ACT518 - Active-Semi

ACT518
Rev 0, 13-Jun-14
ActiveQRTM Quasi-Resonant PWM Power Switch
conventional solutions and exceeds the latest
ES2.0 efficiency standard with good margin.
FEATURES
• Integrated Power MOSFET
ACT518 integrates comprehensive protection. In
case of over temperature, over voltage, short
winding, short current sense resistor, open loop an
d overload conditions, it would enter into auto
restart mode including Cycle-by-Cycle current
limiting.
• CCM and Quasi-Resonant Operation
• Adjustable up to 75kHz Switching Frequency
• Integrated Patented Frequency Foldback
Technique
•
•
•
•
Integrated Patented Line Compensation
•
•
•
•
Current Sense Resistor Short Protection
ACT518 is to achieve no overshoot and very short
rise time even with big capacitive load with the builtin fast and soft start process.
Built-in Soft-Start Circuit
OCP/OLP Protection
100mW Standby Power
In full load condition, ACT518 is able to be
designed to work in both CCM mode and DCM
mode to meet different types of applications. QuasiResonant (QR) operation mode can effectively
improve efficiency during DCM operation, and
reduce the EMI noise and further reduce the
components in input filter.
Complies with Global Energy Efficiency and
CEC Average Efficiency Standards
ACT518SH is for application up to 10 Watt and
ACT518DF is for application up to 18 Watt.
Line Under-Voltage, Thermal, Output Overvoltage, Output Short Protections
Transformer Short Winding Protection
• SOP-8 and DIP-7 Packages
Figure 1:
Simplified Application Circuit
APPLICATIONS
• Power Supplies for Portable Media Player,
DSCs, Set-top boxes, DVD players, records
• Adaptors for Small home appliances
• Auxiliary Power Supply for PC,LCD TV and
PDP TV
GENERAL DESCRIPTION
ACT518 is a high performance peak current mode
PWM power switch. It
applies ActiveQRTM
and frequency foldback technique to reduce EMI
and improve efficiency. Its maximum design
switching frequency is set at 75kHz. Very low
standby power, good dynamic response and
accurate voltage regulation is achieved with an
opto-coupler and the secondary side control circuit.
The Idle mode operation enables low standby
power of 100mW with small output voltage ripple.
By applying frequency foldback and ActiveQRTM
technology, The integrated power switch increases
the average system efficiency compared to
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Copyright © 2014 Active-Semi, Inc.
ACT518
Rev 0 , 13-Jun-14
ORDERING INFORMATION
PART NUMBER
TEMPERATURE RANGE
PACKAGE
PINS
PACKING
METHOD
ACT518SH-T
-40°C to 85°C
SOP-8
8
TUBE & REEL
ACT518SH
ACT518DF
-40°C to 85°C
DIP-7
7
TUBE
ACT518DF
TOP MARK
PIN CONFIGURATION
SOP-8
ACT518SH
DIP-7
ACT518DF
PIN DESCRIPTIONS
PIN
NAME
DESCRIPTION
1
CS
Current Sense Pin. Connect an external resistor (RCS) between this pin and ground to set peak
current limit for the primary switch.
2
FB
Feedback Pin. Connect this pin to optocouplers’s collector for output regulation.
3
VDET
Valley Detector Pin. Connect this pin to a resistor divider network from the auxiliary winding to
detect zero-crossing points for valley turn on operation.
4
VDD
Power Supply. This pin provides bias power for the IC during startup and steady state operation.
5,6
GND
Ground.
7,8
DRAIN
MOSFET Drain Pin.
