A LINFINITY M I C R O S E M I LX8610-xx 1A BiCMOS Very Low Dropout Regulators C O M P A N Y P RODUCTION D ATASHEET KEY FEATURES DESCRIPTION W W W. Microsemi .COM The LX8610 family are positive very low dropout regulators. They are designed to provide a power supply for very low headroom applications, such as 3.3V– 2.5V. BiCMOS technology allows an effective series pass element resistance, RDS(ON) of 250mΩ resulting in a typical dropout voltage of 250mV at 1A. Low Quiescent Current and LogicControlled Shutdown help conserve battery life and increase system efficiency. Typical quiescent current is under 400µA irrespective of ! Dropout Voltage Typically 250mA At 1A And 50mV At 10mA ! Low Quiescent Current, Under 400µA, Irrespective Of Load ! Shutdown Current 10µA ! Adjustable Output Version In 8pin SOIC Package ! Fixed Outputs Of 2.5V, 3.3V Available In 3-Pin SOT-223 Package ! Low Reverse Leakage Current ! Short-Circuit And Thermal Shutdown Protection load current, while the shutdown current is only 10µA. The device will enter shutdown mode when the SHDN pin is pulled low. Thermal & Short-Circuit Current Limiting: the LX8610 limits the current when the output is shorted, so protecting sensitive load circuits. The device will also turn off if the junction temperature exceeds 155°C. Available in small outline SOT-223 and 8-pin SOIC: Adjustable versions use the 8-pin SOIC and fixed output voltage devices are supplied in the 3lead SOT-223. APPLICATIONS/BENEFITS APPLICATIONS/BENEFITS ! 3.3V & 2.5V Supplies For Memory, Microprocessors, Clock Circuits, Etc. ! Portable Equipment IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com PRODUCT HIGHLIGHT LX8610-xx Sim plified Block Diagram V OUT V IN Reference Current Current Lim it RA Charge Pum p ADJ* 1.25V + RB - SHDN* GND V IN /2 RA Reverse Voltage Sense Therm al Shutdown RB LX8610-00 - - LX8610-25 25K 25K LX8610-33 41K 25K LX8610-XX * Adjustable version in 8 lead package only. TJ (°°C) 0 to 125°C PACKAGE ORDER INFO PLASTIC SOT-223 OUTPUT ST 3-PIN VOLTAGE 3.3 LX8610-33CST 2.5 LX8610-25CST ADJ (00) – DM Plastic Power SOIC 8-PIN LX8610-33CDM LX8610-25CDM LX8610-00CDM Note: Available in Tape & Reel. Append the letter “T” to the part number. (i.e. LX8610CDMT) Copyright 2000 Rev. 1.0c, 2001-11-16 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 A LINFINITY M I C R O S E M I LX8610-xx 1A BiCMOS Very Low Dropout Regulators C O M P A N Y P RODUCTION D ATASHEET ABSOLUTE MAXIMUM RATINGS PACKAGE PIN OUT TAB IS GN D Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of specified terminal. THERMAL DATA ST V OU T 2 GN D/HS 1 V IN ST PACKAGE (Top View) V OUT 1 8 ADJ GND/HS 2 7 GND/HS GND/HS 3 6 G ND/HS SHDN 4 5 V IN Plastic SOT-223 Package 3-Pin DM PACKAGE (Top View) THERMAL RESISTANCE-JUNCTION TO TAB, θJT THERMAL RESISTANCE-JUNCTION TO AMBIENT, DM 3 W W W. Microsemi .COM Input Voltage (VIN).......................................................................................................6.5V SHDN Pin..............................................................................................