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| VERY LOW DROPOUT 1.5 AMP REGULATOR WITH ENABLE October 3, 2000 SC1565 TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com DESCRIPTION The SC1565 is a high performance positive voltage regulator designed for use in applications requiring very low dropout voltage at up to 1.5 Amps. 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 thus allowing the elimination of costly heatsinks. Additionally, the 5-lead TO-220 and SO-8 versions have an enable pin to further reduce power dissipation while shut down. The SC1565 provides excellent regulation over variations in line, load and temperature. The SC1565 is available in the popular SO-8 surface mount package with two internally preset output voltage options, which are also adjustable using external resistors. Also available are 5-lead and 3-lead TO-220 2.5V options (fixed output only for the 3-lead option) and fixed output SOT-223 options. FEATURES *= 350mV dropout @ 1.5A *= Adjustable output from 1.2V to 4.8V(1) *= 2.5V and 1.8V options (adjustable externally using resistors)(1) *= Over current and over temperature protection *= Enable pin(1) *= 10A quiescent current in shutdown(1) *= Low reverse leakage (output to input) *= Surface mount and through-hole packages *= Full industrial temperature range Note: (1) SO-8 and TO-220-5L packages only. APPLICATIONS *= Battery powered systems *= Motherboards *= Peripheral cards *= PCMCIA cards ORDERING INFORMATION DEVICE (1) PACKAGE SO-8 SOT-223 TO-220-3 TO-220-5 (2) SC1565IS-X.X.TR(2) SC1565IST-X.X.TR SC1565IT-X.X (3) (3) SC1565I5T-X.X Notes: (1) Where -X.X denotes voltage options. Available voltages are: 2.5V and 1.8V. Output voltage can be adjusted (except SOT-223 and TO-220-3) using external resistors, see Pin Description. (2) Only available in tape and reel packaging. A reel contains 2500 devices. (3) Only available in tube packaging (no suffix required). TYPICAL APPLICATIONS U1 ENABLE VIN VO 1 2 3 4 R1 EN VIN VO ADJ GND GND GND GND 8 VIN 7 6 5 3 C1 R2 C2 ENABLE 1 2 U1 SC1565I5T-2.5 VIN EN VO GND ADJ 4 5 R1 VO SC1565IS-X.X C1 C2 R2 VO 1.200 (R1 + R2) R2 U1 ENABLE VIN VO 1 2 3 4 C1 C2 EN VIN VO ADJ GND GND GND GND 8 7 6 5 GND C1 2 C2 = 1.200 (R1 + R2) R2 Volts VO = Volts 1 U1 SC1565IT-2.5V and SC1565IST-X.X 3 VIN VO VIN VO SC1565IS-X.X Notes: (1) Maximum VO setpoint for 1.8V parts = 5.4V. (2) This device is designed to operate with ceramic input and output capacitors. 1 (c) 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT 1.5 AMP REGULATOR WITH ENABLE October 3, 2000 SC1565 ABSOLUTE MAXIMUM RATINGS Parameter Input Voltage Power Dissipation Thermal Resistance Junction to Ambient SO-8(1) SOT-223 TO-220-X Thermal Resistance Junction to Case SO-8 SOT-223 TO-220-X Operating Ambient Temperature Range Operating Junction Temperature Range Storage Temperature Range Lead Temperature (Soldering) 10 Sec. ESD Rating (Human body model) Symbol VIN PD JA Max 5.5 Internally Limited 65 63 50 39 27 3 -40 to 85 -40 to 150 -65 to 150 300 4 Units V W C/W JC C/W TA TJ TSTG TLEAD ESD C C C C kV Note: (1) 1 square inch of FR-4, double sided, 1 oz. minimum copper weight. ELECTRICAL CHARACTERISTICS Unless specified: VEN = VIN Adjustable