RT9261/A Preliminary VFM Step-Up DC/DC Converter General Description Features The RT9261 Series are VFM Step-up DC/DC ICs with ultra low supply current by CMOS process and suitable for use with battery-powered instruments. z The RT9261 IC consists of an oscillator, a VFM control circuit, a driver transistor (LX switch), a reference voltage unit, an error amplifier, resistors for voltage detection, and a LX switch protection circuit. A low ripple and high efficiency step-up DC/DC converter can be constructed of this RT9261 IC with only three external components. z z z z z z z z The RT9261A IC provides with a drive pin (EXT) for an external transistor, so that a power transistor can be externally applied. Therefore, the RT9261A IC is recommended for applications where large currents are required. EN pin enables circuit to set the standby supply current at a maximum of 0.5μA. ± 2% High Output Voltage Accuracy Low Ripple and Low Noise Low Start-up Voltage, 0.85V at 1mA 75% Efficiency with Low Cost Inductor +50 ppm/ °C Low Temperature-Drift SOT-89 and SOT-23-5 Small Packages RoHS Compliant and 100% Lead (Pb)-Free Applications z z z Ordering Information Minimal Number of External Components ( Only an Inductor, a Diode, and a Capacitor) Ultra Low Input Current ( 5μ μA at Switch Off) Power source for battery-powered equipment Power source for cameras, camcorders, VCRs, PDAs, pagers, electronic data banks, and hand-held communication equipment Power source for applications, which require higher voltage than that of batteries used in the appliances RT9261/APackage Type B : SOT-23-5 X : SOT-89 Marking Information For marking information, contact our sales representative Operating Temperature Range directly or through a RichTek distributor located in your P : Pb Free with Commercial Standard G : Green (Halogen Free with Commer- area, otherwise visit our website for detail. cial Standard) Output Voltage Pin Configurations 15 : 1.5V 16 : 1.6V : (TOP VIEW) 49 : 4.9V 50 : 5.0V Use external switch Use internal switch Note : 1 2 3 1 2 3 RichTek Pb-free and Green products are : `RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. `Suitable for use in SnPb or Pb-free soldering processes. `100% matte tin (Sn) plating. DS9261/A-12 March 2007 GND VOUT LX (TAB) GND VOUT EXT (TAB) RT9261- CX RT9261A- CX SOT-89 www.richtek.com 1 RT9261/A Preliminary EN 1 VOUT 2 NC 3 LX 5 EN 1 VOUT 2 NC 3 GND 4 RT9261- CB 5 EXT 4 GND RT9261A- CB SOT-23-5 Typical Application Circuit D1 1N5819 L1 100uH VIN + RT9261CX LX VOUT GND COUT 22uF VOUT Figure 1 L1 D1 27uH 1N5819 Cb 0.01uF ZTX 650 Tr Rb 300 + VIN RT9261ACX EXT VOUT GND COUT 22uF VOUT Figure 2 D1 1N5819 L1 100uH VIN NC EN + RT9261CB LX VOUT VOUT COUT 22uF GND Figure 3 www.richtek.com 2 DS9261/A-12 March 2007 RT9261/A Preliminary L1 D1 27uH 1N5819 NC Cb 0.01uF RT9261ACB VOUT COUT 22uF EXT ZTX 650 Tr Rb 300 EN VOUT + VIN GND Figure 4 D1 1N5819 L1 27uH VIN NC Chip Enable EN + RT9261CB LX VOUT VOUT COUT 22uF GND Figure 5 DS9261/A-12 March 2007 www.richtek.com 3 RT9261/A Preliminary Functional Pin Description Pin No. Pin Name Pin Function 4 GND Ground 2 2 VOUT Output Voltage -- 5 -- LX Pin for Switching -- 3 -- 5 EXT Drive External Device -- -- 1 1 EN Chip Enable (Active High) -- -- 3 3 NC No Connected -xxCX A-xxCX -xxCB A-xxCB 1 1 4 2 2 3 Function