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NCL30000
Power Factor Corrected
Dimmable LED Driver
The NCL30000 is a switch mode power supply controller intended
for low to medium power single stage power factor (PF) corrected
LED Drivers. The device is designed to operate in critical conduction
mode (CrM) and is suitable for flyback as well as buck topologies.
Constant on time CrM operation is particularly suited for isolated
flyback LED applications as the control scheme is straightforward and
very high efficiency can be achieved even at low power levels. These
are important in LED lighting to comply with regulatory requirements
and meet overall system luminous efficacy requirements. In CrM, the
switching frequency will vary with line and load and switching losses
are low as recovery losses in the output rectifier are negligible since
the current goes to zero prior to reactivating the main MOSFET
switch.
The device features a programmable on time limiter, zero current
detect sense block, gate driver, trans-conductance error amplifier as
well as all PWM control circuitry and protection functions required to
implement a CrM switch mode power supply. Moreover, for high
efficiency, the device features low startup current enabling fast, low
loss charging of the VCC capacitor. The current sense protection
threshold has been set at 500 mV to minimize power dissipation in the
external sense resistor. To support the environmental operation range
of Solid State Lighting, the device is specified across a wide junction
temperature range of −40C to 125C.
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SOIC−8
CASE 751
PIN CONNECTION
MFP
Comp
Ct
CS
(Top View)
MARKING DIAGRAM
8
1
Features
VCC
DRV
GND
ZCD
Very Low 24 mA Typical Startup Current
Constant On Time PWM Control
Cycle-by-Cycle Current Protection
Low Current Sense Threshold of 500 mV
Low 2 mA Typical Operating Current
Source 500 mA/Sink 800 mA Totem Pole Gate Driver
Reference Design for TRIAC and Trailing Edge Line Dimmers
Wide Operating Temperature Range
No Input Voltage Sensing Requirement
Enable Function and Overvoltage Protection
These Devices are Pb-Free, Halogen Free/BFR Free and are RoHS
Compliant
A
L
Y
W
G
L0000
ALYW
G
= Assembly Location
= Wafer Lot
= Year
= Work Week
= Pb-Free Package
ORDERING INFORMATION
Device
Package
Shipping†
NCL30000DR2G
SOIC−8
(Pb−Free)
2,500/Tape & Reel
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specifications
Brochure, BRD8011/D.
Typical Applications
LED Driver Power Supplies
LED Based Down Lights
Commercial and Residential LED Fixtures
TRIAC Dimmable LED Based PAR Lamps
Power Factor Corrected Constant Voltage Supplies
Semiconductor Components Industries, LLC, 2012
September, 2012 − Rev. 1
1
Publication Order Number:
NCL30000/D
NCL30000
OVP
+
−
+
VOVP
UVP
−
+
+
VUVP
(Enable EA)
E/A −
+
MFP
gm
+
RMFP
VREF
Fault
COMP
VControl
VEAH
Clamp
mVDD
VDD
Power Good
VDD
PWM
275 mA*
−
+
Add Ct
Offset
Ct
S Q
DRV
CS
VCC
VCC
Management
LEB
195 ns*
+
OCP
R Q
−
+
VCC
VILIM
+
ZCD
+
S Q
−
VZCD(ARM)
+
+
−
VZCD(TRIG)
Demag
R Q
R Q
Reset
mVDD
180 ms*
S Q
Off Timer
R Q
ZCD
Clamp
* Typical Values Shown
DRV
S Q
All SR Latches are Reset Dominant
Figure 1. Block Diagram
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2
GND
NCL30000
Table 1. PIN FUNCTION DESCRIPTION
Pin
Name
Function
1
MFP
The multi-function pin is connected to the internal error amplifier. By pulling this pin below the Vuvp threshold, the
controller is disabled. In addition, this pin also has an over voltage comparator which will disable the controller in the
event of a fault.
2
COMP
The COMP pin is the output of the internal error amplifier. A compensation network is connected between this pin
and ground to set the loop bandwidth. Normally this bandwidth is set at a low frequency (typically 10 Hz − 20 Hz) to
achieve high power factor and low total harmonic distortion (THD).
3
Ct
The Ct pin sources a regulated current to charge an external timing capacitor. The PWM circuit controls the power
switch on time by comparing the Ct voltage to an internal voltage derived from VControl. The CT pin discharges the
external timing capacitor at the end of the on time cycle.
4
CS
The CS input is used to sense the instantaneous switch current in the external MOSFET. This signal is filtered by an
internal leading edge blanking circuit.
5
ZCD
The voltage of an auxiliary zero current detection winding is sensed at this pin. When the ZCD control block circuit
detects that the winding has been demagnetized, a control signal is sent to the gate drive block to turn on the
external MOSFET.
6
GND
This is the analog ground for the device. All bypassing components should be connected to the GND pin with a short
trace length.
7
DRV
The high current capability of the totem pole gate drive (+0.5/−0.8 A) makes it suitable to effectively drive high gate
charge power MOSFETs. The driver stage provides both passive and active pull down circuits that force the output to
a voltage less than the turn-on threshold voltage of the power MOSFET when VCC(on) is not reached.
8
VCC
This pin is the positive supply of the controller. The circuit starts to operate when VCC exceeds VCC(on), nominally
12 V and turns off when VCC goes below VCC(off), typically 9.5 V. After startup, the operating range is 10.2 V up to
20 V.
AC
Line
Input
Ï
D out
EMI
FILTER
C in
R SU
Ra
Ï
Ï
D1
Cv
8
R ZCD
NCL30000
1
MFP
VCC
8
2
COMP
DRV
7
3
CT
GND
6
Q1
C1
R2
Rx
Ï
ÏÏ
ÏÏ
VCC
RL
R1
Rb
OUT2
7
+
−
IN2+ 5
IN2− 6
Rt
NCS1002
OUT1
1
2
− IN1−
+
IN1+ 3
Ccomp
GND
Cc
4
CS
ZCD
Ry
4
5
C tim
C OUT
Rc
R CS
Figure 2. Simplified Flyback Application with Secondary side Constant Current Control
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3
RLED
NCL30000
Overview
the power switch is on for the same length of time over a half
cycle of input power. The current in the primary of the
transformer starts at zero each switching cycle and is directly
proportional to the applied voltage times the on-time.
Therefore with a fixed on-time, the current will follow the
applied voltage generating a current of the same shape. Just
as in a traditional boost PFC circuit, the control bandwidth
is low so that the on-time is constant throughout a single line
cycle. The feedback signal from the secondary side is used
to modify the average on-time so the current through the
LEDs is properly regulated regardless of forward voltage
variation of the LED string.