Option (VADJ > VTH(ADJ)): VIN = 2.2 to 5.5V and IO = 10A to 1.5A Fixed Options (VADJ = GND): VIN = (VO + 0.7V) to 5.5V and IO = 0A to 1.5A Values in bold apply over the full operating temperature range. Parameter VIN Supply Voltage Range Quiescent Current Symbol Test Conditions Min Typ Max Units VIN IQ VIN = 3.3V VIN = 5.5V, VEN = 0V 2.2 0.75 10 5.5 1.75 35 V mA A VO Output Voltage(1) (Internal Fixed Voltage) Line Regulation (1) (1) VO VIN = VO + 0.7V, IO = 10mA 0.99VO 0.98VO VO VO 0.035 0.2 1.01VO 1.02VO 0.3 0.4 V REG(LINE) REG(LOAD) VIN = (VO + 0.25V) to 5.5V, IOUT = 10mA VIN = VO + 0.7V % % Load Regulation 2 (c) 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT 1.5 AMP REGULATOR WITH ENABLE October 3, 2000 SC1565 ELECTRICAL CHARACTERISTICS Unless specified: VEN = VIN Adjustable Option (VADJ > VTH(ADJ)): VIN = 2.2 to 5.5V and IO = 10A to 1.5A Fixed Options (VADJ = GND): VIN = (VO + 0.7V) to 5.5V and IO = 0A to 1.5A Values in bold apply over the full operating temperature range. Parameter Dropout Voltage (2) Symbol VD Test Conditions ILOAD = 10mA ILOAD = 500mA ILOAD = 1A ILOAD = 1.5A Min Typ 2.5 Max 10 20 Units mV 115 300 400 mV 225 400 500 mV 350 500 600 mV Minimum Load Current Current Limit ADJ Reference Voltage(1) (3) IO ICL VREF VIN = VO + 0.7V 1.50 1 2.50 10 3.50 A A VIN = 2.2V, VADJ = VOUT, IO = 10mA 1.188 1.176 1.200 1.212 1.224 V Adjust Pin Current(4) Adjust Pin Threshold EN Enable Pin Current Enable Pin Threshold (5) IADJ VTH(ADJ) VADJ = VREF 0.10 10 0.20 50 0.40 nA V IEN VIH VIL VEN = 0V, VIN = 3.3V VIN = 3.3V VIN = 3.3V 1.8 1.5 10 A V 0.4 OVER TEMPERATURE PROTECTION High Trip level Hysteresis THI THYST 170 20 C 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 (c) 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT 1.5 AMP REGULATOR WITH ENABLE October 3, 2000 SC1565 BLOCK DIAGRAM * * * Not on 3-lead TO-220 PIN DESCRIPTIONS Pin Name ADJ Pin Functiom 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 EN 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. Use all four pins on the SO-8 device for heatsinking. Use the tab on the TO-220 devices for heatsinking. Input voltage. For regulation at full load, the input to this pin must be between (VO + 0.7V) and 5.5V. Minimum VIN = 2.2V. This pin is the power output of the device. GND VIN VO 4 (c) 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT 1.5 AMP REGULATOR WITH ENABLE October 3, 2000 SC1565 PIN CONFIGURATIONS SC1565 3-PIN VERSIONS PIN 1 2 3 FUNCTION VIN GND VO PIN 1 2 3 FUNCTION VIN GND VO TAB IS GROUND TAB IS GROUND SOT-223 TO-220-3 Top View SC1565 5-PIN VERSIONS PIN 1 2 3 4 5 FUNCTION EN VIN GND VO ADJ TAB IS GROUND SO-8 TO-220-5 5 (c) 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT 1.5 AMP REGULATOR WITH ENABLE October 3, 2000 SC1565 TYPICAL CHARACTERISTICS Dropout Voltage vs. Output Current vs. Junction Temperature 600 500 400 VD (mV) 300 200 100 0 0.00 150C 600 500 400 VD (mV) 300 IO = 0.5A 200 100 0 0.25 0.50 0.75 IO (A) 1.00 1.25 1.50 1.75 -50 -25 0 25 50 TJ (C) 75 100 125 150 IO = 1.0A Dropout Voltage vs. Junction Temperature vs. Output Current IO = 1.5A 25C 0C -40C Output Voltage (2.5V) vs. Junction Temperature vs. Output Current 2.550 VIN = 3.2V 2.540 2.530 