July 7, 2009
IRS2552D
CCFL/EEFL BALLAST CONTROLLER IC
Features
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Product Summary
Drives up to two IGBT/MOSFET power devices
Integrated programmable oscillator
Soft start function
15.6 V voltage clamp on VCC
Micro-power startup
0 V to 5 V input analog dimming
Programmable ignition frequency
Programmable ignition time
Lamp current control
Programmable deadtime
Supports multi-lamp operation
Burst dimming with soft start at every burst
Latched open circuit protection
Integrated bootstrap functionality
Excellent latch immunity on all inputs & outputs
Integrated ESD protection on all pins
Topology
Half-Bridge
VOFFSET
600 V
VOUT
VCC
IO+ & IO- (typical)
300 mA & 450 mA
Deadtime
(programmable)
500ns ~ 2µs
Package Options
Typical Application
•
CCFL/EEFL inverter
16-Lead PDIP
16-Lead SOIC (Narrow Body)
Typical Application Diagram
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© 2009 International Rectifier
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IRS2552D
Table of Contents
Page
Typical Application Diagram
1
Qualification Information
4
Absolute Maximum Ratings
5
Recommended Operating Conditions
6
Electrical Characteristics
7
Functional Block Diagram
10
Lead Definitions
12
Lead Assignments
13
State Diagram
14
Application Information and Additional Details
15
Package Details
29
Part Marking Information
30
Ordering Information
32
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© 2009 International Rectifier
2
IRS2552D
Description
The IRS2552D incorporates a high voltage half-bridge gate driver with a front end that incorporates full control
functionality for CCFL/EEFL ballasts. Includes a programmable ignition and supports dimming via analog or PWM
control voltage. HVIC and latch immune CMOS technologies enable ruggedized monolithic construction. The
output driver features a high pulse current buffer stage designed for minimum driver cross-conduction. Noise
immunity is achieved with low di/dt peak of the gate drivers, and with an undervoltage lockout hysteresis of
approximately 1 V. The IRS2552D also includes protection features for over-current and over-voltage of the lamps.
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IRS2552D
Qualification Information†
Qualification Level
Moisture Sensitivity Level
Machine Model
ESD
Human Body Model
IC Latch-Up Test
RoHS Compliant
Industrial††
(per JEDEC JESD 47E)
Comments: This family of ICs has passed JEDEC’s
Industrial qualification. IR’s Consumer qualification level is
granted by extension of the higher Industrial level.
MSL3†††
SOIC16
(per IPC/JEDEC J-STD-020C)
Not applicable
PDIP16
(non-surface mount package style)
Class C
(per JEDEC standard EIA/JESD22-A115-A)
Class 3A
(per EIA/JEDEC standard JESD22-A114-B)
Class I, Level A
(per JESD78A)
Yes
†
††
Qualification standards can be found at International Rectifier’s web site http://www.irf.com/
Higher qualification ratings may be available should the user have such requirements. Please contact your
International Rectifier sales representative for further information.
††† Higher MSL ratings may be available for the specific package types listed here. Please contact your
International Rectifier sales representative for further information.
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© 2009 International Rectifier
4
IRS2552D
Absolute Maximum Ratings
Absolute maximum ratings indicate sustained limits beyond which damage to the device may occur. All voltage
parameters are absolute voltages referenced to COM, all currents are defined positive into any lead. The thermal
resistance and power dissipation ratings are measured under board mounted and still air conditions.
Symbol
VB
VS
VH
VL
VCO
VCT
VDT
MIN
DIM
CR
CD
SD
CS
ICC
dVS/dt
PD
RΘJA
TJ
TS
TL
†
Definition
High-side floating supply voltage
High-side floating supply offset voltage
High-side floating output voltage
Low-side output voltage
VCO pin voltage
CT pin voltage
DT pin voltage
MIN pin voltage
DIM pin voltage
CR pin voltage
CD pin voltage
SD pin voltage
CS pin voltage
†
Supply current
Allowable offset voltage slew rate
Package power dissipation @ TA ≤ +25
ºC
16L-PDIP
16L-SOIC
16L-PDIP
16L-SOIC
Thermal resistance, junction to ambient
Junction temperature
Storage temperature
Lead temperature (soldering, 10 seconds)
Min.
