Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 600mA, 650kHz Micropower Synchronous Boost Converter with Output Disconnect DESCRIPTION FEATURES converter delivering high efficiency in a SOT23-6 package. The device has an internal NMOS switch and PMOS synchronous rectifier and has the capacity of supplying 3.3V at 100mA from a single AA cell input. Up to 96% efficiency Low start-up voltage 0.8V Internal synchronous rectifier Up to 2MHz switching allows for tiny external components 0.5V to 4.4V input range 2.5V to 5.0V output range (Note 3) Feedback Voltage: 1.00V +/-2% Logic controlled shutdown (<1µA) Low 250µA operating supply current (measured at VOUT) Pulse skipping at light load for extended battery life Generates 3.3V at 100mA from single AA cell Stable with ceramic output capacitor Low profile 6-Leads SOT23-6 package High frequency switching (up to 2MHz) minimizes the board area by allowing the use of tiny, low profile inductors and ceramic capacitors. The KB3436 provides automatic pulse skipping at light loads, thus reducing the supply current for extended battery life. At shutdown, the KB3436 fully discharges the output to ground and draws no supply current. The KB3436 is available in small SOT23-6 package with both fixed and adjustable output voltage versions. APPLICATIONS PDAs and organizers Digital cameras Wireless mice/ keyboards Portable medical equipment Cordless phones Wireless Headsets TYPICAL APPLICATION 2-Cell to 3.3V Efficiency 100 100 VIN = 3V 4.7µH 4.7µF SW VIN VOUT 460K KB3436 OFF ON SHDN GND VOUT 3.3V 250mA 4.7µF FB 80 70 60 10 EFFICIENCY VIN = 2.4V 1 0.1 VIN = 2.4V VIN = 3V 0.01 POWER LOSS (W) 2-CELL AA 90 EFFICIENCY (%) + 200K POWER LOSS 50 Figure 1. 2-Cell to 3.3V Synchronous Boost Converter 40 0.1 0.001 1 10 100 OUTPUT CURRENT (mA) 0.0001 1000 1 Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 ABSOLUTE MAXIMUM RATINGS ORDER PART NUMBER TOP VIEW SW 1 GND 2 FB 3 ● DGABF VIN Voltage .............................................. – 0.3V to 4.4V SW Voltage ................................................. – 0.3V to 6V SHDN, FB Voltage ....................................... – 0.3V to 6V VOUT ........................................................... – 0.3V to 6V Operating Temperature Range ................ – 40°C to 85°C Storage Temperature Range ................... – 65°C to 150° Lead Temperature (Soldering, 10 sec).................. 300°C PACkAGE/ORDER INFORMATION KB3436 6 VIN 5 VOUT 4 SHDN TOP MARKING DGABF TJMAX = 125°C, eJC = 102°C/W ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 1.2V, VOUT = 3.3V, unless otherwise specified. PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Start-Up Voltage ILOAD = 1mA, VOUT = 0V 0.80 Minimum Operating Voltage SHDN = VIN (Note 3) 0.5 0.65 V Output Voltage Adjust Range (Note 5) 5 V 1.000 1.020 V 2.5 ● Feedback Voltage +/-2% 0.980 V Feedback Input Current VFB = 1.05V 1 50 nA Quiescent Current (Burst Mode Operation) VFB = 1.2V (Note 4) 20 30 µA Quiescent Current (Shutdown) VSHDN = 0V, Not Including Switch Leakage, VOUT = 0V 0.01 1 µA Quiescent Current (Active) Measured on VOUT, Nonswitching 350 500 µA NMOS Switch Leakage VSW = 5V 0.1 5 µA PMOS Switch Leakage VSW = 5V, VOUT = 0V 0.1 5 µA 1 NMOS Switch On Resistance 0.35 PMOS Switch On Resistance 0.45 1 850 mA 1.25 mA 40 ns NMOS Current Limit Burst Mode Operation Current Threshold 600 L = 4.7µH (LTC3429 Only) Current Limit Delay to Output Max Duty Cycle VFB = 0.9V Switching Frequency SHDN Input High ● 80 90 ● 500 650 1 Soft-Start Time 2 0.35 VSHDN = 5.5V SHDN to 90% of VOUT kHz V SHDN Input Low SHDN Input Current % 800 0.01 2.5 1 V µA ms Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 TYPICAL PERFORMANCE CHARACTERISTICS (TA = 25°C unless otherwise specified) Single-Cell to 3.3V Efficiency 2-Cell to 3.3V Efficiency Efficiency vs Input Voltage 100 100 100 100 100 10 90 VOUT = 3.3V IOUT = 50mA VIN = 1.2V 70 0.1 VIN = 1.2V 0.01 