LM3668SD-2833 NSC [National Semiconductor], LM3668SD-2833 Datasheet

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LM3668 1A, High Efficiency Dual Mode Single Inductor Buck-Boost DC/DC Converter General Description The LM3668 is a synchronous buck-boost DC-DC converter optimized for powering low voltage circuits from a Li-Ion bat- tery and input voltage rails between 2.5V and 5.5V. ...

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Functional Block Diagram www.national.com FIGURE 1. Functional Block Diagram 2 20191404 ...

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... Die Attach Pad, connect the DAP to SGND on PCB layout to enhance thermal performance. It should not be used as a primary ground connection. Ordering Information Order Number LM3668SD - 2833 LM3668SDX - 2833 LM3668SD - 3034 LM3668SDX - 3034 LM3668SD - 4550 LM3668SDX - 4550 Note example option is 3.0V/3.4V, when V OUT options. 20191402 Description ) to set output Voltage ...

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Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications Pin, SW1, SW2 & IN, DD OUT Voltage to SGND & PGND FB, EN ,MODE, ...

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Typical Performance Characteristics C = 10µ 22µF (Note 8 25°C , unless otherwise stated. IN OUT A Supply Current vs. Temperature (Not switching 3.4V) OUT NFET_RDS (on) vs. Temperature (V = 3.4V) OUT ILIMIT ...

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Efficiency at V OUT (Auto Mode) Efficiency at V OUT (Auto Mode) Efficiency at V OUT (Auto Mode) www.national.com = 2.8V 20191428 = 3.0V 20191417 = 3.3V 20191476 6 Efficiency 3.0V OUT (Forced PWM Mode) 20191473 Efficiency ...

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Efficiency 3.4V OUT (Auto Mode) 20191478 Efficiency 4.5V OUT (Auto Mode) 20191474 Efficiency 5.0V OUT (Auto Mode) 20191470 Efficiency at V OUT (Forced PWM Mode) Efficiency at V OUT (Forced PWM ...

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Line Transient in Boost Mode ( V = 3.4V, Load = 500mA) OUT Load Transient in Buck Mode (Forced PWM Mode 4.2V 3.4V, Load = 0-500mA IN OUT Load Transient in Buck-Boost Operation (Forced PWM Mode) ...

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Load Transient in Boost Mode (Forced PWM Mode 2.7V 3.0V, Load = 0-500mA IN OUT Load Transient in Buck Mode (Auto Mode 4.2V 3.3V, Load = 50-150mA IN OUT Load Transient in ...

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Load Transient in Boost Mode (Forced PWM Mode 3.5V 5.0V, Load = 0-500mA IN OUT Typical Switching Waveform in Buck Mode (PWM Mode 3.6V 3.0V, Load = 500mA IN OUT Typical Switching ...

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Typical Switching Waveform in Buck Mode (PWM Mode 4V 3.4V, Load = 500mA IN OUT Typical Switching Waveform in Buck Mode (PFM Mode 4V 3.4V, Load = 50mA IN OUT Start up ...

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Circuit Description The LM3668, a high-efficiency Buck or Boost DC-DC con- verter, delivers a constant voltage from either a single Li-Ion or three cell NIMH/NiCd battery to portable devices such as mobile phones and PDAs. Using a voltage mode architecture ...

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Internal Synchronous Rectification While in PWM mode, the LM3668 uses an internal MOSFET as a synchronous rectifier to reduce rectifier forward voltage drop and associated power loss. Synchronous rectification provides a significant improvement in efficiency whenever the output voltage is ...

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FIGURE OUT IN In the buck PFM operation always turned on and N2 is always turned off , P1 and N1 power switches are switching. P1 and N1 are turned off to enter " ...

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Dissipation Rating Table ≤ ≤ θ T 25°C T 60° 34°C 2941mW 1912mW layers board per JEDEC standard) Inductor Selection There are two main considerations when choosing an induc- tor: the inductor should not saturate, ...

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Table 1 lists several capacitor suppliers. The output filter capacitor smooths out current flow from the inductor to the load, helps maintain a steady output voltage during transient load changes and reduces output voltage ...

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Physical Dimensions inches (millimeters) unless otherwise noted 12–Pin LLP NS Package Number SDF12A 17 www.national.com ...

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