2.520 VO (V) 2.510 2.500 2.490 2.480 2.470 2.460 2.450 -50 -25 0 25 50 TJ (C) 75 100 125 150 IO = 1.5A IO = 10mA VO (V) 2.540 2.530 2.520 2.510 2.500 2.490 2.480 2.470 2.460 2.450 -50 2.550 Output Voltage (2.5V) vs. Junction Temperature vs. Output Current VIN = 5.5V IO = 10mA IO = 1.5A -25 0 25 50 TJ (C) 75 100 125 150 Reference Voltage vs. Junction Temperature vs. Output Current 1.225 VIN = 2.2V 1.220 1.215 1.210 VREF (V) 1.205 1.200 1.195 1.190 1.185 1.180 1.175 -50 -25 0 25 50 TJ (C) 75 100 125 150 IO = 1.5A IO = 10mA VREF (V) 1.220 1.215 1.210 1.205 1.200 1.195 1.190 1.185 1.180 1.175 -50 1.225 Reference Voltage vs. Junction Temperature vs. Output Current VIN = 5.5V IO = 10mA IO = 1.5A -25 0 25 50 TJ (C) 75 100 125 150 6 (c) 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT 1.5 AMP REGULATOR WITH ENABLE October 3, 2000 SC1565 TYPICAL CHARACTERISTICS (Cont.) Quiescent Current vs. Junction Temperature 600 VIN = 3.3V 590 580 570 IQ (A) 560 550 540 530 520 510 500 -50 -25 0 25 50 TJ (C) 75 100 125 150 IQ(OFF) (A) 9 8 7 6 5 4 3 2 1 0 -50 -25 0 25 50 TJ (C) 75 100 125 150 10 VIN = 5.5V Off-State Quiescent Current vs. Junction Temperature APPLICATIONS INFORMATION Introduction The SC1565 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 very little pcb real estate. 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 4.7F 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. Output capacitor - a minimum bulk capacitance of 10F, along with a 0.1F 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 SC1565 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 10A is recommended to ensure a well regulated output (thus R2 120k). Thermal Considerations The power dissipation in the SC1565 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 ) * I Q ( MAX ) For a typical scenario, VIN = 3.3V 5%, VOUT = 2.8V and IO = 1.5A, therefore: VIN(MAX) = 3.465V, VOUT(MIN) = 2.744V and IQ(MAX) = 1.75mA, Thus PD(MAX) = 1.09W. Using this figure, and assuming TA(MAX) = 70C, we can calculate the maximum thermal impedance allowable to maintain TJ 150C: R TH( J - A )(MAX ) = (T J( MAX ) - TA ( MAX ) PD ( MAX ) ) = (150 - 70 ) = 73.4 C / W 109 . This should be achievable for the SO-8 package using pcb copper area to aid in conducting the heat away, such as one square inch of copper connected to the ground pins of the device. The SOT-223 and TO-220 packages would not require heatsinking. Internal ground/power planes and air flow will also assist in removing heat. For higher ambient temperatures it may be necessary to use additional copper area. 7 (c) 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT 1.5 AMP REGULATOR WITH ENABLE October 3, 2000 SC1565 OUTLINE DRAWING - SO-8 JEDEC REF: MS-012AA LAND PATTERN - SO-8 8 (c) 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT 1.5 AMP REGULATOR WITH ENABLE October 3, 2000 SC1565 DEVICE OUTLINE SOT-223 LAND PATTERN SOT-223 9 (c) 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 VERY LOW DROPOUT 1.5 AMP REGULATOR WITH ENABLE October 3, 2000 SC1565 DEVICE OUTLINE - TO-220-3L DEVICE OUTLINE - TO-220-5L ECN00-1357 10 (c) 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 |
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