NOT RECOMMENDED FOR NEW DESIGN SC1462 High Output Current Charge Pump Doubler POWER MANAGEMENT Description Features Input supply voltage range of 1.65V to 5.5V Small size - 6 pin SOT-23 package Typical efficiency of : 91% @ VIN = 2.5V, IOUT = 45mA 94% @ VIN = 3.6V, IOUT = 55mA Short circuit and over-temperature protection 140μA typical input current @ no load Shutdown current <1μA Designed to work with ceramic or tantalum capacitors Fixed frequency of 160kHz All specifications rated over full temperature range (-40°C to 85°C) The SC1462 is a versatile charge pump designed for use in battery operated power supply applications over the wide input range of 1.65 to 5.5 volts. A simple, low quiescent current charge pump doubler can be implemented without costly inductors or capacitors. Internal MOSFETs and control circuitry eliminate the need for costly board space and design time. The small 6 lead SOT-23 package helps minimize board space. N O FO T R R EC N O EW M M D EN ES D IG ED N The SC1462 charge pump can be used for applications that require up to 80mA of output current with VIN = 2.5V to 5.5V. Typical dropout voltage (2×VIN)-VOUT is shown below for several values of VIN. Typical Dropout Voltage vs. IOUT @TA = 25 Deg. C. 0.9 Output Dropout Voltage (V) 0.8 0.7 0.6 VIN = 1.5V VIN = 2.5V VIN = 3.6V VIN = 4.5V VIN = 5.5V Applications 0.5 0.4 0.3 0.2 Cellular phones Handheld devices LCD Display Typical Application Circuit 0.1 0.0 000E+0 20E-3 40E-3 60E-3 80E-3 100E-3 IOUT (A) Typical Application Circuit 4 Logic Control or GND SC1462 SHDN VOUT 5 VOUT COUT 1 VIN 3.3μF VIN C+ CIN 6 CBUCKET 3.3μF C- 3 3.3μF GND 2 December 12, 2005 1 www.semtech.com NOT RECOMMENDED FOR NEW DESIGN SC1462 POWER MANAGEMENT Absolute Maximum Ratings (1) Exceeding the specifications below may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Symbol Maximum Units Supply Voltage VIN -0.3 to +6.0 V Output Voltage VOUT -0.3 to +12 V VOUT Short Circuit Duration SC Indefinite Thermal Resistance Junction to Ambient(2) θJA 230 °C/W Operating Ambient Temperature Range TA -40 to +85 °C N O FO T R R EC N O EW M M D EN ES D IG ED N Parameter Junction Temperature Range TJ -40 to +125 °C Storage Temperature Range TSTG -65 to +150 °C Peak IR Flow Temperature, SC1462ISKTR TLEAD 240 °C Peak IR Flow Temperature, SC1462ISKTRT TLEAD 260 °C Notes: 1) This device is ESD sensitive. Use of standard ESD handlng precautions is required. 2) Calculated from package in still air, mounted to 3” x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad as per JESD51 standards. Electrical Characteristics Unless specified: TA = -40°C to 85°C, SHDN = GND, 1.65V ≤ VIN ≤ 5.5V, Frequency =160kHz, CIN = COUT = CBUCKET = 3.3μF (ESR = 0.3Ω). Parameter Input Supply Voltage Input Supply Current Symbol Conditions VIN IIN Min Typ 1.65 Max Units 5.5 V IOUT = 0, VIN = 2.5V 140 260 μA IOUT = 0, VIN = 3.6V 200 400 μA SHDN = VIN 0.1 1 μA Ouput Resistance(1) ROUT VIN = 2.5V 9.5 13.5 Ω Output Resistance(1) ROUT VIN = 3.6V 7.5 10.5 Ω Total Switch Resistance(2) RSW VIN = 2.5V 3 4.5 Ω Total Switch Resistance(2) RSW VIN = 3.6V 2 3 Ω VIN = 2.5V 80 mA VIN = 3.6V 80 mA 200 kHz Output Current Oscillator Frequency © 2005 Semtech Corp. IOUT fOSC 100 2 160 www.semtech.com NOT RECOMMENDED FOR NEW DESIGN SC1462 POWER MANAGEMENT Electrical Characteristics (Cont.) Parameter Symbol Conditions Short Circuit Current ISC VOUT = 0V 200 