Figure 2 illustrates how the NCL30000 is configured to
implement an isolated power factor corrected flyback
switch mode power supply. On the secondary side is the
NCS1002, a constant voltage, constant current controller
which senses the average LED current and the output
voltage and provides a feedback control signal to the
primary side through an opto-coupler interface. One of the
key benefits of active power factor correction is that it makes
the load appear like a linear resistance similar to an
incandescent bulb. High power factor requires generally
sinusoidal line current and minimal phase displacement
between the line current and voltage. The NCL30000
operates in a fixed on-time variable frequency mode where
Table 2. MAXIMUM RATINGS
Rating
Symbol
Value
Unit
MFP Voltage
VMFP
−0.3 to 10
V
MFP Current
IMFP
10
mA
COMP Voltage
VControl
−0.3 to 6.5
V
COMP Current
IControl
−2 to 10
mA
Ct Voltage
VCt
−0.3 to 6
V
Ct Current
ICt
10
mA
CS Voltage
VCS
−0.3 to 6
V
CS Current
ICS
10
mA
VZCD
−0.3 to 10
V
ZCD Voltage
ZCD Current
IZCD
10
mA
DRV Voltage
VDRV
−0.3 to VCC
V
IDRV(sink)
800
mA
IDRV(source)
500
mA
VCC
−0.3 to 20
V
ICC
20
mA
PD
450
DRV Sink Current
DRV Source Current
Supply Voltage
Supply Current
Power Dissipation (TA = 70C, 2.0 Oz Cu, 55
mm2
Printed Circuit Copper Clad)
Thermal Resistance Junction-to-Ambient
(2.0 Oz Cu, 55 mm2 Printed Circuit Copper Clad)
Junction-to-Air, Low conductivity PCB (Note 3)
Junction-to-Air, High conductivity PCB (Note 4)
Operating Junction Temperature Range
Maximum Junction Temperature
Storage Temperature Range
Lead Temperature (Soldering, 10 s)
mW
C/W
RqJA
RqJA
RqJA
178
168
127
TJ
−40 to 125
C
TJ(MAX)
150
C
TSTG
−65 to 150
C
TL
300
C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
1. This device series contains ESD protection and exceeds the following tests:
Pins 1–8: Human Body Model 2000 V per JEDEC Standard JESD22−A114E.
Pins 1– 8:Machine Model Method 200 V per JEDEC Standard JESD22−A115−A.
2. This device contains Latch-up protection and exceeds 100 mA per JEDEC Standard JESD78.
3. As mounted on a 40 40 1.5 mm FR4 substrate with a single layer of 80 mm2 of 2 oz copper traces and heat spreading area. As specified
for a JEDEC 51 low conductivity test PCB. Test conditions were under natural convection or zero air flow.
4. As mounted on a 40 40 1.5 mm FR4 substrate with a single layer of 650 mm2 of 2 oz copper traces and heat spreading area. As specified
for a JEDEC 51 high conductivity test PCB. Test conditions were under natural convection or zero air flow.
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4
NCL30000
Table 3. ELECTRICAL CHARACTERISTICS
VMFP = 2.4 V, VControl = 4 V, Ct = 1 nF, VCS = 0 V, VZCD = 0 V, CDRV = 1 nF, VCC = 12 V, unless otherwise specified
(For typical values, TJ = 25C. For min/max values, TJ = −40C to 125C, unless otherwise specified)
Characteristic
Test Conditions
Symbol
Min
Typ
Max
Unit
Startup Voltage Threshold
VCC Increasing
VCC(on)
11
12
12.5
V
Minimum Operating Voltage
VCC Decreasing
VCC(off)
8.8
9.5
10.2
V
HUVLO
2.2
2.5
2.8
V
0 V < VCC < VCC(on) − 200 mV
Icc(startup)
−
24
35
mA
CDRV = Open, 70 kHz Switching,
VCS = 2 V
Icc1
−
1.4
1.7
mA
70 kHz Switching, VCS = 2 V
Icc2
−
2.1
2.6
mA
No Switching, VMFP = 0 V
Icc(fault)
−
0.75
0.95
mA
VOVP/VREF
105
106
108
%
VOVP(HYS)
20
60
100
mV
VMFP = 2 V to 3 V ramp,
dV/dt = 1 V/ms
VMFP = VOVP to VDRV = 10%
tOVP
−
500
800
ns
Undervoltage Detect Threshold
VMFP = Decreasing
VUVP
0.25
0.31
0.4
V
Undervoltage Detect Threshold
Propagation Delay
VMFP = 1 V to 0 V ramp,
dV/dt = 10 V/ms
VMFP = VUVP to VDRV = 10%
tUVP
100
200
300
ns
TJ = 25C
TJ = −40C to 125C
VREF
2.475
2.460
2.500
2.500
2.525
2.540
V
VCC(on) + 200 mV < VCC < 20 V
VREF(line)
−10
−
10
mV
VMFP = 2.6 V
VMFP = 1.08*VREF
VMFP = 0.5 V
IEA(sink)
IEA(sink)OVP
IEA(source)
6
10
−110
10
20
−210
20
30
−250
mA
VMFP = 2.4 V to 2.6 V
TJ = 25C
TJ = −40C to 125C
gm
90
70
110
110
120
135
VMFP = VUVP to VREF
RMFP
2
4.6
10
MW
VMFP = 2.5 V
IMFP
0.25
0.54
1.25
mA
STARTUP AND SUPPLY CIRCUITS
Supply Voltage Hysteresis
Startup Current Consumption
No Load Switching
Current Consumption
Switching Current Consumption
Fault Condition Current Consumption
OVERVOLTAGE AND UNDERVOLTAGE PROTECTION
Overvoltage Detect Threshold
VMFP = Increasing
Overvoltage Hysteresis
Overvoltage Detect Threshold
Propagation Delay
ERROR AMPLIFIER
Voltage Reference
Voltage Reference Line Regulation
Error Amplifier Current Capability
Transconductance
Feedback Pin Internal Pull−Down
Resistor
Feedback Bias Current
Control Bias Current
Maximum Control Voltage
Minimum Control Voltage to Generate
Drive Pulses
Control Voltage Range
mS
VMFP = 0 V
IControl
−1
−
1
mA
IControl(pullup) = 10 mA,
VMFP = VREF
VEAH
5
5.5
6
V
VControl = Decreasing until
VDRV is low, VCt = 0 V
Ct(offset)
0.37
0.65
0.88
V
VEAH – Ct(offset)
VEA(DIFF)
4.5
4.9
5.3
V
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5
NCL30000
Table 3. ELECTRICAL CHARACTERISTICS (Continued)
VMFP = 2.4 V, VControl = 4 V, Ct = 1 nF, VCS = 0 V, VZCD = 0 V, CDRV = 1 nF, VCC = 12 V, unless otherwise specified
(For typical values, TJ = 25C. For min/max values, TJ = −40C to 125C, unless otherwise specified)
Characteristic
Test Conditions
Symbol
Min
Typ
Max
Unit
VCOMP = open
VCt(MAX)
4.775
4.93
5.025
V
VCOMP = open
VCt = 0 V to VCt(MAX)
Icharge
235
275
297
mA
VCOMP = open
VCt = VCt(MAX) −100 mV to 500 mV
tCt(discharge)
−
50
150
ns
dV/dt = 30 V/ms
VCt = VControl − Ct(offset)
to VDRV = 10%
tPWM
−
130
220
ns
ZCD Arming Threshold
VZCD = Increasing
VZCD(ARM)
1.25
1.4
1.55
V
ZCD Triggering Threshold
VZCD = Decreasing
VZCD(TRIG)
0.6
0.7
0.83
V
VZCD(HYS)
500
700
900
mV
RAMP CONTROL
Ct Peak Voltage
On Time Capacitor Charge Current
Ct Capacitor Discharge Duration
PWM Propagation Delay
ZERO CURRENT DETECTION
ZCD Hysteresis
ZCD Bias Current
VZCD = 5 V
IZCD
−2
−
+2
mA
Positive Clamp Voltage
IZCD = 3 mA
VCL(POS)
9.8
10
12
V
Negative Clamp Voltage
IZCD = −2 mA
VCL(NEG)
−0.9
−0.7
−0.5
V
ZCD Propagation Delay
VZCD = 2 V to 0 V ramp,
dV/dt = 20 V/ms
VZCD = VZCD(TRIG) to VDRV = 90%
tZCD
−
100
170
ns
Minimum ZCD Pulse Width
tSYNC
−
70
−
ns
Falling VDRV = 10% to
Rising VDRV = 90%
tstart
75
165
300
ms
Isource = 100 mA
Isink = 100 mA
ROH
ROL
−
−
12
6
20
13
W
Rise Time
10% to 90%
trise
−
35
80
ns
Fall Time
90% to 10%
tfall
−
25
70
ns
VCC = VCC(on)−200 mV,
Isink = 10 mA
Vout(start)
−
−
0.2
V
VILIM
0.45
0.5
0.55
V
VCS = 2 V, VDRV = 90% to 10%
tLEB
100
195
350
ns
dV/dt = 10 V/ms
VCS = VILIM to VDRV = 10%
tCS
40
100
170
ns
VCS = 2 V
ICS
−1
−
1
mA
Maximum Off Time in Absence of ZCD
Transition
DRIVE
Drive Resistance
Drive Low Voltage
CURRENT SENSE
Current Sense Voltage Threshold
Leading Edge Blanking Duration
Overcurrent Detection Propagation
Delay
Current Sense Bias Current
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6
NCL30000
VOVP(HYS), OVERVOLTAGE HYSTERESIS (mV)
107
106
105
−50
−25
0
25
50
75
100
125
80
70
60
50
40
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (C)
TJ, JUNCTION TEMPERATURE (C)
Figure 3. Overvoltage Detect Threshold vs.