Block Diagram VLX Limiter LX VREF LXSW Buffer VOUT GND - VFM Control EXT + Error Amplifier OSC 100kHz Chip Enable EN Notes: (1) LX Pin...... only for 9261- (2) EXT Pin.... only for 9261A- (3) EN Pin...... only for 9261- www.richtek.com 4 CX and 9261CX and 9261ACB and 9261A- CB CB CB DS9261/A-12 March 2007 RT9261/A Preliminary Absolute Maximum Ratings Output Voltage -------------------------------------------------------------------------------------------------------LX Pin Voltage (1) -----------------------------------------------------------------------------------(2) z EXT Pin Voltage --------------------------------------------------------------------------------------------------(3) z EN Pin Voltage ---------------------------------------------------------------------------------------------------(1) z LX Pin Output Current -------------------------------------------------------------------------------------------(2) z EXT Pin Current --------------------------------------------------------------------------------------------------z Power Dissipation, PD @ TA = 25°C SOT-89 -----------------------------------------------------------------------------------------------------------------SOT-23-5 --------------------------------------------------------------------------------------------------------------z Package Thermal Resistance SOT-89, θJC -----------------------------------------------------------------------------------------------------------SOT-89, θJA -----------------------------------------------------------------------------------------------------------SOT-23-5, θJA ---------------------------------------------------------------------------------------------------------z Operating Temperature Range ------------------------------------------------------------------------------------z Storage Temperature Range --------------------------------------------------------------------------------------z Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------Notes: (1) Applicable to RT9261CX and RT9261CB (2) Applicable to RT9261ACX and RT9261ACB (3) Applicable to RT9261CB and RT9261ACB z z Electrical Characteristics 8V 8V − 0.3 to VOUT +0.3V − 0.3 to VOUT +0.3V 250mA ± 50mA 0.5W 0.25W 100° C/W 300° C/W 250° C/W − 20 to +85°C 165°C 260°C (Refer to Figure 1) Parameter Symbol Test Conditions Min Typ Max Units Output Voltage Accuracy ΔVOUT -2 -- +2 % Input Voltage VIN -- -- 7 V Start-up Voltage VST IOUT = 1mA, VIN: 0 → 2V -- 0.85 1.0 V Hold-on Voltage VHO IOUT = 1mA, VIN: 2 → 0V 0.7 -- -- V To be measured at VIN at no load -- 15 18 -- 18 24 -- 5 8 60 -- -- 80 -- -- -- -- 0.5 μA 80 120 160 kHz 65 75 85 % -- 75 -- % 0.65 0.8 1.0 V Input Current 1 VOUT ≤ 3.5V (1) 3.5V < VOUT ≤ 5V (2) To be measured at VOUT in switch off condition Input Current 2 LX Switching Current VOUT ≤ 3.5V (1) ISWITCHING VLX = 0.4V LX Leakage Current ILEAKAGE VLX = 6V Maximum Oscillator FMAX Oscillator Duty Cycle DOSC 3.5V < VOUT ≤ 5V (2) On ( VLX ” L ” ) side Efficiency VLX Voltage Limit LX switch on μA μA mA Notes: (1)Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical Application (2)Unless otherwise provided, VIN = 3V, VSS = 0V, IOUT = 10mA, TOPT = 25° C, and External Circuit of Typical Application DS9261/A-12 March 2007 www.richtek.com 5 RT9261/A Preliminary Electrical Characteristics (Refer to Figure 2) Parameter Symbol Test Conditions Min Typ Max Units Output Voltage Accuracy ΔVOUT -2 -- +2 % Input Voltage VIN -- -- 7 V IOUT = 1mA, VIN : 0 → 2V -- 0.85 1.0 V -- 30 50 (2) To be measured at VIN at no load -- 60 90 (2) To be measured at VOUT in switch off condition -- 6 10 -1.5 -- -- (2) VEXT = VOUT – 0.4V -2 -- -- 1.5 -- -- (2) VEXT = 0.4V 2 -- -- 80 120 160 kHz 65 75 85 % Start-up Voltage Input Current 1 Input Current 2 EXT “H” Output Current EXT “L” Output Current VST VOUT ≤ 3.5V (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (1) 3.5V < VOUT ≤ 5V Maximum Oscillator Frequency FMAX Oscillator Duty Cycle DOSC VEXT ” H ” side μA μA mA mA Notes: (1)Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25° C, and use External Circuit of Typical Application (2)Unless otherwise provided, VIN = 3V, VSS= 0V, IOUT = 10mA, TOPT = 25° C, and External Circuit of Typical Application www.richtek.com 6 DS9261/A-12 March 2007 RT9261/A Preliminary Electrical Characteristics (Refer to Figure 3) Parameter Symbol Test Conditions Min Typ Max Output Voltage Accuracy ΔVOUT -2 -- +2 % Input Voltage VIN -- -- 7 V Start-up Voltage VST IOUT = 1mA, VIN : 0 → 2V -- 0.85 1.0 V VHO IOUT = 1mA, VIN : 2 → 0V 0.7 -- -- V -- 75 -- -- 85 -- -- 15 18 -- 18 24 -- 5 8 -- 6 10 60 -- -- 80 -- -- -- -- 0.5 μA Hold-on Voltage Efficiency Input Current 1 Input Current 2 LX Switching Current VOUT ≤ 3.5V (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (2) To be measured at VIN at no load (2) To be measured at VOUT in switch off condition (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (2) (1) 3.5V < VOUT ≤ 5V LX Leakage Current (2) ISWITCHING VLX = 0.4V ILEAKAGE VLX = 6V % μA μA mA EN “H” Level VIN = VOUT × 0.9 0.4× VOUT -- -- V EN “ L” Level VIN = VOUT × 0.9 -- -- 0.2 V EN “ H” Input Current EN = VOUT -- -- 0.5 μA EN “ L“ Input Current EN = 0V -0.5 -- -- μA 80 120 160 kHz 65 75 85 % 0.65 0.8 1.0 V Maximum Oscillator Frequency FMAX Oscillator Duty Cycle DOSC VLX Voltage Limit On (VLX ” L” ) side LX switch on Notes: (1)Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and use External Circuit of Typical Application (2)Unless otherwise provided, VIN = 3V, VSS= 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical Application DS9261/A-12 March 2007 www.richtek.com 7 RT9261/A Preliminary Electrical Characteristics (Refer to Figure 4) Parameter Symbol Test Conditions Min Typ Max Units Output Voltage Accuracy ΔVOUT -2 -- +2 % Input Voltage VIN -- -- 7 V -- 0.85 1.0 V -- 75 -- -- 85 -- -- 30 50 -- 60 90 -- 6 10 -1.5 -- -- -2 -- -- 1.5 -- -- 2 -- -- Start-up Voltage Efficiency Input Current 1 Input Current 2 EXT “H” Output Current EXT “L” Output Current VST VOUT ≤ 3.5V 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (2) To be measured at VOUT in switch off condition (2) VEXT = VOUT – 0.4V (2) VEXT = 0.4V (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (2) To be measured at VIN at no load (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (2) (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V IOUT = 1mA, VIN : 0 → 2V (1) (1) 3.5V < VOUT ≤ 5V % μA μA mA mA EN “H” Level VIN = VOUT × 0.9 0.4× VOUT -- -- V EN “ L” Level VIN = VOUT × 0.9 -- -- 0.2 V EN “ H” Input Current EN = VOUT -- -- 0.5 μA EN “ L“ Input Current EN = 0V -0.5 -- -- μA 80 120 160 kHz 