RT9261B-49PX

Preliminary RT9261B VFM Step-Up DC/DC Converter General Description The RT9261B Series are VFM Step-up DC/DC converter ICs with ultra low supply current by CMOS process and suitable for use with battery-powered instruments. The RT9261B 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 with the RT9261B IC and only three external components. The EN pin enables the circuit to set the standby supply current at a maximum of 0.5μA. Features Minimal Number of External Components (Only an Inductor, a Diode, and a Capacitor) Ultra Low Input Current (6.5μA at Switch Off) Capable of Supplying 50mA Output Current with Internal Switch ± 2% Output Voltage Accuracy Low Ripple and Low Noise Low Start-up Voltage, 0.8V at 1mA 80% 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 Ordering Information RT9261BP ackage Type B : SOT-23-5 X : SOT-89 Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) Output Voltage 15 : 1.5V 16 : 1.6V : 49 : 4.9V 50 : 5.0V Applications 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 appliances, which require higher voltage than that of batteries used in the appliances Pin Configurations (TOP VIEW) EN 1 2 3 4 GND 5 LX Note : 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. NC VOUT SOT-23-5 Marking Information For marking information, contact our sales representative directly or through a RichTek distributor located in your area, otherwise visit our website for detail. 1 2 3 GND VOUT (TAB) LX SOT-89 DS9261B-12 March 2007 www.richtek.com 1 RT9261B Typical Application Circuit Preliminary D1 1N5819 L1 RT9261B LX VOUT GND VOUT + VIN COUT 22uF D1 1N5819 L1 LX VIN EN RT9261B VOUT GND VOUT COUT 22uF + * L1 ranges from 27μH to 120μH Functional Pin Description Pin No. -xxCX 1 2 3 ---xxCB 4 2 5 1 3 GND VOUT LX EN NC Ground Output Voltage Pin for Switching Chip Enable (Active High) No Connection Pin Name Pin Function Function Block Diagram LX LXSW VLX Limiter VREF Buffer + Error Amplifier VOUT GND OSC 190kHz Chip Enable EN www.richtek.com 2 DS9261B-12 March 2007 Preliminary Absolute Maximum Ratings Output Voltage -------------------------------------------------------------------------------------------------------LX Pin Voltage --------------------------------------------------------------------------------------------------------EN Pin Voltage(1) -----------------------------------------------------------------------------------------------------LX Pin Output Current ----------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C SOT-89 -----------------------------------------------------------------------------------------------------------------SOT-23-5 --------------------------------------------------------------------------------------------------------------Package Thermal Resistance SOT-89, θJC -----------------------------------------------------------------------------------------------------------SOT-89, θJA -----------------------------------------------------------------------------------------------------------SOT-23-5, θJA ---------------------------------------------------------------------------------------------------------Operating