A Product Line of Diodes Incorporated PAM3131 3A ADJUSTABLE LOW VOLTAGE LOW DROPOUT CMOS REGULATOR Description Pin Assignments The PAM3131 is a 3A CMOS adjustable LDO regulator that features a low quiescent current, ultra low input, output, and dropout voltages, as well as over temperature protection. It is available in TO-263 and PSOP-8 (Exposed Pad) packages. The output voltage is adjustable from 0.9V to 3.3V. The PAM3131 is stable with a ceramic output capacitor of 1.0μF or higher. This family of regulators can provide either a stand alone power supply solution or act as a post regulator for switch mode power supplies. They are particularly well suited for applications requiring low input and output voltages. Features • Low-Dropout Regulator Supports Input Voltages Down to 1.4V • Low Dropout Voltage: 300mV@ 3A • Output Voltage Adjustable from 0.9V-3.3V • Stable with a Ceramic Output Capacitor of 1.0μF or Higher • Low Quiescent Current • Current Limit • Over Temperature Shutdown • Short Circuit Current Protection • Low Temperature Coefficient • Standard TO-263 and PSOP-8 (Exposed Pad) Packages • Pb-Free Package Applications • DSP, FPGA, and Microprocessor Power Supplies • 1.2V Core Voltage for DSPs • SATA Power Supply • LCD TV/ Monitors • Wireless Devices • Communication Devices • Portable Electronics • Post Regulator for SMPS Typical Applications Circuit PAM3131 Document number: DSxxxxx Rev. 1 - 1 1 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Pin Description Pin Name Pin Number Function TO263-5L PSOP-8(EPD) VIN EN ADJ VOUT 1 2 Input 2 3 Enable Pin 4 6 Adjustable Pin 5 7 Output GND PWRGD 3 — 1, 4, 8 5 Ground Power Good Functional Block Diagram Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.) These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. All voltages are with respect to ground. Parameter Input Voltage Output Pin Voltage Operation Temperature Range Operation Junction Range Maximum Output Current Storage Temperature Maximum Junction Temperature Soldering Temperature PAM3131 Document number: DSxxxxx Rev. 1 - 1 Rating 4.0 Unit V -0.3 to VIN +0.3 -40 to +85 -40 to +125 °C °C PD/(VIN–VO) -65 to +150 150 300, (5sec) °C °C °C V — 2 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.) Rating Unit Supply Voltage Range Parameter 1.4 to 3.6 V Operation Temperature Range -40 to +85 Junction Temperataure Range -40 to +125 °C Thermal Information Parameter Symbol Thermal Resistance (Junction to Case) θJC Thermal Resistance (Junction to Ambient) θJA Internal Power Dissipation (TA = 25°C) PD PAM3131 Document number: DSxxxxx Rev. 1 - 1 Package Max TO-263 7 PSOP-8 10 TO-263 35 PSOP-8 50 TO-263 2800 PSOP-8 2000 3 of 14 www.diodes.com Unit °C/W mW October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Electrical Characteristics (@TA = +25°C, VIN = VO +1V, CIN = 4.7µF, CO = 4.7µF, unless otherwise specified.) Parameter Input Voltage Range ADJ Reference Voltage Symbol Test Conditions VREF IO = 3.0A ISC Output Current IO Quiescent Current IQ Ground Pin Current IGND Line Regulation LNR Load Regulation LDR Over Temperature Shutdown Over Temperature Hysteresis OTS OTH Temperature Coefficient Power Supply Ripple Rejection Output Noise Notes: Vn Units V 0.918 V VO = 0.9V 330 500 VO = 1.0V 220 400 2.5V > VO ≥ 1.2V 50 200 150 VO ≥ 2.5V 40 VO = 0.9V 500 VO = 1.0V 400 2.5V > VO ≥ 1.2V 350 VO ≥ 2.5V 300 mV 1.0 VO < 0.3V 3.0 A 150 µA 1.0 mA 0.2 1.0 %/V 0.5 2 %/A VO > 0.8V VO ≤ 2.5V, IO = 10mA VIN = VO +0.5V to VO +1.5V VO > 2.5V, IO = 10mA VIN = 3.3V to 3.6V IO = 1mA to 3.0A, VIN = VO +0.5A IO = 100mA, VO = 1.5V f = 10Hz to 100kHz f = 100Hz f = 1kHz A Note 2 90 IO = 0mA TC PSRR Max 0.900 0.882 VDROP Short Circuit Current Typ 3.6 IO = 100mA IO = 500mA Dropout Voltage Min Note 1 VIN 150 50 °C °C 40 ppm/°C 64 58 dB 40 µVRMS 1. The minimum input voltage ( ) of the PAM3131 is determined by output voltage and dropout voltage. The minimum input voltage is defined as: 2. Output current is limited by PD, maximum IO = PD/(VIN(MAX) -VO). PAM3131 Document number: DSxxxxx Rev. 1 - 1 4 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Typical Performance Characteristics (@TA = +25°C, CIN =4.7µF, CO = 2.2µF, unless otherwise specified.) PAM3131 Document number: DSxxxxx Rev. 1 - 1 5 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Typical Performance Characteristics (cont.) (@TA = +25°C, CIN =4.7µF, CO = 2.2µF, unless otherwise specified.) PAM3131 Document number: DSxxxxx Rev. 1 - 1 6 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Typical Performance Characteristics (cont.) (@TA = +25°C, CIN =4.7µF, CO = 2.2µF, unless otherwise specified.) PAM3131 Document number: DSxxxxx Rev. 1 - 1 7 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Typical Performance Characteristics (cont.) (@TA = +25°C, CIN =4.7µF, CO = 2.2µF, unless otherwise specified.) PAM3131 Document number: DSxxxxx Rev. 1 - 1 8 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Typical Performance