RT9261-21CB

Preliminary RT9261/A VFM Step-up DC/DC Converter General Description 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. 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. 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. CE pin enables 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 ( 5µA at Switch Off) ± 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-25 Small Packages Applications Power source for battery-powered equipment Power source for cameras, camcorders, VCRs, PDAs, pagers, electronic data banks, and handheld communication equipment Power source for applications, which require higher voltage than that of batteries used in the appliances Ordering Information RT9261APackage type B : SOT-25 X : SOT-89 Operating temperature range C: Commercial standard Output voltage 15 : 1.5V 16 : 1.6V : 49 : 4.9V 50 : 5.0V A : Use external switch Use internal switch Pin Configurations Part Number RT9261CX Pin Configurations TOP VIEW 1. GND 2. VOUT (TAB) 3. LX TOP VIEW 1. GND 2. VOUT (TAB) 3. EXT TOP VIEW 5 4 (Plastic SOT-89) 1 2 3 RT9261A- CX 1 2 3 (Plastic SOT-89) RT9261- CB (Plastic SOT-25) 1 2 3 1. 2. 3. 4. 5. CE VOUT NC GND LX RT9261A- CB TOP VIEW 5 4 (Plastic SOT-25) 1 2 3 1. 2. 3. 4. 5. CE VOUT NC GND EXT DS9261/A-03 January 2002 www.richtek-ic.com.tw 1 RT9261/A Absolute Maximum Ratings Output Voltage LX Pin Voltage CE Pin Voltage (1) (2) Preliminary 8V 8V -0.3 to VOUT +0.3V (1) EXT Pin Voltage (3) -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 CB CB CB LX Pin Output Current EXT Pin Current SOT-89 SOT-25 (2) Power Dissipation, PD @ TA = 25°C Package Thermal Resistance SOT-89, θJC SOT-89, θJA SOT-25, θJA Operating Temperature Range Storage Temperature Range Lead Temperature (Soldering, 10 sec.) Notes: (1) Applicable to RT9261(2) Applicable to RT9261A(3) Applicable to RT9261CX and RT9261CX and RT9261ACB and RT9261A- Electrical Characteristics (Refer to Fig. 1) Parameter Output Voltage Accuracy Input Voltage Start-up Voltage Hold-on Voltage Input Current 1 Input Current 2 LX Switching Current LX Leakage Current Maximum Oscillator Oscillator Duty Cycle Efficiency VLX Voltage Limit 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 DS9261/A-03 January 2002 (1) (2) Symbol ∆VOUT VIN VST VHO Test Conditions Min -2 -- Typ --0.85 -15 18 5 ---120 75 75 0.8 Max Units +2 7 1.0 -18 24 8 --0.5 160 85 -1.0 % V V V µA µA mA µA KHz % % V IOUT = 1mA, VIN: 0 → 2V IOUT = 1mA, VIN: 2 → 0V To be measured at VIN at no load To be measured at VOUT in switch off condition -0.7 ---60 80 -80 65 -0.65 VOUT ≤ 3.5V 3.5V < VOUT ≤ 5V VOUT ≤ 3.5V (1) (2) 3.5V < VOUT ≤ 5V ISWITCHING ILEAKAGE FMAX DOSC VLX = 0.4V VLX = 6V On ( VLX ” L ” ) side LX switch on 2 Preliminary Electrical Characteristics (Refer to Fig. 2) Parameter Output Voltage Accuracy Input Voltage Start-up Voltage Input Current 1 Input Current 2 EXT “H” Output Current EXT “L” Output Current VOUT ≤ 3.5V VOUT ≤ 3.5V VOUT ≤ 3.5V VOUT ≤ 3.5V (1) (2) RT9261/A Min -2 -Typ --0.85 30 60 6 ----120 75 Max Units +2 7 1.0 50 90 10 ----160 85 % V V µA µA mA mA KHz % Symbol ∆VOUT VIN VST Test Conditions IOUT = 1mA, VIN : 0 → 2V To be measured at VIN at no load To be measured at VOUT in switch off condition VEXT = VOUT – 0.4V VEXT = 0.4V -----1.5 -2 1.5 2 80 65 3.5V < VOUT ≤ 5V (1) 3.5V < VOUT ≤ 5V (1) (2) 3.5V < VOUT ≤ 5V (1) (2) 3.5V < VOUT ≤ 5V (2) Maximum Oscillator Frequency Oscillator Duty Cycle