OLED dual channel boost converter

TI oriented OLED and white LED display applications launch dual channel output boost converter

High integration of 1.2MHz power conversion IC can not only simplify the power supply design, but also for the background lighting applications drive up to 12 white LED

April 19, 2005, Beijing daily news, TI (TI) announced the launch of two new high efficiency dual output DC/DC converter, these products are available through a single chip with the inductor to 2 groups (n = 6) white LED. The above device can achieve 3V to 6V input voltage with up to 0.7A of output current, which is ideal for driving the OLED sub display with the LCD main display. At present, these two kinds of display are widely used in white light LED background lighting. For more details, please visit: www.ti.com/sc06093.

The TI TPS61140 device enables the designer of portable electronic devices to be programmed with different voltages and current levels by external resistors. In order to further improve the flexibility, the designer can also use the special selection of each channel output pins to open them separately or at the same time.

If the TPS61140 voltage output is activated, the boost converter is controlled by pulse frequency modulation (PFM) to achieve high efficiency over a wide range of loads. If the current output is selected, then the device will use 1.2 MHz pulse width modulation (PWM) control method to maximize the output current. External PWM signal can be used to select the pin to reduce the output current, so as to achieve the dimming of white LED.

High efficiency white LED background lighting

With dual regulated current output of the new TPS61150 TI high frequency boost converter can drive the flip phone in the main screen and the auxiliary display screen LCD backlight lighting white LED. Like TPS61140, the device can also reduce the output current by using the PWM signal on the select pin or the analog voltage on the ISET pin in order to achieve the PWM dimming of the white LED. The TPS61150 regulator with a fixed switching frequency of the 1.2MHz can reduce the output ripple, thus avoiding the large noise generated by the PFM control. Backlit dual channel output of the device can also drive the display and keypad, which can drive up to 12 white LED in a single large screen.

TPS61140 and TPS61150 without the support of external active power components, can achieve high efficiency and design flexibility. These two devices are using power MOSFET and power diodes. In addition, the higher switching frequency can reduce the size of the required external inductors and capacitors.

Key features of TPS61140 and TPS61150:

The input voltage range of 3V to 6V; double channel output voltage in each channel is as high as 27V; 0.7A integrated switch; built-in power diode; for white LED driver 1.2MHz PWM for OLED PFM; power supply; high efficiency up to 82%; the PWM dimming frequency up to 30 kHz; independent programmable input to output; output overvoltage and isolation; short-circuit protection; internal overtemperature protection; undervoltage protection.

Price and availability

TPS61140 and TPS61150TI are now in mass production, can be ordered through TI and its authorized distributors. These two devices are using micro 10 pin 3 mm x mm QFN package, batch for 1000 seconds, TPS61140 and TPS61150 unit price of $1.85 and $1.65, respectively. If you want to get these two converter evaluation board, the application manual and the latest version of TI power management selection guide, please visit: power.ti.com.