VERY LOW DROPOUT, LOW QUIESCENT 500mA REGULATOR PRELIMINARY - September 11, 2000 SC1563 TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com DESCRIPTION The SC1563 is a high performance positive voltage regulator designed for use in applications requiring very low dropout voltage at up to 500 milliamps. Since it has superior dropout characteristics compared to regular LDOs, it can be used to supply 2.5V on motherboards or 2.8V on peripheral cards from the 3.3V supply with no heatsink. Additionally, the SC1563 has a shutdown pin, to further reduce power dissipation while shut down. The SC1563 provides excellent regulation over variations in line, load and temperature. The SC1563 is available as a five terminal fixed or adjustable output voltage device with enable. The device is available in a 5-pin SOT-23 package and an 8-pin MSOP package for higher power dissipation/ lower junction temperature. FEATURES •= 450mV dropout @ 500mA •= Designed to operate with ceramic capacitors •= Adjustable output from 1.200V to 3.3V •= Multiple output voltage options (all parts also •= •= •= •= •= adjustable externally using resistors) Over current and over temperature protection Enable pin 1µA quiescent current in shutdown Low reverse leakage (output to input) Full industrial temperature range APPLICATIONS •= Battery powered systems •= Motherboards •= Peripheral cards •= PCMCIA cards ORDERING INFORMATION (1)(2)(3) DEVICE SC1563ISK-X.XTR SOT-23-5L SC1563IMS-X.XTR MSOP-8 Notes: (1) Where -X.X denotes voltage options. Available voltages are: 1.8V, 2.5V, 2.8V, 3.0V, 3.1V and 3.3V. (2) Output voltage can be adjusted using external resistors, see Pin Description. (3) Only available in tape and reel packaging. A reel contains 2500 devices (MSOP-8) or 3000 devices (SOT-23-5L). TYPICAL APPLICATION Internally Preset Output Voltage U1 5 VIN 1 SHDN C1 Externally Set Output Voltage SC1563ISK-X.X VIN VO SHDN GND 2 U1 4 VO (X.XV) 5 VIN VO SHDN GND SHDN C2 SC1563ISK-X.X VIN 1 ADJ 3 PACKAGE 2 C1 4 ADJ VO R1 3 C2 R2 VO = 1.200 (R1 + R2) R2 Volts 1 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT, LOW QUIESCENT 500mA REGULATOR SC1563 PRELIMINARY - September 11, 2000 ABSOLUTE MAXIMUM RATINGS Parameter Symbol Maximum Units Input Voltage VIN 5.5 V Power Dissipation PD Internally Limited W θJA 206 95 256 °C/W Thermal Resistance Junction to Case MSOP-8 SOT-23-5L θJC 39 81 °C/W Operating Ambient Temperature Range TA -40 to+85 °C Operating Junction Temperature Range TJ -40 to 150 °C Storage Temperature Range TSTG -65 to 150 °C Lead Temperature (Soldering) 10 Sec. TLEAD 300 °C ESD Rating ESD 2 kV Thermal Resistance Junction to Ambient MSOP-8(1) MSOP-8(2) SOT-23-5L(1) Notes: (1) Minimum pad size. (2) 1 square inch of FR-4, double sided, 1oz. minimum copper weight. ELECTRICAL CHARACTERISTICS Unless specified: VSHDN = 0V Adjustable Option (VADJ > VTH(ADJ)): VIN = 2.2 to 5.5V and IO = 10µA to 500mA Fixed Options (VADJ = GND): VIN = (VO + 0.7V) to 5.5V and IO = 0A to 500mA Values in bold apply over the full operating temperature range. Parameter Symbol Test Conditions Min Typ Max Units 5.5 V VIN Supply Voltage Range Quiescent Current VIN IQ 2.2 VIN = 3.3V 100 150 µA VIN = 5.5V, VSHDN = Open 0.5 2 µA 0.99VO VO 1.01VO V 0.98VO VO 1.02VO VO Output Voltage(1) VO VIN = VO + 0.7V, IO = 10mA (Internal Fixed Voltage) (1) Line Regulation (1) Load Regulation REG(LINE) VIN = (VO + 0.25V) to 5.5V, IOUT = 10mA 0.035 0.3 % REG(LOAD) VIN = VO + 0.7V 0.2 0.4 % 2 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT, LOW QUIESCENT 500mA REGULATOR SC1563 PRELIMINARY - September 11, 2000 ELECTRICAL CHARACTERISTICS (Cont.) Unless specified: VSHDN = 0V Adjustable Option (VADJ > VTH(ADJ)): VIN = 2.2 to 5.5V and IO = 10µA to 500mA Fixed Options (VADJ = GND): VIN = (VO + 0.7V) to 5.5V and IO = 0A to 500mA Values in bold apply over the full operating temperature range. Parameter Symbol Test Conditions VD ILOAD = 2mA Min Typ Max Units 1 5 mV VO (Cont.) Dropout Voltage(2) 10 ILOAD = 100mA 75 100 mV 150 ILOAD = 250mA 200 300 mV 400 ILOAD = 500mA 450 550 mV 700 Minimum Load Current (3) Current Limit IO VIN = VO + 0.7V ICL 1 0.50 10 µA 1.00 A 1.212 V ADJ Reference Voltage(1) VREF VIN = 2.2V, VADJ = VOUT, IO = 10mA 1.188 1.200 1.176 (4) Adjust Pin Current Adjust Pin Threshold(5) IADJ VADJ = VREF VTH(ADJ) 0.10 1.224 50 100 nA 0.20 0.40 V 1 10 µA SHDN Shutdown Pin Current Shutdown Pin Threshold ISHDN VSHDN = 0V, VIN = 3.3V VIH VIN = 3.3V VIL VIN = 3.3V V 1.8 0.4 OVER TEMPERATURE PROTECTION High Trip Level Hysteresis THI 165 °C THYST 10 °C 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% below the value measured at a differential of 0.7V. (3) Required to maintain regulation. Voltage set resistors R1 and R2 are usually utilized to meet this requirement. Adjustable versions only. (4) Guaranteed by design. (5) When VADJ exceeds this threshold, the “Sense Select” switch disconnects the internal feedback chain from the error amplifier and connects VADJ instead. 