LTC3809-1 Linear Technology, LTC3809-1 Datasheet
LTC3809-1
Related parts for LTC3809-1
LTC3809-1 Summary of contents
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... Switching frequency is fi xed at 550kHz. Fault protection is provided by an overvoltage comparator and a short-circuit current limit comparator. The LTC3809-1 is available in tiny footprint thermally enhanced DFN and 10-lead MSOP packages. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst is a registered trademark of Linear Technology Corporation ...
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... LTC3809-1 ABSOLUTE MAXIMUM RATINGS Input Supply Voltage (V ) ........................ –0.3V to 10V IN RUN, TRACK/SS, MODE, IPRG Voltages ............................... –0. www.datasheet4u.com Voltages ...................................... –0. Voltage ......................... – TG, BG Peak Output Current (<10μs) ......................... 1A Operating Temperature Range (Note 2)....–40°C to 85°C PIN CONFIGURATION TOP VIEW ...
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... A Note 4: Dynamic supply current is higher due to gate charge being delivered at the switching frequency. Note 5: The LTC3809-1 is tested in a feedback loop that servos I a specifi ed voltage and measures the resultant V Note 6: Peak current sense voltage is reduced dependent on duty cycle to a percentage of value as shown in Figure 1. ...
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... LTC3809-1 TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency vs Load Current www.datasheet4u.com 100 FIGURE 8 CIRCUIT V = 2.5V OUT 3.3V OUT 1.2V OUT 1.8V OUT MODE = 100 1k LOAD CURRENT (mA) Load Step (Burst Mode Operation) V OUT 200mV/DIV AC COUPLED I L 2A/DIV 100μs/DIV ...
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... TEMPERATURE (°C) 38091 G012 1.04 1.02 1.00 0.98 0.96 0. 100 TEMPER ATURE (°C) 38091 G15 LTC3809 25°C, unless otherwise noted. A Start-Up with Ratiometric Tracking ( 0s) OUT V x 2.5V V OUT 1.8V 500mV/DIV 10ms/DIV 590 1.69k TB FIGURE 8 CIRCUIT Shutdown (RUN) Threshold vs Temperature 1 ...
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... LTC3809-1 TYPICAL PERFORMANCE CHARACTERISTICS Oscillator Frequency vs Temperature www.datasheet4u.com –2 –4 –6 –8 –10 –60 –40 – TEMPERATURE (°C) Sleep Current vs Input Voltage 130 120 110 100 INPUT VOLTAGE (V) 6 Oscillator Frequency vs Input Voltage ...
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... MOSFET and the inductor. GND (Exposed Pad, Pin 11): Ground connection for internal circuits, the gate drivers and the negative input to the reverse current comparator. The Exposed Pad must or be soldered to the PCB ground. IN LTC3809-1 and SW pins IN , GND or fl oat to select ...
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... LTC3809-1 FUNCTIONAL DIAGRAM www.datasheet4u.com VOLTAGE V REF REFERENCE 0.6V UNDERVOLTAGE SENSE LOCKOUT 0.7μA RUN 0.74ms INTERNAL SOFT-START GND 11 1μA MUX TRK/SS TRACK/SS 2 MODE BURSTDIS 1 BURST DEFEAT FCB 8 IPRG 6 SLOPE CLK ICMP R SWITCHING + – LOGIC AND ...
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... Shutdown, Soft-Start and Tracking Start-Up (RUN and TRACK/SS Pins) The LTC3809-1 is shut down by pulling the RUN pin low. In shutdown, all controller functions are disabled and the chip draws only 9μA. The TG output is held high (off) and the BG output low (off) in shutdown. Releasing the RUN pin allows an internal 0.7μ ...
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... LTC3809-1 OPERATION (Refer to Functional Diagram) In sleep mode, much of the internal circuitry is turned off, reducing the quiescent current that the LTC3809-1 draws. The load current is supplied by the output capacitor. As www.datasheet4u.com the output voltage decreases, the EAMP increases the I voltage. When the I voltage reaches 0.925V, the ...
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... P-channel MOSFET and the inductor. Undervoltage Lockout To prevent operation of the P-channel MOSFET below safe input voltage levels, an undervoltage lockout is incorporated in the LTC3809-1. When the input supply voltage (V ) drops below 2.25V, the external P- and IN N-channel MOSFETs and all internal circuits are turned off except for the undervoltage block, which draws only a few microamperes ...