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ACT518
Rev 0 , 13-Jun-14
ABSOLUTE MAXIMUM RATINGSc
PARAMETER
VALUE
UNIT
-0.3 to + 650
V
FB, CS, VDET to GND
-0.3 to + 6
V
VDD to GND
-0.3 to + 28
V
SOP-8
2
A
DIP-7
4
A
SOP-8
1.1
A
DIP-7
2.9
A
SOP-8
0.95
W
DIP-7
1.5
W
SOP-8
105
˚C/W
DIP-7
80
˚C/W
Operating Junction Temperature
-40 to 125
˚C
Storage Temperature
-55 to 150
˚C
300
˚C
DRAIN to GND
Continuous Drain Current, TC=25˚C
Continuous Drain Current, TC=100˚C
Maximum Power Dissipation
Junction to Ambient Thermal Resistance (θJA)
Lead Temperature (Soldering, 10 sec)
c: Do not exceed these limits to prevent damage to the device. Exposure to absolute maximum rating conditions for long periods.
ELECTRICAL CHARACTERISTICS
(VDD = 14V, LM = 1.3mH, RCS = 1.65Ω, VOUT = 5V, NP = 114, NS =9, NA =23, TA = 25°C, unless otherwise specified.)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Supply
VDD Turn-On Voltage
VDDON
VDD Rising from 0V
11.3
12.3
13.3
V
VDD Turn-Off Voltage
VDDOFF
VDD Falling after Turn-on
6.7
7.4
8.1
V
VDD Over Voltage Protection
VDDOVP
VDD Rising from 0V
25
VDD = 10V, before VDD Turn-on
8
Start Up Supply Current
IDDST
IDD Supply Current
IDD
V
15
µA
VDD = 15V, after VDD Turn-on ,FB
floating
0.6
mA
IDD Supply Current at Standby
IDDSTBY
FB = 1.3V
0.4
mA
IDD Supply Current at Fault
IDDFAULT
Fault mode, FB Floating
250
µA
Feedback
FB Pull up Resistor
RFB
15
kΩ
CS to FB Gain
ACS
3
V/V
3 + VBE
V
VFB at Max Peak Current
FB Threshold to Stop Switching
VFBBM1
1.32
V
FB Threshold to Start Switching
VFBBM2
1.41
V
4.2
V
320
ms
Output Overload Threshold
OverLoad/Over Voltage Blanking
Time
TOVBLANK
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Copyright © 2014 Active-Semi, Inc.
ACT518
Rev 0 , 13-Jun-14
ELECTRICAL CHARACTERISTICS CONT’D
(VDD = 14V, LM = 1.3mH, RCS = 1.65Ω, VOUT = 5V, NP = 114, NS =9, NA =23, TA = 25°C, unless otherwise specified.)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Power Mosfet
Drain Source Breakdown Voltage
BVDSS
Drain On Resistor
RDSON
VGS=0V,ID=250uA
650
VGS=10V,ID=1A,SOP-8
V
5.1
Ω
VGS=10V,ID=2A,DIP-7
3.6
Ω
Current Limit
CS Current Limit Threshold
Leading Edge Blanking Time
VCSLIM
0.91
0.96
1.01
V
TCSBLANK
240
300
360
ns
Oscillator
Maximum Switching Frequency
fMAX
Switching Frequency Foldback
fMIN
75
kHz
fMAX/3
kHz
75
%
100
mV
3.5
µs
1
µA
2
µs
CS Short Detection Threshold
0.115
V
CS Open Threshold Voltage
1.73
V
Abnormal OCP Blanking Time
150
ns
Thermal Shutdown Temperature
135
˚C
Maximum Duty Cycle
FB = 2.3V+VBE
DMAX
65
Valley Detection
ZCD Threshold Voltage
VDETTH
After valley detection time
window, if no valley detected, forcedly turn-on
main switch
Valley Detection Time Window
VDET Leakage Current
Protection
CS Short Waiting Time
Line UVLO
IVDETUVLO
0.1
mA
Line OVP
IVDETOVP
2
mA
VDET Over Voltage Protection
VDETVOOVP
2.448
2.72
2.992
V
VDET Vo Short Threshold
VDETVOshort
0.406
0.58
0.754
V
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Copyright © 2014 Active-Semi, Inc.