-0.3
VB - 25
VS – 0.3
-0.3
-0.3
-0.3
-0.3
-0.3
-0.3
-0.3
-0.3
-0.3
-0.3
---50
---------55
-55
---
Max.
625
VB + 0.3
VB + 0.3
VCC + 0.3
VCC + 0.3
VCC + 0.3
VCC + 0.3
VCC + 0.3
VCC + 0.3
VCC + 0.3
VCC + 0.3
VCC + 0.3
VCC + 0.3
25
50
1.3
1.4
70
82
150
150
300
Units
V
mA
V/ns
W
ºC/W
ºC
This IC contains a voltage clamp structure between the chip VCC and COM which has a nominal breakdown
voltage of 15.6 V. Please note that this supply pin should not be driven by a DC, low impedance power source
greater than the VCLAMP specified in the Electrical Characteristics section.
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5
IRS2552D
Recommended Operating Conditions
For proper operation the device should be used within the recommended conditions.
Symbol
VBS
VS
VCC
ICC
TJ
†
††
Definition
High-side floating supply voltage
Steady-state high-side floating supply offset voltage
Supply voltage
Supply current
Junction temperature
Min.
VCC – 0.7
†
-3.0
VCCUV+ +0.1V
††
-40
Max.
VCLAMP
600
VCLAMP
10
125
Units
V
mA
ºC
Care should be taken to avoid output switching conditions where the VS node flies inductively below ground
by more than 5 V.
Enough current should be supplied to the VCC pin of the IC to keep the internal 15.6 V zener diode clamping
the voltage at this pin.
Recommended Component Values
Symbol
RMIN
RMAX
RDT
CT
CDT
CR
CD
Component
MIN pin resistor value
MAX pin resistor value
DT pin resistor value
CT pin capacitor value
DT pin capacitor value
CR pin capacitor value
CD pin capacitor value
Min.
5
5
22
330
47
1
1
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Max.
Units
---
kΩ
---
pF
---
nF
© 2009 International Rectifier
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IRS2552D
Electrical Characteristics
VBIAS (VCC, VBS) = 14 V, CT = 1 nF and TA = 25 °C unless otherwise specified. The input parameters are referenced to
COM. The VO and IO parameters are referenced to COM and are applicable to the respective output leads: HO or
LO.
Symbol
Definition
Low Voltage Supply Characteristics
Min
Typ
Max
VCCUV+
Rising VCC undervoltage lockout threshold
9.5
10.5
11.5
VCCUV-
Falling VCC undervoltage lockout threshold
8.5
9.5
10.5
VCC undervoltage lockout hysteresis
0.5
1
1.5
Micropower startup VCC supply current
---
300
350
Quiescent VCC supply current
---
4.0
4.5
IQCCFLT
VCC supply current
---
0.9
1.3
ICC,FMIN
VCC current @ fosc = fMIN
---
4.7
5.3
VCLAMP
VCC clamp voltage
14.6
15.6
16.6
Micropower startup VBS supply current
---
6
20
VBS supply current
---
1000
1200
VBSUV+
VBS supply undervoltage positive going
threshold
6.5
7.5
8.5
VBSUV-
VBS supply undervoltage negative going
threshold
6.0
7.0
8.0
