® RT9266 Tiny Package, High Efficiency, Step-up DC/DC Converter General Description Features The RT9266 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. It operates in stable waveforms without external compensation. z 1.0V Low Start-up Input Voltage z High Supply Capability to Deliver 3.3V 100mA with 1 Alkaline Cell 17μ μA Quiescent (Switch-off) Supply Current Zero Shutdown Mode Supply Current 90% Efficiency 450kHz Fixed Switching Frequency Providing Flexibility for Using Internal and External Power Switches Small SOT-23-6 & SOT-89-5 Package RoHS Compliant and 100% Lead (Pb)-Free The low start-up input voltage below 1V makes RT9266 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 efficiency maintains long battery lifetime. The output voltage is set with two external resistors. Both internal 2A switch and driver for driving external power devices (NMOS or NPN) are provided. Ordering Information RT9266 z z z z z z z Applications z z z z z z z Package Type E : SOT-23-6 X5 : SOT-89-5 PDA DSC LCD Panel RF-Tags MP3 Portable Instrument Wireless Equipment Pin Configurations Lead Plating System P : Pb Free G : Green (Halogen Free and Pb Free) Richtek products are : RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. ` GND LX 5 4 FB VDD LX Note : ` (TOP VIEW) 6 5 4 2 3 2 3 EN VDD FB EN EXT GND Suitable for use in SnPb or Pb-free soldering processes. Marking Information 1 SOT-23-6 SOT-89-5 For marking information, contact our sales representative directly or through a Richtek distributor located in your area. Copyright © 2013 Richtek Technology Corporation. All rights reserved. DS9266-16 June 2013 is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT9266 Typical Application Circuit L1 + VIN D1 3.3 to 10 µH C3 100µF 1N5819 VOUT 3.3V/5V C2 1µF R1 1.6M/3M VDD RT9266 LX EXT GND FB + EN C1 100µF R2 980k/1M Figure 1. RT9266 Typical Application for Portable Instruments 3.1V to 5V for 12V 2.8V to 5V for 9V VIN L1 D1 + 4.7µH C4 100µF 1N5819 RVDD 100 CVDD 1µF VDD EN Q1 N MOS EXT LX GND FB 12V/9V 300mA R1 C3 0.1µF 860k/620k RM 0.22 R2 100k C2 1µF + RT9266 C1 100uF Figure 2. RT9266 High Voltage Applications Copyright © 2013 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 is a registered trademark of Richtek Technology Corporation. DS9266-16 June 2013 RT9266 L1 D1 VOUT 3.3V/5V + VIN 3.3 to 10 µH C3 100µF 1N5819 C2 1µF VDD EN LX RT9266 EXT R1 1.6M/3M + GND Q1 N MOS FB C1 100µF R2 980k/1M Figure 3. RT9266 for Higher Current Applications L1 VIN 3.3V/5V R3 100 C2 1µF 4.7µH C8 1µF C3 10µF C1 1µF Q1 EN VDD LX RT9266 FB GND N MOS C4 10µF C6 C7 1µF 0.1µF VOUT2 +18V 10mA VOUT1 +9V 10mA R1 620k EXT R2 100k C5 10µF VOUT3 -9V 10mA Figure 4. RT9266 for Multi-Output Applications Copyright © 2013 Richtek Technology Corporation. All rights reserved. DS9266-16 June 2013 is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT9266 Test Circuit I (VIN) L1 D1 10µH + A VIN C3 100µF 1N5819 VOUT 3.3V/5V R1 1.6M/3M VDD EN RT9266 LX EXT GND FB + C2 1µF A I (VDD) C4 102 C1 100µF C5 106 R2 980k/1M Functional Pin Description Pin No. Pin Name Pin Function SOT-23-6 SOT-89-5 1 1 EN Chip Enable (Active High). 2 -- EXT Output Pin for Driving External N-MOSFET. 3 5 GND Ground. 4 4 LX Pin for Switching. 5 2 VDD Input Positive Power Pin of RT9266. 