-0.3V to VIN+0.3V Output Current ................................................................................................................1A Operating Junction Temperature Plastic (ST & DM) Packages................................. 125°C Storage Temperature....................................................................................-65°C to 150°C Lead Temperature (Soldering, 10 Seconds)............................................................... 300°C θJA 15°C/W 150° C/W HEAT SINK APPROACH Plastic SOIC Package 8-Pin THERMAL RESISTANCE-JUNCTION TO TAB, θJT THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 30° C/W 90° C/W Junction Temperature Calculation: TJ = TA + (PD x θJA). The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow. θJA can be improved with package soldered copper area over backside ground plane or internal power plane. θJA can vary from 45°C/W > 75°C/W depending on mounting technique. See table below for thermal resistance guidelines: Copper Area (Backside)* 2.0 sq” (1290mm2) 1.0 sq” (645 mm2) 0.5 sq” (323 mm2) 0.25 sq” (161 mm2) 1.0 sq” (645 mm2) 0.5 sq” (323 mm2) 0.1 sq” (65 mm2) 0.1 sq” (65 mm2) 2.0 sq” (1290mm2) 1.0 sq” (645 mm2) 0.5 sq” (323 mm2) 0.25 sq” (161 mm2) 1.0 sq” (645 mm2) 0.5 sq” (323 mm2) 0.1 sq” (65 mm2) 0.1 sq” (65 mm2) Board Area ST (SOT-223) 2.0 sq” (1290mm2) 1.0 sq” (645 mm2) 0.5 sq” (323 mm2) 0.25 sq” (161 mm2) Thermal Resistance (θ θJA) 45°C/W 50°C/W 60°C/W 70°C/W 1 8 2 7 3 6 4 5 PACKAGE DATA Copper Area (Topside)* Possible Heat Sink Approaches using PCB Copper DM (SOIC) 2.0 sq” (1290mm2) 1.0 sq” (645 mm2) 0.5 sq” (323 mm2) 0.25 sq” (161 mm2) 60°C/W 67°C/W 70°C/W 75°C/W *Tab of device attached to topside copper, or leads 2,3,5,6 of SOIC package Copyright 2000 Rev. 1.0c, 2001-11-16 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 A LINFINITY M I C R O S E M I LX8610-xx 1A BiCMOS Very Low Dropout Regulators C O M P A N Y P RODUCTION D ATASHEET FUNCTIONAL PIN DESCRIPTION DESCRIPTION VIN Positive supply input for the regulator. Bypass to GND with at least 2.2µF of low ESR, ESL capacitance if supply source is further than 1 inch from the device. VOUT Output for the regulator. It is recommended to bypass to GND with at least 10µF although this is not required for regulation, rather it is needed for transient response. Size your output capacitor to meet the transient loading requirement. If you have a very dynamic load, a larger capacitor will improve the response to these load steps. GND/HS Reference ground. The input and output bypass capacitors should be connected to this pin. In addition the tab on the SOT-223 package and pins 2,3,6, and 7 on the SOIC package are also used for heat sinking the device. ADJ Feedback pin for the regulator. For the LX8610-00, the output voltage can be set by two external resistors with the following relationship: VOUT = 1.25V * (1 + RA / RB) where RA is the resistor connected between VOUT and ADJ, and RB is the resistor connected between ADJ and GND. SHDN Shutdown input. This pin has a threshold of about VIN / 2, it should be actively pulled high to enable the