LED controller meets voltage range for industrial use
The LT3762 is a 60V output, high efficiency, synchronous, boost LED driver controller from Analog Devices. The Power by Linear device has a programmable internal LED PWM signal generator and spread spectrum frequency modulation that yield low EMI noise, adds the company.
The versatile LED driver controller includes a rail-to-rail current sense amplifier, enabling high side or low side current sensing that, in addition to synchronous boost, facilitates synchronous buck-mode and buck-boost mode topologies and non-synchronous SEPIC designs.
The 2.5 to 38.5V input voltage range and synchronous operation make the LT3762 suitable for automotive power systems, portable instruments, industrial applications, medical instruments and architectural lighting. An auxiliary on-chip buck-boost converter provides the necessary gate drive voltage in low voltage systems, and when combined with a low 500 microA maximum quiescent current and one microA shutdown current (TA = 25 degree C), results in high efficiency over wide input voltage and output current ranges.
In systems where EMI is a concern, the LT3762’s optional spread spectrum frequency modulation can be enabled to reduce the effective switching frequency noise, says Analog Devices. An on-chip PWM signal generator is synchronised to the internal oscillator for lowest noise performance. Internal PWM generation provides 250:1 dimming; external 3000:1 dimming or analogue dimming can also be employed.
Other features of the constant current and constant voltage LT3762 include current mode operation with cycle-by-cycle current limiting, adjustable 100kHz to 1MHz switching, programmable under-voltage lockout, open LED and short-circuit protection with fault status indicators, LED over-current protection and thermal shutdown.
The LT3762 is available in thermally enhanced 28-lead TSSOP and QFN packages, measuring 4.0 x 5.0mm. Three temperature grades are available, with operation from –40 to +125 degree C (junction) for the extended and industrial grades, and a high temperature grade of –40 to +150 degree C.
