Document
FL7732 — Single-Stage PFC Primary-Side-Regulation Offline LED Driver
October 2012
FL7732 Single-Stage PFC Primary-Side-Regulation Offline LED Driver
Features
Cost-Effective Solution: No Input Bulk Capacitor or
Feedback Circuitry
Power Factor Correction Accurate Constant-Current (CC) Control,
Independent Online Voltage, Output Voltage, and Magnetizing Inductance Variation
Linear Frequency Control Improves Efficiency and
Simplifies Design
Open-LED Protection Short-LED Protection Cycle-by-Cycle Current Limiting Over-Temperature Protection with Auto Restart Low Startup Current: 20 μA Low Operating Current: 5 mA VDD Under-Voltage Lockout (UVLO) Gate Output Maximum Voltage Clamped at 18 V SOP-8 Package Application Voltage Range: 80 VAC ~ 308 VAC
Applications
LED Lighting System
Description
This highly integrated PWM controller provides several features to enhance the performance of low-power flyback converters. The proprietary topology, TRUECURRENT® enables simplified circuit design for LED lighting applications.
By using single-stage topology with primary-side regulation, a LED lighting board can be implemented with few external components and minimized cost. No input bulk capacitor or feedback circuitry is required. To implement good power factor and low THD, constant on-time control is utilized with an external capacitor connected to the COMI pin.
Precise constant-current control regulates accurate output current versus changes in input voltage and output voltage. The operating frequency is proportionally adjusted by the output voltage to guarantee DCM operation with higher efficiency and simpler design.
FL7732 provides open-LED, short-LED, and overtemperature protection features. The current limit level is automatically reduced to minimize output current and protect external components in a short-LED condition.
The FL7732 controller is available in an 8-pin SmallOutline Package (SOP).
Ordering Information
Part Number
FL7732M_F116
Operating Temperature Range
Package
-40°C to +125°C 8-Lead, Small Outline Integrated Circuit Package (SOIC)
Packing Method
Tape & Reel
© 2011 Fairchild Semiconductor Corporation FL7732 • Rev. 1.0.6
www.fairchildsemi.com
FL7732 — Single-Stage PFC Primary-Side-Regulation Offline LED Driver
Application Diagram
Internal Block Diagram
Figure 1. Typical Application
© 2011 Fairchild Semiconductor Corporation FL7732 • Rev. 1.0.6
Figure 2. Functional Block Diagram
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FL7732 — Single-Stage PFC Primary-Side-Regulation Offline LED Driver
Marking Information Pin Configuration
F: Fairchild Logo Z: Plant Code X: 1-Digit Year Code Y: 1-Digit Week Code TT: 2-Digit Die Run Code T: Package Type (M=SOP) M: Manufacture Flow Code
Figure 3. Top Mark
Figure 4. Pin Configuration
Pin Definitions
Pin #
1
2 3 4 5
6
7 8
Name
CS
GATE GND VDD NC
VS
COMI GND
Description
Current Sense. This pin connects a current-sense resistor to detect the MOSFET current for the output-current regulation in constant-current regulation.
PWM Signal Output. This pin uses the internal totem-pole output driver to drive the power MOSFET.
Ground
Power Supply. IC operating current and MOSFET driving current are supplied using this pin.
No Connect
Voltage Sense. This pin detects the output voltage information and discharge time for maximum frequency control and constant current regulation. This pin is connected to an auxiliary winding of the transformer via resistors of the divider.
Constant Current Loop Compensation. This pin is connected to a capacitor between the COMI and GND pin for compensation current loop gain.
Ground
© 2011 Fairchild Semiconductor Corporation FL7732 • Rev. 1.0.6
3
www.fairchildsemi.com
FL7732 — Single-Stage PFC Primary-Side-Regulation Offline LED Driver
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only.
Symbol
Parameter
Min. Max. Unit
VVDD
DC Supply Voltage(1,2)
30 V
VVS VS Pin Voltage
-0.3 7
V
VCS CS Pin Input Voltage
-0.3 7
V
VCOMI COMI Pin Input Voltage
-0.3 7
V
VGATE GATE Pin Input Voltage
-0.3 30
V
PD Power Dissipation (TA<50°C)
633 mW
ΘJA Thermal Resistance (Junction-to-Air)
158 °C /W
ΘJC Thermal Resistance (Junction-to-Case)
39 °C /W
TJ Maximum Junction Temperature
150 °C
TSTG Storage Temperature Range
-55 150
°C
TL Lead Temperature (Soldering 10 s)
260 °C
Notes:
1. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. 2. All voltage values, except differential voltages, are given with respect to the GND pin.
© 2011 Fairchild Semiconductor Corporation FL7732 • Rev. 1.0.6
4
www.fairchildsemi.