ML9266 Step-up DC/DC converter ■ General Description ■ Features The ML9266 is a small, 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. It operates in stable waveforms without external compensation. The low start-up input voltage below 1V makes ML9266 suitable for 1 to 4 battery cells applications of providing up to 300mA output current. The 450KHz high switching rate minimized the size of external components. Besides, the 17µA low quiescent current together with high effic- ◆ 90% Efficiency ◆ High Supply Capability to Deliver 3.3V 100mA with 1 Alkaline cell ◆ 17µA Quiescent (switch-off) Supply Current ◆ 450KHz Fixed Switching Frequency ◆ Zero Shutdown Mode Supply Current ◆ Providing Flexibility for Using Internal and External Power Switches ◆ 1.0V Low Start-up Input Voltage ◆ Small SOT-26 & SOT89-5 Package iency maintains long battery lifetime. The ML9266 is available in small package SOT-26 and ■ Ordering Information SOT89-5 Item ML9266MRG ML9266PRG Package SOT-26 SOT-89-5 Shipping 3000pcs/Reel&Tape 1000pcs/Reel&Tape ■ Applications ■ Package Information ◆ ◆ ◆ ◆ ◆ ◆ LCD Panel DSC MP3 Wireless Equipment Portable Instrument PDA ■ Typical Application Circuit L1 Vin C3 100uF VDD ML9266 GND SOT-23-6 ■ Pin Configurations 1N5819 C2 1uF EXT D1 3.3~10uH + CE SOT89-5 FB Vout 3.3V/5V R1 1.6M/3M LX + R2 SOT-26 1 2 3 4 5 6 C1 100uF 980k/1M P1 / 5 SOT-89-5 Pin NamePin Function 1 CE Chip enable EXT Output 5 GND Ground 4 LX Switching 2 VDD Input 3 FB Feedback input 1.25V Rev. C, Sep 2005 ML9266 IPCore ■ Function Block Diagram ■ Marking Information ① ② ③④ ■ Test Circuit Symbol Descripation Step-up DC-DC Converter 9 ML9266 1 Control Code i L1 I(V ) Vin An 10uH + C3 100uF I(VDD) A C2 1uF LX + C4 R1 C1 1.6M/3M 102uF 100uF C5 106uF ML9266 FB EXT GND SOT-26 Vout 3.3V/5V R3 100 VDD CE D1 1N5819 R2 980K/1M SOT-89-5 P2 / 5 Rev. C, Sep 2005 ML9266 IPCore ■ Absolute Maximum Ratings (Ta=25℃ ℃） Paramenter Supply Voltage LX Pin Switch Voltage Other I/O Pin Voltages Lx Pin Switch Current EXT Pin Driver Current Package Thermal Resistance SOT-26 SOT-89-5 Operating Junction Temperature Storage Temperature Range Symbol Ratings Vin - 0.3V ～ 7V - 0.3 ～ (VDD + 0.8V) VLX - 0.3V ～ (VDD + 0.3V) Vss 2.5 ILX 200 IEXT Pd 145 45 Tj 125 - 65 ~ +150 Tstg Unit V V V A mA ℃/W ℃/W ℃ ℃ ■ Electrical Characteristics (Vin =1.5V, VDD=3.3V, I=0, Ta = 25℃, unless otherwise specified) Parameter Start-UP Voltage Operating VDD Range No Load Current I (VIN) Switch-off Current I (VDD) Shutdown Current I (VIN) Feedback Reference Voltage Switching Frequency Maximum Duty LX ON Resistance Current Limit Setting EXT ON Resistance to VDD EXT ON Resistance to GND Line Regulation Load Regulation CE Pin Trip Level Temperature Stability for Vout Thermal Shutdown Thermal Shutdown Hysterises Symbol VST VDD INO LOAD ISWITCH OFF IOFF VREF FS DMAX ILIMIT △VLINE △VLOAD Test Conditions IL = 1mA VDD pin voltage VIN = 1.5V, VOUT = 3.3V VIN = 6V CE Pin = 0V, VIN = 4.5V Close Loop, VDD = 3.3V VDD = 3.3V