Leadies launched a new four white noise series LED driver circuit

Leadis Technology Co. Ltd. (Leadis Technology Inc.) has recently announced the supply of high-performance product samples four white noise LED driver circuit of LDS8845 and LDS8846. This series is aimed at a new generation of low-cost mobile phones and portable devices with lower VF white light LED and lower cost TFT-LCD components. Ridis is the first to develop analog and mixed signal semiconductor devices suitable for consumer electronics products, including color display drivers, power management, LED drives, and audio integrated circuits.

Leadies LED Driver Senior Director Adolfo Garcia said: "leadies launched LDS8845 and LDS8846, for the latest trends in the market with mobile phone use low VF white LED applications. He added: low VF white LED can reduce the need to increase the drive output voltage when the built-in boost converter, easy to make LED current up to the absolute accuracy of the current and the accuracy of the circuit pairing. Current white LED drive products are commonly used in dual mode (1 times /2 times) or a three mode (1 times /1.5 times /2) charge pump converter. Reducing the boost converter means saving up to two ceramic capacitors at a cost. Other advantages include: (1) can reduce the whole circuit of Form Factor (up to 13%); (2) the LED driver does not produce noise; and (3) because the current battery supply device and the overall LED output current of the same amount, so compared with other competitors in each charge can longer battery life. "

Although this series of white LED driver design is simplified, but its performance is not inferior. The 7.5% series of all products corresponding to each part of LED are better than the current precision, circuit between the accuracy is better than that of 3%, dual mode or three mode charge pump compared to other white LED driver with a minimum of more than 25% increase. In order to reduce or eliminate the audio noise jamming devices, these two products provide real load off the output current, overload protection, protection and 100 kHz LED rated current control interface automatically shut down overheating.

For the lithium battery to 98% efficiency, LDS8845 and LDS8846 using PowerLite current regulator made independent thinking patent to maintain voltage differential pressure below 50 mv. The company's PCR technology is applied to this device, so that the new series of white LED driver LDS8845 and LDS8846 can operate at lower system power down voltage, and can still maintain excellent LED rectifier function.

LDS8845 profile

LDS8845 devices use 0.8 mm high, 16 pin TQFN package (3 mm x 3 mm), operating voltage from 2.7 volts (V) to 5.5 volts. The 15 thousand and 800 ohm resistor with a low price will achieve the full output current value of the device to a full load of 30 Ma, and allow the system to be designed to be fully loaded with a LED output below the full load level when needed. The 2 pin PIN interface can set one or several circuit on or off, you can also set the 4 as a group at the same time control, on the other hand, the control interface also supports the tunable pulse width signal LED (PWM), the average current controlled by adjusting the load cycle. In addition to 16 pin TQFN package, LDS8845 will launch in the second quarter of 2008, 0.8 mm high 12 pin 3x3 mm TDFN package.

LDS8846 profile

LDS8846 is very similar to the LDS8845, adds third control PIN pins, uses a 0.8 mm high TQFN package with a 16 pin (3 mm x and a 4 mm x mm). Added third control pins, so that system engineers can set the LDS8846, select any of the 8 circuit settings (circuit on or off), to provide the most flexible choice. As with the LDS8845, the input control of the LDS8846 can accept the PWM signal to regulate the average LED current. Independent thinking is expected to stand into the second quarter of 2008, 0.8 mm high 12 pin TDFN package (3 mm X3 mm) LDS8846 will also be launched in the market

Source: power system