60 VIN = 2.4V 80 EFFICIENCY (%) 1 EFFICIENCY 70 1 0.1 VIN = 2.4V VIN = 3V 60 0.01 POWER LOSS (W) EFFICIENCY 80 90 10 VIN = 1.5V POWER LOSS (W) EFFICIENCY (%) 90 EFFICIENCY (%) VIN = 3V 80 70 60 VIN = 1.5V POWER LOSS POWER LOSS 50 40 0.1 40 0.1 0.0001 1000 1 10 100 OUTPUT CURRENT (mA) 40 0.0001 1000 1 10 100 OUTPUT CURRENT (mA) VIN > VOUT PMOS LDO MODE 50 0.001 50 0.001 0.5 100 100 100 100 35 10 30 L = 4.7µH VIN = 3V 90 10 1 VIN = 2.4V 70 0.1 VIN = 3V 0.01 60 EFFICIENCY (%) VIN = 2.4V 80 1 70 0.1 VIN = 3.6V VIN = 4.2V 60 POWER LOSS 0.001 40 0.1 0.0001 1000 1 10 100 OUTPUT CURRENT (mA) 600 L = 4.7µH 100 VOUT = 3.3V 3.9 4.4 3.4 1.9 2.4 2.9 INPUT VOLTAGE (V) 3.9 4.4 CURRENT SINK LOAD 1.7 400 VOUT = 3.3V 300 VOUT = 5V 200 0 0.5 1.4 1.9 L = 4.7µH 1.5 RESISTOR LOAD 1.3 1.1 0.9 100 1.9 2.4 2.9 3.4 INPUT VOLTAGE (V) VOUT = 5V 10 Minimum Start-Up Input Voltage vs Load Current INPUT VOLTAGE (V) OUTPUT CURRENT (mA) INPUT CURRENT (µA) VOUT = 5V 1.4 VOUT = 3.3V 15 0 0.9 500 10 0.9 20 5 0.0001 1000 1 10 100 OUTPUT CURRENT (mA) 25 Maximum Load Current Capability at Output 4% Below Regulation Point No Load Input Current vs Input Voltage 1000 0.01 POWER LOSS 50 0.001 50 40 0.1 VIN = 3.6V POWER LOSS (W) EFFICIENCY 80 POWER LOSS (W) EFFICIENCY (%) EFFICIENCY OUTPUT CURRENT (mA) VIN = 4.2V 90 4.5 Burst Mode Output Current Threshold vs Input Voltage Li-Ion to 5V Efficiency 2-Cell to 5V Efficiency 1.5 2.5 3.5 INPUT VOLTAGE (V) 1 3 3.5 1.5 2 2.5 INPUT VOLTAGE (V) 0.7 4 4.5 0 50 100 OUTPUT CURRENT (mA) 150 3 Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 TYPICAL PERFORMANCE CHARACTERISTICS (TA = 25°C unless otherwise specified) Normalized Oscillator Frequency vs Temperature Output Voltage vs Temperature 3.44 3.40 Burst Mode Quiescent Current vs Temperature 1.02 VIN = 1.5V IOUT = 30mA 40 35 VOUT (V) 3.36 3.32 3.28 3.24 QUIESCENT CURRENT (µA) NORMALIZED FREQUECY 1.00 0.98 0.96 0.94 3.20 VOUT = 5V 30 25 VOUT = 3.3V 20 15 10 5 3.16 20 40 60 –60 –40 –29 0 TEMPERATURE (°C) 80 100 0.92 –60 –40 –20 0 20 40 60 TEMPERATURE (°C) 0 20 40 60 –60 –40 –20 0 TEMPERATURE (°C) 100 SW Pin Discontinuous Mode Antiringing Operation SW Pin Fixed Frequency Continuous Mode Operation 50mA IOUT 120µA VIN = 1.5V VOUT = 3.3V IOUT = 50mA L = 10µH COUT = 10µF CPL = 150pF 200ns/DIV VIN = 1.5V VOUT = 3.3V IOUT = 20mA L = 10µH COUT = 10µF CPL = 150pF 200ns/DIV VOUT 1V/DIV INDUCTOR CURRENT 100mA/DIV 90mA 40mA VIN = 1.5V 100µs/DIV VOUT = 3.3V IOUT = 40mA TO 90mA STEP L = 10µH COUT = 10µF CPL = 150pF 4 Inrush Current Control and Soft-Start VOUT 2V/DIV VOUT 100mV/DIV AC-COUPLED IOUT VIN = 1.5V 5ms/DIV VOUT = 3.3V IOUT = 120µA TO 50mA STEP L = 10µH COUT = 10µF CPL = 150pF Inrush Current Control and Soft-Start Output Voltage Transient Response INDUCTOR CURRENT 200mA/DIV VIN = 1.5V VOUT = 3.3V IOUT = 10mA L = 4.7µH COUT = 10µF CPL = 100pF 500µs/DIV 80 100 Fixed Frequency and Burst Mode Operation VOUT 100mV/DIV AC-COUPLED VSW 1V/DIV VSW 1V/DIV 80 VIN = 2.5V VOUT = 5V IOUT = 50mA L = 4.7µH COUT = 10µF CPL = 100pF 2ms/DIV Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 PIN FUNCTIONS SW (Pin 1): Switch Pin. Connect inductor between SW and VIN. Keep these PCB trace lengths as short and wide as possible to reduce EMI and voltage overshoot. If the inductor current falls to zero, or SHDN is low, an internal 1501 antiringing switch is connected from SW to VIN to minimize EMI. SHDN = Low: Shutdown, quiescent current < 1µA. Output capacitor can be completely discharged through the load or feedback resistors. A 1501 resistor is internally connected between SW and VIN. VOUT (Pin 5): Output Voltage Sense Input and Drain of the Internal Synchronous Rectifier MOSFET. Bias is derived from VOUT. PCB trace length from VOUT to the output filter capacitor(s) should be as short and wide as possible. VOUT is completely disconnected from VIN when SHDN is low due to the output disconnect feature. GND (Pin 2): Signal and Power