Document
OB3340
High PF, High CC Buck Topology LED driver
Product Specification
GENERAL DESCRIPTION
The OB3340 is a high power factor and high constant current precision LED driver for LED lighting applications. An analog multiplier for power factor correction (PFC), zero current detector (ZCD) to ensure TM operation and a feedback circuit to achieve constant LED current, a current sensing comparator with built-in leadingedge blanking ensures safe operation during short-circuit at the output, and a totem pole output ideally suited for driving a power MOSFET. OB3340 provides comprehensive protection features including system VCC under voltage lockout (UVLO), Output short\open protection, Cycle by cycle current limiting, and gate drive output clamping for external power MOSFET protection.
FEATURES
High Precision Constant Output Current Analog multiplier for High Power Factor
Correction Low Start-up Current and Operating Current Internal Startup Timer for Stand-alone
Applications Transition Mode (TM) Operation Internal Leading Edge Blanking Cycle-by-Cycle Current Limiting Totem Pole Output with High State Clamping Under Voltage Lockout with Hysteresis VCC over voltage protection Output short/open protection Audio Noise Free 11V to 32V wide range of VCC voltage
APPLICATIONS
LED Lighting Power
TYPICAL APPLICATION
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Preliminary Datasheet OB_DOC_DS_334000
GENERAL INFORMATION
Terminal Assignment In SOP8 Package.
FB 1
8
VCC
COMP
2
7 GD
MULT
3
6 GND
CS 4
5 ZCD
Ordering Information
Part Number OB3340CP
Description 8 Pin SOP, Pb-free in Tube
OB3340CPA
8 Pin SOP, Pb-free in T&R
Package Dissipation Rating
Package
RJA (℃/W)
SOP8
150
OB3340
High PF, High CC Buck Topology LED driver
Absolute Maximum Ratings
Symbol VCC
I_ZCD
CS FB COMP MULT
Tj
Tstg
Lead Temperature
Parameter DC Supply voltage Zero Current Detector Max. Current
Analog inputs & outputs
Min/Max Operating Junction Temperature Min/Max Storage Temperature (Soldering, 10secs)
Value Vz 50mA(source) -10mA(sink)
-0.3 to 7V
-40 to 150 ℃
-55 to 150 ℃ 260 ℃
Note: Stresses beyond those listed under “absolute
maximum ratings” may cause permanent damage to the device. These are stress ratings only, functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute maximum-rated conditions for extended periods may affect device reliability.
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Preliminary Datasheet OB_DOC_DS_334000
Marking Information
OB3340
High PF, High CC Buck Topology LED driver
YWWZZZ OB3340CP
s
Y: Year Code WW: Week Code (01-52) ZZZ: Lot Code C: SOP8 P:Pb-free s: internal code
TERMINAL DESCRIPTIONS
Pin Num Pin Name 1 FB
2 COMP
3 MULT
4 CS 5 ZCD 6 GND 7 GD 8 VCC
I/O Description
I Input of error amplifier.
Output of error amplifier. A compensation network is placed between
O COMP and the GND pin. The voltage between COMP and GND pin
generate PWM duty cycle.
Input of multiplier. Connected to line voltage after bridge diodes via a
I resistor divider to provide sinusoidal reference voltage to the current
loop.
I Current sense input pin. Connected to MOSFET current sensing node.
I
Zero Current Detection input. When activated, A new switching cycle starts.
P Ground pin
O Gate driver output. Drive power MOSFET.
P DC supply voltage.
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©On-Bright Electronics
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Preliminary Datasheet OB_DOC_DS_334000
BLOCK DIAGRAM
OB3340
High PF, High CC Buck Topology LED driver
On-Bright Confidential to
©On-Bright Electronics
Confidential -4-
Preliminary Datasheet OB_DOC_DS_334000
On-Bright Confidential to
OB3340
High PF, High CC Buck Topology LED driver
ELECTRICAL CHARACTERISTICS
(TA = 25℃ if not otherwise noted)
Symbol Pin Parameter
SUPPLY VOLTAGE SECTION
Vcc 8 Operating Range
UVLO(OFF) 8
VCC under voltage lockout exit
UVLO(ON) 8
VCC under voltage lockout enter
Hys 8 Hysteresis
Vz
8
VCC Zener Voltage
Clamp
Vcc_ovp 8 VCC OVP threshold
SUPPLY CURRENT SECTION
Icc-start 8 Start-up Current
Iq
8
Quiescent Current, Switching
No
Icc 8 Operating Supply Current
ERROR AMPLIFIER SECTION
VREF
1 EA Reference
Gm EA transconductance
ICOMP
2
Source Current Sink Current
VCOMP 2
Upper Clamp Voltage Lower Clamp Voltage
MULTIPLIER SECTION
Vmult
3 Linear Operating Range
K Gain
CURRENT SENSE COMPARATOR
Vcs
4
Current Sense Reference Clamp
Td(H-L) 4 Delay to Output
ZERO CURRENT DETECTOR
Vzcd
5
Input Threshold Voltage Trigger level
Vzcd_hys
ZCD trigger Hysteresis
Vzcd
5 Upper Clamp Voltage
Vzcd
5 Lower Clamp Voltage
Izcd 5 Source Current Capability
Izcd 5 Sink Current Capability
TIMER Tstart Ton_max
Re-Start Timer Period Maximum Ton
GATE DRIVE SECTION VoL 7 Low Output Voltage VoH 7 High Output Voltage Tr 7 Rising Time Tf 7 Falling Time Voclamp.