RT9261/A Preliminary VFM Step-up DC/DC Converter General Description Features The RT9261 Series are VFM Step-up DC/DC ICs z with ultra low supply current by CMOS process and suitable for use with battery-powered instruments. Minimal Number of External Components ( Only an inductor, a diode, and a capacitor) z Ultra Low Input Current ( 5µ µA at Switch Off) The RT9261 IC consists of an oscillator, a VFM z ± 2% High Output Voltage Accuracy Low Ripple and Low Noise control circuit, a driver transistor (LX switch), a z Low Start-up Voltage, 0.85V at 1mA reference voltage unit, an error amplifier, resistors for z 75% Efficiency with Low Cost Inductor voltage detection, and a LX switch protection circuit. z A low ripple and high efficiency step-up DC/DC +50 ppm/°°C Low Temperature-Drift z SOT-89 and SOT-25 Small Packages z converter can be constructed of this RT9261 IC with only three external components. The RT9261A IC provides with a drive pin (EXT) for an external transistor, so that a power transistor can Applications z Power source for battery-powered equipment z Power source for cameras, camcorders, VCRs, PDAs, pagers, electronic data banks, and hand- be externally applied. Therefore, the RT9261A IC is recommended for applications where large currents are required. CE pin enables circuit to set the standby supply current at a maximum of 0.5µA. Ordering Information RT9261A- held communication equipment z Power source for applications, which require higher voltage than that of batteries used in the appliances Pin Configurations Part Number Package type B : SOT-25 X : SOT-89 TOP VIEW RT9261- CX 1 2 3 TOP VIEW RT9261A- CX 1. GND 2. VOUT (TAB) 3. EXT (Plastic SOT-89) 1 RT9261- CB (Plastic SOT-25) A : Use external switch Use internal switch (Plastic SOT-25) 2 3 TOP VIEW 5 1 RT9261A- CB 4 2 3 1. 2. 3. 4. 5. CE VOUT NC GND LX TOP VIEW 5 1 DS9261/A-03 January 2002 1. GND 2. VOUT (TAB) 3. LX (Plastic SOT-89) Operating temperature range C: Commercial standard Output voltage 15 : 1.5V 16 : 1.6V : 49 : 4.9V 50 : 5.0V Pin Configurations 4 2 3 1. 2. 3. 4. 5. CE VOUT NC GND EXT www.richtek-ic.com.tw 1 RT9261/A Preliminary Absolute Maximum Ratings z z z Output Voltage LX Pin Voltage 8V (1) EXT Pin Voltage 8V (2) -0.3 to VOUT +0.3V (3) z CE Pin Voltage z LX Pin Output Current -0.3 to VOUT +0.3V (1) 250mA (2) z EXT Pin Current z Power Dissipation, PD @ TA = 25°C z SOT-89 0.5W SOT-25 0.25W z ±50mA Package Thermal Resistance SOT-89, θJC 100°C/W SOT-89, θJA 300°C/W SOT-25, θJA 250°C/W z Operating Temperature Range -20 to +85°C z Storage Temperature Range 165°C z Lead Temperature (Soldering, 10 sec.) 260°C Notes: (1) Applicable to RT9261- CX and RT9261- CB (2) Applicable to RT9261A- CX and RT9261A- CB (3) Applicable to RT9261- CB and RT9261A- CB Electrical Characteristics (Refer to Fig. 1) Parameter Symbol Test Conditions Min Typ Max Units Output Voltage Accuracy ∆VOUT -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 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 Hold-on Voltage 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) VIN = 1.8V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical Application (2) VIN = 3V, VSS = 0V, IOUT = 10mA, TOPT = 25°C, and External Circuit of Typical Application www.richtek-ic.com.tw 2 DS9261/A-03 January 2002 RT9261/A Preliminary Electrical