Document
55AA24204K0HKz H35ZV B3u6cVk DPCWtoMDCBCuoncvkerDteCr /DC Converter
SC2678
General Description
Features
The SC2678 is a 240 KHz fixed frequency monolithic step down switch mode regulator with a built in internal Power MOSFET. It achieves 5A continuous output current over a wide input supply range with excellent load and line regulation. The device includes a voltage reference, oscillation circuit, error amplifier, internal PMOS and etc.
The PWM control circuit is able to adjust the duty ratio linearly from 0 to 100%. An enable function, an over current protection function and a short circuit protection function are built inside. An internal compensation block is built in to minimize external component count.
The SC2678 serves as ideal power supply units for portable devices.
5A Constant Output Current 80mΩ RDSON Internal Power PMOSFET
Switch Up to 95% Efficiency Fixed 240KHz Frequency Wide 3.6V to 35V Input Voltage Range Output Adjustable from 1.222V to 30V Built in Frequency Compensation Built in Thermal Shutdown Function Built in Current Limit Function TO-263 Package is Available The minimum dropout up to 0.3V
Applications
Portable DVD LCD Monitor / TV Battery Charger ADSL Modem Telecom / Networking Equipment
TO263-5L
Figure 1 Package Type of SC2678
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55AA24204K0HKz H35ZV B3u6cVk DPCWtoMDCBCuoncvkerDteCr /DC Converter
SC2678
Pin Configurations
TO263-5L
5 ON/OFF 4 Feedback 3 Output 2 Gnd 1 Vin
EXPOSED PAD ON BACKSIDE CONNECT TO PIN3
Pin Description
Figure 2 Pin Configuration of SC2678 (Top View)
Pin Number 1 3 2
4 5
Pin Name Vin
Output GND
FB EN
Description
Supply Voltage Input Pin. SC2678 operates from a 3.6V to 35V DC voltage. Bypass Vin to GND with a suitably large capacitor to eliminate noise on the input. Power Switch Output Pin. SW is the switch node that supplies power to the output.
Ground Pin. Care must be taken in layout. This pin should be placed outside of the Schottky Diode to output capacitor ground path to prevent switching current spikes from inducing voltage noise into SC2678. Feedback Pin. Through an external resistor divider network, FB senses the output voltage and regulates it. The feedback threshold voltage is 1.222V. Enable Pin. EN is a digital input that turns the regulator on or off .Drive EN pin high to turn on the regulator, drive it low to turn it off.
Ordering Information
SC2678 X
X
Circuit Type
Package S: TO263-5L
Packing
Blank: Tube R: Type and Reel
TEL:0755-27668758/29469758
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55AA24204K0HKz H35ZV B3u6cVk DPCWtoMDCBCuoncvkerDteCr /DC Converter Function Block
SC2678
Figure 3 Function Block Diagram of SC2678
Absolute Maximum Ratings
Parameter Input Voltage Feedback Pin Voltage Enable Pin Voltage Switch Pin Voltage Output Power Limited Operating Junction Temperature Storage Temperature Lead Temperature (Soldering, 10 sec) ESD (HBM) Thermal Resistance-.