Offset supply leakage current
---
---
50
VCCUVHYS
IQCCUV
IQCC
Units
Test Conditions
V
N/A
µA
VCC = VCCUV+
-100 mV rising
RMIN = 12 kΩ, RUN
MODE CT = 0 V
mA
Fault mode
RMIN = 12 kΩ, RUN
MODE
V
ICC = 19 mA
Floating Supply Characteristics
IQBSUV
IBS
ILK
VCC ≤ VCCUV-,
µA
VCC = VBS
HO oscillating
V
N/A
μA
VB = VS = 600 V
Oscillator I/O Characteristics
fMIN
Minimum oscillator frequency
36.5
39
42.5
fMAX
Maximum oscillator frequency
67
69
71
VCT+
Upper CT ramp voltage threshold
4.8
5.0
5.2
VCT-
Lower CT ramp voltage threshold
---
0
---
CT pin source current
350
410
470
VMIN
VMIN pin voltage
4.8
5.0
5.2
VMAX
VMAX pin voltage
4.8
5.0
5.2
VMIN,FLT
VMIN voltage in fault mode
---
0
---
VMAX,FLT
VMAX voltage in fault mode
---
0
---
kHz
ICT
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RMIN = 12 kΩ, RUN
MODE
RMAX = 6.8 kΩ,
IGNITION MODE
V
N/A
μA
RMIN =12 kΩ, RUN
MODE
V
N/A
© 2009 International Rectifier
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IRS2552D
Electrical Characteristics
VBIAS (VCC, VBS) = 14 V, CT = 1 nF and TA = 25 °C unless otherwise specified. The input parameters are referenced to
COM. The VO and IO parameters are referenced to COM and are applicable to the respective output leads: HO or
LO.
Symbol
Ignition
Definition
Min
Typ
Max
Units
Test Conditions
ICR,IGN
Source current at CR pin in IGN mode
3.7
4.5
5.3
μA
RMIN = 12 kΩ,
IGNITION MODE
VCS,IGN
Ignition detection threshold
0.57
0.6
0.63
V
N/A
V
Gate Driver Output Characteristics
VOH
High-level output voltage, VBIAS – VO
---
VCC
---
VOL
Low-level output voltage, VO
---
COM
---
VOL,UV
UV-mode output voltage, VO
---
COM
---
tR
Output rise time
---
80
150
tF
Output fall time
---
45
100
tD
Output deadtime (HO or LO)
1.0
1.1
1.2
IO+
Output source current
---
300
---
IO-
Output sink current
---
450
---
13.2
13.5
mV
IO = 0 A
IO = 0 A,
VCC ≤ VCCUV-
ns
μs
N/A
RDT = 2.2 kΩ,
CDT = 1 nF
mA
N/A
---
V
N/A
Bootstrap FET Characteristics
VB,ON
VB when the bootstrap FET is on
IB,CAP
VB source current when FET is on
40
55
---
mA
CBS = 0.1 μF
IB,10V
VB source current when FET is on
9
12
---
mA
VB = 10 V
Shutdown threshold at SD pin
1.9
2.0
2.1
V
N/A
CD pin source current
3.7
4.5
5.3
μA
Threshold at which CD triggers shutdown
4.8
5.0
5.2
V
Shutdown
VSD,TH
ICD,source
VCD,TH
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VSD>VSD,TH,
RMIN = 12 kΩ
VCC = 14 V
© 2009 International Rectifier
8
IRS2552D
Electrical Characteristics
VBIAS (VCC, VBS) = 14 V, CT = 1 nF and TA = 25 °C unless otherwise specified. The input parameters are
referenced to COM. The VO and IO parameters are referenced to COM and are applicable to the respective
output leads: HO or LO.