Characteristics (Refer to Fig. 2) Parameter Symbol Test Conditions Min Typ Max Units Output Voltage Accuracy ∆VOUT -2 -- +2 % Input Voltage VIN -- -- 7 V Start-up Voltage VST IOUT = 1mA, VIN : 0 → 2V -- 0.85 1.0 V To be measured at VIN at no load -- 30 50 (2) -- 60 90 (2) To be measured at VOUT in switch off condition -- 6 10 VEXT = VOUT – 0.4V -1.5 -- -- (2) -2 -- -- VEXT = 0.4V 1.5 -- -- (2) 2 -- -- 80 120 160 KHz 65 75 85 % Input Current 1 Input Current 2 EXT “H” Output Current EXT “L” Output Current 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 DS9261/A-03 January 2002 www.richtek-ic.com.tw 3 RT9261/A Preliminary Electrical Characteristics (Refer to Fig. 3) Parameter Symbol Test Conditions Min Typ Max Units Output Voltage Accuracy ∆VOUT -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 -- 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 To be measured at VIN at no load -- 15 18 -- 18 24 To be measured at VOUT in switch off condition -- 5 8 (2) -- 6 10 60 -- -- 80 -- -- -- -- 0.5 µA (1) 3.5V < VOUT ≤ 5V LX Leakage Current % (2) (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (2) (2) ISWITCHING VLX = 0.4V ILEAKAGE VLX = 6V µA µA mA CE “H” Level VIN = VOUT × 0.9 0.4× VOUT -- -- V CE “ L” Level VIN = VOUT × 0.9 -- -- 0.2 V CE “ H” Input Current CE = VOUT -- -- 0.5 µA CE “ L“ Input Current CE = 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 www.richtek-ic.com.tw 4 DS9261/A-03 January 2002 RT9261/A Preliminary Electrical Characteristics (Refer to Fig. 4) Parameter Symbol Test Conditions Min Typ Max Units Output Voltage Accuracy ∆VOUT -2 -- +2 % Input Voltage VIN -- -- 7 V Start-up Voltage VST -- 0.85 1.0 V -- 75 -- -- 85 -- -- 30 50 -- 60 90 -- 6 10 -1.5 -- -- -2 -- -- 1.5 -- -- 2 -- -- Efficiency Input Current 1 Input Current 2 EXT “H” Output Current EXT “L” Output Current VOUT ≤ 3.5V (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V To be measured at VIN at no load (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) (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (2) (1) 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V IOUT = 1mA, VIN : 0 → 2V (1) 3.5V < VOUT ≤ 5V % µA µA mA mA CE “H” Level VIN = VOUT × 0.9 0.4× VOUT -- -- V CE “ L” Level VIN = VOUT × 0.9 -- -- 0.2 V CE “ H” Input Current CE = VOUT -- -- 0.5 µA CE “ L“ Input Current CE = 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-03 January 2002 www.richtek-ic.com.tw 5 RT9261/A Preliminary Function Block Diagram VLX Limiter LX Vref LXSW VOUT Buffer GND _ VFM Control + Error Amp. OSC 100kHz EXT Chip Enable CE Notes: (1) LX Pin .…… only for 9261- CX and 9261- CB (2) EXT Pin …… only for 9261A- CX and 9261A- CB (3) CE Pin …… only for 9261- CB and 9261A- CB 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 CE Chip Enable (Active High) -- -- 3 3 NC No Connected -xxCX A-xxCX -xxCB A-xxCB 1 1 4 2 2 3 www.richtek-ic.com.tw 6 DS9261/A-03 January 2002 RT9261/A Preliminary Typical Application Circuit D1 1N5819 L1 RT9261CX LX VOUT 100µH GND VOUT + Co _ 22µF VIN Fig. 1 L1 D1 27µH VIN 0.01µF Cb ZTX 650 1N5819 RT9261ACX EXT VOUT GND Tr Rb 300Ω VOUT + Co _ 22µF Fig. 2 D1 L1 100µH VIN 1N5819 LX NC RT9261CB EXT VOUT VOUT CE GND + Co _ 22µF Fig. 3 DS9261/A-03 January 2002 www.richtek-ic.com.tw 7 RT9261/A Preliminary L1 D1 27µH 0.01µF NC Cb 1N5819 RT9261ACB LX EXT VIN ZTX 650 