Data Sheet No. PD94137 IRU1117-18 800mA LOW DROPOUT POSITIVE FIXED 1.8V REGULATOR PRELIMINARY DATA SHEET FEATURES DESCRIPTION Guaranteed < 1.2V Dropout at 800mA Load Current Fast Transient Response 1% Voltage Reference Initial Accuracy Built-In Thermal Shutdown Available in SOT-223, D-Pak, Ultra Thin-Pak and 8-Pin SOIC Surface-Mount Packages APPLICATIONS Low Voltage IC Supply Applications PC Clock Supply Voltage The IRU1117-18 is a low dropout three-terminal fixed output regulator with minimum of 800mA output current capability. This product is specifically designed to provide well regulated supply for low voltage IC applications as well as generating clock supply for PC applications. The IRU1117-18 is guaranteed to have <1.2V dropout at full load current making it ideal to provide well regulated with 3.8V input supply. The IRU1117-18 is specifically designed to be stable with low cost aluminum capacitors while maintaining stability with low ESR tantalum caps. TYPICAL APPLICATION 3.3V C1 10uF Vin 3 IRU1117-18 Vout Gnd 2 1.8V / 800mA C2 10uF 1 Figure 1 - Typical set-up of the IRU1117-18 in a 3.3V to 1.8V regulator application PACKAGE ORDER INFORMATION Tj (°C) 0 To 125 Rev. 1.1 06/29/01 2-PIN PLASTIC TO-252 (D-Pak) IRU1117-18CD 3-PIN PLASTIC SOT-223 (Y) IRU1117-18CY 2-PIN PLASTIC Ultra Thin-Pak (P) IRU1117-18CP 8-PIN PLASTIC SOIC (S) IRU1117-18CS 1 IRU1117-18 ABSOLUTE MAXIMUM RATINGS Input Voltage (Vin) .................................................... Power Dissipation ..................................................... Storage Temperature Range ...................................... Operating Junction Temperature Range ..................... 7V Internally Limited -65°C To 150°C 0°C To 125°C PACKAGE INFORMATION 2-PIN PLASTIC TO-252 (D-Pak) 3-PIN PLASTIC SOT-223 (Y) 2-PIN ULTRA THIN-PAK (P) FRONT VIEW 8-PIN PLASTIC SOIC (S) FRONT VIEW 3 TOP VIEW Vin 3 Tab is Vout Tab is Vout 1 Gnd θJA=70°C/W for 0.5" Sq pad 3 Vin 2 Vout 1 Gnd θJA=90°C/W for 0.4" Sq pad TOP VIEW Vin Vin NC NC Gnd Tab is Vout 1 Gnd θJA=70°C/W for 0.5" Sq pad 1 8 2 7 3 6 4 5 Vout Vout Vout Vout θJA=55°C/W for 1" Sq pad ELECTRICAL SPECIFICATIONS Unless otherwise specified, these specifications apply over Cin=1µF, Vin=5V,Cout=10µF, and Tj=0 to 125!C. Typical values refer to Tj=25!C. PARAMETER Output Voltage Line Regulation Load Regulation (Note 1) Dropout Voltage (Note 2) Current Limit Thermal Regulation Ripple Rejection Temperature Stability Long Term Stability RMS Output Noise SYM Vo TEST CONDITION Io=10mA, Tj=25!C Io=10mA Io=10mA, 4.75V<Vin<7V 10mA<Io<800mA Io=1A Io=800mA dVo=100mV 30ms Pulse, Io=800mA f=120Hz, Co=25µF Tantalum, Io=0.5A Io=10mA Tj=125!C, 1000Hrs Tj=25!C, 10Hz<f<10KHz MIN TYP 1.782 1.800 1.764 1.800 1.2 1.1 1.1 MAX 1.818 1.896 7 17 1.3 1.2 UNITS V mV mV V 0.01 A %/W 70 0.5 0.3 0.003 dB % % %Vo Note 1: Low duty cycle pulse testing with Kelvin connections is required in order to maintain accurate data. Note 2: Dropout voltage is defined as the minimum differential voltage between Vin and Vout required to maintain regulation at Vout. It is measured when the output voltage drops 1% below its nominal value. 2 Rev. 1.1 06/29/01 IRU1117-18 PIN DESCRIPTIONS PIN# 1 PIN SYMBOL PIN DESCRIPTION Ground pin. This pin must be connected to ground plane using a low inductance short Gnd connection. 2 Vout The output of the regulator. This pin is also connected to the tab of the package. An output capacitor must be connected to this pin to insure stability of the regulator. 3 Vin Input pin of the regulator. Typically a large storage capacitor is connected from this pin to ground to insure that the input voltage does not sag below the minimum dropout voltage during the load transient response. This pin must always be 1.3V higher than Vout in order for the device to regulate properly. BLOCK DIAGRAM Vin 3 2 Vout + 1.25V + CURRENT LIMIT THERMAL SHUTDOWN 1117-18blk1-1.0 1 Gnd Figure 2 - Simplified block diagram of the IRU1117-18 Rev. 1.1 06/29/01 3 IRU1117-18 Notes IR WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, USA Tel: (310) 252-7105 TAC Fax: (310) 252-7903 Visit us at www.irf.com for sales contact information. Data and specifications subject to change without notice. 02/01 4 Rev. 1.1 06/29/01