Junction Temperature
Figure 4. Overvoltage Hysteresis vs. Junction
Temperature
0.325
0.320
0.315
0.310
0.305
0.300
−50
−25
0
25
50
75
100
125
RMFP, FEEDBACK PIN INTERNAL PULL−
DOWN RESISTOR (MW)
VUVP, UNDERVOLTAGE DETECT THRESHOLD (V)
VOVP/VREF, OVERVOLTAGE DETECT
THRESHOLD (%)
TYPICAL CHARACTERISTICS
7
6
5
4
3
2
1
0
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (C)
TJ, JUNCTION TEMPERATURE (C)
Figure 5. Undervoltage Detect Threshold vs.
Junction Temperature
Figure 6. MFP Pin Internal Pull−Down Resistor
vs. Junction Temperature
VREF, REFERENCE VOLTAGE (V)
2.54
2.53
2.52
2.51
2.50
2.49
2.48
2.47
2.46
−50
−25
0
25
50
75
100
TJ, JUNCTION TEMPERATURE (C)
Figure 7. Reference Voltage vs. Junction
Temperature
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7
125
NCL30000
TYPICAL CHARACTERISTICS
220
14
12
10
8
6
−50
−25
0
25
50
75
100
200
195
190
VMFP = 0.5 V
185
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (C)
Figure 8. Error Amplifier Sink Current vs.
Junction Temperature
Figure 9. Error Amplifier Source Current vs.
Junction Temperature
115
110
105
100
95
90
−25
0
25
50
75
100
200
TJ, JUNCTION TEMPERATURE (C)
200
180
180
Phase
160
160
140
140
120
120
Transconductance
100
125
Figure 10. Error Amplifier Transconductance
vs. Junction Temperature
100
80
60
40
20
0
80
RControl = 100 kW
CControl = 2 pF
VMFP = 2.5 Vdc, 1 Vac
VCC = 12 V
TA = 25C
0.01
0.1
60
40
1
10
20
0
1000
100
f, FREQUENCY (kHz)
Figure 11. Error Amplifier Transconductance
and Phase vs. Frequency
1.0
278
Icharge, Ct CHARGE CURRENT (mA)
Ct(offset), MINIMUM CONTROL VOLTAGE
TO GENERATE DRIVE PULSES (V)
205
TJ, JUNCTION TEMPERATURE (C)
120
0.9
0.8
0.7
0.6
0.5
0.4
0.3
−50
210
180
−50
125
125
85
−50
215
q, PHASE (DEGREES)
gm, ERROR AMPLIFIER TRANSCONDUCTANCE (mS)
IEA(source), ERROR AMPLIFIER
SOURCE CURRENT (mA)
VMFP = 2.6 V
gm, ERROR AMPLIFIER TRANSCONDUCTANCE (mS)
IEA(sink), ERROR AMPLIFIER SINK
CURRENT (mA)
16
−25
0
25
50
75
100
125
276
274
272
270
268
266
264
−50
TJ, JUNCTION TEMPERATURE (C)
−25
0
25
50
75
100
TJ, JUNCTION TEMPERATURE (C)
Figure 12. Minimum Control Voltage to Generate
Drive Pulses vs. Junction Temperature
Figure 13. On Time Capacitor Charge Current
vs. Junction Temperature
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8
125
NCL30000
TYPICAL CHARACTERISTICS
5.5
5.0
4.5
4.0
−50
−25
0
25
50
75
100
125
170
160
150
140
130
120
110
100
−50
−25
0
25
50
75
100
TJ, JUNCTION TEMPERATURE (C)
TJ, JUNCTION TEMPERATURE (C)
Figure 14. Ct Peak Voltage vs. Junction
Temperature
Figure 15. PWM Propagation Delay vs.
Junction Temperature
125
220
tLEB, LEADING EDGE BLANKING
DURATION (ns)
0.520
0.515
0.510
0.505
0.500
0.495
0.490
0.485
0.480
−50
−25
0
25
50
75
100
210
200
190
180
−50
125
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (C)
TJ, JUNCTION TEMPERATURE (C)
Figure 16. Current Sense Voltage Threshold
vs. Junction Temperature
Figure 17. Leading Edge Blanking Duration vs.
Junction Temperature
205
18
200
16
DRIVE RESISTANCE (W)
tstart, MAXIMUM OFF TIME IN ABSENCE OF ZCD TRANSITION (ms)
VILIM, CURRENT SENSE VOLTAGE THRESHOLD (V)
tPWM, PWM PROPAGATION DELAY (ns)
VCt(MAX), Ct PEAK VOLTAGE (V)
6.0
195
190
185
180
175
170
ROH
14
12
10
8
6
ROL
4
2
165
−50
−25
0
25
50
75
100
125
0
−50
−25
0
25
50
75
100
TJ, JUNCTION TEMPERATURE (C)
TJ, JUNCTION TEMPERATURE (C)
Figure 18. Maximum Off Time in Absence of
ZCD Transition vs. Junction Temperature
Figure 19. Drive Resistance vs. Junction
Temperature
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9
125
NCL30000
TYPICAL CHARACTERISTICS
VCC, SUPPLY VOLTAGE
THRESHOLDS (V)
13
VCC(on)
12
11
10
VCC(off)
9
8
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (C)
Figure 20. Supply Voltage Thresholds vs.
Junction Temperature
ICC(startup), STARTUP CURRENT
CONSUMPTION (mA)
26
24
22
20
18
16
14
−50
−25
0
25
50
75
100
125
TJ, JUNCTION TEMPERATURE (C)
Figure 21. Startup Current Consumption vs.
Junction Temperature
ICC2, SWITCHING CURRENT CONSUMPTION (mA)
2.16
2.14
2.12
2.10
2.08
2.06
2.04
2.02
2.00
−50
−25
0
25
50
75
100
TJ, JUNCTION TEMPERATURE (C)
Figure 22. Switching Current Consumption vs.
Junction Temperature
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125
NCL30000
THEORY OF OPERATION
eliminated except for a small capacitor, the voltage to the
flyback converter now follows a rectified sine shape at twice
the line frequency. By employing a critical conduction mode
control technique such that the input current is kept to the
same shape, high power factor can be achieved. The
NCL30000 is a voltage mode, fixed on-time controller
specifically intended for such applications.