Characteristics (cont.) (@TA = +25°C, CIN =4.7µF, CO = 2.2µF, unless otherwise specified.) PAM3131 Document number: DSxxxxx Rev. 1 - 1 9 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Application Information The PAM3116 family of low-dropout (LDO) regulators have several features that allow them to apply to a wide range of applications. The family operates with very low input voltage and low dropout voltage (typically 300mV at full load), making it an efficient stand-alone power supply or post regulator for battery or switch mode power supplies. The 1.5A output current make the PAM3116 family suitable for powering many microprocessors and FPGA suppl ies. The PAM3116 family also has low output noise (typically 50μVRMS with 4.7μF output capacitor), making it ideal for use in telecom equipment. External Capacitor Requirements A 4.7μF or larger ceramic input bypass capacitor, connected between VIN and GND and located close to the PAM3116, is required for stability. A 4.7µF minimum value capacitor from VO to GND is also required. To improve transient response, noise rejection, and ripple rejection, an additional 1 0μF or larger, low ESR capacitor is recommended at the output. A higher-value, low ESR output capacitor may be necessary if large, fast-rise-time load transients are anticipated and the device is located several inches from the power source, especially if the minimum input voltage of 2.5V is used. Regulator Protection The PAM3116 features internal current limiting, thermal protection and short circuit protection. During normal operation, the PAM3116 limits output current to about 2.5A. When current limiting engages, the output voltage scales back linearly until the over current condition ends. While current limiting is designed to prevent gross device failure, care should be taken not to exceed the power dissipation ratings of the package. If the temperature of the device exceeds +150°C, thermal-protection circuitry will shut down. Once the device has cooled down to approximately +40°C below the high temp trip point, regulator operation resumes. The short circuit current of the PAM3116 is about 0.7A when its output pin is shorted to ground. Thermal Information The amount of heat that an LDO linear regulator generates is: PD = (VIN − V O )IO All integrated circuits have a maximum allowable junction temperature (TJ(MAX)) above which normal operation is not assured. A system designer must design the operating environment so that the operating junction temperature (TJ) does not exceed the maximum junction temperature (TJ(MAX)). The two main environmental variables that a designer can use to improve thermal performance are air flow and external heat sinks. The purpose of thi s information is to aid the designer in determining the proper operating environment for a linear regulator that is operating at a specific power level. In general, the maximum expected power (PD(MAX)) consumed by a linear regulator is computed as: Where: • VI(AVG) is the average input voltage. • VO(AVG) is the average output voltage. • IO(AVG) is the average output current. • I(Q) is the quiescent current. For most LDO regulators, the quiescent current is insignificant compared to the average output current; therefore, the term VI(AVG) xIQ can be neglected. The operating junction temperature is computed by adding the ambient temperature (TA) and the increase in temperature due to the regulator's power dissipation. The temperature rise is computed by multiplying the maximum expected power dissipation by the sum of the thermal resistances between the junction and the case RθJC), the case to heatsink (RθCS), and the heatsink to ambient (RθSA). Thermal resistances are measures of how effectively an object dissipates heat. Typically, the larger the device, the more surface area available for power dissipation so that the object’s thermal resistance will be lowers. PAM3131 Document number: DSxxxxx Rev. 1 - 1 10 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Ordering Information Part Number PAM3131AMBR PAM3131BECR Package Type TO236-5L PSOP-8 Standard Package 800 Units/Tape&Reel 2500 Units/Tape&Reel Marking Information PAM3131 Document number: DSxxxxx Rev. 1 - 1 11 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Package Outline Dimensions (All dimensions in mm.) TO263-5L PAM3131 Document number: DSxxxxx Rev. 1 - 1 12 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 Package Outline Dimensions (cont.) (All dimensions in mm.) PSOP-8 PAM3131 Document number: DSxxxxx Rev. 1 - 1 13 of 14 www.diodes.com October 2012 © Diodes Incorporated A Product Line of Diodes Incorporated PAM3131 IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or trademark rights, nor the rights of others. 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Copyright © 2012, Diodes Incorporated www.diodes.com PAM3131 Document number: DSxxxxx Rev. 1 - 1 14 of 14 www.diodes.com October 2012 © Diodes Incorporated