Notes: FMAX DOSC VEXT ” H ” side (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 Parameter Output Voltage Accuracy Input Voltage Start-up Voltage Hold-on Voltage Efficiency Input Current 1 Input Current 2 LX Switching Current VOUT ≤ 3.5V VOUT ≤ 3.5V VOUT ≤ 3.5V VOUT ≤ 3.5V (1) (2) Preliminary Electrical Characteristics (Refer to Fig. 3) Symbol ∆VOUT VIN VST VHO 3.5V < VOUT ≤ 5V (1) (2) Test Conditions Min -2 --0.7 ------60 80 -0.4× VOUT ---0.5 80 65 0.65 Typ --0.85 -75 85 15 18 5 6 -------120 75 0.8 Max +2 7 1.0 ---18 24 8 10 --0.5 -0.2 0.5 -160 85 1.0 Units % V V V % µA µA mA µA V V µA µA KHz % V IOUT = 1mA, VIN : 0 → 2V IOUT = 1mA, VIN : 2 → 0V 3.5V < VOUT ≤ 5V (1) To be measured at VIN at no load To be measured at VOUT in switch off condition ISWITCHING ILEAKAGE VLX = 0.4V VLX = 6V VIN = VOUT × 0.9 VIN = VOUT × 0.9 CE = VOUT CE = 0V FMAX DOSC On (VLX ” L” ) side LX switch on 3.5V < VOUT ≤ 5V (1) (2) 3.5V < VOUT ≤ 5V (2) LX Leakage Current CE “H” Level CE “ L” Level CE “ H” Input Current CE “ L“ Input Current Maximum Oscillator Frequency Oscillator Duty Cycle VLX Voltage Limit 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 DS9261/A-03 January 2002 4 Preliminary Electrical Characteristics (Refer to Fig. 4) Parameter Output Voltage Accuracy Input Voltage Start-up Voltage Efficiency Input Current 1 Input Current 2 EXT “H” Output Current EXT “L” Output Current CE “H” Level CE “ L” Level CE “ H” Input Current CE “ L“ Input Current Maximum Oscillator Frequency Oscillator Duty Cycle VLX Voltage Limit Notes: FMAX DOSC On (VLX ” L” ) side LX switch on VOUT ≤ 3.5V VOUT ≤ 3.5V VOUT ≤ 3.5V VOUT ≤ 3.5V VOUT ≤ 3.5V (1) (2) RT9261/A Min -2 --------1.5 -2 1.5 2 0.4× VOUT ---0.5 80 65 0.65 Typ --0.85 75 85 30 60 6 --------120 75 0.8 Max +2 7 1.0 --50 90 10 -----0.2 0.5 -160 85 1.0 Units % V V % µA µA mA mA V V µA µA KHz % V Symbol ∆VOUT VIN VST Test Conditions IOUT = 1mA, VIN : 0 → 2V 3.5V < VOUT ≤ 5V (1) 3.5V < VOUT ≤ 5V (1) (2) To be measured at VIN at no load To be measured at VOUT in switch off condition VEXT = VOUT – 0.4V VEXT = 0.4V VIN = VOUT × 0.9 VIN = VOUT × 0.9 CE = VOUT CE = 0V 3.5V < VOUT ≤ 5V (1) (2) 3.5V < VOUT ≤ 5V (1) (2) 3.5V < VOUT ≤ 5V (2) (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 Function Block Diagram Preliminary LX LXSW VLX L imiter Buffer Vref VOUT _ + GND VFM Control Error Amp. OSC 100kHz EXT C hip Enable CE Notes: (1) LX Pin .…… (2) EXT Pin …… (3) CE Pin …… only for 9261only for 9261Aonly for 9261CX and 9261CX and 9261ACB and 9261ACB CB CB Pin Description Pin No. -xxCX 1 2 3 ---A-xxCX 1 2 -3 ---xxCB 4 2 5 -1 3 A-xxCB 4 2 -5 1 3 Pin Name GND VOUT LX EXT CE NC Pin Function Ground Output Voltage Pin for Switching Drive External Device Chip Enable (Active High) No Connected www.richtek-ic.com.tw DS9261/A-03 January 2002 6 Preliminary Typical Application Circuit RT9261/A D1 L1 100µH VIN 1N5819 RT9261CX LX VOUT GND + Co _ 22 µF VOUT Fig. 1 L1 D1 27 µH 0.01 µF Cb 1N5819 RT9261ACX EXT VOUT GND Tr Rb 300Ω Fig. 2 + Co _ 22 µF VOUT VIN ZTX 650 D1 L1 LX NC 1N5819 RT9261CB VOUT VOUT + Co _ 22µF 100µH VIN EXT CE GND Fig. 3 DS9261/A-03 January 2002 www.richtek-ic.com.tw 7 RT9261/A Preliminary L1 D1 27 µH 0.01 µF NC Cb VIN ZTX 650 Rb Tr 300Ω Fig. 4 1N5819 RT9261ACB LX EXT CE VOUT GND VOUT + Co _ 22 µF D1 L1 1N5819 RT9261CB LX NC CE EXT VOUT + Co _ 22µF 27 µH VIN VOUT CE GND Fig. 5 www.richtek-ic.com.tw DS9261/A-03 January 2002 8 