High power factor requires generally sinusoidal line
current and minimal phase displacement between the line
current and voltage. Normally this is not the case with a
traditional isolated flyback topology so the first step to
achieve high power factor is to have minimal capacitance
before the switching stage to allow a more sinusoidal input
current. A simplified block diagram is illustrated in
Figure 23. Since the input bulk capacitor has virtually been
AC
Line
Input
Ï
Primary
EMI
Filter
Secondary
Zero
Current
Detect
& Bias
Winding
CC/CV
Control
NCL30000
Controller
Figure 23. Simplified Block Diagram
line. Figure 24 illustrates the theoretical current waveform
through the primary and secondary transformer windings.
The energy delivered to the load through the transformer
will follow the product of voltage and current which is a
sine-squared shape. As a result of this sine-squared energy
transfer, the load will experience ripple at twice the line
frequency, either 100 or 120 Hz depending on the source.
The delivered power through the transformer starts at zero,
rises to a peak and returns to zero following the shape of the
rectified input line. The 100/120 Hz ripple is superimposed
on the normal switching waveform of the PWM converter.
The maximum on-time must be set such that the maximum
power is delivered at the minimum required operation
voltage. The LED current required for a particular
application is generally specified as an average value. LEDs
can tolerate ripple current as long as the ripple frequency is
above the visible range of the human eye and the peak
current does not exceed the rating of the LEDs. Just like a
standard flyback, the output capacitors filter the pulsing
power from the transformer to match the average current
required by the LED and must be sized appropriately to limit
the peak current through the LEDs.
Since the input voltage waveform to the flyback is
sinusoidal, with a fixed on-time control scheme, the current
through the transformer primary will increase directly with
the line voltage and the average current drawn from the line
will have a sinusoidal shape. When the switch is turned off
the energy from the primary will be transferred to the
secondary. By monitoring the auxiliary winding the
controller can detect when the secondary current reaches
zero and restart the switching cycle to transfer additional
energy to the load. The current in the primary of the
transformer starts at zero each switching cycle and is directly
proportional to the applied voltage times the on-time. One
of the primary benefits of this CrM approach is that we can
operate with zero current switching which results in a very
efficient architecture for low to medium power applications.
A secondary side control loop monitors the average LED
current and adjusts the on-time to maintain proper
regulation. To achieve high power factor, the control loop
bandwidth must be sufficiently low such that the on-time is
constant across a line half cycle. Since the off time varies
depending on the energy transferred through the transformer
and the load, the switching frequency varies with load and
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NCL30000
The NCL30000 (refer to the block diagram − Figure 1) is
composed of 4 key functional blocks along with protection
circuitry to ensure reliable operation of the controller.
On-time Control
Zero Current Detection Control
MOSFET Gate Driver
Startup and VCC Management
Ipr(peak)
IS(t)
Ipr(t)
Iin(t)
Iin(peak)
On Time Control
The on-time control circuitry (Figure 25) consists of a
precision current source which charges up an external
capacitor (Ct) in a linear ramp. The voltage on Ct (after
removing an internal offset) is compared to an external
control voltage and the output of the comparator is used to
turn off the output driver thus terminating the switching
cycle. A signal from the driver is fed back to the on-time
control block to discharge the Ct capacitor thus preparing the
circuit for the start of the next switching cycle.
The state of Vcontrol is determined by the external
regulation loop and varies with the rms input voltage and the
output load. To achieve high power factor, the regulation
loop is designed so that in steady state, the Vcontrol value is
held constant over a line half cycle. This results in fixed on
time operation. The range of on-time is determined by the
charging slope of the Ct capacitor and is clamped at 4.93 V
nominal. The Ct capacitor is sized to ensure that the required
on-time is reached at maximum output power and the
minimum input line voltage condition. Because the ramp has
a wide dynamic range, the control loop can accommodate
wide variation of line voltage and load power range.
ON
MOSFET
OFF
Figure 24. Theoretical Switching Waveform
The LED current is compared to a reference and an error
signal is passed to the NCL30000 controller to maintain the
desired average level. This error signal adjusts the on-time
of the power switch to pass the required energy through the
flyback transformer to achieve proper regulation of the LED
load. Just like in a traditional PFC boost converter, the loop
bandwidth must be low enough to filter out the twice line
frequency ripple otherwise the power factor correction
element of the circuit will be compromised. In the event of
an open LED fault, a constant voltage loop regulates the
output voltage across the output capacitor to assure safe
operation.
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NCL30000
VControl
MOSFET Conduction
COMP
VDD
VEAH
Output Rectifier Conduction
PWM
Icharge
Ct
+
−
+
ton
Iprimary
0A
Isecondary
0A
DRV
Ct(offset)
VCt
VCt(off)
VControl − Ct(offset)
VControl
ton(max)
DRV
DRV
Figure 25. On Time Control
0V
Off Time Sequence
Vout
In a fixed on-time CRM flyback converter, energy stored
in the primary of the flyback transformer varies directly with
input line voltage on a cycle-by-cycle basis. When the
switching cycle is terminated, the energy stored in the
transformer is transferred to the secondary. The auxiliary
winding used to provide bias to the NCL30000 is also used
to detect when the current in the secondary winding has
dropped to zero. This is illustrated in Figure 26.
0V
VZCD(WIND)
VZCD(WIND),off
0V
VZCD(WIND),on
VCL(POS)
VZCD(ARM)
VZCD(TRIG)
0V
VCL(NEG)
ton
tdiode
toff
tSW
Figure 26. Ideal CrM Waveforms with ZCD Winding
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NCL30000
ZCD Detection Block
the next switching cycle at the precise time. To avoid
inadvertent false triggering, the ZCD input has a dual
comparator input structure to arm the latch when the ZCD
detect voltage rises above 1.4 V (nominal) thus setting the
latch. When the voltage on ZCD falls below 0.7 V (nominal)
a zero current event is detected and a signal is asserted which
initiates the next switching cycle. This is illustrated in
Figure 27. The input of the ZCD has an internal circuit
which clamps the positive and negative voltage excursions
on this pin. The current into or out of the ZCD pin must be
limited to 10 mA with an external resistor.
A dedicated circuit block is necessary to implement the
zero current detection. The NCL30000 provides a separate
input pin to signal the controller to turn the power switch
back on just after the flyback transformer discharges all the
stored energy to the secondary winding. When the output
winding current reaches zero the winding voltage will
reverse. Since all windings of the transformer reflect the
same voltage characteristic this voltage reversal appears on
the primary bias winding. Coupling the winding voltage to
the ZCD input of the NCL30000 allows the controller to start
Varm
NZCD
Vtrig
+
−
S
Q
Reset
Dominant
Latch
R
Q
+
VZCD(ARM)
+
−
DRIVE
Demag
+
VZCD(TRIG)
ZCD
Bias Winding Voltage
RZCD
ZCD Clamp
Figure 27. ZCD Operation
At startup, there is no energy in the ZCD winding and no
voltage signal to activate the ZCD comparators. To enable
the controller to start under these conditions, an internal
watchdog timer is provided which initiates a switching cycle
in the event that the output drive has been off for more than
180 ms (nominal).
The timer is deactivated only under an OVP or UVP fault
condition which will be discussed in the next section.