Symbol
Definition
Min
Typ
Max
Units
Test Conditions
Over-Current Compensation
VCS,TH
Current compensation threshold at CS pin
1.15
1.21
1.27
V
ICD,OC
Source current at CD pin when the IC is in
current compensation mode
3.7
4.5
5.3
μA
VCD,oc
Voltage on CD where duty cycle reaches
minimum
4.8
5.0
5.2
V
DCMIN
Minimum HO duty cycle
---
10%
---
---
VCR+
CR pin upper threshold voltage
4.8
5.0
5.2
VCR-
CR pin lower threshold voltage
---
0.2
---
125
150
175
N/A
VCS>VCS,TH,
RMIN = 12 kΩ
N/A
VCD = 4.7 V,
RUN MODE
Dimming
ICR,RUN
Source current at CR pin in RUN mode
V
N/A
μA
RMIN = 12 kΩ
CR = 100 nF,
fCR
Frequency at CR pin
240
310
370
Hz
RUN MODE,
RMIN = 12 kΩ
Soft Start
DCMIN
Minimum HO duty cycle
---
10%
---
---
VCR,SS
End of soft start voltage
0.88
0.96
1.04
VDIM,SS
Soft start disable threshold
---
4.8
---
VENATH
Enable threshold
1.9
2.2
2.5
V
VENAHYS
Enable hysteresis
---
200
---
mV
V
VCR = 0 V,
VDIM < VDIM,SS
VDIM < VDIM,SS
N/A
Enable
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N/A
© 2009 International Rectifier
9
IRS2552D
Functional Block Diagram
IMIN
ICD
ICR_IGN
12
ICR_RUN
CS
0.6V
5V
1.21V
MIN 5
IGNITION
LOGIC
IMAX
5V
MAX 6
OVER
CURRENT
CONTROL
BAND
GAP
REF
5V
SOFT
START
CONTROL
CT 3
VBG
S
5V
0V
Q
R1
DEAD TIME
CONTROL
EN R2 Q
DUTY
CYCLE
CONTROL
DT 4
CD 10
LEVEL
SHIFT
5V
SD 11
2V
CR 9
DIM 7
Q
S
Q
R
PULSE
FILTER &
LATCH
16
VB
15
HO
14
VS
BOOT
STRAP
DRIVE
UV
1
5V
UVLO
UV
OUTPUT
LOGIC
EN
13
VCC
LO
15.6V
2
0.2V
8
COM
ENA
2.2V
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10
IRS2552D
Input/Output Pin Equivalent Circuit Diagrams: IRS2552D
VB
ESD
Diode
25V
HO
VCC
ESD
Diode
ESD
Diode
VS
CT
600V
ESD
Diode
VCC
RESD
RESD
ESD
Diode
COM
LO
25V
ESD
Diode
COM
VCC
ESD
Diode
MIN,
MAX
RESD
ESD
Diode
COM
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11
IRS2552D
Lead Definitions
Symbol
VCC
COM
Description
Logic and internal gate drive supply voltage
IC power and signal ground
CT
Oscillator timing capacitor
DT
Independent dead time R and C
MIN
RFMIN sets running frequency
MAX
RFMAX sets ignition mode frequency
DIM
0 to 5 V DC burst mode dimming control input
ENA
Chip Enable (2 V logic threshold)
CR
Burst dimming ramp
CD
Shutdown delay timing
SD
Open load detection
CS
Ignition detection (0.6 V threshold), over-current (1.2 V threshold)
LO
Low side output
VS
Half bridge
HO
High side output
VB
High side floating supply
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IRS2552D
Lead Assignments
VB 16
2 COM
HO 15
3 CT
4 DT
5 MIN
6 MAX
IRS2552D
1 VCC
VS 14
LO 13
CS 12
SD 11
7 DIM
CD 10
8 ENA
CR
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13
IRS2552D
State Diagram†
†
All values are typical. Applies to application circuit on page 1.
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IRS2552D
Application Information and Additional Details
Information regarding the following topics is included as subsections within this section of the datasheet.
•
•
•
•
•
•
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•
IGBT/MOSFET Gate Drive
Undervoltage Lockout Protection
Oscillator
Deadtime
Ignition
Run Mode
Lamp Current Control
Frequency, Current and Deadtime Calculation
Dimming Function
Soft Start
PCB Layout Tips
Additional Documentation
IGBT/MOSFET Gate Drive
The IRS2552D HVICs are designed to drive up to two MOSFET or IGBT power devices. Figures 1 and 2 illustrate
several parameters associated with the gate drive functionality of the HVIC. The output current of the HVIC, used to
drive the gate of the power switch, is defined as IO. The voltage that drives the gate of the external power switch is
defined as VHO for the high-side power switch and VLO for the low-side power switch; this parameter is sometimes
generically called VOUT and in this case does not differentiate between the high-side or low-side output voltage.
