300mA AND 500mA LOW DROPOUT VOLTAGE REGULATORS WITH ENABLE PRELIMINARY - May 1, 2000 TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com DESCRIPTION The SC1540 and SC1540A are high performance low dropout positive voltage regulators designed for use in applications where power management is critical, such as battery powered systems. Additionally, the SC1540(A) provides excellent regulation over variations in line, load and temperature. Outstanding features include low dropout performance at rated current, fast transient response, internal current limiting and thermal shutdown protection of the output device. A very low quiescent current of 10µA in shutdown mode reduces power dissipation. With three voltage options available, the SC1540(A) comes in the popular SO-8 surface mount package. APPLICATIONS •= Active SCSI termination •= Low voltage microcontrollers •= Switching power supply post-regulator BLOCK DIAGRAM SC1540 SC1540A FEATURES •= Low dropout performance, 1.3V max •= Full current rating over line and temperature •= Fast transient response •= +2% total output regulation over line, load and •= •= •= •= •= temperature 10µA max. quiescent current in shutdown Three fixed output voltages Line regulation 0.2% max. Load regulation 0.4% max. SO-8 package ORDERING INFORMATION (1)(2) DEVICE OUTPUT CURRENT PACKAGE SC1540CS-X.X 300mA SO-8 SC1540ACS-X.X 500mA SO-8 Notes: (1) Where X.X denotes voltage options. Available voltages are: 1.8V, 2.5V and 3.3V. Contact factory for additional voltage options. (2) Only available in tape and reel packaging (suffix ‘.TR’) e.g. SC1540CS-X.X-.TR. ABSOLUTE MAXIMUM RATINGS Parameter Symbol Maximum Units Maximum Input Pin Voltage VIN, EN 7 V PD Internally Limited W Thermal Resistance Junction to Case SO-8 θJC 47 °C/W Thermal Resistance Junction to Ambient SO-8(1) θJA 65 °C/W Operating Junction Temperature Range TJ 0 to 125 °C Storage Temperature Range TSTG -65 to 150 °C Lead Temperature (Soldering) 10 Sec TLEAD 260 °C Power Dissipation PIN CONFIGURATIONS Top View SO-8 Notes: (1) 2 inch square of 1/16” FR-4, double sided, 1 oz. minimum copper weight. 1 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 300mA AND 500mA LOW DROPOUT VOLTAGE REGULATORS WITH ENABLE SC1540 SC1540A PRELIMINARY - May 1, 2000 ELECTRICAL CHARACTERISTICS Unless otherwise specified: IO = 0mA to 300mA (500mA for SC1540A), EN = VIN 1.5V Option: VIN = 2.9V to 7.0V 2.5 Option: VIN = 3.9V to 7.0V 3.3V Option: VIN = 4.7V to 7.0V Values in bold apply over full operating temperature range. Test Conditions Parameter Symbol (1) Output Voltage VO (1) Line Regulation VIN = 5V, IO = 0mA Test Limits Min Typ Max Units 0.99|VO| VO 1.01|VO| V 0.98|VO| VO 1.02|VO| REG(LINE) IO = 10mA 0.035 0.2 % REG(LOAD) VIN = 5V 0.2 0.4 % Dropout Voltage SC1540 SC1540A VD IO = 300mA IO = 500mA 1.10 1.30 V Current Limit(1) SC1540 SC1540A ICL Quiescent Current IQ (1) Load Regulation (1)(2) mA 330 550 VIN = 5V, EN = VIN 5 7 mA 10 VIN = 5V, EN < 0.25V 6 8 µA 10 Enable Pin Control Voltage EN Device OFF 0.25 Device ON Enable Pin Current IEN V 0.45 (VO+0.5) (VO+0.8) EN = 0V, VIN = 5V (OFF) 0.1 1.0 EN = VIN = 5V (ON) 15 25 µA Temperature Coefficient TC 0.005 %/°C Temperature Stability TS 0.5 % VN 0.003 %VO 72 dB RMS Output Noise (3) (4) Ripple Rejection Ratio RA VIN = 5V 60 NOTES: (1) Low duty cycle pulse testing with Kelvin connections required. (2) ∆VOUT, ∆ VREF = 1% (3) Bandwidth of 10 Hz to 10kHz. (4) 120Hz input ripple. 2 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 300mA AND 500mA LOW DROPOUT VOLTAGE REGULATORS WITH ENABLE SC1540 SC1540A PRELIMINARY - May 1, 2000 TYPICAL APPLICATION U1 VIN ENABLE SIGNAL SC1540(A) VIN EN C1 10uF Tantalum VO VOUT GND C2 10uF min. Tantalum NOTES (1) Input and output capacitors should be located close to the device. (2) Connect all pins to PCB for optimal thermal characteristics. (3) Increasing the output capacitor value will improve the overall transient response. (4) The device is enabled when EN = VIN, and shut down when EN is pulled to ground. EN should not be taken higher than VIN. A CMOS signal referenced to VIN would be ideal for switching the SC1540(A) on and off. 3 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320 300mA AND 500mA LOW DROPOUT VOLTAGE REGULATORS WITH ENABLE SC1540 SC1540A PRELIMINARY - May 1, 2000 OUTLINE DRAWING - SO-8 JEDEC REF: MS-012AA LAND PATTERN - SO-8 (1) Note: (1) More copper area should be used to lower RTH(J-A) as needed. ECN00-1038 4 © 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320