CE VOUT GND Rb Tr 300Ω VOUT + Co _ 22µF Fig. 4 D1 L1 27µH VIN 1N5819 RT9261CB LX NC EXT CE CE GND VOUT VOUT + Co _ 22µF Fig. 5 www.richtek-ic.com.tw 8 DS9261/A-03 January 2002 RT9261/A Preliminary Typical Operating Charateristics RT9261(2.7V) Output Current vs. Ripple Voltage 1.4 120 1.2 Ripple Voltage (mV p-p) Start-up/Hold-on Voltage Vstart/Vhold (V) RT9261(2.7V) Start-up/Hold-on Voltage vs. Output Current Vstart 1.0 0.8 Vhold 0.6 0.4 0.2 100 2.0V 60 40 0.9V RT9261 VOUT = 2.7V 0 0 10 20 30 40 50 0 Output Current (mA) 3.0 0.9V 2.0 1.5 1.0 0.5 RT9261 VOUT = 2.7V 0.0 0 20 40 60 80 2.75 2.70 2.65 RT9261 VOUT = 2.7V 2.60 -40 100 -20 2.0V 40 60 80 Supply Current vs. Temperature RT9261 VOUT = 2.7V 60 Supply Current (µ A) 2.5V 1.5V 0.9V 20 70 80 60 0 Temperature (° C) RT9261(2.7V) Efficiency vs. Output Current 70 100 2.80 Output Current (mA) 90 80 2.85 Output Voltage (V) Output Voltage (V) 2.5 60 Output Voltage vs. Temperature 2.0V 1.5V 40 2.90 2.5V 1.0V 20 Output Current (mA) RT9261(2.7V) Output Voltage vs. Output Current Efficiency (%) 2.5V 1.5V 20 RT9261 VOUT = 2.7V 0.0 80 1.0V 50 40 30 20 50 40 30 20 Input Current 2 RT9261 VOUT = 2.7V 10 0 0 20 40 60 Output Current (mA) DS9261/A-03 January 2002 80 100 10 Input Current 1 0 -40 -20 0 20 40 60 80 Temperature (° C) www.richtek-ic.com.tw 9 RT9261/A Preliminary RT9261A (2.7V) Output Voltage vs. Output Current 3.0 140 2.5V 1.5V 2.5 120 Output Voltage (V) Maximum Oscillator Frequency (kHz) Maximum Oscillator Frequency vs. Temp. 160 100 80 60 1.0V 0.9V 2.0 1.5 1.0 40 0.5 RT9261 VOUT = 2.7V 20 -20 0 20 40 Temperature ( ° C) 60 RT9261A VOUT = 2.7V 0.0 0 -40 0 80 30 60 90 120 RT9261A (2.7V) Efficiency vs. Output Current 100 80 2.5V 90 60 Efficiency (%) Oscillator Duty Cycle (%) 70 80 70 2.0V 0.9V 50 1.0V 1.5V 40 30 20 60 RT9261 VOUT = 2.7V 50 -40 -20 0 20 40 60 RT9261A VOUT = 2.7V 10 0 0 80 30 Temperature ( °C) 60 90 120 150 Output Current (mA) RT9261A (2.7V) Output Current vs. Ripple Voltage Start-up/Hold-on Voltage vs. Output Current 1.6 120 1.4 1.2 Ripple Voltage (mV p-p) Start-up/Hold-on Voltage Vstart/Vhold (V) 150 Output Current (mA) Oscillator Duty Cycle vs. Temperatrue Vstart 1.0 0.8 Vhold 0.6 0.4 RT9261A VOUT = 2.7V 0.2 0.0 0 30 www.richtek-ic.com.tw 10 2.0V 60 90 Output Current (mA) 120 150 100 2.5V 80 2.0V 60 1.5V 40 0.9V RT9261A VOUT = 2.7V 20 0 0 30 60 90 120 150 Output Current (mA) DS9261/A-03 January 2002 RT9261/A Preliminary Package Information D A D1 H B C C1 e e 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 -- 4.242 -- 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 0.355 0.432 0.014 0.017 3-Lead SOT-89 Surface Mount DS9261/A-03 January 2002 www.richtek-ic.com.tw 11 RT9261/A Preliminary D 5 4 C B 1 b 3 H A e Symbol L A1 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 0.102 0.254 0.004 0.010 L 0.356 0.610 0.014 0.024 SOT- 25 Surface Mount Package www.richtek-ic.com.tw 12 DS9261/A-03 January 2002 Preliminary DS9261/A-03 January 2002 RT9261/A www.richtek-ic.com.tw 13 RT9261/A Preliminary RICHTEK TECHNOLOGY CORP. RICHTEK TECHNOLOGY CORP. Headquarter Taipei Office (Marketing) 6F, No. 35, Hsintai Road, Chupei City 8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5510047 Fax: (8863)5537749 Tel: (8862)89191466 Fax: (8862)89191465 Email: [email protected] www.richtek-ic.com.tw 14 DS9261/A-03 January 2002