regulator. This can be accomplished with a resistive pull-up. When low, it turns off the regulator and puts the device in a low current shutdown state. W W W. Microsemi .COM PIN NAME TYPICAL APPLICATION VIN 5 IN OUT LX8610-00 CIN SHDN 4 GND 2,3 6,7 VOUT 1 RA ADJ 8 VREF COUT RB RA RB VOUT = VREF 1 + PACKAGE DATA Figure 1 – Typical Application Copyright 2000 Rev. 1.0c, 2001-11-16 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 A LINFINITY M I C R O S E M I LX8610-xx 1A BiCMOS Very Low Dropout Regulators C O M P A N Y P RODUCTION D ATASHEET RECOMMENDED OPERATING CONDITIONS Symbol Min LX8610 Typ Units Max Input Voltage VIN 3.1 5.5 V Load Current (with adequate heatsinking) 10 1000 mA Input Capacitor (VIN to GND) 2.2 10 µF Output Capacitor (VOUT to GND) 10 22* µF * Size your output capacitor to meet the transient loading requirement. If you have a very dynamic load, a larger capacitor will improve the response to these load steps. ELECTRICAL CHARACTERISTICS Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C ≤ TA ≤ 125°C except where otherwise noted. Test conditions: VIN = VOUT + 1.5V; IOUT = 10mA; CIN = 10µF; COUT = 22µF; TJ = TA. Parameter ! Test Conditions Min LX8610-xx Typ Max Units LX8610-33 FIXED 3.3V, 1A Output Voltage VOUT Line Regulation Load Regulation VREG IREG Dropout Voltage (VDO = VIN–VOUT) VDO Short Circuit Current ISC Quiescent Current IQ Reverse Leakage Current ! Symbol W W W. Microsemi .COM Parameter IREV Shutdown Threshold * VSHDN SHDN Bias Current * ISHDN TJ = 25°C VIN = 3.8 to 5.5V, IOUT = 10mA to 1A VIN = 3.45V to 5.5V IOUT = 10mA to 1A IOUT = 1A, VOUT = ∆VOUT –1% IOUT = 0.5A, VOUT = ∆VOUT – 1% IOUT = 10mA, VOUT = ∆VOUT – 1% VOUT = 0V IOUT = 10mA to 1A VIN = 4.8V; VSHDN < 0.8V 0V < VIN < VOUT, VOUT <3.4V (at VOUT) 0V < VIN < VOUT, VOUT <3.4V (at VIN) VSHDN falling 3.25 3.22 -50 0.8 VSHDN rising VSHDN < 0.8V VSHDN = 3V 3.3 4 5 0.25 0.15 0.05 1.25 400 1 400 0 (VIN / 2) (VIN / 2) -2 -1 3.35 3.38 8 10 0.45 0.25 0.15 1.7 600 40 650 V mV mV V A µA µA mA V µA LX8610-25 FIXED 2.5V, 1A VOUT Line Regulation Load Regulation VREG IREG Dropout Voltage (VDO = VIN–VOUT) VDO Short Circuit Current ISC Quiescent Current IQ Reverse Leakage Current IREV Shutdown Threshold * VSHDN SHDN Bias Current * ISHDN Copyright 2000 Rev. 1.0c, 2001-11-16 TJ = 25°C VIN = 3.1V, IOUT = 10mA to 1A VIN = 3.1V to 5.5V, IOUT = 10mA IOUT = 10mA to 1A IOUT = 1A, VOUT = ∆VOUT –1% IOUT = 0.5A, VOUT = ∆VOUT – 1% IOUT = 10mA, VOUT = ∆VOUT – 1% VOUT = 0V IOUT = 10mA to 1A VIN = 4.8V; VSHDN < 0.8V 0V < VIN < VOUT, VOUT < 2.6V (at VOUT) 0V < VIN < VOUT, VOUT <2.6V (at VIN) VSHDN falling 2.46 2.44 -50 0.8 2.5 2.5 4 5 0.25 0.15 0.05 1.25 300 1 400 0 VIN / 2 VSHDN rising (VIN / 2) VSHDN < 0.8V -2 VSHDN = 3V -1 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 2.54 2.56 8 10 0.45 0.25 0.15 1.7 600 40 650 V mV mV V A µA µA mA V µA Page 4 ELECTRICALS Output Voltage A LINFINITY M I C R O S E M I LX8610-xx 1A BiCMOS Very Low Dropout Regulators C O M P A N Y P RODUCTION D ATASHEET ELECTRICAL CHARACTERISTICS (CONTINUED) ! Symbol Test Conditions Min LX8610-xx Typ Max Units