6 3 FB Feedback Input Pin. Internal Reference Voltage for the Error Amplifier is 1.25V. Function Block Diagram EXT RT9266 VDD LX - FB Loop Control Circuit + 1.25V Q1 N MOS R1 VDD R2 Shut Down EN Q2 N MOS Over Temp. Detector Copyright © 2013 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 GND is a registered trademark of Richtek Technology Corporation. DS9266-16 June 2013 RT9266 Absolute Maximum Ratings z z z z z z z z −0.3V to 7V −0.3V to 7V −0.3V to (VDD + 0.3V) Supply Voltage -----------------------------------------------------------------------------------------------------LX Pin Switch Voltage --------------------------------------------------------------------------------------------Other I/O Pin Voltages -------------------------------------------------------------------------------------------LX Pin Switch Current --------------------------------------------------------------------------------------------EXT Pin Driver Current --------------------------------------------------------------------------------------------Package Thermal Resistance SOT-23-6, θJC ------------------------------------------------------------------------------------------------------SOT-89-5, θJC ------------------------------------------------------------------------------------------------------Operating Junction Temperature -------------------------------------------------------------------------------Storage Temperature Range ------------------------------------------------------------------------------------- 2.5A 200mA 145°C/W 45°C/W 125°C −65°C to +150°C NOTE: Absolute Maximum ratings are threshold limit values that must not be exceeded even for an instant under any conditions. Moreover, such values for any two items must not be reached simultaneously. Operation above these absolute maximum ratings may cause degradation or permanent damage to the device. These are stress ratings only and do not necessarily imply functional operation below these limits Recommended Operating Conditions z z (1) −40°C to 125°C −40°C to 85°C Junction Temperature Range -------------------------------------------------------------------------------------Ambient Temperature Range -------------------------------------------------------------------------------------- Electrical Characteristics (VIN = 1.5V, VDD set to 3.3V, Load Current = 0, TA = 25° C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Start-UP Voltage VST IL = 1mA -- 0.98 1.05 V Operating VDD Range VDD VDD pin voltage 2 -- 6 V Shutdown Current I (VIN) IOFF EN Pin = 0V, VIN = 4.5V -- 0.01 1 μA Switch-off Current I (VDD) ISWITCH OFF VIN = 6V -- 17 25 μA Continuous Switching Current ISWITCH 0.4 0.55 0.7 mA -- μA VIN = EN = 3.3V, VFB = GND (2) No Load Current I (VIN) INO LOAD VIN = 1.5V, VOUT = 3.3V -- Feedback Reference Voltage VREF Close Loop, VDD = 3.3V 1.225 1.25 1.275 V Switching Frequency FS VDD = 3.3V 425 500 575 kHz Maximum Duty DMAX VDD = 3.3V 85 95 -- % VDD = 3.3V -- 0.3 1.1 Ω LX ON Resistance Current Limit Setting 75 (3) VDD = 3.3V 1.6 2 EXT ON Resistance to VDD VDD = 3.3V -- 5 8.5 Ω EXT ON Resistance to GND VDD = 3.3V -- 5 8.5 Ω ILIMIT Copyright © 2013 Richtek Technology Corporation. All rights reserved. DS9266-16 June 2013 2.6 A is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT9266 Parameter Symbol Test Conditions Min Typ Max Unit 10 mV/V -- mV/mA Line Regulation ΔVLINE VIN = 3.5 ~ 6V, IL = 1mA -- 1.5 Load Regulation ΔVLOAD VIN = 2.5V, IL = 1 ~ 100mA -- 0.25 EN Pin Trip Level VDD = 3.3V (4) 0.4 0.8 1.2 V Temperature Stability for VOUT TS -- 50 -- ppm/°C Thermal Shutdown Hysteresis ΔTSD -- 10 -- °C Note : (1). The device is not guaranteed to function outside its operating conditions. (2). No Load Current is highly dependent on practical system design and component selection that cannot be covered by production testing. Typical No Load Current is verified by typical application circuit with recommended components. No Load Current