Ground. Provide a short direct PCB path between GND and the (–) side of the output capacitor(s). FB (Pin 3): Feedback Input to the gm Error Amplifier. Connect resistor divider tap to this pin. The output voltage can be adjusted from 2.5V to 5V by: VIN (Pin 6): Battery Input Voltage. The device gets its start-up bias from VIN. Once VOUT exceeds VIN, bias comes from VOUT. Thus, once started, operation is completely independent from VIN. Operation is only limited by the output power level and the battery’s internal series resistance. VOUT = 1.00V • [1 + (R1/R2)] SHDN (Pin 4): Logic Controlled Shutdown Input. SHDN = High: Normal free running operation, 650kHz typical operating frequency. SIMPLIFIED BLOC DIAGRAM L1 + 1V TO 4.4V 6 VIN 1 SW CIN + VOUT GOOD – START-UP OSC A A/B MUX WELL SWITCH 0.451 B VOUT 2.5V TO 5V 5 SYNC DRIVE CONTROL PWM CONTROL RAMP GEN 650kHz VIN 2.3V CPL (OPTIONAL) CURRENT SENSE Y SLOPE COMP 0.351 R1 PWM COMPARATOR – – + FB Burst Mode OPERATION CONTROL CC 150pF SHDN 4 SHUTDOWN CONTROL SHUTDOWN + SLEEP – RC 80k 3 1.00V REF gm ERROR AMP CP2 2.5pF COUT R2 2 GND 5 Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 OPERATION The KB3436 are 650kHz, synchronous boost converters housed in a 6-lead SOT-23 package. Able to operate from an input voltage below 1V, the device features fixed frequency, current mode PWM control for exceptional line and load regulation. Low RDS(ON) internal MOSFET switches enable the device to maintain high efficiency over a wide range of load current. Detailed descriptions of the different operating modes follow. Operation can be best understood by referring to the Block Diagram. LOW VOLTAGE START-UP The KB3436 include an independent start-up oscillator designed to start up at input voltages of 0.8V typically. The frequency and duty cycle of the start-up oscillator are internally set to 150kHz and 67% respectively. In this mode, the IC operates completely open-loop and the current limit is also set internally to 600mA. Once the output voltage exceeds 2.3V, the start-up circuitry is disabled and normal close-loop PWM operation is initiated. In normal mode, the KB3436 power themselves from VOUT instead of VIN. This allows the battery voltage to drop to as low as 0.5V without affecting the circuit operation. The only limiting factor in the application becomes the ability of the battery to supply sufficient energy to the output. Soft-start and inrush current limiting are provided during start-up as well as normal mode operation. Soft-Start The KB3436 provide soft-start by charging an internal capacitor with a very weak current source. The voltage on this capacitor, in turn, slowly ramps the peak inductor current from zero to a maximum value of 850mA. The soft-start time is typically 2.5ms, the time it takes to charge the capacitor from zero to 1.20V. However, this time varies greatly with load current, output voltage and input voltage (see Typical Performance Characteristics, Inrush Current Control and Soft-Start). The soft-start capacitor is discharged completely in the event of a commanded shutdown or a thermal shutdown. It is discharged only partially in case of a short circuit at the output. 6 LOW NOISE FIXED FREQUENCY OPERATION Oscillator The frequency of operation is internally set to 650kHz. Error Amp The error amplifier is an internally compensated transconductance type (current output) with a transconductance (gm) = 33 microsiemens. The internal 1.00V reference voltage is compared to the voltage at the FB pin to generate an error signal at the output of the error amplifier. A voltage divider from VOUT to ground programs the output voltage via FB from 2.5V to 5V using the equation: VOUT = 1.00V • [1 + (R1/R2)] Current Sensing Lossless current sensing converts the NMOS switch current signal to a voltage to be summed with the internal slope compensation. The summed signal is compared to the error amplifier output to provide