LX8610-00 ADJUSTABLE OUTPUT, 1A Reference Voltage VREF Line Regulation Load Regulation Short Circuit Current VREG IREG ISC Dropout Voltage (VDO = VIN–VOUT) VDO Quiescent Current IQ Quiescent Current in Shutdown Reverse Leakage Current IREV Bias Current at ADJ Pin IBIAS Shutdown Threshold * V SHDN SHDN Bias Current * I SHDN 1.23 1.22 TJ = 25°C VIN = 3.1V, IOUT = 10mA to 1A VIN = 3.1V to 5.5V, IOUT = 10mA IOUT = 10mA to 1A VOUT = 0V IOUT = 1A, VIN > 4V IOUT = 0.5A, VIN > 3V IOUT = 10mA, VIN > 3V IOUT = 10mA to 1A, VIN = 5.5V VIN = 4.8V; VSHDN < 0.8V 0V < VIN < VOUT, VOUT < 5.5V (at VOUT) 1.22 1.25 4 7 1.25 0.25 0.15 0.05 400 1.27 1.28 8 15 1.7 0.45 0.25 0.15 600 1 40 400 650 V mV mV A V µA µA 0V < VIN < VOUT, VOUT <5.5V (at VIN) -50 0 mA 100 nA V SHDN falling 0.8 (VIN / 2) V SHDN rising (VIN / 2) V SHDN < 0.8V -2 V SHDN = 3V -1 W W W. Microsemi .COM Parameter V µA * Note: Shutdown Threshold and Shutdown Bias Current apply only to 8-Pin SOIC package outline versions DROPOUT VOLTAGE VS. OUTPUT CURRENT L X 861 0 D ropout vs. L oad vs. T em p 350 300 250 200 0 25 75 100 125 150 ELECTRICALS 100 50 0 0 0 .2 5 0 .5 0 .7 5 1 FIGURE 2 – Dropout Voltage Vs. Output Current (Typical – LX8610-25CST) Copyright 2000 Rev. 1.0c, 2001-11-16 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 A LINFINITY M I C R O S E M I LX8610-xx 1A BiCMOS Very Low Dropout Regulators C O M P A N Y P RODUCTION D ATASHEET ST W W W. Microsemi .COM MECHANICAL DIMINSIONS 3-Pin Plastic SOT-223 D Dim B1 E H 2 1 3 B F G L K A J DM I C A B B1 C D E F G H I J K L MILLIMETERS MIN MAX 1.55 1.80 0.65 0.85 2.95 3.15 0.25 0.35 6.30 6.70 3.30 3.70 2.30 BSC 4.60 BSC 6.71 7.29 – 0.91 0.02 0.10 10° MAX .084 1.04 INCHES MIN MAX 0.061 0.071 0.026 0.033 0.116 0.124 0.010 0.014 0.248 0.264 0.130 0.146 0.0905 BSC 0.181 BSC 0.264 0.287 – 0.036 .0008 .004 10° MAX 0.033 0.041 MILLIMETERS MIN MAX 4.83 5.00 3.81 3.94 1.35 1.75 0.33 0.51 – 0.77 1.27 BSC 0.19 0.25 0.13 0.25 4.80 5.21 – 8° 5.79 6.20 – 0.10 INCHES MIN MAX 0.190 0.197 0.150 0.155 0.053 0.069 0.013 0.020 – 0.030 0.050 BSC 0.007 0.010 0.005 0.010 0.189 0.205 – 8° 0.228 0.244 – 0.004 8-Pin Plastic SOIC A Dim P B G L D K J F *Lead Coplanarity Note: Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006”) on any side. Lead dimension shall not include solder coverage. Copyright 2000 Rev. 1.0c, 2001-11-16 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 MECHANICALS M C A B C D F G J K L M P *LC A LINFINITY M I C R O S E M I C O M P A N Y LX8610-xx 1A BiCMOS Very Low Dropout Regulators P RODUCTION D ATASHEET W W W. Microsemi .COM NOTES NOTES PRODUCTION DATA – Information contained in this document is proprietary to LinFinity and is current as of publication date. This document may not be modified in any way without the express written consent of LinFinity. Product processing does not necessarily include testing of all parameters. LinFinity reserves the right to change the configuration and performance of the product and to discontinue product at any time. Copyright 2000 Rev. 1.0c, 2001-11-16 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7