SC441TETRT Semtech, SC441TETRT Datasheet
SC441TETRT
Specifications of SC441TETRT
Related parts for SC441TETRT
SC441TETRT Summary of contents
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... The internal thermal shutdown protects the IC from overheating at abnormal conditions. The SC441 is available in a thermally-enhanced TSSOP-20 EDP package VIN VOUT VOUT EN OVPIN OVPIN FFLAG OVPRTN PWM SC441 4 IO1-4 IO1- 4 COMP COMP IOSET IOSET AGND AGND IOGND SS SS EDP PGND PGND PGND SC441 Strings 10 www.semtech.com 1 ...
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... C/W JA (TSSOP-20 EDP Marking Information © 2010 Semtech Corporation Ordering Information 2 1 Device SC441TETRT IO3 D SC441EVB IO4 Notes: PGND (1) Available in tape and reel only. A reel contains 2,500 devices. SW (2) Available in lead-free package only. Device is WEEE and RoHS SW C compliant. ...
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... Compensation Sourcing Current Sinking Current © 2010 Semtech Corporation Recommended Operating Conditions Input Voltage Range ……………………………… 4.5V~21V 22W Maximum Output Voltage ……………………………… 36V Maximum LED Current … ...
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... VOUT Leakage Current Current Source (IO1 ~ IO4) Current Accuracy Current Matching Maximum LED Current LED Short-Circuit Protection Leakage Current Over-Temperature Protection Thermal Shutdown Temperature Thermal Shutdown Hysteresis Notes: (1) Guaranteed by design. © 2010 Semtech Corporation Symbol Conditions V V EN_H, PWM_H V V EN_L, PWM_L I ...
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... Temperature 0.93 0.91 VIN = 4.5V 0.89 0.87 0.85 0.83 0.81 VIN = 21V 0.79 VOUT = VIN + 3V 0.77 0.75 -40 25 Temperature ( C) o © 2010 Semtech Corporation UVLO Hysteresis vs. Temperature 247 246 245 244 243 242 241 240 239 238 237 105 -40 25 Temperature ( SINK / SOURCE Current vs ...
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... PWM Dimming Minimum Pulse Width vs. PWM Dimming Frequency 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 0 PWM Dimming Frequency (kHz) Condition: VIN = 12V, VOUT = 30V / 150mA x 4 strings © 2010 Semtech Corporation OVPRTN Saturation Voltage vs. Temperature 100uA OVPRTN 160 -40 25 Temperature ( C) o ...
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... Output = 30V / 150mA x 4 LED strings Main Power Switching Waveform VSW (20V/DIV) VOUT Accoupling (200mV/DIV) Time (1uS/DIV) Conditions: VIN = 12V, Output = 36V / 150mA x 4 LED strings © 2010 Semtech Corporation Shut Down VIN (5V/DIV) VSS (2V/DIV) VSW (20V/DIV) VOUT (20V/DIV) Time (200mS/DIV) ...
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... VOUT (20V/DIV) IO1 (10V/DIV) IO2 (1V/DIV) Time (10mS/DIV) Conditions: VIN = 12V, IO2 LED String is open circuit, Output = 36V / 150mA x 3 LED strings © 2010 Semtech Corporation LED Short Circuit Protection VIN (10V/DIV) VOUT (20V/DIV) IO1 (5V/DIV) IO2 (1V/DIV) Time (10mS/DIV) ...
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... IO3 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 SC441 9 www.semtech.com ...
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... CIRCUIT PROTECTION IO1 LED CURRENT SETTING IOSET IOGND VOUT OVP OVPIN OVP OVPRTN Fault Detect 0.9mA 0.9mA SS HICCUP 5 4 © 2010 Semtech Corporation 3 HICCUP FAULT-1 DISABLE1 CURRENT SOURCE HICCUP CONTROL 3V3 LOGIC HICCUP 3.5uA 3.5uA 1uA 1uA Figure 1. SC441 Block Diagram 3 SC441 ...
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... SS pin voltage. When the SS pin voltage reaches its switching threshold, output © 2010 Semtech Corporation voltage increases. Proper decoupling is required on the VIN pin, especially for a lower input voltage condition. A 22µF, 6.3V rated X5R ceramic capacitor is recommended for a 5V input system ...
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... If some designers do not want pulse skipping mode, based on the conditions provided above, © 2010 Semtech Corporation there are some choices. 1) Leave some room between Vin range and Vo. 2) Operate the Boost converter at normal load (less Ro) 3) Increases the Boost inductance (L) ...
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... IO current sources are turned off discharged by a 1µA current source, and a 0.9mA discharge path is © 2010 Semtech Corporation turned on to pull down VOUT. As temperature falls below the TSD trip point, SC441 will retry when SS falls below ...
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... One may use 3.9nF or less in the circuit. In some applica- tions, circuit designers tend to select the decoupling ca- pacitors in the range of (100pF ~ 1nF). © 2010 Semtech Corporation For some low LED current (e.g. 10mA) applications recommended to add 1M-10Mohm resistor from IO pin to GND in order to reduce IO pin voltage during PWM dimming ...
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... LED current at a fixed value. Overall, this allows usage of small output caps while ensuring precision LED current regulation. Although © 2010 Semtech Corporation the mechanics of regulation and frequency dependence may be complex, actual selection of output capacitor can be simplified because this capacitor is mainly selected for the output ripple of the converter ...
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... IO pins from noise influence. C14~C17 should be placed close to each corresponding IO pin. Use an isolated local AGND plane underneath the con- troller and tie it to the negative side of output capacitor through R14 for better noise immunity. © 2010 Semtech Corporation SC441 16 www.semtech.com ...
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... C16, C17 C8 R1, R14 2 10 R2, R3, R4 R8, R10, R11 R12, R13 © 2010 Semtech Corporation 10K 10K 11 FFLAG 12 VIN C1 C1 1nF 1nF 13 OVPRTN 10K 10K 2.2uF/25V 2.2uF/25V 14 OVPIN SC441 SC441 PGND 220K 220K 16 SW VOUT PGND R10 R10 IO4 20 IO3 ...
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... NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441A Outline Drawing - TSSOP-20 EDP © 2010 Semtech Corporation © 2010 Semtech Corporation SC441 18 www.semtech.com ...
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... NOT RECOMMENDED FOR NEW DESIGNS: SEE SC441A Land Pattern -TSSOP-20 EDP Contact Information © 2010 Semtech Corporation Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111 Fax: (805) 498-3804 www.semtech.com SC441 19 www.semtech.com ...