LTC1701_1 LINER
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DC/DC Converters in SOT-23 n PDAs/Palmtop PCs n Digital Cameras n Cellular Phones n Portable Media Players n PC Cards n Handheld Equipment , LTC and LT are registered trademarks of Linear Technology Corporation. n Tiny 5-Lead SOT-23 Package n Uses Tiny Capacitors and Inductor n High Frequency Operation: 1MHz n High Output Current: 500mA n Low RDS(ON) Internal Switch: 0.28W n High Efficiency: Up to 94% n Current Mode Operation for Excellent Line and Load Transient Response n Short-Circuit Protected n Low Quiescent Current: 135mA (LTC1701) n Low Dropout Operation: 100% Duty Cycle n Ultralow Shutdown Current: IQ < 1mA n Peak Inductor Current Independent of Inductor Value n Output Voltages from 5V Down to 1.25V The LTC 1701/LTC1701B are the industry’s first SOT-23 step-down, current mode, DC/DC converters. Intended for low to medium power applications, they operate from 2.5V to 5.5V input voltage range and switch at 1MHz, allowing the use of tiny, low cost capacitors and inductors 2mm or less in height. The output voltage is adjustable from 1.25V to 5V. A built-in 0.28W switch allows up to 0.5A of output current at high efficiency. OPTI-LOOP TM compensation allows the transient response to be optimized over a wide range of loads and output capacitors. The LTC1701 incorporates automatic power saving Burst Mode TM operation to reduce gate charge losses when the load current drops below the level required for continuous operation. The LTC1701B operates continuously to very low load currents to provide low ripple at the expense of light load efficiency. With no load, the LTC1701 draws only 135mA. In shutdown, both devices draw less than 1 mA, making them ideal for current sensitive applications. Their small size and switching frequency enables a complete DC/DC converter function to consume less than 0.3 square inches of PC board area. VIN ITH/RUN SW VFB GND LTC1701 4.7µH C1: TAIYO YUDEN JMK316BJ106ML C2: SANYO POSCAP 6TPA47M D1: MBRM120L L1: SUMIDA CD43-4R7 5.1k 330pF 10µF 121k 121k 47µF1701 F01a VOUT (2.5V/ 500mA) VIN 2.5V TO 5.5V Figure 1. 2.5V/500mA Step-Down Regulator Burst Mode and OPTI-LOOP are trademarks of Linear Technology Corporation.
FEATURES
LOAD CURRENT (mA) 1 10 100 1000 EFFICIENCY (%) 100
1701 F01b
VIN = 3.3V VOUT = 2.5V LTC1701 LTC1701B
MARKINGTJMAX = 125°C, qJA = 250°C/W Consult factory for parts specified with wider operating temperature ranges. LTKG LTUD LTC1701ES5 LTC1701BES5 ABSOLUTE AXI U RATI GSW WW U PACKAGE/ORDER I FOR ATIOUU W (Voltages Referred to GND Pin) Operating Temperature Range (Note 2) .. – 40°C to 85°C (Note 1) The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 3.3V, RITH/RUN = 1Meg (from VIN to ITH/RUN) unless otherwise specified. (Note 2) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VIN Operating Voltage Range 2.5 5.5 V IFB Feedback Pin Input Current (Note 3) – 0.1 mA VFB Feedback Voltage (Note 3) l 1.22 1.25 1.28 V DVLINE REG Reference Voltage Line Regulation V IN = 2.5V to 5V (Note 3) 0.04 0.1 %/V DVLOAD REG Output Voltage Load Regulation Measured in Servo Loop, V ITH = 1.5V, (Note 3) 0.01 0.70 % Measured in Servo Loop, VITH = 1.9V, (Note 3) – 0.80 –1.50 % Input DC Supply Current (Note 4) Active Mode V FB = 0V 185 300 mA Sleep Mode V FB = 1.4V (LTC1701 only) 135 200 mA Shutdown V ITH/RUN = 0V 0.25 1 mA VITH/RUN Run Threshold High I TH/RUN Ramping Down 1.4 1.6 V Run Threshold Low I TH/RUN Ramping Up 0.3 0.6 V IITH/RUN Run Pullup Current V ITH/RUN = 1V 50 100 300 mA ISW(PEAK) Peak Switch Current Threshold V FB = 0V 0.9 1.1 A RDS(ON) Switch ON Resistance V IN = 5V, VFB = 0V 0.28 W VIN = 3.3V, VFB = 0V 0.30 W VIN = 2.5V, VFB = 0V 0.35 W ISW(LKG) Switch Leakage Current V IN = 5V, VITH/RUN = 0V, VFB = 0V 0.01 1 mA tOFF Switch Off-Time 400 500 600 ns
ELECTRICAL CHARACTERISTICS
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC1701E/LTC1701BE guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the – 40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: The LTC1701/LTC1701B are tested in a feedback loop which servos V FB to the midpoint for the error amplifier without RITH/RUN = 1MHz (VITH = 1.7V unless otherwise specified). Note 4: Dynamic supply current is higher due to the internal gate charge being delivered at the switching frequency. Note 5: TJ is calculated from the ambient TA and power dissipation PD according to the following formula: LTC1701ES5/LTC1701BES5: TJ = TA + (PD • 250°C/W) SW 1 GND 2 VFB 3
5 VIN
4 ITH/RUN
LOAD CURRENT (mA) EFFICIENCY (%) 100 10 100 1000 1701 • G01 VIN = 5.0V VIN = 3.3V VOUT = 2.5V LTC1701 LTC1701B INPUT VOLTAGE (V) EFFICIENCY (%) 1701 • G02 3 4 5 100 ILOAD =100mA ILOAD =10mA VOUT = 2.5V LTC1701 LTC1701B INPUT VOLTAGE (V) SUPPLY CURRENT (mA) 1701 • G03 300 250 200 150 100 2 3 4 5 6 ACTIVE SLEEP SUPPLY VOLTAGE (V) ON RESISTANCE (mW ) 1701 • G04 370 350 330 310 290 270 250 2 3 4 5 6 LOAD CURRENT (mA) VOUT ERROR (%) 200 400 1701 • G05 0.60 0.40 0.20 0.00 –0.20 –0.40 –0.60 –0.80 –1.00 –1.20 –1.40 600 VOUT = 5.0V VOUT = 3.3V VIN (V) VOUT ERROR (%) 1701 • G06 0.30 0.25 0.20 0.15 0.10 0.05 2 3 4 5 6 ILOAD = 200mA ILOAD = 400mA VIN (V) 3.0 VOUT (V) 3.8 701 • G07 3.2 3.4 3.6 3.4 3.3 3.2 3.1 3.0 2.9 2.8 2.7 2.6 ILOAD = 100mA ILOAD = 500mA ILOAD = 200mA VOUT = 3.3V FIGURE 1
1701 G09
VIN = 3.3V, VOUT = 2.5V CIRCUIT OF FIGURE 1 I LOAD = 100mA TO 500mA STEP IL 200mA/DIV TYPICAL PERFORMANCE CHARACTERISTICS UW Efficiency vs Load Current Efficiency vs Input Voltage DC Supply Current Switch Resistance vs Supply Voltage Load Regulation Line Regulation Dropout Characteristics Start-Up Transient Response
1701 G08
VIN = 3.3V, VOUT = 2.5V CIRCUIT OF FIGURE 1 R LOAD = 6W ITH 2V/DIV IL 500mA/DIV
SW (Pin 1): The Switch Node Connection to the Inductor. This pin swings from V IN to a Schottky diode (external) voltage drop below ground. The cathode of the Schottky diode must be closely connected to this pin. GND (Pin 2): Ground Pin. Connect to the (–) terminal of COUT, the Schottky diode and (–) terminal of CIN. VFB (Pin 3): Receives the feedback voltage from the external resistive divider across the output. Nominal volt- age for this pin is 1.25V. ITH/RUN (Pin 4): Combination of Error Amplifier Compen- sation Point and Run Control Input. The current compara- tor threshold increases with this control voltage. Nominal voltage range for this pin is 1.25V to 2.25V. Forcing this pin below 0.8V causes the device to be shut down. In shutdown all functions are disabled. V IN (Pin 5): Main Supply Pin and the (+) Input to the Current Comparator. Must be closely decoupled to ground. PI FU CTIO S UU U BLOCK DIAGRA W 1.25V BANDGAP REFERENCE ITH/REF CLAMP SHDN 50µA VREF VREF 1.4V 1.5V VREF (1.25V) + OVER VOLTAGE COMP ITH COMP ERROR AMP (1.25V TO 2.25V) CURRENT COMP VREF CURRENT SENSE AMP SW GND 1701 BD VIN OFF-TIMER AND GATE CONTROL LOGIC GATE DRIVER VFB ITH/RUN PULSE STRETCHER VFB < 0.6V VIN VIN (LTC1701 only) Pin Limit Table NOMINAL (V) ABSOLUTE MAX (V) PIN NAME DESCRIPTION MIN TYP MAX MIN MAX 1 SW Switch Node – 0.3 V IN VIN – 8.5 V IN + 0.3
2 GND Ground Pin 0
3V FB Output Feedback Pin 0 1.25 1.35 – 0.3 3 4I TH/RUN Error Amplifier Compensation and RUN Pin 0 2.25 – 0.3 3 5V IN Main Power Supply 2.5 5.5 – 0.3 6
The LTC1701 uses a contant off-time, current mode archi- tecture. The operating frequency is then determined by the off-time and the difference between VIN and VOUT. The output voltage is set by an external divider returned to the VFB pin. An error amplfier compares the divided output voltage with a reference voltage of 1.25V and adjusts the peak inductor current accordingly. Main Control Loop During normal operation, the internal PMOS switch is turned on when the V FB voltage is below the reference voltage. The current into the inductor and the load in- creases until the current limit is reached. The switch turns off and energy stored in the inductor flows through the external Schottky diode into the load. After the constant off-time interval, the switch turns on and the cycle repeats. The peak inductor current is controlled by the voltage on the I TH/RUN pin, which is the output of the error amplifier.This amplifier compares the VFB pin to the 1.25V reference. When the load current increases, the FB voltage decreases slightly below the reference. This decrease causes the error amplifier to increase the I TH/RUN voltage until the average inductor current matches the new load current. The main control loop is shut down by pulling the I TH/RUN pin to ground. When the pin is released an external resistor is used to charge the compensation capacitor. When the voltage at the I TH/RUN pin reaches 0.8V, the main control loop is enabled and the error amplifier drives the ITH/RUN pin. Soft-start can be implemented by ramping the voltage on the I TH/RUN pin (see Applications Information sec- tion). Low Current Operation To optimize efficiency when the load is relatively light, the LTC1701 automatically switches to Burst Mode operation in which the internal PMOS switch operates intermittently based on load demand. The main control loop is inter- rupted when the output voltage reaches the desired regu- lated value. The hysteretic voltage comparator trips when I TH/RUN is below 1.5V, shutting off the switch and reduc- ing the power consumed. The output capacitor and the inductor supply the power to the load until the output voltage drops slightly and the I TH/RUN pin exceeds 1.5V, turning on the switch and the main control loop which starts another cycle. For reduced output ripple, the LTC1701B doesn't use Burst Mode operation and operates continuously down to very low currents where the part starts skipping cycles. Dropout Operation In dropout, the internal PMOS switch is turned on continu- ously (100% duty cycle) providing low dropout operation with V OUT at VIN. Since the LTC1701 does not incorporate an under voltage lockout, care should be taken to shut down the LTC1701 for V IN < 2.5V. APPLICATIO S I FOR ATIOWU UU The basic LTC1701 application circuit is shown in Figure␣ 1. External component selection is driven by the load requirement and begins with the selection of L1. Once L1 is chosen, the Schottky diode D1 can be selected followed by C IN and COUT. L Selection and Operating Frequency The operating frequency is fixed by V IN, V OUT and the constant off-time of about 500ns. The complete expres- sion for operating frequency is given by: fO = - æ Łç ö æ Łç ö VV VV T IN OUT IN D OFF Although the inductor does not influence the operating frequency, the inductor value has a direct effect on ripple current. The inductor ripple current DI L decreases with higher inductance and increases with higher VIN or VOUT: D= -æ Łç ö æ Łç ö ł÷I VV fL VV VV L IN OUT OUT D IN D where VD is the output Schottky diode forward drop.
APPLICATIO S I FOR ATIOWU UU Accepting larger values of DIL allows the use of low inductances, but results in higher output voltage ripple and greater core losses. A reasonable starting point for setting ripple current is DIL = 0.4A. The inductor value also has an effect on low current operation. Lower inductor values (higher DIL) will cause Burst Mode operation to begin at higher load currents, which can cause a dip in efficiency in the upper range of low current operation. In Burst Mode operation, lower inductance values will cause the burst frequency to de- crease. Inductor Core Selection Once the value for L is selected, the type of inductor must be chosen. Basically, there are two kinds of losses in an inductor —core and copper losses. Core losses are dependent on the peak-to-peak ripple current and core material. However, it is independent of the physical size of the core. By increasing inductance, the peak-to-peak inductor ripple current will decrease, there- fore reducing core loss. Unfortunately, increased induc- tance requires more turns of wire and, therefore, copper losses will increase. High efficiency converters generally cannot afford the core loss found in low cost powdered iron cores, forcing the use of more expensive ferrite, molypermalloy or Kool Mm cores. Ferrite designs have very low core loss and are preferred at high switching frequencies. Ferrite core ma- terial saturates “hard,” which means that inductance col- lapses abruptly when the peak design current is exceeded. This results in an abrupt increase in inductor ripple current and consequent output voltage ripple. Do not allow the core to saturate! Molypermalloy (from Magnetics, Inc.) is a very good, low loss core material for toroids, but it is more expensive than ferrite. A reasonable compromise from the same manu- facturer is Kool Mm core material. Toroids are very space efficient, expecially when you can use several layers of wire. Because they generally lack a bobbin, mounting is more difficult. However, surface mount designs that do not increase the height significantly are available Catch Diode Selection The diode D1 shown in Figure 1 conducts during the off- time. It is important to adequately specify the diode peak current and average power dissipation so as not to exceed the diode ratings. Losses in the catch diode depend on forward drop and switching times. Therefore, Schottky diodes are a good choice for low drop and fast switching times. Since the catch diode carries the load current during the off-time, the average diode current is dependent on the switch duty cycle. At high input voltages, the diode con- ducts most of the time. As V IN approaches VOUT, the diode conducts only a small fraction of the time. The most stressful condition for the diode is when the regulator output is shorted to ground. Under short-circuit conditions (V OUT = 0V), the diode must safely handle I SC(PK) at close to 100% duty cycle. Under normal load conditions, the average current con- ducted by the diode is simply: II VV VVDIODE avg LOAD avg IN OUT IN D () () = - æ Łç ö Remember to keep lead lengths short and observe proper grounding (see Board Layout Considerations) to avoid ringing and increased dissipation. The forward voltage drop allowed in the diode is calculated from the maximum short-circuit current as: V P I VV VD D SC avg IN D IN æ Łç ö Łç ö where PD is the allowable diode power dissipation and will be determined by efficiency and/or thermal requirements (see Efficiency Considerations). Most LTC1701 circuits will be well served by either an MBR0520L or an MBRM120L. An MBR0520L is a good choice for I OUT(MAX) £ 500mA, as long as the output doesn’t need to sustain a continuous short. Kool Mm is a registered trademark of Magnetics, Inc.
Input Capacitor (CIN) Selection In continuous mode, the input current of the converter is a square wave with a duty cycle of approximately V OUT/ VIN. To prevent large voltage transients, a low equivalent series resistance (ESR) input capacitor sized for the maxi- mum RMS current must be used. The maximum RMS capacitor current is given by: II VV V V RMS MAX OUT IN OUT IN -() where the maximum average output current IMAX equals the peak current (1 Amp) minus half the peak-to-peak ripple current, IMAX = 1 – DIL/2. This formula has a maximum at VIN = 2VOUT, where IRMS = IOUT/2. This simple worst-case is commonly used to design because even significant deviations do not offer much relief. Note that capacitor manufacturer’s ripple current ratings are often based on only 2000 hours life- time. This makes it advisable to further derate the capaci- tor, or choose a capacitor rated at a higher temperature than required. Several capacitors may also be paralleled to meet the size or height requirements of the design. An additional 0.1mF to 1mF ceramic capacitor is also recom- mended on V IN for high frequency decoupling. Output Capacitor (COUT) Selection The selection of C OUT is driven by the required ESR. Typically, once the ESR requirement is satisfied, the capacitance is adequate for filtering. The output ripple (DV OUT) is determined by: D» D + æ Łç ö ł÷V I ESR fCOUT L OUT where f = operating frequency, COUT = output capacitance and DIL = ripple current in the inductor. With DIL = 0.4 IOUT(MAX) the output ripple will be less than 100mV with: ESRCOUT < 100mW Once the ESR requirements for COUT have been met, the RMS current rating generally far exceeds the IRIPPLE(P-P) requirement. When the capacitance of C OUT is made too small, the output ripple at low frequencies will be large enough to trip the ITH comparator. This causes Burst Mode operation to be activated when the LTC1701 would normally be in continuous mode operation. The effect can be improved at higher frequencies with lower inductor values. In surface mount applications, multiple capacitors may have to be paralleled to meet the capacitance, ESR or RMS current handling requirement of the application. Alumi- num electrolyte and dry tantulum capacitors are both available in surface mount configurations. In the case of tantalum, it is critical that the capacitors are surge tested for use in switching power supplies. An excellent choice is the AVX TPS, AVX TPSV and KEMET T510 series of surface mount tantalums, avalable in case heights ranging from 2mm to 4mm. Other capacitor types include Nichicon PL series, Sanyo POSCAP and Panasonic SP. Ceramic Capacitors Higher value, lower cost ceramic capacitors are now becoming available in smaller case sizes. These are tempt- ing for switching regulator use because of their very low ESR. Unfortunately, the ESR is so low that it can cause loop stability problems. Solid tantalum capacitor ESR generates a loop “zero” at 5kHz to 50kHz that is instrumen- tal in giving acceptable loop phase margin. Ceramic ca- pacitors remain capacitive to beyond 300kHz and usually resonate with their ESL before ESR becomes effective. Also, ceramic caps are prone to temperature effects which requires the designer to check loop stability over the operating temperature range. For these reasons, most of the input and output capaci- tance should be composed of tantalum capacitors for stability combined with about 0.1 mF to 1 mF of ceramic capacitors for high frequency decoupling. Great care must be taken when using only ceramic input and output capaci- tors. The OPTI-LOOP compensation allows transient re- sponse to be optimized for all types of output capacitors, including low ESR ceramics. Setting the Output Voltage The LTC1701 develops a 1.25V reference voltage between the feedback pin, V FB, and the signal ground as shown in APPLICATIO S I FOR ATIOWU UU
Figure 2. The output voltage is set by a resistive divider
1701 F02
be estimated by examining the rise time at the pin. Figure 2. Setting the Output Voltage stability without breaking the feedback loop. loop compensation and a means to shut down the LTC1701. ing can also be accomplished using this pin. normal operating range of 1.25V to 2.25V.
charge of the internal MOSFET switch. count for less than 2% total additional loss. nearby must also be considered. Figure 3. ITH/RUN Pin Interfacing the output power divided by the input power times 100%. loss that increases with VIN, even at no load.
1701 F03
1701 F04
Figure 4. LTC1701 Layout Diagram (See Board Layout Checklist) Table 1. Measured Thermal Resistance *Device is mounted on topside. the absolute maximum junction temperature of 125°C.
