IC can launch 4 parallel WLED drive

The day before, professional power management IC supplier Siwang electronic (Seaward ELectronics Inc.) launched a ChargePump WLED driver IC SE3362 type inductor. The driver IC can simultaneously drive 4 parallel WLED, maximum current up to 30mA/WLED, suitable for mobile phones, PDA, DSC and PMP, such as LCD backlight screen LED.

The SE3362 structure uses inductance type ChargePump, effectively avoid the problem of EMI mobile phone; peripheral capacitance only 3 simple 1uF, and a WLED current setting resistor (RSET) can work normally, and each WLED can be through the 2-bit input terminal of the switch control separately. The enable input pin allows the device to enter a quiescent current "almost zero" power down mode.

According to the characteristics of the lithium battery, SE3362 adopts the 1x/2x mode automatic conversion design, in order to improve the efficiency of the lithium battery in the whole working cycle, and prolong the working time of the lithium battery. When the Vin is higher than that of 3.8V (Typ), IC adopts 1x mode, the output voltage and input voltage to maintain a low pressure at this time, IC has a very low quiescent current, only 170uA (Typ.); when the battery voltage drops to 3.8V (Typ.) when the IC switch to 2x mode, the output voltage stability in 4.5V (Typ.), WLED current keep stable.

SE3362 internal design with current matching control circuit, can effectively control the LED current, so that each WLED current has a high degree of matching, to ensure the consistency of WLED brightness. RSET can be set by an external resistor on the current WLED, the brightness can be adjusted through a variety of ways: (1) the current use of a DC voltage setting the RSET pin, thereby changing the current WLED, brightness adjustment; (2) the PWM signal is used as a control signal, the duty cycle adjustable brightness; (3) GPIO will be applied to the control terminal, the duty cycle adjust brightness; (4) in the conversion of RSET is connected in parallel with different resistance to change, adjust the brightness of the WLED current.

SE3362 has the functions of output short circuit protection, output overvoltage protection and temperature protection. Available in a small 16 pin 3mm * 3mm QFN compact package.

The main features of SE3362

2.85V to 5.5V input voltage range;

Support 4 parallel WLED;

Each WLED output current up to 30mA;

2-Bit digital control On/Off per WLED;

Automatic conversion of two working modes of 1x/2x;

WLED current external settings;

Low value ceramic capacitor;

Pin configuration compatible with RT9362;

1MHz fixed charge pump operating frequency;

Automatic output short circuit protection;

QFN 16-lead 3mm x 3mm package

Packaging, pricing and supply

The SE3362 uses 16 pin QFN-16 3mm x 3mm package

Source: International Electronic Business