Texas Instruments pushes dual channel output boost converter for OLED

Description: Texas Instruments introduces a dual-channel output boost converter for OLED and white LED display applications. The highly integrated 1.2MHz power conversion IC not only simplifies power supply design, but also drives up to 12 white LEDs for backlight applications.

On April 19, 2005, Beijing Instruments, Texas Instruments (TI) announced two new high-efficiency dual-channel output DC/DC boost converters that can manage two groups with a single chip and inductor ( 6 in each group) white LEDs. These devices are capable of input voltages from 3V to 6V and output currents up to 0.7A, making them ideal for driving OLED secondary displays and LCD primary displays. These two displays are currently widely used for white LED backlighting in flip phones. For more information, please visit

The TI TPS61140 device enables designers of portable electronic devices to program different voltage and current levels through external resistors. For added flexibility, designers can also use dedicated select pins for each channel output to turn them on separately or simultaneously.

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

High-Efficiency White LED Background Illumination with Dual Regulated Current Output TI's new TPS61150 high-frequency boost converter is capable of driving white LEDs in flip phones for primary and secondary display LCD backlighting. Like the TPS61140, the device can also reduce the output current by using a PWM signal on the select pin or an analog voltage on the ISET pin for PWM dimming of white LEDs. The 1.2MHz fixed switching frequency of the TPS61150 regulator reduces output ripple, which prevents PFM control from producing large noise. The device's dual-channel output also drives backlighting of the display and keypad, which can drive up to 12 white LEDs on a single large display.

The TPS61140 and TPS61150 achieve high efficiency and design flexibility without the need for external active power components. Both devices use power MOSFETs and power diodes. In addition, the higher switching frequency also reduces the size of the external inductors and capacitors required.

Key features of the TPS61140 and TPS61150: 3V to 6V input voltage range; up to 27V per channel in dual output; 0.7A integrated switch; built-in power diode; 1.2MHz PWM for white LED Driver; for OLED power supply PFM; efficiency up to 82%; PWM dimming frequency up to 30 kHz; independently programmable output; input to output isolation; overvoltage and short circuit protection; internal overtemperature protection;


Price and availability
The TPS61140 and TPS61150TI are available now in volume quantities and can be ordered through TI and its authorized distributors. Both devices are available in a tiny 10-pin 3mm x 3mm QFN package, and the TPS61140 and TPS61150 are priced at $1.85 and $1.65, respectively, in quantities of 1000. For evaluation boards, application notes, and the latest TI Power Management Selection Guide for both converters, visit power.ti.com.

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