mA Output Ripple (pk-pk)(3)(4) VR IOUT = 45mA, VIN = 2.5V 75 mV Power Efficiency(3) η IOUT = 45mA, VIN = 2.5V VOUT IOUT = 0mA Time to Regulation at Turn-On(5) tON IOUT = 0 to 60mA, VIN = 3.6V Input High Threshold VIN SHDN pin, 2.5V ≤ VIN ≤ 5.5V VIL SHDN pin, 2.5V ≤ VIN ≤ 5.5V Input Low Threshold N O FO T R R EC N O EW M M D EN ES D IG ED N Maximum Output Voltage(4) Over-Temperature Protection(4) Over-Temperature Hystereis(4) TOT Hysteresis Min Typ Max Units 86 % 2×VIN 500 V μs 1.6 V 0.4 V 140 °C 20 °C Notes: 1) The internal switch resistance, the capacitor ESR and the oscillator’s switching frequency all contribute to ROUT. See the CAPACITOR SELECTION section on Page 6 for information on applying the ROUT specification. 2) The parameter RSW is equal to the total resistance of all 4 internal switches. See the CAPACITOR SELECTION section for information on applying the RSW specification. The parameter was calculated from actual output resistance and the equation on Page 6 for ROUT. 3) All electrical characteristics are for the Typical Application Circuit on Page 1. 4) Guaranteed by design. 5) Soft start functionality is performed along with short circuit protection. If VOUT is less than VIN - 200mV, then all switches are turned off and VOUT is charged with a 200mA current source from VIN. When VOUT reaches VIN - 200mV all switches are enabled. © 2005 Semtech Corp. 3 www.semtech.com NOT RECOMMENDED FOR NEW DESIGN SC1462 POWER MANAGEMENT Pin Configuration Ordering Information DEVICE(1) PACKAGE SC1462ISKTR SOT-23-6 SC1462ISKTRT(2) SOT-23-6 (1) Pin Descriptions N O FO T R R EC N O EW M M D EN ES D IG ED N Notes: 1) Available in tape and reel only. A reel contains 3,000 devices. 2) This Pb free device is WEEE and RoHS compliant. Pin# Pin Name 1 VIN 2 GND 3 C- 4 SHDN 5 VO 6 C+ Block Diagram Pin Function Supply input voltage. Ground. This pin should be connected to the negative terminal of the external charging capacitor. Shutdown pin. When this pin is connected to VIN, the device enters sleep mode. Voltage output. This pin should be connected to the positive terminal of the external charging capacitor. Marking Information Top Mark 1462 yyww Bottom Mark yyww = Datecode (Example : 0552) © 2005 Semtech Corp. 4 www.semtech.com NOT RECOMMENDED FOR NEW DESIGN SC1462 POWER MANAGEMENT Pin Configuration Applications Information If VOUT is less than VIN - 200mV, then all switches are turned off and VOUT is charged with a 200mA current source from VIN. When VOUT reaches VIN - 200mV, the current source is disconnected from output and the charge pump circuitry is enabled again. Theory of Operation The SC1462 utilizes a switched capacitor charge pump to generate an output voltage approximately 2×VIN. An internal oscillator generates two out of phase fixed frequency clock signals which turn on and off internal MOSFET switches. During phase 1, the flying charge pump capacitor is charged to VIN through switches S1 and S2. During phase 2, the flying charge pump capacitor is connected in series with the input voltage via S3 and S4, producing an output voltage. Output Current N O FO T R R EC N O EW M M D EN ES D IG ED N The dropout voltage for a charge pump doubler is defined as (2×VIN) - VOUT. The maximum output current is usually specified as that which will not cause the dropout voltage to exceed the requirements of the application. The calculation of the dropout