VDD = 3.3V VDD = 3.3V VDD = 3.3V VDD = 3.3V VDD = 3.3V VIN = 1.5 ~ 2.5V, IL = 1mA VIN = 2.5V, IL = 1 ~ 100mA VDD = 3.3V TS TSD △TSD Min -2 ---1.225 --------0.4 ---- Typ 0.98 -75 17 0.01 1.25 450 95 0.3 2 5 5 10 0.25 0.8 50 165 10 Max 1.05 6.5 --1 1.275 --------1.2 ---- Units V V µA µA µA V KHz % Ω A Ω Ω mV/V mV/mA V ppm/℃ ℃ ℃ * Note: The CE pin shall be tied to VDD pin and inhibit to act the ON/OFF state whenever the VDD pin voltage may reach to 5.5V or above. P3 / 5 Rev. C, Sep 2005 ML9266 IPCore ■ Applications ■ Application Note ● High Current Application ● Output Voltage Setting Referring to application circuits, the output voltage of the switching regulator (VOUT) can be set L1 3.3--10uH Vin + C5 100uF VOUT1 = (1 + 1N5819 C2 1uF VDD CE Vout 3.3V/5V D1 Q1 NMOS ML9266 GND + C1 100uF LX FB ◆ Follow Equation A ◆ Higher R reduces the quiescent current (Path current =1.25V/R2), however resistors beyond 5MΩ are not R2 980k/1M recommended. ◆ Lower R gives better noise immunity, and is less sensitive to interference, layout parasitics, FB node ● High Voltage Application Vin=3.1V～5V Vout=12V Vin=2.8V ～ 5V Vout=9V leakage, and improper probing to FB pins. L1 C4 100uF C1=100uF C2=1uF D1 4.7uH RVDD 100 + C3=0.1uF R1=860K/620K R2=100K RM=0.22 CVDD=1uF 1N5819 CVDD VDD CE ・・・A ) × 1.25V ● Feedback Loop Design Referring to application circuits, The selection of R1and R2 based on the trade-off between quiescent current consumption and interference immunity is stated below: R1 1.6M/3M EXT R1 R2 12V / 9V 300mA Q1 NMOS EXT ML9266 LX R1 C3 FB GND RM R2 + C2 C1 ◆ A proper value of feed forward capacitor parallel with R1 can improve the noise immunity of the feedback loops, especially in an improper layout. An empirical suggestion is around 0~33pF for feedback resistors of MΩ, and 10nF~0.1µF for feedback resistors of tens to hundreds KΩ. For applications without standby or suspend modes, lower values of R1 and R2 are preferred. For applications concerning the current consumption in standby or suspend modes, the higher values of R1and R2 are feedback needed. Such "high impedance loops" are sensitive to any interference, which require careful layout and avoid any interference, e.g. probing to FB pin. ● Multi-Output Applications R1=620K R2=100 C6=0.1uF D1 Vin 3.3V/5V 1N5819 L1 3.3--10uH R3 100 C2 10uF Vout2 +18V 10mA C8 1uF C3 10uF Q1 NMOS C1 1uF C4 10uF C7 1uF VDD CE EXT ML9266 LX GND FB C6 R1 Vout1 +9V 100mA Vout3 -9V 10mA C5 10uF R2 P4 / 5 Rev. C, Sep 2005 ML9266 IPCore ■ Package Dimensions ● SOT-89-5 Symbol A b B b1 C C1 D D1 e H Units: mm Min Max 1.400 1.600 0.360 0.520 2.400 2.600 0.406 0.533 -4.250 0.800 -4.400 4.600 -1.700 1.400 1.600 0.380 0.430 Symbol A A1 B b C D e H L Units: mm Min Max 0.889 1.295 -0.152 1.397 1.803 0.356 0.559 2.591 2.997 2.692 3.099 0.838 1.041 0.102 0.254 0.356 0.610 ● SOT-26 DISCLAIMER: The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. No liability will be accepted by the publisher for any P5 / 5 Rev. C, Sep 2005