OCP
VILIM
optional
Figure 28. OCP Circuitry with Optional
External RC Filter
The dedicated CS pin of the NCL30000 senses the current
through the MOSFET switch and the primary side of the
transformer. This provides an additional level of protection
in the event of a fault. If the voltage of the CS pin exceeds
VILIM, the internal comparator will detect the event and turn
off the MOSFET. The peak switch current is calculated
using Equation 1:
V ILIM
R sense
+
−
LEB
+
Rsense
Overcurrent Protection (OCP)
I SW(peak) +
CS
DRV
MFP Input
The multi-function pin is connected to the input of the
transconductance amplifier, the undervoltage and
overvoltage protection comparators. This allows this pin to
perform several functions. To place the device in standby,
the MFP pin should be pulled below the Vuvp threshold. This
is illustrated in Figure 29. Additionally, raising the MFP pin
above Vovp will also suspend switching activity but not place
the controller in the standby mode. This can be used
implement overvoltage monitoring on the bias winding and
add an additional layer of fault protection.
(eq. 1)
To avoid the probability of false switching, the
NCL30000 incorporated a built in leading edge blanking
circuit (LEB) which masks the CS signal for a nominal time
of 190 ns. If required, an optional RC filter can be added
between Rsense and CS to provide additional filtering. This
is illustrated below.
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NCL30000
+
VOVP
Bias
+
R1
OVP Fault
POWER GOOD
− UVP
+
UVP Fault
VUVP
MFP
−
+
RFB
R2
COMP
+
Shutdown
+ OVP
−
EA
(Enable EA)
gm
VREF
VControl
CCOMP
Figure 29. Multi−Function Pin Operation
The positive input of the transconductance amplifier is
connected to a 2.5 V (nominal) reference. This allows the
controller to be used in non-isolated applications where the
MFP could be configured in a more classical feedback input
configuration.
time for the device to start switching and allow the bias from
the auxiliary winding to supply VCC.
Example Design
A practical design case will be used to illustrate the overall
power supply functional blocks and the overall design
methodology. The power supply specification in this
example is listed below and covers an extended universal
input range which includes the normal 90−265 Vac for
global power supplies with an extended upper range to
support 277 Vac commercial lighting in the United States.
Input voltage: 90 to 305 Vac
Power factor: > 0.9
Output current: 350 mA Typical
LED load voltage: 12 to 50 Vdc
Full Load Efficiency: > 85%
VCC Management
The NCL30000 incorporates a supervisory circuitry to
manage the startup and shutdown of the circuit. By
managing the startup and keeping the initial startup current
at less than 35 mA, a startup resistor connected between the
rectified ac line and VCC charges the VCC capacitor to
VCC(on). Turn on of the device occurs when the startup
voltage has exceeded 12 V (nominal) when the internal
reference and switching logic are enabled. A UVLO
comparator with a hysteresis of 2.5 V nominal gives ample
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16
1A
1
Line
1
Neutral
J1-2
F1
47nF
C1
BAW56 D7
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R10
6.2k
2
RT1
R11
100k
4
27mH
1 L1 3
T
4.7k
R14
R2 5K6
L2 2.2mH
R15
100k
RV1
CS
Ct
ZCD
GND
Comp DRV
VCC
NCL30000
C4
100nF
MFP
C9
820 pF
4
3
2
1
C8
10uF
D4
MRA4007
V300LA4
1nF R17
100
C7
L3 2.2mH
R3 5K6
C2
47nF
Q2
MMBTA06
D9
MMBZ5245
Q1
D8
Figure 30. Wide Input Main, 4−15 LED 350 mA Load Schematic
15V
MMBTA06
BZX84C5V1
5.1V
R9 6.2k
5
6
7
8
Q3
SPD02N80
R20
0.33 W
R18 100
4
3
T1A
T1E
T1D
C12
470uF
+
+
D10 MURD330
C10 4.7 nF
U2
PS2561L_1
2
T1C
1
5
3
R7
47K T1B
R6
47K
R19 10
R16
47k
D6
BAS21
D5
ES1M
4700 pF
C5
4
R22
1k
BZX84C5V6
1
D11
2
MMBTA06
Q5
MMBTA06
R24
47k
100pF
C14
1k
R25
C15
220nF
U3
8
IN1+
1 VCC IN1−
OUT1
IN2+
OUT2
7
IN2−
GND
LM2904
D12
BZX84C56
R23
1k
D13 BAW56
3
J1-1
3
2
5
6
4
R28
470
R27
200
16k
R26
0.2 W
R29
R30
24k
U4
TL431A
24k
R31
C16
100nF
LED
Cathode
J2-2
1
LED
Anode
J2-1
1
NCL30000
Q4
C13
100nF
NCL30000
Zero Current Detection (ZCD)
The low input capacitance approach taken in this design
to meet high power factor has the added benefit of not
needing inrush current limiting.
The signal controlling the ZCD function is taken from the
primary bias winding. Raising the ZCD pin above 1.4 V
arms the zero detection circuit. When the pin voltage
subsequently falls below 0.7 V, the controller issues the
command to turn the power switch back on. The current in
or out of the ZCD pin must be limited to 10 mA by an
external resistor. For this reference circuit a resistance of
47 kW provides the required voltage thresholds and limits
current to less than 10 mA.
Start-up Circuit and Primary Bias
Rapid start up is enhanced by the low current draw of the
NCL30000. Resistors connected from the rectified ac line to
the VCC circuit provide start up power. Some of the current
is needed for the control chip and bias network while the
remaining portion charges up a storage capacitor. When the
voltage on the capacitor reaches 12 V nominal, the internal
references and logic of the NCL30000 are turned on and the
part starts switching. The turn on comparator has hysteresis
(2.5 V nominal) to ensure sufficient time for the auxiliary
winding to start supplying current directly to the VCC
capacitor. Resistor divider R9 (6.2 kW) and R15 (100 kW)
bias the MFP at the proper voltage to enable the NCL30000.
An optional thermal shutdown is implemented with
positive temperature coefficient (PTC) thermistor RT1. This
thermistor is placed close to the switching FET Q3 sensing
temperature stress related to load and surrounding
temperature. Situations causing excessive temperature will
cause RT1 to switch to a high impedance turning off the
NCL30000. When RT1 cools down, normal operation will
resume.
Feedback Control
The secondary feedback signal is routed through an
optocoupler to the primary side NCL30000 controller. LED
current is measured with a 0.2 W resistor which for 350 mA
has a voltage drop of 70 mV.
The control loop must be designed to filter out the rectified
sine wave ripple component to provide an average feedback
level to the pulse width controller. In order to maintain high
power factor operation, the compensation components
around the error amplifier must be set well below 50/60 Hz.
The corner frequency typically falls between 10 and 40 Hz.
The low frequency response means the control loop will be
slow to compensate for rapidly changing situations. In
particular, the slow response can introduce overshoot at turn
on.
To compensate for the slow steady state loop this circuit
utilizes a second current control loop to minimize overshoot.
The second loop is set for higher than nominal operating
current with a very fast response loop. This error amp takes
control of the feedback loop until the main error amp is able
to respond. In this way the maximum current is limited to
safe established level.
The current set point of the fast control loop should be set
above the peak of the ripple current of normal operation. U4
is a 2.5 V reference which in conjunction with R26, R27, and
R28 establishes the nominal reference voltage of 70 mV
mentioned above but also the higher threshold for the fast
current loop. In this example, the average output current is
350 mA and the fast loop is set for a 500 mA level.
Transformer Design
Single stage high power factor flyback converters process
power in a sine-squared manner. To support the average
LED load current, the flyback converter must be capable of
processing 2 times the average output power. In this case,
the flyback transformer is designed to handle a peak power
of 42 W to power a 17.5 W LED load scaled for the
efficiency. The complete details of the transformer design
process are found in Application Note AND8451.