VB
(or VCC)
IO+
HO
(or LO)
+
VHO (or VLO)
VS
(or COM)
-
Figure 1: HVIC sourcing current
Figure 2: HVIC sinking current
Undervoltage Lock-Out
The IRS2552D includes an under voltage lockout circuit such that it remains in micro-power mode until the
voltage at VCC pin exceeds the VCCUV+ threshold. When VCC exceeds the VCCUV+ threshold the IRS2552D
oscillator starts up and gate drive signals appear at the LO and HO outputs, provided the ENABLE pin is
connected to a voltage source above VENATH. The LO output will always go high first in order to pre-charge the
bootstrap capacitor before the IRS2552D begins normal operation.
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IRS2552D
Oscillator
During UVLO and shutdown and the voltage at the MIN and MAX pins remain at 0 V. When VCC is raised above
VCCUV+ the oscillator will start and LO and HO will produce output drive waveforms at frequency FMAX. The MAX
pin sources 5 V and the resistance connected from this point to COM determines the CT charging current and
consequently the frequency. RMIN is always connected from the MIN pin to COM, which sets the RUN mode
frequency. In IGNITION mode the MAX pin supplies 5 V to RMAX, which is connected to COM setting a higher CT
charging current and consequently a higher ignition frequency, as RMAX is smaller than RMIN. In RUN mode the
MAX pin is no longer active and the voltage will drop to 0V. CT charges until the voltage reaches the 5 V
threshold and then it is discharged rapidly to VCT-. It then begins to charge again, repeating this sequence and
producing a saw tooth waveform. The MIN pin sources 5 V during IGNITION and RUN modes. The current
flowing through FMIN to COM determines the charging current of CT during RUN mode and also serves as a
current reference for the currents supplied from the CD and CR pins.
VCC
VCCUV+
CT
VCT+
VCT-
DT
1/3*VCC
LO
HO
Figure 3: Oscillator waveforms
Deadtime
In the IRS2552D the dead time is determined by an independent external timing circuit comprising of RDT and
CDT and is not affected by the values of CT, RMIN or RMAX. The DT pin voltage is held at COM when LO or HO is
high. CDT is charged through RDT, which is connected to VCC, when DT is internally disconnected from COM at
the start of the dead time. The dead time ends when CDT has charged to 1/3 VCC. This allows the dead time to
remain consistent over the working range of VCC, i.e. from UVLO+ to the clamp voltage of 15.6 V.
Ignition
During the IGNITION phase the CR capacitor is charged through an internal current source ICR_IGN. When CR
reaches VCR+ then if the voltage at CS is greater than VCSIGN, the IRS2552D will enter RUN mode. If the voltage
at the CS pin is less than VCSIGN the IRS2552D will enter FAULT mode whereby LO and HO will both go low and
the IRS2552D will shut down until VCC is reduced below VCCUV- and then increased above VCCU+. The ignition
function is achieved by applying a frequency somewhat above resonance to the output step up transformer and
resonant load. This should develop sufficient voltage across the lamps to allow partial ignition and some arc
current to flow. The combined lamp current is fed back to the CS pin through a suitable isolating network to
determine whether the lamps have ignited successfully. If a successful ignition is detected after the voltage at CR
has reached VCR+ then RMAX is disconnected inside the IRS2552D and the frequency will switch immediately to
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© 2009 International Rectifier
16
IRS2552D
to FMIN, therefore applying maximum power to the lamps. At this point the burst mode dimming function will be
enabled.
Run Mode
In RUN mode an additional current source ICR_RUN is also switched into the circuit. This causes CR to ramp up
to VCR+ much more rapidly than before. The CR pin is used to provide ignition timing as well as the burst mode
dimming low frequency ramp.