ACT518
Rev 0 , 13-Jun-14
FUNCTIONAL BLOCK DIAGRAM
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Copyright © 2014 Active-Semi, Inc.
ACT518
Rev 0 , 13-Jun-14
FUNCTIONAL DESCRIPTION
ACT518 is a high performance peak current mode
PWM integrated power IC. It includes the most
advance features that are required in the adaptor
applications up to 12 Watt. Unique fast startup,
frequency foldback, QR switching technique,
accurate peak current line compensation, Idle
mode, short winding protection, OCP, OTP, OVP
and UVLO are included in the controller.
reaction, the feedback voltage increases. When the
feedback voltage reaches VFBBM2, ACT518 start
switching again. Feedback voltage drops again and
output voltage starts to bounds back and forward
with very small output ripple. ACT518 leaves Idle
mode when load is added strong enough to pull
feedback voltage exceed VFBBM2.
Figure 2:
Idle Mode
Startup
Startup current of ACT518 is designed to be very
low so that VDD could be charged to VDDON
threshold level and device starts up quickly. A large
value startup resistor can therefore be used to
minimize the power loss yet reliable startup in
application. For a typical AC/DC adaptor with
universal input range design, two 1MΩ, 1/8 W
startup resistors could be used together with a VDD
capacitor(4.7uF) to provide a fast startup and yet
low power dissipation design solution.
During startup period, the IC begins to operate with
minimum Ippk to minimize the switching stresses
for the main switch, output diode and transformers.
And then, the IC operates at maximum power
output to achieve fast rise time. After this, VOUT
reaches about 90% VOUT , the IC operates with a
‘soft-landing’ mode(decrease Ippk) to avoid output
overshoot.
Vo 12V
Io
0A
Vfb
Vfb_olp
Vfb_fl
Vfbbm2
Vfbbm1
Ip Ilim
Ip_FL
t
Primary Inductor Current Limit
Compensation
The ACT518 integrates a primary inductor peak
current limit compensation circuit to achieve
constant OLP over wide line and wide inductance.
Constant Voltage (CV) Mode Operation
Frequency Foldback
In constant voltage operation, the ACT518
regulates its output voltage through secondary side
control circuit . The output voltage information is
sensed at FB pin through OPTO coupling. The error
signal at FB pin is amplified through TL431 and
OPTO circuit. When the secondary output voltage is
above regulation, the error amplifier output voltage
decreases to reduce the switch current. When the
secondary output voltage is below regulation, the
error amplifier output voltage increases to ramp up
the switch current to bring the secondary output
back to regulation. The output regulation voltage is
determined by the following relationship:
VOUTCV
R
= VREF _ TL 431 × (1 + F 1 )
RF 2
When the load drops to 75% of full load level,
ACT518 starts to reduce the switching frequency,
which is proportional to the load current ,to improve
the efficiency of the converter.
ACT518’s load adaptive switching frequency
enables applications to meet all latest green energy
standards. The actual minimum average switching
frequency is programmable with output
capacitance, feedback circuit and dummy load
(while still meeting standby power).
Valley Switching
ACT518 employed valley switching from no load to
heavy load to reduce switching loss and EMI. In
discontinuous mode operation, the resonant voltage
between inductance and parasitic capacitance on
MOSFET source pin is coupled by auxiliary winding
and reflected on VDET pin through feedback
network R6, R7. Internally, the VDET pin is
connected to an zero-crossing detector to generate
the switch turn on signal when the conditions are
met.
(1)
where RF1 (R13) and RF2 (R14) are top and bottom
feedback resistor of the TL431.
No Load Idle Mode
In no load standby mode, the feedback voltage falls
below VFBBM2 and reaches VFBBM1, ACT518 stop
switching. After it stops, as a result of a feedback
Innovative PowerTM
ActiveQRTM is a trademark of Active-Semi.
2A
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Copyright © 2014 Active-Semi, Inc.
