RT9273

RT9271 : The RT9271 is a step-up DC/DC converter specifically designed to drive white LEDs with a constant current. The device can drive one to three LEDs in series from a Li-Ion cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The RT9271 switches at 1.1 MHz, allowing the use of tiny external components. The input and output capacitor can be as small as 1uF, saving space and cost versus alternative solutions. A low 0.25V feedback voltage minimizes power loss in the current setting resistor for better efficiency. The RT9271 is available in low profile SOT-26 package. Ordering Information RT9271 Package T.

RT9272 : The RT9272 is a high efficiency step-up DC-DC converter specifically designed for dual panel mobile phone applications. According to SP status, RT9272 can either regulates output current flowing through series-connected LEDs for main panel or for sub panel with a common output LC filter. This along with compact VDFN-10L 3x3 package and high switching frequency allows less part count and smaller external components for space and cost saving. Pulling low EN pin shuts down the chip and reduces the supply current to less than 1μA. The EN pin also accepts PWM signal for LED brightness dimming control. The averaged LED current is well proportional to the duty cycle of the PWM signal. The internal .

RT9275 : The RT9275 is a compact, high efficiency, and low voltage step-up DC/DC converter with an Adaptive Current Mode PWM control loop, includes an error amplifier, ramp generator, comparator, switch pass element and driver in which providing a stable and high efficient operation over a wide range of load currents. The low start-up input voltage below 1V makes RT9275 suitable for 1 to 4 battery cells applications. Both internal 2.5A switch and driver for driving external power devices (NMOS or NPN) are provided. It is incorporating with softstart function, Under Voltage protection function. RT9275 is available in SOT-23-6 package. Ordering Information RT9275 Package Type E : SOT-23-6 Operating Tem.

RT9276 : Features The RT9276 is a synchronous boost converter, which is based on a fixed frequency Pulse-Width-Modulation (PWM) controller using a synchronous rectifier to obtain maximum efficiency. The converter provides a power supply solution for products powered by a variety of batteries such as single cell, dual cell alkaline, NiMH and NiCd battery. At light load currents, the converter enters power save mode to maintain a high efficiency over a wide load current range. The output voltage can be programmed by an external resistor divider, or fixed at a certain voltage. Moreover, the converter can be disabled to minimize battery drain. During shutdown, the load is completely disconnected from t.

RT9277A : The RT9277A/B is a high performance, low noise, fixed frequency step up DC-DC Converter. The RT9277A/B converters input voltage ranging 2.5V to 5.5V into output voltage up to 16V. Current mode control with external compensation network makes it easy to stabilize the system and keep maximum flexibility. Soft start function minimizes impact on the input power system. Internal power MOSFET with very low RDS(ON) provides high efficiency. The RT9277A/B automatically transits from PWM to PSM (Pulse Skipping Mode) during light load condition further increasing efficiency. 640kHz and 1.2MHz operation frequency options provide flexibiltity of minimum output inductor size, maximum efficiency and low B.

RT9277B : The RT9277A/B is a high performance, low noise, fixed frequency step up DC-DC Converter. The RT9277A/B converters input voltage ranging 2.5V to 5.5V into output voltage up to 16V. Current mode control with external compensation network makes it easy to stabilize the system and keep maximum flexibility. Soft start function minimizes impact on the input power system. Internal power MOSFET with very low RDS(ON) provides high efficiency. The RT9277A/B automatically transits from PWM to PSM (Pulse Skipping Mode) during light load condition further increasing efficiency. 640kHz and 1.2MHz operation frequency options provide flexibiltity of minimum output inductor size, maximum efficiency and low B.

RT9277C : Features The RT9277C/D is a high performance, low noise, fixed frequency step up DC-DC Converter. The RT9277C/D converters input voltage ranging 2.5V to 5.5V into output voltage up to 16V. Current mode control with external compensation network makes it easy to stabilize the system and keep maximum flexibility. Soft start function minimizes impact on the input power system. Internal power MOSFET with very low RDS(ON) provides high efficiency. The RT9277C/D with 640kHz and 1.2MHz operation frequency options provide flexibiltity of minimum output inductor size, maximum efficiency and low BOM cost. z Efficiency up to 90% z VIN Operating Range : 2.5V to 5.5V z 1.6A, 0.2Ω, 16V Internal Power M.

RT9277D : Features The RT9277C/D is a high performance, low noise, fixed frequency step up DC-DC Converter. The RT9277C/D converters input voltage ranging 2.5V to 5.5V into output voltage up to 16V. Current mode control with external compensation network makes it easy to stabilize the system and keep maximum flexibility. Soft start function minimizes impact on the input power system. Internal power MOSFET with very low RDS(ON) provides high efficiency. The RT9277C/D with 640kHz and 1.2MHz operation frequency options provide flexibiltity of minimum output inductor size, maximum efficiency and low BOM cost. z Efficiency up to 90% z VIN Operating Range : 2.5V to 5.5V z 1.6A, 0.2Ω, 16V Internal Power M.

RT9278 : Features The RT9278 is a compact, high efficiency, synchronous step-up converter, it provides a power supply solution for products powered by either two-cell, three-cell Alkaline/ NiMH or one-cell Li-Ion/Li-polymer battery. The RT9278 is boost converter with PWM control loop, provide up to 95% efficiency by using a synchronous rectifier. The maximum peak current in the internal switch is limited to up to 2A. It keeps the output voltage regulated when the input voltage exceeds the setting output voltage. The output voltage can be set by an external resister divider, or be fixed to reduce external components. It integrates a linear controller for linear regulator. RT9278 is available in VDFN.