3 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT, LOW QUIESCENT 500mA REGULATOR SC1563 PRELIMINARY - September 11, 2000 BLOCK DIAGRAM PIN CONFIGURATIONS Top View Top View SOT-23-5L MSOP-8 PIN DESCRIPTION Pin Pin Number Name SOT-23-5L MSOP-8 ADJ 3 3 Pin Function This pin, when grounded, sets the output voltage to that set by the internal feedback resistors. If external feedback resistors are used, the output voltage will be (See Application Circuit): VO = 1.200 (R1+ R2) R2 Volts GND 2 5-8 Reference ground. Connect all MSOP-8 GND pins. These pins may be used for heatsinking purposes. VIN 5 1 Input voltage. For regulation at full load, the input to this pin must be between (VO + 0.7V) to 5.5V. Minimum VIN = 2.2V. VO 4 4 This pin is the power output of this device. SHDN 1 2 Shutdown Input. Leaving this pin open turns the regulator off, reducing the quiescent current to a fraction of its operating value (typically <100nA). The device will be enabled if this pin is pulled below 0.4V. Connect to GND if not being used. 4 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT, LOW QUIESCENT 500mA REGULATOR SC1563 PRELIMINARY - September 11, 2000 (1)(2) TYPICAL APPLICATION (Externally Set Output Voltage) U1 5 VIN 1 SHDN SC1563IS-X.X VIN 4 VO VO R1 SHDN GND ADJ 2 C1 1uF 3 C2 10uF R2 1.200 (R1 + R2) R2 = VO Volts (2) TYPICAL APPLICATIONS (Internally Set Output Voltage) U1 5 VIN 1 SHDN C1 1uF SC1563IS-X.X VIN 4 VO SHDN GND 2 VO (X.XV) ADJ 3 C2 10uF U1 SC1563IMS-X.X 1 VIN 2 SHDN 3 4 VO (X.XV) C1 1uF VIN GND SHDN GND ADJ GND VO GND 8 7 6 5 C2 10uF Notes: (1) Maximum VO setpoint is 3.3V. (2) This device is designed to operate with ceramic input and output capacitors. 5 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT, LOW QUIESCENT 500mA REGULATOR SC1563 PRELIMINARY - September 11, 2000 APPLICATIONS INFORMATION Introduction The SC1563 is intended for applications such as graphics cards where high current capability and very low dropout voltage are required. It provides a very simple, low cost solution that uses little pcb real estate and typically does not require a heatsink. Additional features include an enable pin to allow for a very low power consumption standby mode, and a fully adjustable output. Component Selection Input capacitor - a 1µF ceramic capacitor is recommended. 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 transient response. Additional capacitance may be added if required by the application. Thus PD(MAX) = 0.514W. Using this figure, and assuming TA(MAX) = 85°C, we can calculate the maximum thermal impedance allowable to maintain TJ ≤ 150°C: R TH ( J − A )( MAX ) = (T J( MAX ) − TA ( MAX ) ) PD ( MAX ) = (150 − 70 ) = 156 °C / W 0 .514 This should be achievable using pcb copper area to aid in conducting the heat away from the device. Internal ground/power planes and air flow will also assist in removing heat. For higher ambient temperatures additional board copper may be required. Use of the available MSOP-8 package will allow operation at full load where higher input to output voltage differentials exist. MARKING INFORMATION MSOP-8 Output capacitor - a minimum bulk capacitance of 1µF, along with a 0.1µF 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 SC1563 is extremely tolerant of output capacitor ESR values and thus will also work comfortably with tantalum output capacitors. External voltage selection resistors - the use of 1% resistors, and designing for a current flow ≥ 10µA is recommended to ensure a well regulated output (thus R2 ≤ 120kΩ). SOT-23-5L Thermal Considerations The power dissipation in the SC1563 is approximately equal to the product of the output current and the input to output voltage differential: PD ≈ (VIN − VOUT ) • I O The absolute worst-case dissipation is given by: PD ( MAX ) = (VIN ( MAX ) − VOUT ( MIN ) )• I O ( MAX ) + VIN ( MAX ) • IQ ( MAX ) For a typical scenario, VIN = 3.3V ± 5%, VOUT = 2.5V and IO = 500mA, therefore: 63XX = SC1563, voltage option (example: 6318) yyww = Datecode (example: 0008) XXXX = Lot number (example: E01102) VIN(MAX) = 3.465V, VOUT(MIN) = 2.450V and IQ(MAX) = 1.75mA, 6 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT, LOW QUIESCENT 500mA REGULATOR SC1563 PRELIMINARY - September 11, 2000 DEVICE OUTLINE - SOT-23-5 LAND PATTERN - SOT-23-5 7 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT, LOW QUIESCENT 500mA REGULATOR SC1563 PRELIMINARY - September 11, 2000 OUTLINE DRAWING - MSOP-8 LAND PATTERN - MSOP-8 ECN00-1343 8 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320