ACT518
Rev 0 , 13-Jun-14
FUNCTIONAL DESCRIPTION CONT’D
Figure 3:
Valley Switching
V
Vdrain_gnd
DC voltage
Possible Valley turn on
Ton
t
T
Protection Features
The ACT518 provides full protection functions. The
following table summarizes all protection functions.
Auto-Restart Operation
ACT518 will enter into auto-restart mode when a
fault is identified. There is a startup phase in the
auto-restart mode. After this startup phase the
conditions are checked whether the failure is still
present. Normal operation proceeds once the
failure mode is removed. Otherwise, new startup
phase will be initiated again.
To reduce the power loss during fault mode, the
startup delay control is implemented. The startup
delay time increases over lines.
PROTECTION
FUNCTIONS
FAILURE
CONDITION
PROTECTION
MODE
VDD Over Voltage
VDD > 25V
(4 duty cycle)
Auto Restart
VVDET Over Voltage/No Voltage
VVD > 2.72V or
No switching
for 4 cycles
Auto Restart
Over Temperature
T > 135˚C
Auto Restart
Short Winding/
Short Diode
Over Load/Open
Loop
Output Short
Circuit
VDD Under Voltage
VCS > 1.72V
Auto Restart
IPK = ILIMIT or
VFB = 3.5V + VBE
for 320ms
Auto Restart
VDET < 0.58V
Auto Restart
VDD < 7.4V
Auto Restart
Innovative PowerTM
ActiveQRTM is a trademark of Active-Semi.
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www.active-semi.com
Copyright © 2014 Active-Semi, Inc.
ACT518
Rev 0 , 13-Jun-14
Figure 4:
Universal VAC Input, 5V/2A Output Adaptor
Innovative PowerTM
ActiveQRTM is a trademark of Active-Semi.
-8-
www.active-semi.com
Copyright © 2014 Active-Semi, Inc.
ACT518
Rev 0 , 13-Jun-14
Table 1:
ACT518 5V10W Bill of Materials
ITEM REFERENCE
DESCRIPTION
QTY
MANUFACTURER
IC, ACT518, SOP-8
1
Active-Semi
Capacitor, Electrolytic, 10µF/400V, 10 × 14mm
1
KSC
1
U1
2
C1,C2
3
C3
Capacitor, Ceramic,1000pF/500V,0805,SMD
1
POE
4
C4
Capacitor, Electrolytic, 6.8µF/35V, 5 × 11mm
1
KSC
5
C7,C6
Capacitor, Electrolytic, 470µF/10V, 10 × 11.5mm
2
KSC
6
C8
Capacitor, Ceramic, 0.33µF/50V,0805,SMD
1
POE
7
C9
Capacitor, Ceramic,100pF/100V,0805,SMD
1
POE
8
C5
Capacitor, Ceramic,1000pF/50V,0805,SMD
1
POE
9
BD1
Diode, Rectifier ,1000V1A, MB6S, DO-4
1
Good-Ark
10
D2,D4
Diode, Ultra Fast, RS1M,1000V/1.0A, SMD
2
Good-Ark
11
D3
Diode, Schottky, 45V/10A, SB1045S, DO-201
1
Good-Ark
12
L1
13
Bead1,2
14
L2
15
PCB1
16
F1
17
R1,2
18
R3
19
R11
20
R4,5,9
21
DM Inductor, 1.5mH, DR5
1
SoKa
T6*2*3, R5
2
SoKa
DM Inductor, 10µH, DR5
1
SoKa
PCB, L*W*T = 48.5х29х1.6mm, Cem-1, Rev:A
1
Jintong
Fusible, 1A/250V
1
TY-OHM
Chip Resistor, 1MΩ, 0805, 5%
2
TY-OHM
Carbon Resistor, 750kΩ, 1206, 5%
1
TY-OHM
Chip Resistor, 1.5kΩ, 0805, 5%
1
TY-OHM
Chip Resistor, 22Ω, 0805, 5%
3
TY-OHM
R6
Chip Resistor, 51.1kΩ, 0805, 1%
1
TY-OHM
22
R7
Chip Resistor, 11.1kΩ, 0805, 1%
1
TY-OHM
23
R8
Chip Resistor, 1.65Ω, 1206, 1%