The NCL30000 is a variable frequency CrM controller
and as such the transformer determines the operating
frequency for a given set of input and output conditions. The
transformer turns ratio is controlled by maximum input and
output voltage and the ratings of the FET and output
rectifier. In this case, the turns ratio from primary to
secondary is set at 3.83.
Power switch on-time is set at the low line condition of
90 Vac or 126 V peak and maximum power of 17.5 W.
On-time will be 13.3 ms maximum. Primary inductance is
calculated from the minimum switching frequency and the
conditions listed above as 1.57 mH.
Peak primary current of 1.11 A is calculated from the
primary inductance, applied voltage, and on-time. Core flux
density occurs at the peak of the input rectified sine wave.
Primary turns are established from inductance, current,
maximum flux density and core geometry as 92 turns.
Primary turns, current, and maximum flux density set gap
size and is approximately 0.016 inches for this transformer.
The primary 92 turns divided by the previously calculated
ratio of 3.83 establishes secondary turns at 24. #26 triple
EMI Filter
The EMI filter attenuates the switching current drawn by
the power converter reducing the high frequency harmonics
to within conducted emissions limits. The filter must not
degrade the power factor by introducing a phase shift of the
current with the line-to-line or X capacitors. Low total
capacitance will minimize this effect. Balancing these
attributes is a performance tradeoff considering the wide
input voltage requirements.
A multi-stage filter consisting of 27 mH common mode
inductor and two 2.2 mH differential inductors working
with two 47 nF capacitors provides sufficient attenuation to
pass conducted emissions requirements. A 4.7 nF “Y1”
capacitor bypasses common mode currents created by the
power transformer.
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NCL30000
Output Filter
insulated wire is selected for compliance with safety agency
isolation requirements.
The primary bias winding must supply 10.2 V to maintain
NCL30000 operation. The minimum secondary voltage is
12 V and with 24 turns this means the bias winding needs
20.4 turns. Select 22 turns to meet the minimum.
For maximum primary to secondary coupling, the primary
winding will be split in two equal sections with the
secondary winding placed in between. The bias winding is
wound on top of the second half of the primary winding.
As previously discussed, a high power factor isolated
single-stage converter processes power in a sine squared
manner at twice the line frequency. Energy storage must be
provided on the isolated secondary output just as in normal
flyback converters however significantly more storage
capacity is required due to the sine squared energy transfer
characteristic. Capacitors are used to store energy as the
peak of the 100 or 120 Hz rectified sine wave delivers
maximum power and then releases the stored energy to the
load when the rectified sine wave falls below the target
output power. As the storage capacitor charges and
discharges some ripple current is developed in the LED load.
The magnitude of ripple voltage is controlled by the amount
of filter capacitance and the impedance of the LED string. In
this 350 mA application, two 470 mF capacitors are
sufficient to provide 30% ripple.
High grade electrolytic capacitors should be selected to
match driver lifetime with that of the LEDs. Higher
temperature rated capacitors enhance lifetime for an optimal
solution. To meet ripple requirements in single stage
converters filter capacitance is generally high enough that
capacitor ripple current is well below device ratings.
FET Switch
The NCL30000 controller drives an external power FET
controlling the current in the flyback transformer primary.
The demonstration board was designed to accept the surface
mount DPAK or through-hole TO−220 power packages. The
17.5 W target application in 50C ambient works well with
a DPAK package. The 800 V 2 A rated SPD02N80C3 was
chosen.
Maximum primary current was calculated as 1.11 A. The
NCL30000 has a 0.5 V over-current protection threshold. To
allow for 25% margin, a minimum sense resistor of 0.348 W
is required. A standard 0.33 W resistor will be selected. The
current sense resistor is placed in the source lead of the
power FET and coupled to the controller with a 100 W
resistor. This resistance in conjunction with the inherent
capacitance of the pin filters high frequency noise. In
addition, a leading edge blanking (LEB) function is included
in the controller. This feature avoids spurious activation of
the over-current protection when the power FET is first
turned on.
Secondary Bias
The average mode feedback compensation is
intentionally set to a low frequency as described in the
feedback section. The relatively large feedback
compensation capacitor must charge to normal operating
voltage after initial power up which introduces significant
delay in regulation. Minimizing the required voltage change
on the compensation capacitor allows the feedback loop to
take control of the output quicker therefore reducing
over-current conditions. Maintaining a low bias voltage
reduces the required change in compensation capacitor
voltage. For this example, a bipolar transistor and 5.6 V
zener diode are employed to provide bias voltage of about
5 V. This bias transistor minimizes power loss and allows the
LED driver to operate over a very wide range of output
voltage. This circuit will support as few as 4 LEDs and up
to 15 LEDs.
The secondary bias can be optimized if the application
uses a specific number of LEDs. Fewer components and
better efficiency can be realized by limiting the output
voltage range and adding a secondary bias winding to the
transformer.
On-time Capacitor
Maximum FET switch on-time is controlled by the Ct
capacitor. Limiting the maximum on-time reduces
component stress in transient situations. The formula below
establishes the capacitor value based on charging current of
297 mA and maximum voltage threshold of 4.775. The
symbol h' represents the effective efficiency of the power
transformer stage and secondary losses. It will always be
greater than the measured wall plug efficiency which
includes losses in the EMI filter and primary side compents.
Ct [
Ct [
ǒ4 @ Lpri @ Pout @ IchargeǓ
ǒhȀ @ Vpk2 @ VCT(max)Ǔ
@
ǒ
V pk
N @ V out
ǒ4 @ 0.00157 @ 17.5 @ 297 mAǓ
ǒ
2
0.95 @ ǒǸ2 @ 90Ǔ @ 4.775 V
Ǔ
@
ǒ
Ǔ
)1
Ǹ2 @ 90
3.83 @ 50
(eq. 2)
Ǔ
)1
Open Load Protection
The LED driver behaves like a current source where the
output voltage is determined by the forward voltage of the
LED string. As such, some protection is required to prevent
damage in the event of an open LED situation. Transistor
(Q5) and zener diode (D12) affords the necessary protection.
A 56 V zener is used in this design example.
C t [ 740 pF
The Ct equation is an approximation for simplification. For
example, Vpk assumes no losses through the diode rectifier
bridge and EMI filter. This establishes an initial starting point
for the Ct capacitor and further optimization may be needed.
For this design, 820 pF was used as the final value.
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NCL30000
Performance Data for 90 to 305 Vac LED Driver
LED Current (mA)
350
87%
345
86%
340
85%
335
84%
330
83%
325
82%
320
81%
315
80%
LED Current
310
Efficiency (%)
current does not vary much over the entire input voltage
range. The data is based on the use of an EFD25 transformer.
Shown below in Figure 31 is the line regulation and
efficiency with a 36.9 V, 12 LED load. Note the output
79%
Efficiency
305
78%
300
77%
90
115
140
165
190
215
240
265
290
Input Voltage (Vac)
Figure 31. Output Current and Efficiency with 36.9 V Load
315
20
1.00
18
0.99
16
0.98
14
0.97
12
0.96
10
0.95
8
0.94
6
0.93
4
0.92
THD
2
0.91
PF
0
0.90
90
115
140
165
190
215
Input Voltage (Vac)
240
265
Figure 32. THD and Power Factor with 36.9 V Load
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290
315
Power Factor (PF)
Input Current THD (%)
Power factor and Total Harmonic Distortion are shown in Figure 32 below.
NCL30000
Efficiency is affected by the startup circuit losses in
proportion to load and influenced by higher line voltage.