a peak current control command for the PWM. Peak switch current is limited to approximately 600mA independent of input or output voltage. The switch current signal is blanked for 60ns to enhance noise rejection. Zero Current Comparator The zero current comparator monitors the inductor current to the output and shuts off the synchronous rectifier once this current reduces to approximately 27mA. This prevents the inductor current from reversing in polarity thereby improving efficiency at light loads. Antiringing Control The antiringing control circuitry prevents high frequency ringing of the SW pin as the inductor current goes to zero in discontinuous mode. The damping of the resonant circuit formed by L and CSW (capacitance on SW pin) is achieved by placing a 1501 resistor across the inductor. Synchronous Rectifier To prevent the inductor current from running away, the PMOS synchronous rectifier is only enabled when VOUT > (VIN + 0.1V) and the FB pin is >0.8V. Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 OPERATION Thermal Shutdown An internal temperature monitor will start to reduce the peak current limit if the die temperature exceeds 125°C. If the die temperature continues to rise and reaches 160°C, the part will go into thermal shutdown, all switches will be turned off and the soft-start capacitor will be reset. The part will be enabled again when the die temperature drops by about 15°C. Burst Mode OPERATION Portable devices frequently spend extended time in low power or standby mode, only switching to high power consumption when specific functions are enabled. To improve battery life in these types of products, it is important to maintain a high power conversion efficiency over a wide output power range. The KB3436 provides automatic Burst Mode operation to increase efficiency of the power converter at light loads. Burst Mode operation is initiated if the output load current falls below an internally programmed threshold. This threshold has an inverse dependence on the duty cycle of the converter and also the value of the external inductor (See Typical Performance Characteristics, Output Current Burst Mode Threshold vs VIN). Once Burst Mode operation is initiated, only the circuitry required to monitor the output is kept alive and the rest of the device is turned off. This is referred to as the sleep state in which the IC consumes only 20µA from the output capacitor. When the output voltage droops by about 1% from its nominal value, the part wakes up and commences normal PWM operation. The output capacitor recharges and causes the part to re-enter the sleep state if the output load remains less than the Burst Mode threshold. The frequency of this intermittent PWM or burst operation depends on the load current; that is, as the load current drops further below the burst threshold, the KB3436 turns on less frequently. When the load current increases above the burst threshold, the KB3436 seamlessly resumes continuous PWM operation. Thus, Burst Mode operation maximizes the efficiency at very light loads by minimizing switching and quiescent losses. However, the output ripple typically increases to about 2% peak-to-peak. Burst Mode ripple can be reduced, in some circumstances, by placing a small phase-lead capacitor (CPL) between VOUT and FB pins (refer to the Block Diagram). However, this may adversely affect the efficiency and the quiescent current requirement at light loads. Typical values of CPL range from 15pF to 220pF. OUTPUT DISCONNECT AND INRUSH LIMITING The KB3436 are designed to allow true output disconnect by eliminating body diode conduction of the internal PMOS rectifier. This allows VOUT to go to zero volts during shutdown, drawing zero current from the input source. It also allows for inrush current limiting at start-up, minimizing surge currents seen by the input supply. Note that to obtain the advantage of output disconnect, there must