April 19, 2012 – Linear Technology Korea (CEO Hong Sa-kwak) announced the development of the LT3796, a 100V high-side current sensing DC/DC controller designed to regulate constant current or constant voltage. This product is ideal for driving high brightness (HB) LEDs, and its input voltage range of 6V to 100V supports various applications including automotive, industrial, and architectural lighting. The LT3796 uses an external N-channel MOSFET and can drive white LEDs up to 85V at a nominal 12V input, capable of supplying over 50W. The LT3796 is ideal for charging batteries or supercaps at constant current and voltage.
The LT3796 includes high-side current sensing capability and can be used in boost, buck, buck-boost or SEPIC and flyback topologies. Furthermore, by providing limiting and monitoring functions for both input and output currents, it enhances reliability and design flexibility. The LT3796 delivers efficiency exceeding 94% in boost mode, minimizing the need for external heat sinking. Users can program frequencies in the range of 100kHz to 1MHz using the frequency adjustment pin, optimizing efficiency while minimizing external component size and cost. Using a TSSOP-28 package with enhanced thermal performance, the LT3796 provides a very compact high brightness LED driver or charger solution.
The LT3796 can provide consistent LED color with a 3,000:1 dimming range using True Color PWM™ dimming capability. For less demanding dimming requirements, the CTRL pin can be used to provide a 10:1 analog dimming range. The fixed frequency, current mode architecture ensures stable operation across a wide range of supply and output voltages.
Robust open and short circuit protection functions maximize overall system reliability, and the C/10 detection function optimizes both battery and supercap charging designs. Additionally, this product provides features such as frequency synchronization, programmable UVLO and restart timer on fault occurrence.
The LT3796EFE is offered in a TSSOP-28 package with enhanced thermal performance, with pricing starting at $3.45 per unit. The temperature extended version or I-grade LT3796IFE is also available, with pricing starting at $3.86 per unit. The high temperature or H-grade option LT3796HFE is also being supplied, with pricing at $4.11 per unit. All stated prices are based on quantities of 1,000 units, and all products are currently available for immediate purchase. For detailed product information, refer to www.linear.com/product/LT3796.

Photo caption: 100V, Constant Current and Constant Voltage Controller

Product Features: LT3796

• 3,000:1 True Color PWM™ Dimming
• Wide Input Voltage Range: 6V to 100V
• Current Monitoring up to 100V
• High-side PMOS gate driver and PWM switch driver
• Constant current and constant voltage regulation
• Dual current sense amplifier with report function
• C/10 detection function for battery and supercap charging
• Linear current sense threshold programming
• Short circuit protection function
• Adjustable frequency: 100kHz to 1MHz
• Frequency synchronization
• Open LED protection function programmable with VMODE flag
• Programmable undervoltage lockout function with hysteresis
• Soft start implementation with programmable fault restart timer function
• Low shutdown current: less than 1µA
• Offered in 28-pin TSSOP package