SEMTECH SC4211 handbook
Contents
1. 10mA OUT Load Regulation Vi Vo 0 5V 10mA to 1A OU Dropout Voltage 10mA 500mA Notes 1 Low duty cycle pulse testing with Kelvin connections required 2 Defined as the input to output differential at which the output voltage drops to 1 5 below the value measured at a differential of 0 5V 3 Required to maintain regulation Voltage set resistors R1 and R2 are usually utilized to meet this requirement 4 Guaranteed by design 2004 Semtech Corp 2 www semtech com Va 9 SEMTECH oes POWER MANAGEMENT Electrical Characteristics Cont Unless specified Vy Vys Veg Vo Vy 1 40V to 5 5V Vy Vo 0 5V to 5 5V and 1mA to 1A Values in bold apply over the full operating temperature range Parameter Test Conditions VO Cont Dropout Voltage Minimum Load Current Current Limit Feedback Reference Voltage Vy 3 3V Vg V 10mA OUT Full and V Range OUT Feedback Pin Currentt Veg Var EN Enable Pin Current Va OV Vex 3 3V Enable Pin Threshold V V 33V Vy 33V Over Temperature Protection High Trip level Hysteresis 1 Low duty cycle pulse testing with Kelvin connections reguired 2 Defined as the input to output differential at which the output voltage drops to 1 5 below the value measured at2. R2 VO OVO 0 5V www semtech com SC4211 a P SEM TECH POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device or device malfunction Operation outside of the parameters specified in the Electrical Characteristics section is not implied Parameter Vin EN Vo FB Absolute Voltage 7 Power Dissipation Internally Limited Thermal Resistance Junction to Ambient SOIC 8EDP 36 Thermal Resistance Junction to Case SOIC 8EDP 5 5 Operating Ambient Temperature Range 40 to 85 Operating Junction Temperature Range 40 to 150 Storage Temperature Range T 65 to 150 Lead Temperature Soldering 10 Sec T 300 ESD Rating Human Body Model 2 Note 1 2 square inch of FR 4 double sided 1 oz minimum copper weight Electrical Characteristics Unless specified Vo Na Veg Vo Vy 1 40V to 5 5V Vy Vo 0 5V to 5 5V and 1mA to 1A Values in bold apply over the full operating temperature range Parameter Test Conditions VIN Supply Voltage Range Quiescent Current Vn 33V bur OA OUT Va BEN Vey OV vo Output Voltage Vy Vo 0 5V lur 10mA OUT Internal Fixed Voltage Full and Vy Range OUT Line Regulation Vo 0 5V Vy lt 3 3V bur 10mA OUT Vin Vin V 0 5V Vy gt 3 3V Li
3. X 16 ELEMENTS 6mm X 8mm IN ACCORDANCE THE INTERNATIONAL GRID DETAILED IE IEC PUBLICA N 97 CONTROLLING DIMENSIONS MILLIMETERS 2004 Semtech Corp 7 www semtech com SC4211 C P SEM TECH POWER MANAGEMENT Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road Camarillo CA 93012 Phone 805 498 2111 FAX 805 498 3804 2004 Semtech Corp 8 www semtech com
4. RNA MTECH SC4211 Very Low Input Very Low Dropout 1 Amp Regulator With Enable The SC4211 is a high performance positive voltage regulator designed for use in applications requiring very low Input voltage and very low dropout voltage at up to 1 amp It operates with a Vin as low as 1 4V with output voltage programmable as low as 0 5V The SC4211 fea tures ultra low dropout ideal for applications where Vout is very close to Vin Additionally the SC4211 has an en able pin to further reduce power dissipation while shut down The SC4211 provides excellent regulation over varia tions in line load and temperature The SC4211 is available in the SOIC 8EDP Exposed Die Pad package The output voltage can be set via an exter nal divider or to 0 5V depending on how the FB pin is con figured Typical Application Circuits SC4211 SC4211 Revision October 18 2004 Features Input Voltage as low as 1 4V 250mV dropout 1A Adjustable output from 0 5V to 3 3V Over current and over temperature protection Enable pin 10pA quiescent current in shutdown Low reverse leakage output to input Full industrial temperature range Available in SOIC 8EDP package Applications Telecom Networking cards Motherboards Peripheral cards Industrial Applications Wireless infrastructure Set top boxes Medical equipment Notebook computers Battery powered systems 2000000 OVO 0 5 R1 R2
5. W Using this figure and assuming er 70 C we can cal culate the maximum thermal impedance allowable to main tain T lt 150 C T T R tg aymax l sa 50 20 110 C W D MAX a This should be achievable for the SOIC 8EDP package using PCB copper area to aid in conducting the heat away such as one sauare inch of copper connected to the ground pins of the device Internal ground power planes and air flow will also assist in removing heat For higher ambient temperatures it may be necessary to use additional cop per area www semtech com SC4211 P SEM TECH Outline Drawing SOIC 8EDP M V V AX 107 ITH CIC OO t N l X EXPOSED DIE PAD AD BOTTOM VIEW END USER SHOULD VERIFY ACTUAL SIZE OF EXPOSED THERMA FOR SPECIFIC D JE APPLICATION DIMENSION DOES NOT INC INTER LEAD FLAS DR PROTUSIONS INTER LEAD FLASH AND PRO ONS SHALL NOT EXCEED 25 mm 010 PER SIDE N Ai DOES NOT INCLUDE MOLD FLASH PROT BURRS MOLD FLASH PROTUSIONS AND GATE BURRS SHA 15 mm 0 PER SIDE CONTROLLING DIMENSION MILLIMETER GRID PA GUL GRID PLACEMENT COURTYARD IS 12
