Linear Technology pushes LED drivers without inductors
Linear Technology Corporation introduces the LTC3219, an inductorless, low noise, high efficiency LED driver for cellular phone display and illumination. The LTC3219 provides nine independent configurable current sources for the primary, secondary and RGB displays. The display current is set by a precise internal current reference. These universal current sources are digitally controllable with independent dimming, brightness, flicker and grayscale control and can be programmed via a simple two-wire I2C serial interface.
The LTC3219's 2.9V to 5.5V input voltage range has been optimized for single cell Li-Ion/Polymer battery applications. When driven with a lithium-ion battery (3.6V nominal), the efficiency is 91% and the quiescent current is only 400uA, maximizing battery life. Switching with limited slew rate reduces conducted and radiated noise (EMI).
The LTC3219's multimode charge pump operates at a low noise constant frequency and automatically optimizes efficiency based on the voltage on the LED current source. The device powers up in 1x mode and automatically switches to boost mode (1.5x) when any startup LED current source experiences a dropout voltage, and the subsequent voltage drop switches the device to double voltage mode (2x). Internal circuitry prevents inrush current and excessive input noise during startup and mode switching. In addition, the device features short-circuit and over-temperature protection.
The LTC3219 is available in a low profile (0.75mm) 20-lead QFN (3mm x 3mm) package. The IC requires only five small capacitors to form a tiny, complete LED power and current Controller solution. Buy in 1,000-piece quantities starting at $1.80 each.
Performance Summary: LTC3219
Multi-mode (1x/1.5x/2x), low noise charge pump for up to 91% efficiency
Switching rate limited switches reduce conducted and radiated noise (EMI)
Up to 250mA total output current
9 independently configurable 28mA current sources with 64 linear brightness control stages
Independent on/off, brightness level, flicker and grayscale control for each current source using a two-wire I2C interface
2.9V to 5.5V input voltage range optimized for Li-Ion/Polymer battery applications
Internal current reference
Configurable ENU pin for asynchronous LED on/off control
Automatic or manual mode switching
Internal soft start limits inrush current
Short circuit / overheat protection
Slim, flat 3mm x 3mm x 0.75mm QFN-20 package
1
Bamboo Flooring,Bamboo Strand Woven Flooring,Strand Woven Flooring
Ruixiang M&E Co., Ltd. , http://www.gzcurtainmotor.com