LYT4216E Power Integrations, LYT4216E Datasheet - Page 11

• Manufacturer Part Number: LYT4216E
• Description: LED Lighting Drivers HighPower LED Driver 35W
• Manufacturer: Power Integrations

Specifications of LYT4216E

• Rohs: yes
• Input Voltage: 85 V to 132 V
• Operating Frequency: 124 kHz to 140 kHz
• Maximum Supply Current: 1.2 mA
• Output Current: 2.83 A
• Maximum Operating Temperature: + 150 C
• Mounting Style: Through Hole
• Package / Case: eSIP-7C
• Minimum Operating Temperature: - 40 C

Audible Noise Considerations for Use with
Leading Edge Dimmers
Noise created when dimming is typically created by the input
capacitors, EMI filter inductors and the transformer. The input
capacitors and inductors experience high di/dt and dv/dt every
AC half-cycle as the TRIAC fires and an inrush current flows to
charge the input capacitance. Noise can be minimized by
selecting film vs. ceramic capacitors, minimizing the capacitor
value and selecting inductors that are physically short and wide.
The transformer may also create noise which can be minimized
by avoiding cores with long narrow legs (high mechanical
resonant frequency). For example, RM cores produce less
audible noise than EE cores for the same flux density. Reducing
the core flux density will also reduce the noise. Reducing the
maximum flux density (BM) to 1500 Gauss usually eliminates
any audible noise but must be balanced with the increased core
size needed for a given output power.
Thermal and Lifetime Considerations
Lighting applications present thermal challenges to the driver.
In many cases the LED load dissipation determines the working
ambient temperature experienced by the drive so thermal
evaluation should be performed with the driver inside the final
enclosure. Temperature has a direct impact on driver and LED
Figure 13. DER-350 25 W Layout Example, Top Silk / Bottom Layer.
www.powerint.com
Input EMI Filter
REFERENCE Pin
Resistor
FEEDBACK Pin
Resistor
Capacitor
Bullk
VOLTAGE MONITOR Pin
Resistor
LYT4317EG
lifetime. For every 10 °C rise in temperature, component life is
reduced by a factor of 2. Therefore it is important to properly
heat sink and to verify the operating temperatures of all devices.
Layout Considerations
Primary-Side Connections
Use a single point (Kelvin) connection at the negative terminal of
the input filter capacitor for the SOURCE pin and bias returns.
This improves surge capabilities by returning surge currents
from the bias winding directly to the input filter capacitor. The
BYPASS pin capacitor should be located as close to the
BYPASS pin and connected as close to the SOURCE pin as
possible. The SOURCE pin trace should not be shared with the
main power FET switching currents. All FEEDBACK pin
components that connect to the SOURCE pin should follow the
same rules as the BYPASS pin capacitor. It is critical that the
main power FET switching currents return to the bulk capacitor
with the shortest path as possible. Long high current paths
create excessive conducted and radiated noise.
Secondary-Side Connections
The output rectifier and output filter capacitor should be as
close as possible. The transformer’s output return pin should
have a short trace to the return side of the output filter capacitor.
BYPASS Pin
Capacitor
LYT4211-4218/4311-4318
Clamp Transformer Output
Capacitor
Output
Capacitors
Output
PI-6904-101612
Diode
Rev. B 02/13
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