An introduction of 5V, 1.3A/2.3A LED and LT3518 driver LT3517

Linear Technology Corporation (Linear Technology Corporation) launched LT3517 and LT3518. These two devices are 45V, high-voltage side current detection DC/DC converter, used to drive large current LED. Its 3V to 30V input voltage range (transient protection up to 40V) makes these two devices very suitable for a variety of applications, such as automotive, industrial and architectural lighting. In addition to the switch current limit values, LT3517 and LT3518 are exactly the same. The LT3517 features an internal 1.3A switch, while the LT3518 internal switch is 2.3A.

LT3518 can be driven with 12V input up to 10 350mA white LED, while the LT3517 can drive up to 5, so they are very suitable for a variety of applications, such as automotive display backlighting. The two devices feature a compact 4mm 4mm QFN package, which has an efficiency of up to 90% in the boost mode. They use True Color dimming to achieve constant LED color, dimming ratio is higher than PWMTM (3000:1). In the case of lower dimming requirements, the CTRL pin can be used to provide analog dimming of the 10:1. The fixed frequency and current mode architecture achieves stable operation over a wide power supply and output voltage range. The frequency regulation pin allows the user to optimize the frequency between 250kHz and 2.5MHz in order to optimize the efficiency while minimizing the size of the external components.

LT3517 and LT3518 on the high side of the LED output current detection, buck, buck - boost or boost configuration. Other features include the LED open circuit protection, the gate driver for PMOS LED disconnection and soft start.

LT3517EUF and LT3518EUF are available in 16 pin QFN package, available in stock, purchased in bulk for $2.70 and $2.95 per unit for $1000. Extended temperature version or "I" version (LT3517IUF and LT3518IUF) also available from stock. In 1000 pieces for the bulk purchase, each price of $3.24 and $3.54.

Photo caption: 45V LED driver

Performance overview: LT3517/LT3518

3000:1 True Color dimming PWM

1.3A, 45V internal switch (LT3517)

2.3A, 45V internal switch (LT3518)

100mV high side current detection

LED open circuit protection

adjustable frequency: 250kHz to 2.5MHz

Wide input voltage range:

- work in the 3V to 30V range

Transient protection up to 40V

boost, buck and buck boost mode

gate driver for PMOS LED disconnection

Constant current and constant voltage regulation

CTRL pin provides 10:1 analog dimming

Low shutdown current: