LT3505EMS8E#PBF Linear Technology, LT3505EMS8E#PBF Datasheet

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... The low current (<2µA) shutdown mode provides output disconnect, enabling easy power management in battery-powered systems. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. V OUT 3 ...

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... JMAX JA EXPOSED PAD (PIN 9) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL LT3505EDD#PBF LT3505EDD#TRPBF LT3505IDD#PBF LT3505IDD#TRPBF LT3505EMS8E#PBF LT3505EMS8E#TRPBF LT3505IMS8E#PBF LT3505IMS8E#TRPBF LEAD BASED FINISH TAPE AND REEL LT3505EDD LT3505EDD#TR LT3505IDD LT3505IDD#TR LT3505EMS8E LT3505EMS8E#TR ...

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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T PARAMETER CONDITIONS V Operating Range IN Undervoltage Lockout Feedback Voltage FB Pin Bias Current V FB Quiescent Current Not Switching, R Quiescent Current in Shutdown V SHDN Reference Line Regulation ...

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LT3505 TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency ( 10µH, OUT f = 750kHz 25° 12V ...

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TYPICAL PERFORMANCE CHARACTERISTICS Undervoltage Lockout 4.00 3.90 3.80 3.70 3.60 3.50 3.40 3.30 3.20 3.10 3.00 –50 – 100 125 TEMPERATURE (°C) 3505 G10 Soft-Start 2 25°C A 1.8 1.6 1.4 1.2 1.0 0.8 ...

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LT3505 TYPICAL PERFORMANCE CHARACTERISTICS Switch Current Limit 2.0 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 1.0 –50 – 100 125 TEMPERATURE (°C) R Pin Bias Voltage T 505 V = 0.78V FB 500 495 ...

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PIN FUNCTIONS BOOST (Pin 1): The BOOST pin is used to provide a drive voltage, higher than the input voltage, to the internal bipolar NPN power switch. SW (Pin 2): The SW pin is the output of the internal power ...

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LT3505 BLOCK DIAGRAM INT REG AND UVLO ON OFF SLOPE R3 COMP SHDN 4 C4 OSC GND 5 OPERATION (Refer to Block Diagram) The LT3505 is a constant frequency, current mode step- down regulator. ...

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APPLICATIONS INFORMATION FB Resistor Network The output voltage is programmed with a resistor divider between the output and the FB pin. Choose the 1% resis- tors according to: V   OUT = – 1  ...

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LT3505 APPLICATIONS INFORMATION V SW 20V/DIV I L 0.5A/DIV V OUT 200mV/DIV AC COUPLED 2 s/DIV 0.75A OUT LOAD OUT V = 30V R = 75.0k IN ...

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APPLICATIONS INFORMATION Finite transistor bandwidth limits the speed at which the power switch can be turned on and off, effectively setting the minimum on-time of the LT3505. For a given output volt- age, the minimum on-time determines the maximum input ...

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LT3505 APPLICATIONS INFORMATION Component Selection for Input Voltage Frequency Foldback Circuit To determine the values of R4, R5, and D3 for a specifi c application follow the procedure outlined in this section. First select the value of R4 from Table ...

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... Low inductance may result in discontinuous mode operation, which is okay, but further reduces maximum load current. For details on maximum output current and discontinuous mode operation, see Linear Technology Application Note 44. Table 2. Inductor Vendors VENDOR ...

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LT3505 APPLICATIONS INFORMATION twice its nominal value, possibly exceeding the LT3505’s voltage rating. This situation can be easily avoided; see the Hot Plugging Safely section. Output Capacitor The output capacitor has two essential functions. Along with the inductor, it fi ...

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APPLICATIONS INFORMATION 32. 10.0k 100k 22pF 32. 10.0k 100k 22pF 32. 10.0k 301k 22pF Figure 5. Transient Load Response of the LT3505 with Different Output Capacitors as the Load Current is ...

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LT3505 APPLICATIONS INFORMATION capacitor and a small Schottky diode (such as the BAT-54). For lower output voltages tie a Schottky diode to the input (Figure 6b). The circuit in Figure 6a is more effi cient because the BOOST pin current ...

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... LT3505 circuits. However, these ca- 3505 F08b pacitors can cause problems if the LT3505 is plugged into a live supply (see Linear Technology Application Note 88 for a complete discussion). The low loss ceramic capacitor combined with stray inductance in series with the power source forms an underdamped tank circuit and the voltage = 10µ ...

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LT3505 APPLICATIONS INFORMATION damaging the part. If the input supply is poorly controlled or the user will be plugging the LT3505 into an energized supply, the input network should be designed to prevent this overshoot. Figure 10 shows the waveforms ...

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APPLICATIONS INFORMATION capacitor (C ) and a resistor ( series to ground are C C used. In addition, a lower value fi lter capacitor (C added in parallel. The fi lter capacitor is not a part of the ...

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... BOOST pin. The 12V circuit shows how to overcome this limitation using an additional zener diode. Other Linear Technology Publications Application notes AN19, AN35 and AN44 contain more detailed descriptions and design information for Buck regulators and other switching regulators. The LT1376 data sheet has a more extensive discussion of output ripple, loop compensation and stability testing ...

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TYPICAL APPLICATIONS BOOST 36V SW ON OFF SHDN LT3505 10V FB CMPZ5240B R GND 698k 20.0k 100k 1µF BAT54 BOOST IN 3.6V TO 25V SW ON OFF SHDN ...

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LT3505 TYPICAL APPLICATIONS V IN 4.2V TO 36V ON OFF 1µ 13.5V TO 36V ON OFF 3.3µF *FOR CONTINUOUS OPERATION ABOVE 30V, USE TWO 2k, 0.25W RESISTORS IN PARALLEL 22 750kHz, 3.3V Step-Down Converter 1N4148 V BOOST IN ...

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... LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX 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 representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...

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... OUT Converter with Burst Mode Operation LT3493 36V, 1. 750kHz, High Effi ciency Step-Down OUT DC/DC Converter Burst Mode is a registered trademark of Linear Technology Corporation. 24 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 " 300kHz, 3.3V Step-Down Converter ...