CMOS LED ICs are drop-in replacements for bipolar drivers

Taiwan Semiconductor announces the availability of the TSCR4 family of linear CMOS LED driver ICs, providing a much-improved performance drop-in replacement for legacy bipolar drivers. These constant current drivers provide stable LED current over a wide range of conditions including source voltage variations, changes in load or temperature variations. Compared to legacy bipolar LED drivers, the TSCR4 family offers higher current setpoint accuracy and stability, lower quiescent current, tighter output compliance voltage and improved temperature coefficient. These ICs enable upgrades of existing designs for higher performance with no re-design effort required.

The TSCR4 family of linear constant current LED drivers offers designers a number of benefits and improvements over competing bipolar devices:

• Higher accuracy of output current. Improves manufacturing yields in mass production.
• Lower quiescent current (e.g., 300ma vs 1A @ 24 VDC). Lowers power dissipation and reduces battery standby and operating power consumption.
• More precise output voltage drop. CMOS control of voltage drop enables operation closer to the rail.
• Higher stability of output current. Delivers consistent brightness control and extends LED life.
• Better temperature coefficient (-0.07%/ C). Controls output current with temperature increases to eliminate risk of thermal runaway.
• AEC-Q100 parts available. Ideal for many basic automotive lighting applications.
• PWM dimming. Up to 10KHz digital input for 0 to 100% dimming (TSCR421CX6/H).
• Supply voltage up to 40V. Supports large LED arrays.
• Easy parallel driver structure.

Applications include automobile, truck, and bus interior and exterior lighting, architectural lighting, signage, advertising and decorative lighting, lighting in refrigerators, freezer cases, kiosks and vending machines, emergency lighting (EXIT signs, stairstep and emergency exit pathway lighting systems).

Design resources include a comprehensive datasheet and interactive designer worksheet.

Price in OEM Quantities) for the AEC-Q100 version is from $0.46; General Purpose is from $0.31. Samples in-stock (Digi-Key and Mouser)