LYT4211-4218/4311-4318

LYTSwitch High Power LED Driver IC Family

www.powerint.com

February 2013

Single-Stage Accurate Primary-Side Constant Current (CC) Controller with

PFC for Low-Line Applications, TRIAC Dimming and Non-Dimming Options

™

Product Highlights

•

Better than ±5% CC regulation

•

TRIAC dimmable to less than 5% output

•

Fast start-up

•

<250 ms at full brightness

•

<1s at 10% brightness

•

High power factor >0.9

•

Easily meets EN61000-3-2

•

Less than 10% THD in optimized designs

•

Up to 92% efficient

•

132 kHz switching frequency for small magnetics

High Performance, Combined Driver, Controller, Switch

The LYTSwitch family enables off-line LED drivers with high

power factor which easily meet international requirements for THD

and harmonics. Output current is tightly regulated with better

achieved in typical applications.

Supports a Wide Selection of TRIAC Dimmers

The LYTSwitch family provides excellent turn-on characteristics

for leading-edge and trailing-edge TRIAC dimming applications.

This results in drivers with a wide dimming range and fast

start-up, even when turning-on from a low conduction angle.

Large dimming ratio and low “pop-on” current.

Low Solution Cost and Long Lifetime

LYTSwitch ICs are highly integrated and employ a primary-side

control technique that eliminates the optoisolator and reduces

component count. This allows the use of low-cost single-sided

printed circuit boards. Combining PFC and CC functions into a

single-stage also helps reduce cost and increase efficiency. The

132 kHz switching frequency permits the use of small, low-cost

magnetics.

LED drivers using the LYTSwitch family do not use primary-side

aluminum electrolytic bulk capacitors. This means greatly

extended driver lifetime, especially in bulb and other high

temperature applications.

Figure 1.

Typical Schematic.

CONTROL

Part Number

Input Voltage Range

TRIAC Dimmable

LYT4211-LYT4218

85-132 VAC

No

LYT4311-LYT4318

85-132 VAC

Yes

2.5 W

12 W

LYT4x12E/L

2.5 W

15 W

LYT4x13E/L

3.8 W

18 W

LYT4x14E/L

4.5 W

22 W

LYT4x15E/L

5.5 W

25 W

LYT4x16E/L

6.8 W

35 W

LYT4x17E/L

8.0 W

50 W

LYT4x18E/L

18 W

78 W

Table 1. Output Power Table.

Notes:

1. Performance for typical design. See Applications section.

2. Continuous power in an open-frame design with adequate heat sinking; device

local ambient of 70 °C. Power level calculated assuming a typical LED string

voltage and efficiency >80%.

3. Minimum output power requires C

4. Maximum output power requires C

5. LYT4311 C

6. Package: eSIP-7C, eSIP-7F (see Figure 2).

Figure 2.

Package Options.

eSIP-7F (L Package)

eSIP-7C (E Package)

Optimized for Different Applications and Power Levels