Temperature Range ------------------------------------------------------------------------------------Storage Temperature Range --------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------Notes: (1) Applicable to RT9261B-xxCB RT9261B 8V 8V −0.3 to VOUT +0.3V 400mA 0.5W 0.25W 100° C/W 300° C/W 250° C/W −20 to +85°C −65°C to 150°C 260°C Electrical Characteristics Parameter Output Voltage Accuracy Input Voltage Start-up Voltage Hold-on Voltage Input Current 1 (1) (2) (Refer to Figure 1) Symbol ΔVOUT VIN VST VHO IOUT = 1mA, VIN: 0 → 2V IOUT = 1mA, VIN: 2 → 0V To be measured at VIN in continuous switching To be measured at VOUT in switch off condition Test Conditions Min -2 --0.7 -----120 160 -140 140 65 -LX switch on 0.65 Typ --0.8 -24 36 6.5 18 20 ---190 190 75 80 0.8 Max Units +2 7 1 -36 45 10 36 45 --0.5 240 320 85 -1.0 mA μA kHz kHz % % V % V V V μA μA VOUT ≤ 3.5V (1) (2) 3.5V < VOUT ≤ 5V Input Current 2 Input Current 3 VOUT ≤ 3.5V (1) 3.5V < VOUT ≤ 5V LX Switching Current LX Leakage Current Maximum Oscillator Frequency Oscillator Duty Cycle Efficiency VLX Voltage Limit Notes: (2) To be measured at VIN in no load (guaranteed by I1 and I2) ISWITCHING VLX = 0.4V ILEAKAGE FMAX DOSC VLX = 6V VOUT = 2.5V to 5V VOUT = 1.5V to 2.4V On (VLX “L”) side μA VOUT ≤ 3.5V (1) (2) 3.5V < VOUT ≤ 5V (1) VIN = 1.8V, VSS = 0V, IOUT = 1mA, Topt = 25° C, and use External Circuit of Typical Application (2) VIN = 3V, VSS = 0V, IOUT = 1mA, Topt= 25°C, and External Circuit of Typical Application DS9261B-12 March 2007 www.richtek.com 3 RT9261B Electrical Characteristics Parameter Output Voltage Accuracy Input Voltage Start-up Voltage Hold-on Voltage Efficiency Input Current 1 Input Current 2 Input Current 3 (1) (2) Preliminary (Refer to Figure 2) Symbol ΔVOUT VIN VST VHO VOUT ≤ 3.5V (1) (2) Test Conditions Min -2 -- Typ --0.8 -80 24 36 6.5 18 20 -------190 190 75 0.8 Max Units +2 7 1 --36 45 10 36 45 --0.5 -0.2 0.5 -240 320 85 1.0 % V V V % μA μA μA IOUT = 1mA, VIN: 0 → 2V IOUT = 1mA, VIN: 2 → 0V -0.7 -- 3.5V < VOUT ≤ 5V To be measured at VIN in continuous switching To be measured at VOUT in switch off condition -----120 160 -0.4×VOUT ---0.5 140 140 65 0.65 VOUT ≤ 3.5V VOUT ≤ 3.5V (1) (2) 3.5V < VOUT ≤ 5V (1) To be measured at VIN in no load (guaranteed by I1 and I2) ISWITCHING VLX = 0.4V ILEAKAGE VLX = 6V VIN = VOUT * 0.9 VIN = VOUT * 0.9 EN = VOUT EN = 0V FMAX DOSC VOUT = 2.5V to 5V VOUT = 1.5V to 2.4V On (VLX “L”) side LX switch on LX Switching Current LX Leakage Current EN “H” Level EN “L” Level EN “H” Input Current EN “ L” Input Current 3.5V < VOUT ≤ 5V (2) mA μA V V μA μA kHz kHz % V Maximum Oscillator Frequency Oscillator Duty Cycle VLX Voltage Limit Notes: (1) VIN = 1.8V, VSS = 0V, IOUT = 1mA, Topt = 25°C, and use External Circuit of Typical Application (2) VIN = 3V, VSS = 0V, IOUT = 1mA, Topt= 25°C, and External Circuit of Typical Application www.richtek.com 4 DS9261B-12 March 2007 Preliminary Typical Operating Characteristics Start-up/Hold-on Voltage Vstart/Vhold (V)1 RT9261B Output Voltage vs. Output Current 4.0 3.5 Start-up/Hold-on