sc4540 Semtech Corporation, sc4540 Datasheet
sc4540
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sc4540 Summary of contents
Page 1
... A small external capacitor and series resistor control soft-start and loop compensation. Over-voltage detection protects the SC4540 if the BL pin is fl oating or shorted to ground. The SC4540 is available in an MLPD-8 pin 0.6 (mm) package, with a rated temperature range of -40°C to +85° μ ...
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... MLPD: 2mm x 2mm 8 Lead θ = 74°C/W JA Marking Information FJ0 yw FJ0 = Marking code for SC4540 yw = Date Code Ordering Information Device SC4540ULTRT SC4540EVB Note (1) Available in tape and reel only. A reel contains 3,000 devices. (2) Lead-free package only. Device is WEEE and RoHS compliant. ...
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... T A Min Typ rising 2.40 2.60 120 1.9 0.1 1. 1.8V ±0. 1.8V to 12V ±0.01 EN rising 155 J 20 680 800 = 25°C 92 100 SC4540 (°C/ 25ºC. A Max Units 2. μA V 0.8 V ±1 μA ±5 °C °C 920 kHz % ...
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... L(BL ΔI /Δ 3 ISET A ISET t start-up due to tolerance stackup. To produce output current less than 1mA, set the current > ISET SC4540 Min Typ Max Units 425 725 mA 0.01 1 μA 250 450 mV 5 μ ...
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... SC4540 /P unless otherwise noted. LED IN Effi ciency versus Output Voltage Effi ciency versus Input Voltage ...
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... IN V (100mV/div) OUT 7. (20V/div (50mV/div (100mV/div) OUT PWM Operation at 200Hz and 1% Duty Cycle V (20V/div (10mA/div) OUT V (5V/div) EN SC4540 Typical Waveforms 5.0V IN 1μs/div Typical Waveforms 12V IN 1μs/div 10μs/div 6 6 ...
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... PWM Operation at 20kHz and 10% Duty Cycle V (20V/div (10mA/div) OUT V (5V/div) EN 2μs/div PWM Operation at 50kHz and 20% Duty Cycle V (20V/div (10mA/div) OUT V (5V/div) EN 1μs/div PWM Operation at 32kHz and 17% Duty Cycle V (20V/div (10mA/div) OUT V (5V/div) EN 2μs/div SC4540 7 7 ...
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... LED constant current sink — connect this pin to the cathode end of the LED string Ground Power supply pin — bypass this pin with a capacitor close to the pin Pad for heatsinking purposes — connect to the ground plane using multiple vias. Not connected internally. SC4540 8 8 ...
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... R eference and Internal R egulator parator rror S ignal S election and ation etpoint SC4540 ense ...
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... GPIO pin. The SC4540 provides dimming between 100Hz and 50kHz. The SC4540 is compatible with a wide range of devices by using dimming technology that avoids the audio band by using high frequency PWM dimming. A wide range of ...
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... the duty cycle for continuous operation. Effi ciency (η) can be approximated by using the curves provided in the Typical Characteristics section. Table 1 lists inductors that have been proven to work with SC4540. Table 1 — Recommended Inductors Value DCR Rated Part Number (μH) (Ω ...
Page 12
... The ST Microelectronics STPS05602 is a recommended diode for this application. Selection of Other Components R sets the maximum load current for the SC4540. Use ISET the following equation to select the proper value 230×V ...
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... Applications Information (continued) Application Circuit for Alternate Input voltages The typical applications circuit for the SC4540 is shown in Figure 2. The performance data and specifi cations included in this document are for the typical application circuit (Figure 2). The SC4540 can be used with input voltages lower than 4 ...
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... SC4540 14 14 ...
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... C G .047 .067 1 .70 K .031 0 .80 .020 .012 .030 .106 Tel: 41-32-729-4000 Fax: 41-32-729-4001 Tel: 44-1794-527-600 Fax: 44-1794-527-601 Tel: 33-(0)169-28-22-00 Fax: 33-(0)169-28-12-98 Tel: 49-(0)8161-140-123 Fax: 49-(0)8161-140-124 SC4540 15 15 ...