6. a differential of 0 5V 3 Reguired to maintain regulation Voltage set resistors R1 and R2 are usually utilized to meet this reguirement 4 Guaranteed by design 2004 Semtech Corp 3 www semtech com FE SC4211 P SEM TECH POWER MANAGEMENT Ordering Information Part Number Package Temp Range T SC4211STRT0A SOIC 8EDP 40 to 85 C SC4211EVB Evaluation Board Note 1 Available voltage is 0 5V or Output voltage can be adjusted using external resistors see Pin Descriptions 2 Only available in tape and reel packaging 2500 devices for the SOIC 8EDP package 3 Lead free product Pin Configuration Top View Bottom View SOIC 8EDP SOIC 8EDP Pin Descriptions Pin Name Pin Description FB When this pin is connected to the Vo pin the output voltage will be set at 0 5V If external feedback resistors are used the output voltage will be See Application Circuits on page 1 0 5 R1 R2 VO Volts R2 Enable Input Pulling this pin below 0 4V turns the regulator off reducing the quiescent current to a fraction of its operating value The device will be enabled if this pin is left open Connect to VIN if not being used Reference ground Note The GND pin and the exposed die pad must be connected together at the IC pin Use the exposed die pad on the device for heatsinking Input voltage For regulation at full load the input to this pin must be
7. between VO 0 5V and 5 5V Minimum VIN 1 4V A large bulk capacitance should be placed closely to this pin to ensure that the input supply does not sag below 1 4V Also a minimum of 4 7uF ceramic capacitor should be placed directly at this pin The pinis the power output of the device A minimum of 10uF ceramic capacitor should be placed directly at this pin 2004 Semtech Corp 4 www semtech com SC4211 lt P SEM TECH POWER MANAGEMENT Block Diagram Thermal Shutdown Reverse Voltage Shutdown 2004 Semtech Corp 5 www semtech com L d SEMTECH SC4211 POWER MANAGEMENT Applications Information Introduction The SC4211 is intended for applications where high cur rent capability and very low dropout voltage are required It provides a very simple low cost solution that uses very little PCB real estate Additional features include an en able pin to allow for a very low power consumption standby mode and a fully adjustable output Component Selection Input capacitor A large bulk capacitance of about 100uF should be closely placed to the input supply pin of the SC4211 to ensure that Vin does not sag below 1 4V Also a minimum of 4 7uF ceramic capacitor is recommended to be placed directly next to the Vin pin This allows for the device being some distance from any bulk capacitance on the rail Additionally input droop due to load transients is reduced improving load transi
8. ent response Additional capacitance may be added if required by the application Output capacitor a minimum bulk capacitance of 10pF along with a O 1uF ceramic decoupling capacitor is recommended Increasing the bulk capacitance will improve the overall transient response The use of multiple lower value ceramic capacitors in parallel to achieve the desired bulk capacitance will not cause stability issues Although designed for use with ceramic output capacitors the SC4211 is extremely tolerant of out put capacitor ESR values and thus will also work comfortably with tantalum output capacitors Noise immunity in very electrically noisy environments it is recommended that 0 1uF ceramic capacitors be placed from IN to GND and OUT to GND as close to the device pins as possible External voltage selection resistors the use of 1 resistors and designing for a current flow gt 10A is recommended to ensure a well regulated output thus R2 lt 120kQ 2004 Semtech Corp Thermal Considerations The power dissipation in the SC4211 is approximately equal to the product of the output current and the input to out put voltage differential Pp VIN VOUT eI The absolute worst case dissipation is given by Poux VIN MAX VOUT MIN Je Tomax VIN MAX S Tomax For a typical scenario V 3 3V 5 Vy 2 8V and l 1A therefore Vines 3465W Vonn 2 74 4V and l 175mA OUT MIN MAX Thus P D MAX 5722
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SEMTECH SC4211 handbook