Preliminary Typical Operating Charateristics Start-up/Hold-on Voltage Vstart/Vhold (V) 1.4 RT9261/A RT9261(2.7V) Output Current vs. Ripple Voltage RT9261(2.7V) Start-up/Hold-on Voltage vs. Output Current 120 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 10 20 30 100 80 Vstart Ripple Voltage (mV p-p) Vhold 2.0V 60 1.5V 40 20 0 2.5V RT9261 VOUT = 2.7V 40 50 0.9V RT9261 VOUT = 2.7V 0 20 40 60 80 100 Output Current (mA) Output Current (mA) RT9261(2.7V) Output Voltage vs. Output Current 3.0 2.5 Output Voltage vs. Temperature 2.90 2.85 2.5V 0.9V 1.0V 1.5V 2.0V Output Voltage (V) Output Voltage (V) 2.0 1.5 1.0 0.5 0.0 0 20 40 60 2.80 2.75 2.70 2.65 2.60 -40 -20 0 20 40 RT9261 VOUT = 2.7V 80 100 RT9261 VOUT = 2.7V 60 80 Output Current (mA) Temperature (° C) 90 80 RT9261(2.7V) Efficiency vs. Output Current 2.0V 0.9V 1.0V 1.5V Supply Current vs. Temperature 70 60 Supply Current (µ A) 70 2.5V RT9261 VOUT = 2.7V Efficiency (%) 60 50 40 30 20 10 0 0 50 40 30 20 Input Current 2 RT9261 VOUT = 2.7V 20 40 60 80 100 10 0 -40 -20 0 20 40 60 80 Input Current 1 Output Current (mA) Temperature (° C) DS9261/A-03 January 2002 www.richtek-ic.com.tw 9 RT9261/A Preliminary RT9261A (2.7V) Output Voltage vs. Output Current 3.0 2.5 Maximum Oscillator Frequency vs. Temp. Maximum Oscillator Frequency (kHz) 160 140 2.5V 1.5V 1.0V 0.9V 2.0V Output Voltage (V) 120 100 80 60 40 20 0 -40 -20 2.0 1.5 1.0 0.5 0.0 0 30 60 90 RT9261 VOUT = 2.7V RT9261A VOUT = 2.7V 120 150 Temperature ( ° C) 0 20 40 60 80 Output Current (mA) Oscillator Duty Cycle vs. Temperatrue 100 80 70 RT9261A (2.7V) Efficiency vs. Output Current 2.5V 0.9V 1.0V 1.5V 2.0V Oscillator Duty Cycle (%) 90 60 Efficiency (%) 80 50 40 30 20 70 60 50 -40 -20 0 20 40 RT9261 VOUT = 2.7V 60 80 10 0 0 30 60 90 RT9261A VOUT = 2.7V 120 150 Temperature ( °C) Output Current (mA) Start-up/Hold-on Voltage vs. Output Current Start-up/Hold-on Voltage Vstart/Vhold (V) 1.6 1.4 120 100 RT9261A (2.7V) Output Current vs. Ripple Voltage Ripple Voltage (mV p-p) 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 Vstart 2.5V 80 60 40 20 0 0 30 60 90 2.0V 1.5V Vhold RT9261A VOUT = 2.7V 30 60 90 120 150 0.9V RT9261A VOUT = 2.7V 120 150 Output Current (mA) Output Current (mA) www.richtek-ic.com.tw DS9261/A-03 January 2002 10 Preliminary Package Information D D1 A H RT9261/A C B C1 e e A b b1 b Symbol A b B b1 C C1 D D1 e H Dimensions In Millimeters Min 1.397 0.356 2.388 0.406 -0.787 4.394 1.397 1.448 0.355 Max 1.600 0.483 2.591 0.533 4.242 1.194 4.597 1.753 1.549 0.432 Dimensions In Inches Min 0.055 0.014 0.094 0.016 -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 3-Lead SOT-89 Surface Mount DS9261/A-03 January 2002 www.richtek-ic.com.tw 11 RT9261/A Preliminary 5 D 4 C B 1 b 3 A e L H A1 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 0.102 0.356 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 0.004 0.014 Max 0.051 0.006 0.071 0.022 0.118 0.122 0.041 0.010 0.024 SOT- 25 Surface Mount Package www.richtek-ic.com.tw DS9261/A-03 January 2002 12 Preliminary RT9261/A DS9261/A-03 January 2002 www.richtek-ic.com.tw 13 RT9261/A Preliminary RICHTEK TECHNOLOGY CORP. Headquarter 6F, No. 35, Hsintai Road, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5510047 Fax: (8863)5537749 RICHTEK TECHNOLOGY CORP. Taipei Office (Marketing) 8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek-ic.com.tw www.richtek-ic.com.tw DS9261/A-03 January 2002 14