1
TY-OHM
24
R9
Chip Resistor, 0.87Ω,1W, 1%
1
TY-OHM
25
R10
Chip Resistor, 200Ω, 0805, 5%
1
TY-OHM
26
R12
Chip Resistor, 3.3kΩ, 0805, 5%
1
TY-OHM
27
R13
Chip Resistor, 10.5Ω, 0805, 1%
1
TY-OHM
28
R14
Chip Resistor, 10kΩ, 0805, 1%
1
TY-OHM
29
R17
Chip Resistor, 12kΩ, 0805, 5%
1
TY-OHM
30
T1
Transformer, LP = 1.3mH, EE16
1
31
NTC
Thermistor, SC053
1
TY-OHM
32
TVS
Varistor, 10471
1
TY-OHM
33
CY1
Y capacitance, 2200pF/400V,Y1
1
SEC
34
U2
Opto-coupler, PC817C CTR = 200%
1
Sharp
35
U3
Voltage Regulator, TL431A, VREF = 2.5V
1
ST
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ACT518
Rev 0 , 13-Jun-14
TYPICAL PERFORMANCE CHARACTERISTICS
VDD ON/OFF Voltage vs. Temperature
Startup Supply Current (µA)
VDDON and VDDOFF (V)
11.5
10.5
9.5
8.5
VDDOFF
7.5
8
7
6
0
40
80
120
0
20
80
100
Supply Current at Idle/Fault Mode vs.
Temperature
Maximum Switching Frequency vs.
Temperature
0.3
Fault Mode
0
20
40
60
80
100
120
120
90
ACT518-004
ACT518-003
Idle Mode
0.2
80
70
60
0
20
Temperature (°C)
40
60
80
100
120
Temperature (°C)
VFB Threshold Voltage vs. Temperature
VCS Voltage vs. Temperature
VFB Threshold Voltage (V)
0.9
0.8
0.7
4
ACT518-006
5
ACT518-005
1.0
VCS Voltage (V)
60
Temperature (°C)
0.4
0.6
0
40
Temperature (°C)
Maximum Switching Frequency (KHz)
6.5
Supply Current (mA)
ACT518-002
VDDON
12.5
Startup Supply Current vs. Temperature
9
ACT518-001
13.5
OLP
3
Start Switching
2
Stop Switching
1
0
20
40
60
80
100
0
120
Temperature (°C)
Innovative PowerTM
ActiveQRTM is a trademark of Active-Semi.
20
40
60
80
100
120
Temperature (°C)
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ACT518
Rev 0 , 13-Jun-14
PACKAGE OUTLINE
SOP-8 PACKAGE OUTLINE AND DIMENSIONS
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ActiveQRTM is a trademark of Active-Semi.
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Copyright © 2014 Active-Semi, Inc.
ACT518
Rev 0 , 13-Jun-14
PACKAGE OUTLINE
DIP-7 PACKAGE OUTLINE AND DIMENSIONS
Active-Semi, Inc. reserves the right to modify the circuitry or specifications without notice. Users should evaluate each
product to make sure that it is suitable for their applications. Active-Semi products are not intended or authorized for use
as critical components in life-support devices or systems. Active-Semi, Inc. does not assume any liability arising out of
the use of any product or circuit described in this datasheet, nor does it convey any patent license.
Active-Semi and its logo are trademarks of Active-Semi, Inc. For more information on this and other products, contact
[email protected] or visit http://www.active-semi.com.
is a registered trademark of Active-Semi.
Innovative PowerTM
ActiveQRTM is a trademark of Active-Semi.
- 12 -
www.active-semi.com
Copyright © 2014 Active-Semi, Inc.