LTC3443 Linear Technology, LTC3443 Datasheet

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... MODE/SYNC pin high. If the MODE/ SYNC pin is driven low or with a clock, then fixed fre- quency switching is enabled. Other features include a 1µA shutdown, soft-start control, thermal shutdown and current limit. The LTC3443 is available in a thermally enhanced 12-lead (4mm × 3mm) DFN Package. V OUT 3 ...

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... Switches B and C Switches A and D Boost (% Switch C On) Buck (% Switch A In 5.5V MODE/SYNC When IC is Enabled When Max Boost Duty Cycle V = 5.5V SHDN www.DataSheet4U.com U W ORDER PART TOP VIEW NUMBER LTC3443EDE OUT 6 7 MODE/SYNC ...

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... Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC3443E is 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 ...

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... LTC3443 W U TYPICAL PERFOR A CE CHARACTERISTICS Switch Pins in Buck-Boost Mode SW1 2V/DIV SW2 2V/DIV V = 3.3V 50ns/DIV 3.3V OUT I = 500mA OUT Switch Pins Before Entering Boost Mode SW1 2V/DIV SW2 2V/DIV 50ns/DIV IN 3443 G06 V = 3.3V OUT I = 500mA OUT Burst Mode Quiescent Current ...

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... In Burst Mode operation the operation is variable frequency, which provides a significant efficiency improvement at light loads. The Burst Mode operation will continue until the pin is driven low. LTC3443 www.DataSheet4U.com Current Limit 3 ...

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... LTC3443 CTIO S MODE/SYNC = Low: Disable Burst Mode operation and maintain low noise, constant frequency operation . MODE/SYNC = External CLK : Synchronization of the internal oscillator and Burst Mode operation disable. A clock pulse width between 100ns and 2µs and a clock frequency between 1.38MHz and 2.4MHz (twice the desired frequency) is required to synchronize the IC ...

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... Output Switch Control Figure 1 shows a simplified diagram of how the four internal switches are connected to the inductor, V and GND. Figure 2 shows the regions of operation for the LTC3443 as a function of the internal control voltage, V The V voltage is a level shifted voltage from the output of CI ...

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... LTC3443 U OPERATIO OUT 9 8 PMOS A SW1 SW2 4 5 NMOS B Figure 1. Simplified Diagram of Output Switches 75% D MAX BOOST A ON, B OFF BOOST REGION PWM CD SWITCHES D MIN BOOST BUCK/BOOST REGION FOUR SWITCH PWM D MAX BUCK D ON, C OFF BUCK REGION PWM AB SWITCHES 0% DUTY CYCLE Figure 2 ...

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... Buck/Boost function. The efficiency below 1mA becomes dominated primarily by the quiescent current and not the peak efficiency. The equation is given by: Efficiency Burst where (ηbm) is typically 80% during Burst Mode , is above operation. CI LTC3443 www.DataSheet4U.com • ≈ ) ...

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... LTC3443 U OPERATIO SOFT-START The soft-start function is combined with shutdown. When the SHDN/SS pin is brought above typically 1V, the IC is enabled but the EA duty cycle is clamped from the OUT ≈ – 800mA SW1 SW2 B C 0mA ...

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... Low. Lead Length to Battery Should be Kept Short. V Ceramic Capacitors Close to the IC Pins Inductor Selection The high frequency operation of the LTC3443 allows the use of small surface mount inductors. The inductor cur- rent ripple is typically set to 20% to 40% of the maximum inductor current. For a given ripple the inductance terms ...

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... Schottky diode is required from SW2 to V OUT Output Voltage < 2.4V The LTC3443 can operate as a buck converter with output voltages as low as 0.4V. The part is specified at 2.4V minimum to allow operation without the requirement of a Schottky diode. Synchronous switch D is powered from ...

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... Hz Which is extremely close ZERO 1 f ZERO 2 f POLE 2 Figure 7. Error Amplifier with Type I Compensation Figure 8. Error Amplifier with Type III Compensation LTC3443 ≈ • • • • ...

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... Li-Ion C1 10µ Burst Mode OPERATION 0 = FIXED FREQUENCY 14 Li-Ion to 3.3V at 1.2A Converter L1 D1 6µ SW1 SW2 340k IN OUT 10 12 LTC3443 15k 1 11 SHDN/ MODE/SYNC GND 560pF 3 6 PGND PGND 200k C1: TAIYO YUDEN JMK212BJ106MG C2: TAIYO YUDEN JMK325BJ226MM ...

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... Plastic DFN (4mm × 3mm) (Reference LTC DWG # 05-08-1695) 0.65 ±0.05 PACKAGE OUTLINE 0.50 BSC 3.30 ±0.05 (2 SIDES) 4.00 ±0.10 (2 SIDES 0.20 TYP 3.00 ±0.10 1.70 ± 0.10 (2 SIDES) (2 SIDES) 0.75 ±0.05 0.00 – 0.05 LTC3443 www.DataSheet4U.com 0.38 ± 0. 0.115 TYP 7 12 PIN 1 NOTCH (UE12/DE12) DFN 0603 6 1 0.25 ± 0.05 0.50 BSC 3.30 ±0.10 (2 SIDES) BOTTOM VIEW—EXPOSED PAD ...

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... LTC3443 RELATED PARTS PART NUMBER DESCRIPTION ® LT 1613 550mA (I ) 1.4MHz High Efficiency Step-Up DC/DC Converter SW LT1616 500mA (I ) 1.4MHz High Efficiency Step-Down DC/DC Converter OUT LTC1776 500mA (I ) 200kHz High Efficiency Step-Down DC/DC Converter OUT LTC1877 600mA (I ) 550kHz Synchronous Step-Down DC/DC Converter OUT LTC1878 600mA (I ) 550kHz Synchronous Step-Down DC/DC Converter ...