Voltage vs. Output Current 2.5 Output Voltage (V) 1 2 3.0V 2.5V 1.0V 1.5V 2.0V 3.0 2.5 2.0 1.5 1.0 0.5 0.0 1.5 Vstart 1 0.5 Vhold VOUT = 3.3V L = 47uH VOUT = 3.3V 0 50 100 150 200 0 0 30 60 90 120 150 180 Output Current (mA) Output Current (mA) Output Current vs. Ripple Voltage 300 Output Current vs. Ripple Voltage 90 2.5V 80 3.0V Ripple Voltage (mVp-p) 1 2.0V 3.0V Ripple Voltage (mVp-p)1 250 200 150 100 50 70 60 50 40 30 20 10 0 2.0V 2.5V 1.5V VOUT = 3.3V COUT = 20uF L = 47uH 100 150 200 1.5V 1.0V 0 50 100 1.0V 0 0 50 VOUT = 3.3V COUT = 68uF L = 47uH 150 200 Output Current (mA) Output Current (mA) Output Current vs. Ripple Voltage 25 90 80 Efficiency vs. output Current 3.0V 2.5V 1.0V 1.5V 2.0V Ripple Voltage (mVp-p)1 20 2.5V 70 Efficiency (%)1 60 50 40 30 20 10 0 15 3.0V 10 1.0V VOUT = 3.3V COUT = 170uF L = 47uH 100 150 200 5 0 0 2.0V 1.5V 50 VOUT = 3.3V 0 50 100 150 200 Output Current (mA) DS9261B-12 March 2007 Output Current (mA) www.richtek.com 5 RT9261B Start-up/Hold-on Voltage Vstart/Vhold (V)1 Preliminary Start-up/Hold-on Voltage vs. Output Current 2.5 4.0 3.5 Output Voltage vs. Output Current 3.0V 1.5V 1.0V 2.0V 2.5V Output Voltage (V) 1 2 3.0 2.5 2.0 1.5 1.0 0.5 0.0 1.5 Vstart 1 0.5 Vhold VOUT = 3.3V VOUT = 3.3V 0 50 100 150 200 0 0 20 40 60 80 100 120 Output Current (mA) Output Current (mA) Output Current vs. Ripple Voltage 300 90 Output Current vs. Ripple Voltage 80 2.0V 3.0V 2.5V Ripple Voltage (mVp-p) 1 250 200 150 100 50 Ripple Voltage (mVp-p) 1 70 60 50 40 30 20 10 0 2.5V 3.0V 2.0V 1.0V 1.5V 0 50 100 1.5V 0 0 1.0V 50 100 VOUT = 3.3V COUT = 20uF L = 100uH 150 200 VOUT = 3.3V COUT = 68uF L = 100uH 150 200 Output Current (mA) Output Current (mA) Output Current vs. Ripple Voltage 18 16 Efficiency vs. output Current 100 90 2.5V 3.0V 2.0V 3.0V 1.0V 1.5V 2.0V 2.5V Ripple Voltage (mVp-p) 1 14 12 10 8 6 4 2 0 0 80 Efficiency (%) 1 VOUT = 3.3V COUT = 170uF L = 100uH 100 150 200 70 60 50 40 30 20 10 0 0 1.0V 1.5V 50 VOUT = 3.3V 50 100 150 200 Output Current (mA) www.richtek.com 6 Output Current (mA) DS9261B-12 March 2007 Preliminary Outline Dimension RT9261B H D L C B b A A1 e Symbol A A1 B b C D e H L Dimensions In Millimeters Min 0.889 0.000 1.397 0.356 2.591 2.692 0.838 0.080 0.300 Max 1.295 0.152 1.803 0.559 2.997 3.099 1.041 0.254 0.610 Dimensions In Inches Min 0.035 0.000 0.055 0.014 0.102 0.106 0.033 0.003 0.012 Max 0.051 0.006 0.071 0.022 0.118 0.122 0.041 0.010 0.024 SOT-23-5 Surface Mount Package DS9261B-12 March 2007 www.richtek.com 7 RT9261B Preliminary D D1 A C B C1 e e H A b b Dimensions In Inches Min 0.055 0.014 0.094 0.016 0.155 0.031 0.173 0.055 0.057 0.014 Max 0.063 0.019 0.102 0.021 0.167 0.047 0.181 0.069 0.061 0.017 b1 Symbol A b B b1 C C1 D D1 e H Dimensions In Millimeters Min 1.397 0.356 2.388 0.406 3.937 0.787 4.394 1.397 1.448 0.356 Max 1.600 0.483 2.591 0.533 4.242 1.194 4.597 1.753 1.549 0.432 3-Lead SOT-89 Surface Mount Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Richtek Technology Corporation Taipei Office (Marketing) 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com www.richtek.com 8 DS9261B-12 March 2007