performance is guaranteed by Switch Off Current and Continuous Switching Current. (3). Current Limit is guaranteed by design at TA = 25°C. (4). Load Regulation is not tested at production due to practical instrument limitation. Load Regulation performance is dominantly dependent on DC loop gain and LX ON Resistance that are guaranteed by “ Line Regulation” and “ LX ON Resistance” tests in production. Copyright © 2013 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 is a registered trademark of Richtek Technology Corporation. DS9266-16 June 2013 RT9266 Typical Operating Characteristics (Refer to Test Circuit) Efficiency vs. Output Current Efficiency vs. Output Current 95 95 VOUT = 5V, TA = 25°C VOUT = 3.3V, TA = 25°C 90 VIN = 4.5V VIN = 4.0V VIN = 3.5V VIN = 3.0V VIN = 2.5V VIN = 2.0V 85 80 Efficiency (%) Efficiency (%) 90 75 VIN = 3.0V 85 VIN = 2.5V 80 VIN = 2.0V 75 VIN = 1.5V VIN = 1.5V VIN = 1.0V 70 70 000 001 010 100 0.1 1000 1 1000 21 VIN = 3V, VOUT = 5V VOUT = 5V @ no load 20 Input Current ( μ A) 200 Input Current ( μ A) 100 Input Current I(VDD) vs. Input Voltage Input Current I(VDD) vs. Output Current 250 150 100 50 19 18 17 16 0 15 0.01 0.1 1 10 100 1000 2.5 3.0 3.5 Output Current (mA) 4.0 4.5 5.0 Input Voltage (V) Supply Current I(VIN) vs. Input Voltage Supply Current I(VIN) vs. Input Voltage 180 90 VOUT = 5V @ no load VOUT = 3.3V @ no load 80 150 Supply Current ( μA) Supply Current ( μA) 1 10 Output Current (mA) Output Current (mA) 120 90 60 70 60 50 40 30 30 0 1.5 2.0 2.5 3.0 3.5 4.0 Input Voltage (V) Copyright © 2013 Richtek Technology Corporation. All rights reserved. DS9266-16 June 2013 4.5 1.5 2 2.5 3 3.5 Input Voltage (V) is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT9266 Switching SwichtingFrequency Frequencyvs. vs. VDD VDD Pin PinVoltage Voltage Start Up Voltage vs. Output Current 1.6 VOUT = 3.3V VIN = 2.4V to 2.8V 1.4 VIN = 3V to 5.6V 500 Start Up Voltage (V) Switching Rate Frequency (KHz). Switching Frequency (kHz) 600 400 300 VIN = 1.2V to 2.2V 1.2 1.0 0.8 0.6 0.4 200 0.2 (In C.R. mode) 100 0.0 0 1 2 3 4 5 6 0 30 60 90 120 150 180 VDD Pin Voltage (V) Output Current (mA) LX & Output Ripple LX & Output Ripple VIN = 1V, VOUT = 3.3V @ 10mA VIN = 1V, VOUT = 3.3V @ 100mA Output Ripple Output Ripple LX LX 210 Time (1µs/Div) Time (1µs/Div) LX & Output Ripple LX & Output Ripple LX Time (1µs/Div) Copyright ©2013 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 VIN = 2V, VOUT = 3.3V @ 10mA Output Ripple Output Ripple LX VIN = 2V, VOUT = 3.3V @ 200mA Time (1µs/Div) is a registered trademark of Richtek Technology Corporation. DS9266-16 June 2013 RT9266 LX & Output Ripple LX & Output Ripple VIN = 3V, VOUT = 3.3V @ 10mA Output Ripple Output Ripple LX LX VIN = 3V, VOUT = 3.3V @ 200mA Time (1µs/Div) Time (1µs/Div) LX & Output Ripple LX & Output Ripple LX VIN = 2V, VOUT = 5V @ 20mA Output Ripple Output Ripple LX VIN = 2V, VOUT = 5V @ 200mA Time (1µs/Div) Time (1µs/Div) LX & Output Ripple LX & Output Ripple LX Time (1µs/Div) Copyright ©2013 Richtek Technology Corporation. All rights reserved. DS9266-16 VIN = 3V, VOUT = 5V @ 20mA Output Ripple Output Ripple LX VIN = 3V, VOUT = 5V @ 200mA June 2013 Time (1µs/Div) is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 RT9266 LX & Output Ripple LX & Output Ripple LX VIN = 4.5V, VOUT = 5V @ 20mA Output Ripple Output Ripple LX VIN = 4.5V, VOUT = 5V @ 200mA Time (1µs/Div) Time (1µs/Div) Transient Response VIN = 3V, VOUT = 3.3V IOUT = 10mA IOUT = 10mA 200mA Output Transient Voltage VIN = 2V, VOUT = 3.3V Output Transient Voltage 200mA Time (50µs/Div) Time (50µs/Div) Transient Response