sc441c Semtech Corporation, sc441c Datasheet
sc441c
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sc441c Summary of contents
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... March 04, 2010 High Efficiency Integrated Driver for 4-Strings of 150mA LEDs Description The SC441C is a high-efficiency multiple string WLED driv- er with an integrated boost converter. It operates over a wide input range from 4.5V to 27V with a maximum output voltage of 42V and a 2.5A internal power switch. It can drive WLEDs in 4 strings with current up to 150mA per string ...
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... C/W JA (TSSOP-20 EDP Marking Information Marking for rhe TSSOP 20 EDP Lead package: nnnnn = Part Number (Example: SC441C) yyww = Date (Example: 1052) xxxxxx = Semtech Lot # (Example: A94A01) © 2010 Semtech Corporation Ordering Information 2 1 Device SC441CTETRT IO3 D SC441CEVB ...
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... SAT 12V S_LEAK SW D MAX D MIN T ON_MIN 0.5V EA_SOURCE COMP EA_SINK COMP SC441C ……………………………… 39°C/W (1) Min Typ Max Units 4.3 4.45 V 250 µA 0.56 0.7 0.84 MHz 2.5 3.32 A 200 350 mV 0.1 1 µ ...
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... Min Typ Max 2 0.4 0 50k 0.2 5 200 300 0.25 4.5 1 0.5 0.7 0.85 2.5 1.43 1.52 1.58 0 0.1 0.9 0.1 140 150 160 +/- 2 +/-3 200 ~ V 2.2 2.35 2.55 IO4 = V 0.1 1 IO4 0.963 1.07 1.177 IO4 0.9095 1.07 1.2305 100 150 30 www.semtech.com SC441C Units V V µ µ µ µA mV µA mA µ µ °C °C 4 ...
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... IO3 current(mA) Temperature ( C) o IO4 current(mA) AVG current(mA) LED Current Source SCP Threshold vs. Temperature 2.36 VIN = 12V 2.35 2.34 2.33 2.32 2.31 105 -40 25 Temperature ( C) o SC441C VIN Quiescent Supply Current vs. Temperature 3.40 3.35 3.30 3.25 3.20 SW Saturation Voltage 3.15 3.10 3.05 3.00 105 -40 25 Temperature ( Saturation Voltage at 1A vs. Temperature 230 VIN = 4.5V 220 ...
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... Condition: VIN = 12V, VOUT = 30V / 20mA x 4 strings PWM Dimming Minimum Duty Cycle vs. PWM Dimming Frequency 0 PWM Dimming Frequency (kHz) Condition: VIN = 12V, VOUT = 30V / 150mA x 4 strings www.semtech.com SC441C 105 ...
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... Condition: VIN = 12V, VOUT = 34.5V / 10mA x 4 strings © 2010 Semtech Corporation 150mA PWM Dimming Minimum Pulse Width vs. PWM Dimming Frequency PWM Dimming Frequency (kHz) Condition: VIN = 12V, VOUT = 34.5V / 150mA x 4 strings www.semtech.com SC441C 7 ...
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... VIN (5V/DIV) VSS (2V/DIV) VSW (20V/DIV) VOUT (20V/DIV) Time (200mS/DIV) Conditions: VIN = 12V, Output = 27V / 20mA x 4 LED strings Main Power Switching Waveform VSW (10V/DIV) VOUT Accoupling (100mV/DIV) Time (400nS/DIV) Conditions: VIN = 12V, Output = 27V / 20mA x 4 LED strings SC441C 8 www.semtech.com ...
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... IO2 (1V/DIV) Time (10mS/DIV) Conditions: VIN = 12V, IO1 has one LED short circuit, Output = 36V / 150mA x 4 LED strings PWM Dimming VIN = 12V PWM (2V/DIV) SW (20V/DIV) IO1 (5V/DIV) Time (10mS/DIV) Conditions: VIN = 12V, Output = 36V / 50mA x 4 LED strings SC441C 9 www.semtech.com ...
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... Provides constant current source to LED string 3. EDP Solder to the ground plane of the PCB. Note: Any unused IO pin should be pulled up to VIN. EN STATUS 0 backlight disable 1 backlight enable Note: When the boost is turned OFF and disabled. © 2010 Semtech Corporation SC441C 10 www.semtech.com ...
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... OVPRTN Fault Detect 0.9mA 0.9mA SS HICCUP 5 © 2010 Semtech Corporation 4 HICCUP FAULT DISABLE1 CURRENT SOURCE HICCUP CONTROL 3V3 LOGIC HICCUP 4.5uA 4.5uA 1uA 1uA Figure 1. SC441C Block Diagram DISABLE2 OSC ILIM - - + + ISENSE - - + + - - SS Fault UVLO UVLO & TSD Bandgap TSD ...
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... LED current source. The COMP pin voltage stays level while keeping the LED current in its set point. If the EN pin voltage is pulled below 0.4V, the SC441C will stay in shutdown mode drawing less than 1µA from its input power supply. ...
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... Operate the Boost converter at normal load (less Ro) 3) Increases the Boost inductance (L). Over-Current Protection SC441C provides cycle-by-cycle current limiting for its internal switch. If the switch current exceeds 3.32A (the typical current-limit trip point), then the current-limit comparator ILIM, will set the latch immediately turning off internal power ...
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... IO current sources are turned off discharged by a 1µA current source, and a 0.9mA discharge path is turned on to pull down VOUT. As temperature falls below the TSD trip point, SC441C will retry when SS falls below 0.5V and VOUT falls to VIN. PWM Dimming The PWM input needs to be held high for normal operation ...
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... Consequently, the SC441C LED short- circuit protection may false trip when the noise level is large. Certain ceramic decoupling capacitor on pins IO1 ~ IO4 to GND are useful to prevent the SC441C from noise influence general guideline, the decoupling capacitance should be limited as follows. ...
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... Table 4 shows several different Schottky diodes that work well with the SC441C. Make sure that the diode has a voltage rating greater that the possible maximum ouput voltage. The diode conducts current only when the power switch is turned off ...
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... Schottky diode and output capacitors must be minimized. The LED current programming resistor(R6), compensation network (R9,C5,C7) and soft start capaci- tor (C6) should be placed as close as possible to SC441C. The C14~C17 are decoupling capacitors for LED cur- rent source which prevent IO pins from noise influence. ...
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... Panasonic SM_0603 47nF Panasonic SM_0603 100nF Panasonic SMA B340 Diodes or Any DR125 6.8μH Copper or Any SM_0603 0R SM_0603 10K SM_0603 220K SM_0603 RIOSET SM_0603 1.5K SM_0603 1R EDP TSSOP-20 SC441C SEMTECH www.semtech.com 1.5K 1. 47n 47n Any Any Any Any Any Any 18 ...
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... BSC 6.40 BSC .026 BSC 0.65 BSC .150 .154 3.66 3.81 3.91 .118 .122 2.85 3.00 3.10 .024 .030 0.45 0.60 0.75 (.039) (1. 0° 8° 0° 8° .004 0.10 .004 0.10 .008 0.20 SEE DETAIL SIDE VIEW (L1) A DETAIL www.semtech.com SC441C A 19 ...
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... Contact Information © 2010 Semtech Corporation F DIM Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111 Fax: (805) 498-3804 www.semtech.com SC441C DIMENSIONS INCHES MILLIMETERS (.222) (5.65) .157 4.00 .161 4.10 .126 3.20 .026 0.65 .016 0.40 .061 1.55 .283 7.20 www ...