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... MOSFET ( 2.5V) is required for applications that work close to GS this voltage. When these MOSFETs are used, make sure that the input supply to the LTC3809-1 is less than the absolute maximum MOSFET V rating, which is typically 8V. GS The P-channel MOSFET’s on-resistance is chosen based on the required load current ...
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... GND or V respectively. IN The power dissipated in the MOSFET strongly depends on its respective duty cycles and load current. When the LTC3809-1 is operating in continuous mode, the duty cycles for the MOSFETs are: Top P-Channel Duty Cycle = Bottom N- The MOSFET power dissipations at maximum output ...
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... I V OSC RIPPLE IN Burst Mode Operation Considerations The choice of R and inductor value also determines DS(ON) the load current at which the LTC3809-1 enters Burst Mode operation. When bursting, the controller clamps the peak inductor current to approximately: Δ SENSE MAX ( = I • ...
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... V where f is the operating frequency, C capacitance and I tor. The output ripple is highest at maximum input voltage since I Setting Output Voltage The LTC3809-1 output voltage is set by an external / OUT IN feedback resistor divider carefully placed across the output, as shown in Figure 3. The regulated output voltage ...
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... V FB Figure 3. Setting Output Voltage Run and Soft-Start/Tracking Functions The LTC3809-1 has a low power shutdown mode which is controlled by the RUN pin. Pulling the RUN pin below 1.1V puts the LTC3809-1 into a low quiescent current shutdown mode (I = 9μA). Releasing the RUN pin, an internal 0.7μA ...
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... With the loop in continuous mode, the auxiliary output may nominally be loaded without regard to the primary output load. X LTC3809 OUT 38091 F05b,c TIME ...
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... AUX as the supply is reduced down to 2.4V. Also shown is the effect on V Minimum On-Time Considerations Minimum on-time, t that the LTC3809-1 is capable of turning the top P-channel ) of DS(ON) MOSFET on determined by internal timing delays and the gate charge required to turn on the top MOSFET. Low duty cycle and high frequency applications may approach ...
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... APPLICATIONS INFORMATION If the duty cycle falls below what can be accommodated by the minimum on-time, the LTC3809-1 will begin to skip cycles (unless forced continuous mode is selected). The www.datasheet4u.com output voltage will continue to be regulated, but the ripple current and ripple voltage will increase. The minimum on- time for the LTC3809-1 is typically about 210ns ...
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... The N-channel MOSFET in Si7540DP has 0.017Ω R The short-circuit current is the inductor current rating should be higher than 5.3A. The LTC3809-1 operates at a frequency of 550kHz. For continuous Burst Mode operation with 600mA I the required minimum inductor value is: L MIN . No regulator can OUT A 6A 2.2μ ...
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... GND FB 11 59k 1 MODE IPRG TG LTC3809EDD TRACK/ RUN GND FB 11 59k LTC3809 2.75V TO 8V 10μF L 1.5μH V OUT 2.5V ( OUT 150μF 38091 F08 V IN 2.75V TO 8V 10μF MP Si3447BDV L 1.5μH V OUT 1. Si3460DV ...
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... LTC3809-1 TYPICAL APPLICATIONS www.datasheet4u.com 220pF 15k 1.18k Vx 118k 100pF L: VISHAY IHLP-2525CZ- SANYO 4TPB150MC OUT V < Vx OUT PACKAGE DESCRIPTION 3.50 0.05 1.65 0.05 2.15 0.05 (2 SIDES) 0.25 0.05 2.38 0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS NOTE: 1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-2). CHECK THE LTC WEBSITE DATA SHEET FOR CURRENT STATUS OF VARIATION ASSIGNMENT 2 ...
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... MAX DETAIL “A” SEATING PLANE 0.17 – 0.27 (.007 – .011) 0.50 TYP (.0197) BSC LTC3809-1 2.06 0.102 (.081 .004) 0.29 REF 1.83 0.102 (.072 .004) 0.05 REF DETAIL “B” CORNER TAIL IS PART OF THE LEADFRAME FEATURE. DETAIL “B” FOR REFERENCE ONLY NO MEASUREMENT PURPOSE ...
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... LTC3809-1 RELATED PARTS PART NUMBER DESCRIPTION LTC1628/LTC3728 Dual High Effi ciency, 2-Phase Synchronous Step Down Controllers Constant Frequency, Standby, 5V and 3.3V LDOs, V www.datasheet4u.com LTC1735 High Effi ciency Synchronous Step-Down Controller LTC1773 Synchronous Step-Down Controller LTC1778 Synchronous Step-Down Controller SENSE LTC1872 Constant Frequency Current Mode Step-Up Controller LTC3411 1 ...