SC1408 Semtech Corporation, SC1408 Datasheet
SC1408
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SC1408 Summary of contents
Page 1
... The controller changes frequency in low load conditions to improve efficiency. The SC1408 was designed for two cell Alkaline or sin- gle cell Lithium Ion battery applications. With the proper external components it can be used as a boost converter or a buck/boost converter ...
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... REF 5V < V < 16.5V OUT T = 25° -40°C to +85° 25° -40°C to +85°C A 652 MITCHELL ROAD NEWBURY PARK CA 91320 SC1408 Maximum Units -0 ±0.1 V -0.3 to VBST+0 -40 to +85 °C -40 to +150 °C -65 to +160 °C +300 °C 165 ° ...
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... OUT 16. 25°C OUT -40°C to +85° 5V, 1nF from GATE to GND OUT V = 5V, 1nF from GATE to GND OUT GATE = high or low 652 MITCHELL ROAD NEWBURY PARK CA 91320 SC1408 MIN TYP MAX UNITS 1 µA 85 100 115 mV 80 120 0. µ ...
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... GATE 2 BST SHDN 5 REF 6 AGND 7 GND 8 ISENSE 652 MITCHELL ROAD NEWBURY PARK CA 91320 SC1408 INTERNAL BIAS SHDN BIAS BST 2.5V GATE GND ISENSE 0.1V Pin Function Gate drive output. Supply voltage. Voltage feedback. Logic high shuts down the converter. Reference output pin. ...
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... R2 0.05Ohm (1) See Component Selection D2 1N4148 L1A 22uH C1 1 100uF + 1 Q1 BST GATE IRLL3303 8 SHDN ISENSE 3 REF GND AGND R2 0.05Ohm 3 652 MITCHELL ROAD NEWBURY PARK CA 91320 SC1408 Vout= (1) C8 100uF + R4 C3 10.0k 100uF D1 Vout=5V B130T R3 31. L1B R4 C3 22uH 10.0k 100uF (1) See Component Selection ...
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... GND AGND SC1408IS L1 22uH BST GATE SHDN ISENSE 0.1uF 5 3 REF GND AGND SC1408IS C5 0.1uF 652 MITCHELL ROAD NEWBURY PARK CA 91320 SC1408 D1 25V OUT B130T R3 200k + C8 100uF + 0.05Ohm 10.0k 100uF D1 12V OUT B130T R3 90k Q1 IRLL3303 + C8 100uF + ...
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... R 4 è V REF Inductor The SC1408 will work with a wide range of inductor val- ues. A good choice for most applications Smaller inductor values result in higher peak currents and increased output ripple, while larger values will re- sult in slower loop response. Transistor Selection ...
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... Feed Forward Capacitor The feed forward capacitor should be selected in the same way as for a Boost application. LAYOUT GUIDELINES The SC1408 is fairly insensitive to layout, however fol- lowing some simple guidelines will help ensure success- ful implementation. Whenever possible, lay the circuitry out over a ground plane ...
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... Vo=12V 90% 80% Vin=5.0V Vin=4.0V 70% Vin=3.3V Vin=3.0V 60% 100 1000 1 Vin=12V Vin=9.0V Vin=5.0V Vin=3.0V Vin=1.8V 100 1000 652 MITCHELL ROAD NEWBURY PARK CA 91320 SC1408 20mOhm 25mOhm 35mOhm 50mOhm 100mOhm 3.0 3.5 4.0 4.5 5.0 Vin (V) 20mOhm 25mOhm 35mOhm 50mOhm 100mOhm 6.0 8.0 10.0 12.0 14.0 16.0 Vin (V) Vin=5.0V Vin=3.0V Vin=1.8V 10 100 1000 ...
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... Ch2 = Load Current (0.5A/div) © 2000 SEMTECH CORP. LOW VOLTAGE, BOOST DC-DC CONTROLLER Output Ripple Voltage; Vin=3V, Vo=5V, Io=810mA Ch1 = Output Ripple Ch2 = Voltage at GATE pin Load Transient; Vin=2V, Vo=5V, Io=0 to 500mA Ch1 = Output Voltage Ch2 = Load Current (0.5A/div) 652 MITCHELL ROAD NEWBURY PARK CA 91320 SC1408 10 ...
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... August 22, 2000 OUTLINE DRAWING - SO-8 LAND PATTERN - SO-8 © 2000 SEMTECH CORP. LOW VOLTAGE, BOOST DC-DC CONTROLLER 652 MITCHELL ROAD NEWBURY PARK CA 91320 SC1408 JEDEC REF: MS-012AA 11 ...
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... August 22, 2000 OUTLINE DRAWING - MSOP-8 LAND PATTERN - MSOP-8 ECN00-1275 © 2000 SEMTECH CORP. LOW VOLTAGE, BOOST DC-DC CONTROLLER 652 MITCHELL ROAD NEWBURY PARK CA 91320 SC1408 12 ...