- Is the Schottky diode closely connected between the
- Are the COUT, L1 and D1 closely connected? The Schottky
anode should connect directly to the input capacitor ground.
- The resistor divider, R1 and R2, must be connected
- Keep sensitive components away from the SW pin. The
the SW trace and the components L1 and D1.
All Ceramic Capacitor 2.5V Converter 2mm Nominal Height 1.5V Converter 5V to 3.3V Converter with Push-Button On/Off Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. LOAD CURRENT (mA) EFFICIENCY (%) 10 100 1000 1701TA01b VIN = 2.5V VIN = 3.3V VOUT = 1.5V LTC1701 LTC1701B VIN ITH/RUN SW VFB GND 1µF 5.1k 100k 330pF 15µF 4.7µF +C2 22µF 20k 4.7µHVIN 2.5V TO 5.5V VOUT (1.5V/0.5A) LTC1701 C1: AVX TAJA156M010R C2: AVX TAJA226M006R
1701 TA01a
D1: MBRM120L L1: MURATA LQH3C4R7M24 C4: TAIYO YUDEN LMK212BJ105MG C5: TAIYO YUDEN JMK212BJ475MG LOAD CURRENT (mA) EFFICIENCY (%) 100 10 100 1000
1701 TA02b
VIN = 5.0V VIN = 3.3V VOUT = 2.5V LTC1701 LTC1701B Efficiency Curve Efficiency Curve LTC1701B Low Current Pulse Skip VIN ITH/RUN SW VFB GND 1µF 5.1k 121k 180pF 33pF 10µF 10µF 121k 4.7µHVIN 2.5V TO 5.5V LTC1701 C1, C2: TAIYO YUDEN JMK316BJ106ML C4, C5: TAIYO YUDEN LMK212BJ105MG 1µF V OUT (2.5V/0.5A)
1701 TA02
L1: MURATA LQH3C4R7M24 D1: MBRM120L VIN ITH/RUN SW VFB GND 1µF 5.1kR5 5.1M 20.5k 330pF 15µF 1µF +C2 22µF 34k 4.7µHVIN 3.3V TO 5.5V VOUT (3.3V/ 0.5A) LTC1701 C1: AVX TAJA156M010R C2: AVX TAJA226M006R C4, C5: TAIYO YUDEN LMK212BJ105MG
1701 TA03a
D1: MBRM120L L1: MURATA LQH3C4R7M24 VOUT 20mV/DIV IL 50mA/DIV 5µs/DIV 1701 TA03b VIN = 5V VOUT = 2.5V
ª LINEAR TECHNOLOGY CORPORATION 1 999 1701Bfa LT/TP 1100 REV A 2K • PRINTED IN USA PART NUMBER DESCRIPTION COMMENTS LTC1174/LTC1174-3.3/ High Efficiency Step-Down and Inverting DC/DC Converters Monolithic Switching Regulator, Burst Mode Operatio n, LTC1174-5 IOUT Up to 300mA, SO-8 LTC1265 1.2A, High Efficiency Step-Down DC/DC Converter Monolithic, Burst Mode Operation, High Efficiency LT1375/LT1376 1.5A, 500kHz Step-Down Switching Regulators High Frequency, Small Inductor, High Efficiency, SO-8 LTC1474/LTC1475 Low Quiescent Current High Efficiency Step-Down Converters 10 mA IQ, 8-Pin MSOP and SO Packages LTC1622 Low Input Voltage Current Mode Step-Down DC/DC Controller High Frequency, High Efficiency, 8-Pin MSOP LTC1627 Monolithic Synchronous Step-Down Switching Regulator SO-8, 2.65V £ VIN £ 10V, IOUT Up to 500mA LTC1707 Monolithic Synchronous Step-Down Switching Regulator SO-8, 2.95V £ VIN £ 10V, VREF Output LTC1771 Low Quiescent Current, High Efficiency Step-Down Controller 10 mA IQ, 8-Pin MSOP and SO Packages LTC1772 Low Input Voltage Current Mode Step-Down DC/DC Controller 550kHz, 6-Pin SOT-23, I OUT Up to 5A, 2.2V < VIN < 10V LTC1877/LTC1878 High Efficiency, Monolithic Synchronous Step-Down Regulators 10 mA IQ, 2.65 £ VIN £ 10V, MSOP Package, up to 600mA LTC3404 1.4MHz High Efficiency Monolithic Synchronous Step-Down Reg 95% Efficiency, 10 mA IQ, MSOP Package, up to 600mA RELATED PARTS Single Cell Li-Ion to 3.3V Zeta Converter TYPICAL APPLICATIO U Dimensions in inches (millimeters) unless otherwise noted.PACKAGE DESCRIPTIO U 5-Lead Plastic SOT-23 (LTC DWG # 05-08-1633) Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 l FAX: (408) 434-0507 l www.linear-tech.com 0.95 (0.037) REF 1.50 – 1.75 (0.059 – 0.069) 0.35 – 0.55 (0.014 – 0.020) FIVE PLACES (NOTE 2) S5 SOT-23 0599 2.80 – 3.00 (0.110 – 0.118) (NOTE 3) 1.90 (0.074) REF 0.90 – 1.45 (0.035 – 0.057) 0.90 – 1.30 (0.035 – 0.051) 0.00 – 0.15 (0.00 – 0.006) 0.09 – 0.20 (0.004 – 0.008) (NOTE 2) 2.60 – 3.00 (0.102 – 0.118) NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DIMENSIONS ARE INCLUSIVE OF PLATING 3. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 4. MOLD FLASH SHALL NOT EXCEED 0.254mm 5. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ) VIN ITH/RUN SW VFB GND 22µF + C1 22µF 5.1k 20.5k L2 D1 330pF 1µF
- 5R 34k 4.7µH 4.7µF VIN 2.5V TO 4.2V VOUT (3.3V) LTC1701 C1, C2: AVX TAJA226M006R C6: TAIYO YUDEN JMK212BJ475MG
1701 TA04
VIN IOUT(MAX) 2.5V 200mA 3.0V 225mA 3.5V 250mA 4.0V 280mA 4.2V 290mA D1: MBR0520L L1, L2: SUMIDA CLQ72-4R7 DRG NO 6333-JPS-010