voltage is given in the capacitor selection section on Page 6. Typical dropout voltages versus IOUT are graphed on Page 8. Charge transfer from CIN to CBUCKET ON Thermal Shutdown S1,S2 OFF The thermal shutdown circuit provides added protection to the SC1462. During a VOUT short circuit condition or if the load is excessive, the over-temperature circuitry will shut down the charge pump if the junction temperature exceeds approximately 140°C. The charge pump is enabled only if the junction temperature drops to approximately 120°C. The SC1462 will cycle in and out of thermal shut down until the short circuit or the excessive load condition on VOUT is removed, thereby improving device reliability. The junction temperature can be calculated from the following formula if the ambient temperature (TA) and the charge pump power dissipation (PDISS) are known. ON S3,S4 OFF Charge transfer from: CIN and CBUCKET to COUT (Doubler) S1 1 S4 2 1 2 CBUCKET VIN COUT S2 S3 1 VOUT = 2 x VIN 2 1 2 TJ = TA + PDISS × θJA ; θJA = 230 °C/W Cin Doubler Short Circuit/Soft-Start An internal current limit and soft-start circuit provides protection against output short circuit and limits large current spikes generated during the initial start-up to charge output capacitor. © 2005 Semtech Corp. 5 www.semtech.com NOT RECOMMENDED FOR NEW DESIGN SC1462 POWER MANAGEMENT Applications Information (Cont.) Capacitor Selection Capacitor selection is based on both the maximum acceptable ripple voltage and the maximum tolerable drop at the output. This equation can be used to calculate CBUCKET for a specific VOUT when VIN and IOUT are known. The maximum value for the RSW from the Electrical Characteristics section on Page 2 should be used in order to find a worst-case number. Ripple Layout Consideration The peak-to-peak output ripple voltage is dependent on the following factors: Standard power board layout should be followed to ensure proper operation. Any stray inductance should be minimized, this can be achieved by using large power planes or traces, and reducing the distances between input, output and the load. All components should be placed as close as possible to the SC1462. N O FO T R R EC N O EW M M D EN ES D IG ED N 1) Oscillator frequency 2) ESR of COUT 3) Capacitance value of COUT Item 1 is fixed and depend on the charge pump device used. Item 2, and 3 can be optimized for best performance and reduction of the output ripple. The following table shows typical capacitor characteristics. Component The following formula could be used for an approximation for VOUT_RIPPLE. VOUT_RIPPLE = IOUT 2 × fOSC × COUT VOUT Drop + 2 × I × ESR_ COUT ESR(Ω) ESL(nH) 0.1μF Ceramic 0603 Package 0.050 1.60 1.0μF Ceramic 1206 Package 0.040 0.47 10μF Ceramic 0603 Package 0.075 0.50 47μF Ceramic, 16V Tantalum D case 0.100 0.60 330μF, 6.3V “OSCON” 0.025 2.50 330μF, 16V AL. Electrolytic 0.143 2.37 820μF, 4V “OSCON” 0.012 2.50 1000μF, 10V Al. Electrolytic 0.053 5.00 The voltage drop at the output is specified with the following equation: VOUT_DROP = IOUT × ROUT ROUT is dependent on the following factors: 1) 2) 3) 4) Oscillator frequency ESR of COUT & CBUCKET Capacitance value of COUT and CBUCKET Internal switch resistance (RSW = Total of all 4 switch resistances). A good approximation for calculating the output resistance is shown below. ROUT = 1 fOSC × CBUCKET © 2005 Semtech Corp. + 2 × RSW + 4 × ESR_ CBUCKET + ESR_ COUT 6 www.semtech.com NOT RECOMMENDED FOR NEW DESIGN SC1462 POWER MANAGEMENT Applications Information (Cont.) VIN = 3V to 5.5V CIN 3.3μF U1 SC1462 1 VIN U2 SC2982 5 Vo 4 SHDN C+ 6 3 C- GND 1 2 CBUCKET COUT 3.3μF 3.3μF 3 VIN VOUT = 5V 5 VOUT GND 4 BYPASS EN C2 C3 10nF 1μF 2 N O FO T R R EC N O EW M M D EN ES D IG ED N EN 5 Volts Fixed Ouput Voltage VIN = 2V to 3V CIN 3.3μF U1 SC1462 1 VIN U2 SC1453 Vo 5 4 SHDN C+ 6 C- 3 GND 1 IN CBUCKET COUT 3.3μF 3.3μF OUT 3 EN GND BYP 2 EN 2 VOUT = 3.3V 5 4 C2 C3 10nF 1μF 3.3 Volts Fixed Ouput Voltage VIN = 3.3V 10 4 BSTH DRV H OCSET PHASE BSTL DRV L VCC PGND GND VREF SS/SHDN Sense 6 5 SC1462 1 4 VIN Vo SHDN C+ GND C- 9 5 6 1 8 7 3 14 12 2 13 Power Good 2 PWRGD OVP 11 3 SC1102 (3.3V Input Supply) Battery Operated Synchronous Buck Converter © 2005 Semtech Corp. 7 www.semtech.com NOT RECOMMENDED FOR NEW DESIGN SC1462 POWER MANAGEMENT Typical Characteristics Typical IIN vs. VIN, IOUT = 0mA Typical Dropout vs. IOUT Typical Dropout Voltage vs. IOUT @TA = 25 Deg. C. Typical IIN vs. VIN @TA = 25 Deg. C. 0.9 700E-6 Output Dropout Voltage (V) 600E-6 500E-6 IIN (A) VIN = 1.5V 0.8 400E-6 300E-6 100E-6 VIN = 4.5V VIN = 5.5V 0.6 0.5 0.4 0.3 0.2 0.1 IOUT = 0mA 000E+0 VIN = 3.6V N O FO T R R EC N O EW M M D EN ES D IG ED N 200E-6 VIN = 2.5V 0.7 0.0 1.0 2.0 3.0 4.0 5.0 6.0 000E+0 20E-3 40E-3 VIN (V) Typical IIN vs. TA, IOUT = 0mA 100E-3 Typical Dropout Voltage vs. TA 550E-3 800E-6 VIN = 4.5V VIN = 3.6V 700E-6 VIN = 2.5V VIN = 1.5V 600E-6 500E-6 400E-6 300E-6 200E-6 100E-6 VIN = 2.5V, IOUT = 50mA Output Dropout Voltage (V) VIN = 5.5V IIN (A) 80E-3 Typical Dropout vs. TA Typical IIN vs. TA @ IOUT = 0mA 900E-6 60E-3 IOUT (A) VIN = 3.6V, IOUT = 60mA 500E-3 450E-3 400E-3 350E-3 300E-3 000E+0 -40 -20 0 20 40 60 -40 80 -20 TA (Deg. C.) 0 20 40 60 80 TA (Deg. C.) Typical Output Ripple Typical Efficiency vs. IOUT Typical Efficiency vs. IOUT @TA = 25 Deg. C. 100% VOUT Ripple 50mV/Div. Efficiency (%) 96% 92% 88% VIN = 3.6V IOUT = 60mA CIN = COUT = CBUCKET = 3.3µF VIN = 5.5V VIN = 4.5V 84% VIN = 3.6V VIN = 2.5V VIN = 1.5V 80% 000E+0 20E-3 40E-3 60E-3 80E-3 100E-3 IOUT (A) © 2005 Semtech Corp. 8 www.semtech.com NOT RECOMMENDED FOR NEW DESIGN SC1462 POWER MANAGEMENT Outline Drawing - SOT-23-6L DIM A e1 2X E/2 A A1 A2 b c D E1 E e e1 L L1 N 01 aaa bbb ccc D N EI 1 E 2 ccc C 2X N/2 TIPS e .057 .035 .000 .006 .035 .045 .051 .010 .020 .003 .009 .110 .114 .122 .060 .063 .069 .110 BSC .037 BSC .075 BSC .012 .018 .024 (.024) 6 0° 10° .004 .008 .008 1.45 0.90 0.15 0.00 .90 1.15 1.30 0.25 0.50 0.08 0.22 2.80 2.90 3.10 1.50 1.60 1.75 2.80 BSC 0.95 BSC 1.90 BSC 0.30 0.45 0.60 (0.60) 6 0° 10° 0.10 0.20 0.20 N O FO T R R EC N O EW M M D EN ES D IG ED N B DIMENSIONS INCHES MILLIMETERS MIN NOM MAX MIN NOM MAX D aaa C A2 SEATING PLANE A H A1 C bxN bbb C A-B D GAGE PLANE 0.25 L c 01 (L1) SEE DETAIL A DETAIL A SIDE VIEW NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H- 3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. © 2005 Semtech Corp. 9 www.semtech.com NOT RECOMMENDED FOR NEW DESIGN SC1462 POWER MANAGEMENT Land Pattern - SOT-23-6L X DIM (C) G Z (.098) .055 .037 .024 .043 .141 (2.50) 1.40 0.95 0.60 1.10 3.60 N O FO T R R EC N O EW M M D EN ES D IG ED N Y C G P X Y Z DIMENSIONS MILLIMETERS INCHES P NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111 FAX (805) 498-3804 © 2005 Semtech Corp. 10 www.semtech.com