Transient Response VIN = 3V, VOUT = 5V VIN = 4.5V, VOUT = 5V IOUT = 10mA IOUT = 10mA 200mA Time (50µs/Div) Copyright ©2013 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 Output Transient Voltage Output Transient Voltage Transient Response 200mA Time (50µs/Div) is a registered trademark of Richtek Technology Corporation. DS9266-16 June 2013 RT9266 Output Voltage vs. Temperature Output Voltage vs. Temperature 5 3.34 VIN = 3V, VOUT = 5V, IOUT = 100mA VIN = 1.8V, VOUT = 3.3V, IOUT = 100mA 4.98 Output Voltage(V) Output Voltage(V) 3.32 3.3 3.28 3.26 3.24 3.22 4.94 4.92 4.9 4.88 4.86 4.84 3.2 -40 -10 20 50 80 110 Temperature (°C) Copyright © 2013 Richtek Technology Corporation. All rights reserved. DS9266-16 4.96 June 2013 140 -40 -10 20 50 80 110 140 Temperature (°C) is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT9266 Application Information Output Voltage Setting Layout Guide Referring to Typical Application Circuits, the output voltage of the switching regulator (VOUT) can be set with Equation (1). VOUT = ( 1+ R1 R2 ) × 1.25V (1) Feedback Loop Design Referring to Typical Application Circuits. The selection of R1 and R2 based on the trade-off between quiescent current consumption and interference immunity is stated below: z Follow Equation (1) z Higher R reduces the quiescent current (Path current = 1.25V/R2), however resistors beyond 5MΩ are not recommended. z Lower R gives better noise immunity, and is less sensitive to interference, layout parasitics, FB node leakage, and improper probing to FB pins. z z z A full GND plane without gap break. VDD to GND noise bypass − Short and wide connection for the 1μF MLCC capacitor between Pin5 and Pin3. VIN to GND noise bypass − Add a capacitor close to L1 inductor, when VIN is not an idea voltage source. z Minimized FB node copper area and keep far away from noise sources. z Minimized parasitic capacitance connecting to LX and EXT nodes, which may cause additional switching loss. Board Layout Example (2-Layer Board) (Refer to Typical Application Circuits Figure 2 for the board) VOUT Prober Parasitics R1 FB Pin _ Q + z R2 - Top Layer - 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 R1 and R2 are needed. Such “ high impedance feedback loops” are sensitive to any interference, which require careful layout and avoid any interference, e.g. probing to FB pin. Copyright © 2013 Richtek Technology Corporation. All rights reserved. www.richtek.com 12 - Bottom Layer - is a registered trademark of Richtek Technology Corporation. DS9266-16 June 2013 RT9266 Outline Dimension H D L C B b A A1 e Dimensions In Millimeters Dimensions In Inches Symbol Min Max Min Max A 0.889 1.295 0.031 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.250 0.560 0.010 0.022 C 2.591 2.997 0.102 0.118 D 2.692 3.099 0.106 0.122 e 0.838 1.041 0.033 0.041 H 0.080 0.254 0.003 0.010 L 0.300 0.610 0.012 0.024 SOT-23-6 Surface Mount Package Copyright © 2013 Richtek Technology Corporation. All rights reserved. DS9266-16 June 2013 is a registered trademark of Richtek Technology Corporation. www.richtek.com 13 RT9266 D D1 b1 A C B C1 e e H A b b1 b Dimensions In Millimeters Dimensions In Inches Symbol Min Max Min Max A 1.397 1.600 0.055 0.063 b 0.356 0.508 0.014 0.020 B 2.388 2.591 0.094 0.102 b1 0.406 0.533 0.016 0.021 C 3.937 4.242 0.155 0.167 C1 0.787 1.194 0.031 0.047 D 4.394 4.597 0.173 0.181 D1 1.397 1.702 0.055 0.067 e 1.397 1.600 0.055 0.063 H 0.356 0.432 0.014 0.017 5-Lead SOT-89 Surface Mount Package Richtek Technology Corporation 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries. www.richtek.com 14 DS9266-16 June 2013