380
86%
370
84%
360
82%
350
80%
340
78%
Efficiency
LED Current (mA)
Load regulation from 12.3 to 52.5 (4 to 15 LEDs) for 115
and 230 Vac input is shown below in Figure 4. Efficiency for
this range is also shown. Note the tight regulation.
115V LED Current
230V LED Current
330
76%
115V Efficiency
230V Efficiency
320
12
17
22
27
32
37
42
LED Forward Voltage (Vdc)
47
52
57
74%
Figure 33. LED Current and Efficiency at 115 and 230 Vac
maximum power delivered. This is illustrated at the top of
the output voltage-current transfer function. At the bottom
of the curve, even with a short applied to the output, the
current is limited to less than 1 A.
Figure 34 shows the current regulation as a function of
output voltage (LED forward voltage). The control loop has
been designed to support 4 − 15 LED based on a forward
voltage that ranged from 2.6 − 3.5 V. The maximum on time
of the control loop has been configured to limit the
60
55
LED Forward Voltage (Vdc)
50
45
40
35
30
25
20
15
10
Protection
Region
5
0
0
100
200
300
400
500
600
LED Current (mA)
Figure 34.
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700
800
900
1000
NCL30000
Figure 35 shows output ripple current for 115 Vac input
and 36.9 (12 LED) load operating at 350 mA average. Scale
factor is 67 mA per division. The low frequency ripple
follows the input twice line frequency rectified sine wave
characteristic of single stage converters.
Figure 37. Start up Characteristic with 36.9 V, 350 mA
Load
Typical voltage stress on power FET with 36.9 V, 350 mA
load and 305 Vac input voltage is shown in Figure 38. Scale
factor is 100 V per division.
Figure 35. Output Ripple at 115 Vac and 36.9 V,
350 mA Load
Figure 36 shows output ripple current at the main
switching frequency. Scale factor is 33 mA per division.
This is the signal superimposed over the rectified sine wave
ripple component.
Figure 38. Drain to Source Voltage with 36.9 V,
350 mA Load at 305 Vac Input
Note that while the power supply was designed to meet
agency requirements, it has not been submitted for
compliance. Standard safety practices should be used when
this circuit is energized and in particular when connecting
test equipment. During evaluation, input power should be
sourced through an isolation transformer.
Figure 36. Output Ripple at 115 Vac and 36.9 V,
350 mA Load
Initial start up characteristic is shown in Figure 37 below.
Note the higher current limit controlled by the fast feedback
loop and the transition to the main average mode feedback
control loop. This shows start up at 115 Vac with 36.9 V,
350 mA load. Trace 2 is LED current at 167 mA per division
and trace 3 is applied input voltage at 200 V per division.
Additional Application Information and Tools
An evaluation board is available for this 90 − 305 Vac
design example. Moreover, for applications where it is
desired to dim the LEDs via a TRIAC dimmer, please refer
to Application Note AND8448 which explains the steps
necessary to configure the NCL30000 for TRIAC dimming.
In addition there are two additional TRIAC dimmable
reference designs which illustrate a complete design for
90 − 135 Vac or 180 − 265 Vac operation. There is also an
Microsoft EXCEL spreadsheet tool available to aid in the
design process and assist in developing target winding
requirements for the transformer.
http://onsemi.com
21
MECHANICAL CASE OUTLINE
PACKAGE DIMENSIONS
SOIC−8 NB
CASE 751−07
ISSUE AK
8
1
SCALE 1:1
−X−
DATE 16 FEB 2011
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSION A AND B DO NOT INCLUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 (0.005) TOTAL
IN EXCESS OF THE D DIMENSION AT
MAXIMUM MATERIAL CONDITION.
6. 751−01 THRU 751−06 ARE OBSOLETE. NEW
STANDARD IS 751−07.
A
8
5
S
B
0.25 (0.010)
M
Y
M
1
4
−Y−
K
G
C
N
X 45 _
SEATING
PLANE
−Z−
0.10 (0.004)
H
M
D
0.25 (0.010)
M
Z Y
S
X
J
S
8
8
1
1
IC
4.0
0.155
XXXXX
A
L
Y
W
G
IC
(Pb−Free)
= Specific Device Code
= Assembly Location
= Wafer Lot
= Year
= Work Week
= Pb−Free Package
XXXXXX
AYWW
1
1
Discrete
XXXXXX
AYWW
G
Discrete
(Pb−Free)
XXXXXX = Specific Device Code
A
= Assembly Location
Y
= Year
WW
= Work Week
G
= Pb−Free Package
*This information is generic. Please refer to
device data sheet for actual part marking.
Pb−Free indicator, “G” or microdot “G”, may
or may not be present. Some products may
not follow the Generic Marking.
1.270
0.050
SCALE 6:1
INCHES
MIN
MAX
0.189
0.197
0.150
0.157
0.053
0.069
0.013
0.020
0.050 BSC
0.004
0.010
0.007
0.010
0.016
0.050
0 _
8 _
0.010
0.020
0.228
0.244
8
8
XXXXX
ALYWX
G
XXXXX
ALYWX
1.52
0.060
0.6
0.024
MILLIMETERS
MIN
MAX
4.80
5.00
3.80
4.00
1.35
1.75
0.33
0.51
1.27 BSC
0.10
0.25
0.19
0.25
0.40
1.27
0_
8_
0.25
0.50
5.80
6.20
GENERIC
MARKING DIAGRAM*
SOLDERING FOOTPRINT*
7.0
0.275
DIM
A
B
C
D
G
H
J
K
M
N
S
mm Ǔ
ǒinches
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
STYLES ON PAGE 2
DOCUMENT NUMBER:
DESCRIPTION:
98ASB42564B
SOIC−8 NB
Electronic versions are uncontrolled except when accessed directly from the Document Repository.
Printed versions are uncontrolled except when stamped “CONTROLLED COPY” in red.
PAGE 1 OF 2
ON Semiconductor and
are trademarks of Semiconductor Components Industries, LLC dba ON Semiconductor or its subsidiaries in the United States and/or other countries.
ON Semiconductor reserves the right to make changes without further notice to any products herein. ON Semiconductor makes no warranty, representation or guarantee regarding
the suitability of its products for any particular purpose, nor does ON Semiconductor assume any liability arising out of the application or use of any product or circuit, and specifically
disclaims any and all liability, including without limitation special, consequential or incidental damages. ON Semiconductor does not convey any license under its patent rights nor the
rights of others.