not be an external Schottky diode connected between the SWITCH pin and VOUT. Board layout is extremely critical to minimize voltage overshoot on the SWITCH pin due to stray inductance. Keep the output filter capacitor as close as possible to the VOUT pin and use very low ESR/ESL ceramic capacitors tied to a good ground plane. For applications with VOUT over 4.3V, a Schottky diode is required to limit the peak SWITCH voltage to less than 6V unless some form of external snubbing is employed. This diode must also be placed very close to the pins to minimize stray inductance. See the Applications Information. SHORT CIRCUIT PROTECTION Unlike most boost converters, the KB3436 allow their output to be short circuited due to the output disconnect feature. The devices incorporate internal features such as current limit foldback, thermal regulation and thermal shutdown for protection from an excessive overload or short circuit. In the event of a short circuit, the internal soft-start capacitor gets partially discharged. This, in turn, causes the maximum current limit to foldback to a smaller value. In addition to this, a thermal regulation circuit starts to dial back the current limit farther if the die temperature rises above 125°C. If the die temperature still reaches 160°C, the device shuts off entirely. VIN > VOUT OPERATION The KB3436 will maintain voltage regulation even if the input voltage is above the output voltage. This 7 Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 OPERATION is achieved by terminating the switching of the synchronous PMOS and applying VIN statically on its gate. This ensures that the slope of the inductor current will reverse during the time current is flowing to the output. Since the PMOS no longer acts as a low impedance switch in this mode, there will be more power dissipation within the IC. This will cause a sharp drop in the efficiency (see Typical Performance Characteristics, Efficiency vs VIN). The maximum output current should be limited in order to maintain an acceptable junction temperature. APPLICATIONS INFORMATION PCB LAYOUT GUIDELINES The high speed operation of the KB3436 demands careful attention to board layout. You will not get advertised performance with careless layout. Figure 2 shows the recommended component placement. A large ground pin copper area will help to lower the chip temperature. A multilayer board with a separate ground plane is ideal, but not absolutely necessary. inductor ripple current. Increasing the inductance above 10µH will increase size while providing little improvement in output current capability. The approximate output current capability of the KB3436 versus inductance value is given in the equation below and illustrated graphically in Figure 3. V •D¥ £ IOUT(MAX) = d • ²IP – IN ´ • (1 – D) ¤ f • L • 2¦ where: VIN 1 KB3436 SW VIN 6 2 GND VOUT 5 3 FB SHDN 4 SHDN VOUT d = estimated efficiency IP = peak current limit value (0.6A) VIN = input (battery) voltage D = steady-state duty ratio = (VOUT – VIN)/VOUT f = switching frequency (650kHz typical) L = inductance value 200 RECOMMENDED COMPONENT PLACEMENT. TRACES CARRYING HIGH CURRENT ARE DIRECT. TRACE AREA AT FB PIN IS SMALL. LEAD LENGTH TO BATTERY IS SHORT COMPONENT SELECTION Inductor Selection The KB3436 can utilize small surface mount and chip inductors due to its fast 650kHz switching frequency. Typically, a 4.7µH inductor is recommended for most applications. Larger values of inductance will allow greater output current capability by reducing the 8 160 OUTPUT CURRENT (mA) Figure 2. Recommended Component Placement for Single Layer Board VIN = 1.2V 180 VOUT = 3.3V 140 120 100 VOUT = 5V 80 60 40 20 0 2.2 5 7 9 11 13 15 17 19 21 23 INDUCTANCE (µH) Figure 3. Maximum Output Current vs Inductance Based on 90% Efficiency Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 APPLICATIONS INFORMATION The inductor current ripple is typically set for 