65 75 85 % 0.65 0.8 1.0 V Maximum Oscillator Frequency FMAX Oscillator Duty Cycle DOSC VLX Voltage Limit On (VLX ” L” ) side LX switch on Notes: (1)Unless otherwise provided, VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and use External Circuit of Typical Application (2)Unless otherwise provided, VIN = 3V, VSS= 0V, IOUT = 10mA, TOPT www.richtek.com 8 DS9261/A-12 March 2007 RT9261/A Preliminary Typical Operating Characteristics Output Current vs. Ripple Voltage Start-up/Hold-on Voltage vs. Output Current 120 1.2 Vstart Ripple Voltage (mV p-p) Start-up/Hold-on Voltage Vstart/Vhold (V) 1.4 1 0.8 Vhold 0.6 0.4 0.2 RT9261 VOUT = 2.7V 100 80 2.0V 60 2.5V 1.5V 40 0.9V 20 0 0 0 10 20 30 40 0 50 20 60 80 100 Output Voltage vs. Temperature Output Voltage vs. Output Current 2.90 3 2.0V 1.5V 2.5 0.9V 2.5V 1.0V 2.85 Output Voltage (V) Output Voltage (V) 40 Output Current (mA) Output Current (mA) 2 1.5 1 0.5 RT9261 VOUT = 2.7V 2.80 2.75 2.70 2.65 RT9261 VOUT = 2.7V 2.60 0 0 20 40 60 80 -40 100 -20 Efficiency vs. Output Current 70 80 2.5V 1.5V 1.0V 0.9V 50 40 30 20 RT9261 VOUT = 2.7V 10 Supply Current (uA) 60 2.0V 60 20 40 60 80 Supply Current vs. Temperature 90 70 0 Temperature (° C) Output Current (mA) Efficiency (%) RT9261 VOUT = 2.7V RT9261 VOUT = 2.7V 50 40 30 20 Input Current 2 Input Current 1 10 0 0 0 20 40 60 Output Current (mA) DS9261/A-12 March 2007 80 100 -40 -20 0 20 40 60 80 Temperature (° C) www.richtek.com 9 Preliminary Maximum Oscillator Frequency vs. Temperature Output Voltage vs. Output Current 3 160 140 2.5V 1.5V 2.5 120 Output Voltage (V) Maximum Oscillator Frequency (kHz) A RT9261/A 100 80 60 40 2.0V 0.9V 2 1.5 1 0.5 RT9261 VOUT = 2.7V 20 1.0V 0 RT9261A VOUT = 2.7V 0 -40 -20 0 20 40 60 80 0 30 Temperature (° C) 60 90 120 Efficiency vs. Output Current Oscillator Duty Cycle vs. Temperature 100 80 2.5V 90 60 Efficiency (%) Oscillator Duty Cycle (%) 70 80 70 2.0V 0.9V 50 1.5V 1.0V 40 30 20 60 RT9261 VOUT = 2.7V RT9261A VOUT = 2.7V 10 50 0 -40 -20 0 20 40 60 80 0 30 Temperature (° C) 60 90 120 150 Output Current (mA) Start-up/Hold-on Voltage vs. Output Current Output Current vs. Ripple Voltage 1.6 120 1.4 Ripple Voltage (mV p-p) Start-up/Hold-on Voltage1 Vstart/Vhold (V) 150 Output Current (mA) Vstart 1.2 1 0.8 Vhold 0.6 0.4 RT9261A VOUT = 2.7V 0.2 0 100 2.5V 80 2.0V 60 1.5V 40 0.9V 20 RT9261A VOUT = 2.7V 0 0 30 60 90 Output Current (mA) www.richtek.com 10 120 150 0 30 60 90 120 150 Output Current (mA) DS9261/A-12 March 2007 RT9261/A Preliminary Outline Dimension H D L B C b A A1 e Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.889 1.295 0.035 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.356 0.559 0.014 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-23-5 Surface Mount Package DS9261/A-12 March 2007 www.richtek.com 11 RT9261/A Preliminary D D1 A B C C1 e e H A b Symbol b1 b Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 1.397 1.600 0.055 0.063 b 0.356 0.483 0.014 0.019 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 1.753 0.055 0.069 e 1.448 1.549 0.057 0.061 H 0.356 0.432 0.014 0.017 3-Lead SOT-89 Surface Mount Richtek Technology Corporation Richtek Technology Corporation Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)89191466 Fax: (8862)89191465 Email: [email protected] www.richtek.com 12 DS9261/A-12 March 2007