LTC3453 LINER [Linear Technology], LTC3453 Datasheet
LTC3453
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LTC3453 Summary of contents
Page 1
... In shutdown, the supply current is only 6µA. A high constant operating frequency of 1MHz allows the use of a small external inductor. The LTC3453 is offered in a low profile (0.75mm) thermally enhanced 16-lead (4mm x 4mm) QFN package. ...
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... IN EXPOSED PAD (PIN 17) IS PGND, MUST BE SOLDERED TO PCB ORDER PART NUMBER LTC3453EUF Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: Consult LTC Marketing for parts specified with wider operating temperature ranges. ...
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... Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTC3453E is guaranteed to meet 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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... LTC3453 W U TYPICAL PERFOR A CE CHARACTERISTICS Efficiency vs LED Current 100 FRONT PAGE APPLICATION 3.6V 25°C LED 100 150 200 250 300 350 400 450 500 LED CURRENT (mA) 3453 G07 CTIO S (Pin 1): Signal Voltage Input Supply Pin [2.7V ≤ V ...
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... ERROR AMP – V BIAS SOFT 1.23V START CLAMP ∑ I LED 384 LED CURRENT SETTING AMP 2 I LED 384 SHUTDOWN GND GND 5 8 LTC3453 OPTIONAL SWITCH D V OUT 13 LED1 4 LED DETECT + – 200mA LED2 6 LED + DETECT – LED3 7 LED DETECT V OUT LED4 – ...
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... LTC3453 U OPERATIO Buck-Boost DC-DC Converter The LTC3453 employs an LTC proprietary buck-boost DC/DC converter to generate the output voltage required to drive the LEDs. This architecture permits high-effi- ciency, low noise operation at input voltages above, below or equal to the output voltage by properly phasing four internal power switches. The error amp output voltage on the V pin determines the duty cycle of the switches ...
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... All four LED current source outputs are programmed to the same level. When both enable inputs are logic low, the LTC3453 is in shutdown, the buck-boost is disabled and all LED currents are zero. In shutdown, the input supply current is typically 6µ ...
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... U APPLICATIO S I FOR ATIO Component Selection Inductor Selection The high frequency operation of the LTC3453 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 are given as follows: ...
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... Closing the Feedback Loop The LTC3453 incorporates voltage mode PWM control. The control to output gain varies with operation region (Buck, Boost, Buck/Boost), but is usually no greater than 15. The output filter exhibits a double pole response ...
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... I pins. Figure 3 shows four such methods employing a voltage DAC, a current DAC, a simple potentiometer or a PWM input not recommended to control brightness by PWMing the enable pins directly as this will toggle the LTC3453 in and out of shutdown and result in erratic operation ...
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... APPLICATIO S I FOR ATIO Unused Outputs If fewer than 4 LED pins are to be used, unused LEDx pins should be connected The LTC3453 senses which OUT current source outputs are not being used and shuts off the corresponding output currents to save power. A small trickle current (~30µ ...
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... High Efficiency 4 White LED Driver 4.7µ SW1 SW2 V 4.7µ OUT LED1 LED2 1MHz LED3 BUCK-BOOST LED4 LTC3453 3453 TA02 GND GND PGND COMMENTS V : 1.6V to 18V MS10 Package/EDD Package V : 2.6V to 16V ThinSOT Package 10V ThinSOT Package ...