If the output is open circuit a very large voltage develops at the output. This is fed back to the SD pin through
some suitable isolated sensing network such that the voltage at the SD pin will exceed VSDTH during an overvoltage condition. At this stage the capacitor CD begins to charge through a current source. When VSD >
VSDTH the burst mode dimming function is disabled and the output will be continuous.
If the voltage at SD drops below VSDTH the capacitor CD will be discharged to 0V again. If SD remains above
VSDTH long enough for the CD capacitor voltage to reach VCDMAX or about 5 V then the IRS2552D will shut
down and go into fault mode.
Lamp Current Control
Additionally the half bridge current is monitored at the CS pin so that during running if too much power is
supplied to the lamps the IRS2552D is able to compensate by reducing the oscillator duty cycle while
maintaining the same run frequency. This prevents the lamps from being over driven preventing premature end
of life. When VCS > VCSTH the CD capacitor will begin to charge and the CD pin voltage will rise. As this occurs
the duty cycle will begin to adjust, i.e. the HO on time will become gradually shorter and the LO on time will
become gradually longer. The dead time will remain constant at all times. In this way the power to the output will
be reduced while the frequency remains at fMIN. As the CD voltage rises, the duty cycle will be further reduced. If
VCS then drops below VCSTH then the duty cycle will be regulated at that point and thus the current will be
maintained at this limit. If VCS remains above VCSTH then the voltage will continue to rise on CD until it reaches
VCDMAX, at which point the duty cycle reaches its minimum limit DCMIN and the IRS2552D will enter FAULT
mode, requiring VCC to fall below UVLO- and then rise above UVLO+ in order to re-start.
Frequency, Current, and Dead Time Calculation
The running frequency of the IRS2552D is given by the following formula:
f MIN =
1
2.09 ⋅ CT ⋅ RMIN
where VMIN = 5 V, i.e. When the ignition ramp is complete and RMAX has no further effect on the oscillator.
The ignition frequency given by:
f MAX =
1
2.09 ⋅ CT ⋅ RMAX
and the dead time is calculated by:
t DT = RDT ⋅ C DT ⋅ ln(1.5)
t DT = 0.405 ⋅ RDT ⋅ C DT
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IRS2552D
Maximum duty cycle
DCMAX = 0.5 − (t DT * f )
The ICR charging current during ignition mode and the ICD charging current are given by:
ICRIGN =
ICD =
0.06
RMIN
0.06
RMIN
The ICR charging current and frequency during run mode are given by:
ICRRUN =
f CR =
1.8
RMIN
0.36
RMIN ⋅ CCR
Dimming Function
The IRS2552D supports burst mode dimming, meaning that the output drive to the lamps is pulsed on and off at
a low frequency and the burst duty cycle is adjusted to control the average current and therefore the light output
of the lamps. The IRS2552D contains a low frequency oscillator that generates a ramp waveform at the CR pin
from 0 V to 5 V. The ramp frequency is dependent on the value of the external CR capacitor. A DC dimming
control voltage is fed into the DIM pin which is compared with the dimming ramp by means of an internal
comparator, which generates the PWM signal that is used internally to switch the outputs on and off. Thus when
the DIM voltage is at 5 V the outputs will be on all of the time and when it is at 0 V the outputs will be off all of the
time. Alternatively a PWM dimming control signal from 0 V to 5 V can be fed directly into the DIM pin to allow
external PWM control independent of the dimming ramp. During the off period the LO and HO outputs are both
low.
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© 2009 International Rectifier
18
IRS2552D
5V
CR
DIM
1V
0.2V
Soft Start
Soft Start
Soft Start
LO
HO
Duty cycle
increases from 10%
to 50%
Figure 4: Dimming waveform
RUN MODE
ICCRUN charges CR up to VCR+. CR oscillates at fCR (sawtooth)
Half-bridge oscillates at FMIN. VDC reset to 0V
SOFT START
ON
OFF
DC increases from DC
min to DC max
DC=DCmax
DC=0
VDIM
