SC446TETRT Semtech, SC446TETRT Datasheet
SC446TETRT
Specifications of SC446TETRT
Related parts for SC446TETRT
SC446TETRT Summary of contents
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... The internal thermal shutdown protects the IC from overheating at abnormal conditions. The SC446 is available in a thermally-enhanced TSSOP-16 EDP package. SW VIN VIN VOUT VOUT EN OVPIN OVPIN OVPRTN PWM SC446 3 IO1-4 IO1- 3 COMP COMP IOSET IOSET AGND AGND SS SS PGND EDP PGND SC446 Strings 10 www.semtech.com 1 ...
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... Part Number (Example: SC446) yyww = Date (Example: 0952) xxxx = Semtech Lot # (Example: E901) © 2010 Semtech Corporation Ordering Information 2 1 Device D SC446TETRT 16 IO2 SC446EVB IO3 Notes: PGND (1) Available in tape and reel only. A reel contains 2,500 devices. C (2) Available in lead-free package only. This product is fully WEEE/RoHS SW compliant, Pb free and Halogen free ...
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... Compensation Sourcing Current Sinking Current © 2010 Semtech Corporation Recommended Operating Conditions Input Voltage Range ……………………………… 4.5V~27V 22W Maximum Output Voltage ……………………………… 36V Maximum LED Current … ...
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... Leakage Current Overshoot Protection Threshold Overshoot Protection Hysteresis Over-Temperature Protection Thermal Shutdown Temperature Thermal Shutdown Hysteresis Notes: (1) Guaranteed by design. (2) For achievable PWM dimming minimum pulse-width in applications, see the corresponding curves in Typical Characteristics. © 2010 Semtech Corporation Symbol Conditions V V EN_H, PWM_H V V ...
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... Temperature VIN = 12V VIN = 4.5V 0.800 0.780 0.760 0.740 VIN = 27V 0.720 VOUT = VIN + 3V 0.700 -40 25 Temperature ( C) o © 2010 Semtech Corporation UVLO Hysteresis vs. Temperature 285 275 265 SS current source & sink 255 245 235 105 -40 25 Temperature ( SINK / SOURCE Current vs ...
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... PWM Dimming Frequency (kHz) Condition: VIN = 12V, VOUT = 36V / 100mA x 3 strings © 2010 Semtech Corporation OVPIN Threshold Voltage vs. Temperature 1.534 1.530 1.526 1.522 1.518 VIN = 12V 1.514 105 -40 25 ...
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... PWM (5V/DIV) VOUT (10V/DIV) IO1 (10V/DIV) VSW (20V/DIV) Time (5mS/DIV) Conditions: 12Vin, 36Vout / 100mA x 3 LED strings, 200Hz PWM Dimming, 50% Duty Cycle © 2010 Semtech Corporation Shut Down VIN (12V/DIV) VOUT (15V/DIV) VSS (1.2V/DIV) VSW (20V/DIV) Time (2S/DIV) Conditions: 20V, 36Vout / 100mA x 3 LED strings ...
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... PWM (5V/DIV) VOUT (1V/DIV) IO1 (10V/DIV) SW (20V/DIV) Time (5mS/DIV) Conditions: 12Vin, 36Vout / 100mA x 3 LED strings, 200Hz PWM Dimming, 0.2% Duty Cycle © 2010 Semtech Corporation LED Short Circuit Protection VIN (10V/DIV) VOUT (10V/DIV) IO1 (10V/DIV) IO2 (1V/DIV) Time (10mS/DIV) Conditions: 12V, 36Vout / 100mA x 3 LED strings, ...
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... IO2 Provides constant current source to LED string 2. 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 SC446 9 www.semtech.com ...
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... CIRCUIT PROTECTION IO1 LED CURRENT SETTING IOSET VOUT OVP OVPIN OVPRTN OVP Fault Detect 0.9mA 0.9mA SS HICCUP 5 4 © 2010 Semtech Corporation 3 HICCUP 4 5 FAULT-1 DISABLE1 CURRENT SOURCE HICCUP CONTROL 3V3 LOGIC HICCUP 4.5uA 4.5uA 1uA 1uA Figure 1. SC446 Block Diagram ...
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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 turned on to pull down VOUT. As temperature falls below © 2010 Semtech Corporation the TSD trip point, SC446 will retry when SS falls below 0.5V and VOUT falls to VIN. ...
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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 ...
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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 SC446 16 www.semtech.com ...
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... Evaluation Board Bill of Materials Item Reference Quantity C14, C15, C16 C8 R1, R14 11 R2, R3, R4 R8, R10, R12, R13 16 U1 © 2010 Semtech Corporation VIN C1 4.7nF C1 4.7nF 10 OVPRTN 10K R7 10K 11 OVPIN R5 R5 243K 243K 12 PGND VOUT PGND R10 R10 IO3 IO3 16 IO2 IO2 ...
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... Outline Drawing - TSSOP-16 EDP © 2010 Semtech Corporation © 2010 Semtech Corporation SC446 18 www.semtech.com ...
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... Land Pattern -TSSOP-16 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 SC446 19 www.semtech.com ...