© Semiconductor Components Industries, LLC, 2019
www.onsemi.com
SOIC−8 NB
CASE 751−07
ISSUE AK
DATE 16 FEB 2011
STYLE 1:
PIN 1. EMITTER
2. COLLECTOR
3. COLLECTOR
4. EMITTER
5. EMITTER
6. BASE
7. BASE
8. EMITTER
STYLE 2:
PIN 1. COLLECTOR, DIE, #1
2. COLLECTOR, #1
3. COLLECTOR, #2
4. COLLECTOR, #2
5. BASE, #2
6. EMITTER, #2
7. BASE, #1
8. EMITTER, #1
STYLE 3:
PIN 1. DRAIN, DIE #1
2. DRAIN, #1
3. DRAIN, #2
4. DRAIN, #2
5. GATE, #2
6. SOURCE, #2
7. GATE, #1
8. SOURCE, #1
STYLE 4:
PIN 1. ANODE
2. ANODE
3. ANODE
4. ANODE
5. ANODE
6. ANODE
7. ANODE
8. COMMON CATHODE
STYLE 5:
PIN 1. DRAIN
2. DRAIN
3. DRAIN
4. DRAIN
5. GATE
6. GATE
7. SOURCE
8. SOURCE
STYLE 6:
PIN 1. SOURCE
2. DRAIN
3. DRAIN
4. SOURCE
5. SOURCE
6. GATE
7. GATE
8. SOURCE
STYLE 7:
PIN 1. INPUT
2. EXTERNAL BYPASS
3. THIRD STAGE SOURCE
4. GROUND
5. DRAIN
6. GATE 3
7. SECOND STAGE Vd
8. FIRST STAGE Vd
STYLE 8:
PIN 1. COLLECTOR, DIE #1
2. BASE, #1
3. BASE, #2
4. COLLECTOR, #2
5. COLLECTOR, #2
6. EMITTER, #2
7. EMITTER, #1
8. COLLECTOR, #1
STYLE 9:
PIN 1. EMITTER, COMMON
2. COLLECTOR, DIE #1
3. COLLECTOR, DIE #2
4. EMITTER, COMMON
5. EMITTER, COMMON
6. BASE, DIE #2
7. BASE, DIE #1
8. EMITTER, COMMON
STYLE 10:
PIN 1. GROUND
2. BIAS 1
3. OUTPUT
4. GROUND
5. GROUND
6. BIAS 2
7. INPUT
8. GROUND
STYLE 11:
PIN 1. SOURCE 1
2. GATE 1
3. SOURCE 2
4. GATE 2
5. DRAIN 2
6. DRAIN 2
7. DRAIN 1
8. DRAIN 1
STYLE 12:
PIN 1. SOURCE
2. SOURCE
3. SOURCE
4. GATE
5. DRAIN
6. DRAIN
7. DRAIN
8. DRAIN
STYLE 13:
PIN 1. N.C.
2. SOURCE
3. SOURCE
4. GATE
5. DRAIN
6. DRAIN
7. DRAIN
8. DRAIN
STYLE 14:
PIN 1. N−SOURCE
2. N−GATE
3. P−SOURCE
4. P−GATE
5. P−DRAIN
6. P−DRAIN
7. N−DRAIN
8. N−DRAIN
STYLE 15:
PIN 1. ANODE 1
2. ANODE 1
3. ANODE 1
4. ANODE 1
5. CATHODE, COMMON
6. CATHODE, COMMON
7. CATHODE, COMMON
8. CATHODE, COMMON
STYLE 16:
PIN 1. EMITTER, DIE #1
2. BASE, DIE #1
3. EMITTER, DIE #2
4. BASE, DIE #2
5. COLLECTOR, DIE #2
6. COLLECTOR, DIE #2
7. COLLECTOR, DIE #1
8. COLLECTOR, DIE #1
STYLE 17:
PIN 1. VCC
2. V2OUT
3. V1OUT
4. TXE
5. RXE
6. VEE
7. GND
8. ACC
STYLE 18:
PIN 1. ANODE
2. ANODE
3. SOURCE
4. GATE
5. DRAIN
6. DRAIN
7. CATHODE
8. CATHODE
STYLE 19:
PIN 1. SOURCE 1
2. GATE 1
3. SOURCE 2
4. GATE 2
5. DRAIN 2
6. MIRROR 2
7. DRAIN 1
8. MIRROR 1
STYLE 20:
PIN 1. SOURCE (N)
2. GATE (N)
3. SOURCE (P)
4. GATE (P)
5. DRAIN
6. DRAIN
7. DRAIN
8. DRAIN
STYLE 21:
PIN 1. CATHODE 1
2. CATHODE 2
3. CATHODE 3
4. CATHODE 4
5. CATHODE 5
6. COMMON ANODE
7. COMMON ANODE
8. CATHODE 6
STYLE 22:
PIN 1. I/O LINE 1
2. COMMON CATHODE/VCC
3. COMMON CATHODE/VCC
4. I/O LINE 3
5. COMMON ANODE/GND
6. I/O LINE 4
7. I/O LINE 5
8. COMMON ANODE/GND
STYLE 23:
PIN 1. LINE 1 IN
2. COMMON ANODE/GND
3. COMMON ANODE/GND
4. LINE 2 IN
5. LINE 2 OUT
6. COMMON ANODE/GND
7. COMMON ANODE/GND
8. LINE 1 OUT
STYLE 24:
PIN 1. BASE
2. EMITTER
3. COLLECTOR/ANODE
4. COLLECTOR/ANODE
5. CATHODE
6. CATHODE
7. COLLECTOR/ANODE
8. COLLECTOR/ANODE
STYLE 25:
PIN 1. VIN
2. N/C
3. REXT
4. GND
5. IOUT
6. IOUT
7. IOUT
8. IOUT
STYLE 26:
PIN 1. GND
2. dv/dt
3. ENABLE
4. ILIMIT
5. SOURCE
6. SOURCE
7. SOURCE
8. VCC
STYLE 29:
PIN 1. BASE, DIE #1
2. EMITTER, #1
3. BASE, #2
4. EMITTER, #2
5. COLLECTOR, #2
6. COLLECTOR, #2
7. COLLECTOR, #1
8. COLLECTOR, #1
STYLE 30:
PIN 1. DRAIN 1
2. DRAIN 1
3. GATE 2
4. SOURCE 2
5. SOURCE 1/DRAIN 2
6. SOURCE 1/DRAIN 2
7. SOURCE 1/DRAIN 2
8. GATE 1
DOCUMENT NUMBER:
DESCRIPTION:
98ASB42564B
SOIC−8 NB
STYLE 27:
PIN 1. ILIMIT
2. OVLO
3. UVLO
4. INPUT+
5. SOURCE
6. SOURCE
7. SOURCE
8. DRAIN
STYLE 28:
PIN 1. SW_TO_GND
2. DASIC_OFF
3. DASIC_SW_DET
4. GND
5. V_MON
6. VBULK
7. VBULK
8. VIN
Electronic versions are uncontrolled except when accessed directly from the Document Repository.
Printed versions are uncontrolled except when stamped “CONTROLLED COPY” in red.
PAGE 2 OF 2
ON Semiconductor and
are trademarks of Semiconductor Components Industries, LLC dba ON Semiconductor or its subsidiaries in the United States and/or other countries.
ON Semiconductor reserves the right to make changes without further notice to any products herein. ON Semiconductor makes no warranty, representation or guarantee regarding
the suitability of its products for any particular purpose, nor does ON Semiconductor assume any liability arising out of the application or use of any product or circuit, and specifically
disclaims any and all liability, including without limitation special, consequential or incidental damages. ON Semiconductor does not convey any license under its patent rights nor the
rights of others.
© Semiconductor Components Industries, LLC, 2019
www.onsemi.com
ON Semiconductor and
are trademarks of Semiconductor Components Industries, LLC dba ON Semiconductor or its subsidiaries in the United States and/or other countries.
ON Semiconductor owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of ON Semiconductor’s product/patent
coverage may be accessed at www.onsemi.com/site/pdf/Patent−Marking.pdf. ON Semiconductor reserves the right to make changes without further notice to any products herein.
ON Semiconductor makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does ON Semiconductor assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
Buyer is responsible for its products and applications using ON Semiconductor products, including compliance with all laws, regulations and safety requirements or standards,
regardless of any support or applications information provided by ON Semiconductor. “Typical” parameters which may be provided in ON Semiconductor data sheets and/or
specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer
application by customer’s technical experts. ON Semiconductor does not convey any license under its patent rights nor the rights of others. ON Semiconductor products are not
designed, intended, or authorized for use as a critical component in life support systems or any FDA Class 3 medical devices or medical devices with a same or similar classification
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