National Semiconductor NS (National Semiconductor) introduces the first boosted HighSide synchronous rectified LED driver, the LM3554, which supports dual-LED camera flash for battery-powered portable products such as mobile phones, smart phones and portable Scanner. The LM3554 can drive 1 or 2 high-current LEDs and is a new addition to the NSPowerWise family.
The LM3554 uses the National Semiconductor LM3554 chip's entire LED flash boost converter solution to be very compact and no larger than 23mm2. The chip is available in a 16-pin microSMD package. In addition, this chip has a monitoring pin, which can detect whether other circuits of the system are consuming a large amount of current, and flexibly adjust the current of the LED when necessary, so as to avoid excessive power consumption of the battery and cause the system to malfunction or be damaged. . Since the brightness output of the LED has a nonlinear relationship with the LED current, even with the same amount of light output, the power consumption of the dual LED architecture is still lower than that of the one LED.
The LM3554 flash LED driver is a fixed frequency step-up DC/DC converter featuring two stable current sources that can drive up to 1.2A with a single Li-Ion battery. The LM3554 can use a high-power flash mode to support camera functions, or a low-power flashlight mode to support video recording.
The LM3554 has an adjustable switch current limit that allows the system to use small inductors with low saturation current. The chip provides a 5V power supply to drive the LED backlight and power the audio amplifier. Engineers can use an internal scratchpad or external control pin (Strobe orTorch) to drive 1 or 2 high-current LEDs in high-power flash mode or low-power flashlight mode.
In addition, the system can also independently control the related hardware through the general-purpose input/output (GPIO) pin, so that the I2C interface can fully control the operation of the chip in the event of communication problems. The chip also has an internal soft-start function that suppresses a large amount of surge current during startup and high-frequency switching, allowing the system to use small external components.
The conventional flash LED driver uses a current recovery method to recover the current that drives the high current LED, that is, all current is returned to the driver, causing the driver to generate a large amount of heat, so that the reliability of the system is also affected. The LM3554 uses a dual LED HighSide current drive architecture to provide stable drive current for both LEDs. The cathode of the LED is directly grounded. This grounded design not only enhances heat dissipation, but also simplifies wiring and protects sensitive circuits.
The LM3554 uses the National Semiconductor LM3554 chip's entire LED flash boost converter solution to be very compact and no larger than 23mm2. The chip is available in a 16-pin microSMD package. In addition, this chip has a monitoring pin, which can detect whether other circuits of the system are consuming a large amount of current, and flexibly adjust the current of the LED when necessary, so as to avoid excessive power consumption of the battery and cause the system to malfunction or be damaged. . Since the brightness output of the LED has a nonlinear relationship with the LED current, even with the same amount of light output, the power consumption of the dual LED architecture is still lower than that of the one LED.
The LM3554 flash LED driver is a fixed frequency step-up DC/DC converter featuring two stable current sources that can drive up to 1.2A with a single Li-Ion battery. The LM3554 can use a high-power flash mode to support camera functions, or a low-power flashlight mode to support video recording.
The LM3554 has an adjustable switch current limit that allows the system to use small inductors with low saturation current. The chip provides a 5V power supply to drive the LED backlight and power the audio amplifier. Engineers can use an internal scratchpad or external control pin (Strobe orTorch) to drive 1 or 2 high-current LEDs in high-power flash mode or low-power flashlight mode.
In addition, the system can also independently control the related hardware through the general-purpose input/output (GPIO) pin, so that the I2C interface can fully control the operation of the chip in the event of communication problems. The chip also has an internal soft-start function that suppresses a large amount of surge current during startup and high-frequency switching, allowing the system to use small external components.
The conventional flash LED driver uses a current recovery method to recover the current that drives the high current LED, that is, all current is returned to the driver, causing the driver to generate a large amount of heat, so that the reliability of the system is also affected. The LM3554 uses a dual LED HighSide current drive architecture to provide stable drive current for both LEDs. The cathode of the LED is directly grounded. This grounded design not only enhances heat dissipation, but also simplifies wiring and protects sensitive circuits.
Gravure Printing Ink,Gravure Ink,Printing Ink
Foshan Lanxun Trading Co., Ltd. , http://www.chpigmentpaste.com