cycle or without a dimmer.
TRIAC-Based Dimming Control
The MP4030 can implement TRIAC-based
dimming. The TRIAC dimmer usually consists of
a bi-directional SCR with an adjustable turn-on
phase. Figure 11 shows the leading-edge TRIAC
dimmer waveforms.
Figure 12: Dimming Turn-On Cycle Detector
Input line
voltage before
TRIAC dimmer
Line voltage
after TRIAC
dimmer
Rectified line
voltage
Dimmer
turn on
phase
If the turn-on cycle decreases to less than 75% of
the line cycle, the internal reference voltage
decreases as the dimming turn-on phase
decreasing, and the output current decreases
accordingly to implement dimming. As the
dimming turn-on cycle decreases, the COMP
voltage also decreases. Once the COMP voltage
reaches to 1.9V, it is clamped so that the output
current decreases slowly to maintain the TRIAC
holding current and avoid random flicker. Figure
13 shows the relationship between the dimming
turn-on phase and output current.
Line cycle
Figure 11: TRIAC Dimmer Waveforms
MP4030 Rev.1.02
4/16/2013
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15
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
Io
VCOMP
Dimming Pull-Down MOSFET
The DP MOSFET turns on when the MULT
decreases to 0.25V. Connect a resistor to the D
pin to provide the pull-up current during the
dimming turn-off interval, and pull down the
rectified line voltage to zero quickly to avoid any
mis-detection on the MULT pin.
30%
75%
100%
TRIAC dimming turn on cycle
Figure 13: Dimming Curve
MP4030 Rev.1.02
4/16/2013
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16
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
RIPPLE SUPPRESSOR
(Innovative Proprietary)
For dimming LED lighting application, a single
stage PFC converter needs large output
capacitor to reduce the ripple whose frequency is
double of the Grid. And in deep dimming situation,
the LED would shimmer caused by the dimming
on duty which is not all the same in every line
cycle. What’s more, the Grid has noise or inrush
which would bring out shimmer even flicker.
Figure 14 shows a ripple suppressor, which can
shrink the LED current ripple obviously.
and the Zener voltage of DZ is as small as
possible when guarantee VD VDZ 0.5 VCO _PP .
Optional Protection Circuit
In large output voltage or large LEDs current
application, MOSFET M may be destroyed by
over-voltage or over-current when LED+ shorted
to LED- at working.
Gate-Source(GS) Over-voltage Protection:
DO
NS
D
RO
+ R
CO
C
M
DG
DZ RG
+
Figure 15: Gate-Source OVP Circuit
Figure14: Ripple Suppressor
Principle:
Shown in Figure 14, Resister R, capacitor C, and
MOSFET M compose the ripple suppressor.
Through the RC filter, C gets the mean value of
the output voltage VCo to drive the MOSFET M. M
works in variable resistance area. C’s voltage VC
is steady makes the LEDs voltage is steady, so
the LEDs current will be smooth. MOSFET M
holds the ripple voltage vCo of the output.
Diode D and Zener diode DZ are used to restrain
the overshoot at start-up. In the start-up process,
through D and DZ, C is charged up quickly to turn
on M, so the LED current can be built quickly.
When VC rising up to about the steady value, D
and DZ turn off, and C combines R as the filter to
get the mean voltage drop of VCo.
The most important parameter of MOSFET M is
the threshold voltage Vth which decides the
power loss of the ripple suppressor. Lower Vth is
better if the MOSFET can work in variable
resistance area. The BV of the MOSFET can be
selected as double as VCo and the Continues
Drain current level can be selected as decuple as
the LEDs’ current at least.
About the RC filter, it can be selected
by RC 50 / fLineCycle . Diode D can select 1N4148,
MP4030 Rev.1.02
4/16/2013
Figure 15 shows GS over-voltage protection
circuit. Zener diode DG and resistor RG are used
to protect MOSFET M from GS over-voltage
damaged. When LED+ shorted to LED- at normal
operation, the voltage drop on capacitor C is high,
and the voltage drop on Gate-Source is the same
as capacitor C. The Zener diode DG limits the
voltage VGS and RG limits the charging current to
protect DG. RG also can limit the current of DZ at
the moment when LED+ shorted to LED-. VDG
should bigger than Vth.
Drain-Source Over-voltage and Over-current
Protection
As Figure 16 shows, NPN transistor T, resistor
RC and RE are set up to protect MOSFET M from
over-current damaged when output short occurs
at normal operation. When LED+ shorted to LED-,
the voltage vDS of MOSFET is equal to the vCo
which has a high surge caused by the parasitic
parameter. Zener Dioder DDS protects MOSFET
from over-voltage damaged. Transistor T is used
to pull down the VGS of M. When M turns off, the
load is opened, MP4030 detects there is an OVP
happened, so the IC functions in quiescent. The
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© 2013 MPS. All Rights Reserved.
17
MP4030—PRIMARY-SIDE-CONTROL, OFFLINE LED CONTROLLER WITH PFC
pull
down
point
is
set
by
RC
and
V
RE: RC /RE CO 0.7V .
2
MOSFET LIST
In the Table 1, there are some recommended
MOSFET for ripple suppressor.
RC DDS RE
T
DO
NS
RO
D M
+ R
CO
C
DZ
RG
+
Figure 16: Drain-Source OVP and OCP Circuit
Manufacture P/N
Si4446DY
FTD100N10A
P6015CDG
MP4030 Rev.1.02
4/16/2013
Manufacture
Vishay
IPS
NIKO-SEM
Table 1: MOSFET LIST
VDS/ID
Vth(VDS=VGS@TJ=25°C)
40V/3A
0.6-1.6V@ Id=250μA
100V/17A
1.0-2.0V@ Id=250μA
150V/20A
0.45-1.20V@ Id=250μA
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© 2013 MPS. All Rights Reserved.
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