SC440AMLTRT Semtech, SC440AMLTRT Datasheet
SC440AMLTRT
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SC440AMLTRT Summary of contents
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... SW SW VIN VIN VOUT VOUT SCP_EN SCP_EN OVPIN OVPIN EN EN FFLAG FFLAG OVPRTN OVPRTN 12 12 PWM PWM SC440A SC440A 6 6 IO1-6 IO1-6 COMP COMP IOSET IOSET AGND AGND IOGND IOGND SS SS PGND PGND PGND PGND EDP EDP SC440A 6 Strings 6 Strings www.semtech.com 1 ...
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... Nnnnn = Part number (Example: 440A) yyww = Date Code (Example: 0752) xxxxx = Semtech Lot No. (Example: E9010 xxxxx = © 2010 Semtech Corp. Ordering Information Device SC440AMLTRT SC440AEVB 20 19 Notes: PWM 18 (1) Available in tape and reel only. A reel contains 3,000 devices. 17 (2) Available in Pb-free and Halogen free package only. Device is VOUT WEEE and RoHS compliant ...
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... Switch Leakage Current Compensation Sourcing Current Sinking Current © 2010 Semtech Corp. Recommended Operating Conditions Supply Input Voltage …………………………… 4.5V to 27V 7.5W Maximum Output Voltage ………………………… ...
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... LED Current Matching (1) Maximum LED Current LED Short Circuit Protection Threshold I Off Leakage Current O SCP_EN Bias Over-Temperature Protection Thermal Shutdown Temperature Thermal Shutdown Hysteresis Notes: (1) Guaranteed by design. © 2010 Semtech Corp. < 85° 2kΩ. J IOSET Symbol Conditions 4.5V to 27V EN_H 4.5V to 27V ...
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... Vin=12V, 8 LEDs per string 700 600 500 400 300 200 Ta = 25°C 100 LED Current (mA) OVPIN Threshold Voltage vs Temperature VIN = 12V 1.55 1.54 1.53 1.52 1.51 1.5 -40 - Temperature (ºC) © 2010 Semtech Corp. Rising 805 795 785 775 765 8.5 8 7.5 7 6.5 6 5 ...
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... Temperature (ºC) PWM Dimming Duty Cycle vs LED current 5mA x 6 string load, 8 LEDs per string, L1=MOS6020-10u, C2=10uF Fpwm = 200 Duty Cycle © 2010 Semtech Corp. 2.435 2.43 2.425 VIN=21V 2. -40 0.91 0.90 0.89 0.88 0.87 0.86 0.85 0.84 0. 200 150 ...
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... VOUT(AC) VOUT(AC) 50mV/DIV 50mV/DIV Time ( 0.5us/DIV) Time ( 0.5us/DIV) Conditions: VIN = 5V, Load = 30mA Conditions: VIN = 5V, Load = 30mA x 6 strings, 8 LEDs per string x 6 strings, 8 LEDs per string © 2010 Semtech Corp. Shut down Shut down VIN VIN 5V/DIV 5V/DIV SS SS 2V/DIV 2V/DIV ...
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... FLAG 5V/DIV 5V/DIV Time ( 1s/DIV) Time ( 1s/DIV) Conditions: VIN = 5V, Load = 30mA Conditions: VIN = 5V, Load = 30mA x 6 strings, 8 LEDs per string x 6 strings, 8 LEDs per string © 2010 Semtech Corp. PWM dimming PWM dimming PWM PWM Keep Keep 2V/DIV 2V/DIV Original here ...
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... Thermal pad for heatsinking purposes — connect — not connected internally Note: Any unused IO pin should be pulled up to VIN with the SCP_EN left open. Table 1. EN STATUS 0 backlight disable 1 backlight enable Note: When the boost is turned OFF and disabled. © 2010 Semtech Corp. SC440A www.semtech.com 9 ...
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... CIRCUIT PROTECTION IO3 IO2 IO1 LED CURRENT SETTING IOSET IOGND VOUT OVP OVPIN OVP OVPRTN Fault Detect SS HICCUP SCP_EN © 2010 Semtech Corp. HICCUP FAULT-1 DISABLE1 CURRENT SOURCE HICCUP CONTROL 3V3 LOGIC HICCUP 4uA 5uA Figure 1. SC440A Block Diagram SC440A OSC S Q ...
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... IOSET I is the output current of each string in mA. LED © 2010 Semtech Corp. Start-Up During start-up, when the VIN pin voltage reaches its UVLO threshold, and both EN and PWM signals are set to high, the SS pin begins to source 6μA to the SS capacitor and its voltage begins to rise from 0V to its end value (2 ...
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... OVPIN pin. If the voltage at the OVPIN pin exceeds 1.5V, the boost converter will shut off and a 1mA pull down current source will be applied to the VOUT pin to quickly © 2010 Semtech Corp. discharge the over-voltage capacitor. This additional level of protection prevents a condition where the output ...
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... PWM dimming typical application, a microcontroller sets a register or counter that varies the pulse width on a GPIO pin. The SC440A allows dimming over two decades © 2010 Semtech Corp. in frequency (50Hz-50kHz) in order to allow compatibility with a wide range of devices, including the newest dimming strategies that avoid the audio band by using high frequency PWM dimming ...
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... Forward conduction drop of the output rectifying D diode When the boost converter runs in DCM ( L < L © 2010 Semtech Corp. takes the advantages of small inductance and quick transient response while avoiding the bandwidth- limiting instability of the RHP zero found in CCM boost converters. ...
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... Murata 814-237-1431 Taiyo Yuden 408-573-4150 © 2010 Semtech Corp. Output Rectifying Diode Selection Schottky diodes are the ideal choice for SC440A due to their low forward voltage drop and fast switching speed. Table 4 shows several diff erent Schottky diodes that work well with the SC440A ...
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... The pad at the bottom of the SC440A should be tied to the analog ground. The analog ground should be connected to the power ground at one point for better noise immunity. © 2010 Semtech Corp. SC440A www.semtech.com 16 ...
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... PWM PWM 18 18 PWM PWM GND GND Case 2: Schematic for 5 strings 8 LEDs per string application P1 P1 Input Input 12V 12V 2.2u 2. 1.5k 1.5k 12n 12n © 2010 Semtech Corp. 10uF 10uF 221k 221k 10k 10k 10k 10k R3 R3 20k 20k 6 6 OVPRTN ...
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... IOSET IOSET SCP_EN SCP_EN COMP COMP 12n 12n 6.04k 6.04k 20k 20k VOUT VOUT PWM PWM 18 18 PWM PWM GND GND 19 19 © 2010 Semtech Corp. QUANTITY REFERENCE 4.7uF 4.7uF 4.7uF 4.7uF 4.7uF 4.7uF 50V 50V 50V 50V 50V 50V D1 D1 ...
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... Layout Illustration Diagrams PCB TOP COMPONENTS TOP © 2010 Semtech Corp. SC440A PCB B OTTOM COMPONENTS BOTTOM www.semtech.com 19 ...
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... Outline Drawing - MLPQ-24 PIN 1 INDICATOR (LASER MARK) aaa C NOTES © 2010 Semtech Corp SEATING PLANE LxN E bxN bbb e D/2 CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. DIMENSIONS INCHES MILLIMETERS DIM MIN NOM MAX MIN ...
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... CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. 2. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FAILURE MAY COMPROMISE THE THERMAL AND/OR FUNCTIONAL PERFORMANCE OF THE DEVICE. Contact Information © 2010 Semtech Corp. K DIM ...