20% to 40% of the maximum inductor current (IP). High frequency ferrite core inductor materials reduce frequency dependent power losses compared to cheaper powdered iron types, improving efficiency. The inductor should have low ESR (series resistance of the windings) to reduce the I2R power losses, and must be able to handle the peak inductor current without saturating. Molded chokes and some chip inductors usually do not have enough core to support the peak inductor currents of 850mA seen on the KB3436. To minimize radiated noise, use a toroid, pot core or shielded bobbin inductor. See Table 1 for some suggested components and suppliers. Output and Input Capacitor Selection Table 1. Recommended Inductors Low ESR input capacitors reduce input switching noise and reduce the peak current drawn from the battery. It follows that ceramic capacitors are also a good choice for input decoupling and should be located as close as possible to the device. A 10µF input capacitor is sufficient for virtually any application. Larger values may be used without limitations. Table 2 shows a list of several ceramic capacitor manufacturers. Consult the manufacturers directly for detailed information on their entire selection of ceramic capacitors. PART L (µH) MAX DCR m1 HEIGHT (mm) 2.0 2.0 1.8 1.8 3.5 3.5 0.8 0.8 Sumida www.sumida.com 2.9 2.9 2.9 Coilcraft www.coilcraft.com CDRH5D18-4R1 CDRH5D18-100 CDRH3D16-4R7 CDRH3D16-6R8 CR43-4R7 CR43-100 CMD4D06-4R7MC CMD4D06-3R3MC 4.1 10 4.7 4.7 10 4.7 3.3 57 124 105 170 109 182 216 174 DS1608-472 DS1608-103 DO1608C-472 4.7 10 4.7 60 75 90 VENDOR D52LC-4R7M D52LC-100M 4.7 10 84 137 2.0 2.0 Toko www.tokoam.com LQH32CN4R7M24 4.7 195 2.2 Murata www.murata.com Low ESR (equivalent series resistance) capacitors should be used to minimize the output voltage ripple. Multilayer ceramic capacitors are an excellent choice as they have extremely low ESR and are available in small footprints. A 4.7µF to 15µF output capacitor is sufficient for most applications. Larger values up to 22µF may be used to obtain extremely low output voltage ripple and improve transient response. An additional phase lead capacitor may be required with output capacitors larger than 10µF to maintain acceptable phase margin. X5R and X7R dielectric materials are preferred for their ability to maintain capacitance over wide voltage and temperature ranges. Table 2. Capacitor Vendor Information SUPPLIER WEBSITE AVX www.avxcorp.com Murata www.murata.com Taiyo Yuden www.t-yuden.com 9 Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 TYPICAL APPLICATION Application Circuit for VOUT > 4.3V Where Inrush Current Limiting and Output Disconnect are Not Required L1 4.7µH + 100 100 1 C1 4.7µF 2 AA CELL 6 SW VIN VOUT OFF ON SHDN FB 3 R1 980K C2 4.7µF R2 245k GND 2 VIN = 3V 90 EFFICIENCY 80 10 VIN = 2.4V 1 VIN = 2.4V 70 0.1 VIN = 3V 0.01 60 POWER LOSS (W) KB3436 4 VOUT 5V 150mA 5 EFFICIENCY (%) VIN 2-Cell to 5V Efficiency D1* POWER LOSS 50 0.001 40 0.1 Single AA Cell to 2.5V Synchronous Boost Converter SINGLE AA CELL C1 4.7µF L1 4.7µH 1 6 SW VIN VOUT 5 KB3436 OFF ON 4 SHDN FB GND 2 10 0.0001 1000 Single AA Cell to 3.3V Synchronous Boost Converter L1 4.7µH + 1 10 100 OUTPUT CURRENT (mA) 3 R1 450K R2 250K VOUT 2.8V 120mA C2 4.7µF SINGLE AA CELL + C1 4.7µF 1 6 SW VIN VOUT 5 KB3436 OFF ON 4 SHDN FB GND 2 3 R1 460K R2 200K VOUT 3.3V 100mA C2 4.7µF Kingbor Technology Co.,Ltd KB3436 TEL:(86)0755-26508846 FAX:(86)0755-26509052 PACAGE DESCRIPTION Small Outline SOT23-6 b e E C e1 D E1 r L A A2 A1 SYMBOL A A1 A2 b C D E E1 L e e1 r MIN 0.035 0.000 0.035 0.010 0.003 0.110 0.102 0.059 0.014 00 INCHES 0.037ref 0.075ref Kingbor Technology TEL:(86) 0755-26508846 FAX: (86) 0755-26509052 www.kingbor.com MAX 0.057 0.006 0.051 0.020 0.008 0.122 0.118 0.069 0.022 100 MILLIMETERS MIN MAX 0.90 1.45 0.00 0.15 0.90 1.30 0.25 0.50 0.08 0.20 2.80 3.10 2.60 3.00 1.50 1.75 0.35 0.55 0.95ref 1.90ref 00 100 NOTES - - 11