L I N D O C # : 8610 LX8610-xx 1 A B I C M O S V E RY L O W D R O P O U T R E G U L AT O R S T H E I N F I N I T E P O W E R I O F P N N O VA T I O N R E L I M I N A R Y DESCRIPTION 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 load current, while the D A T A S H E E T K E Y F E AT U R E S ■ Dropout Voltage Typically 250mV At 1A And 50mV At 10mA ■ Low Quiescent Current, Under 400µA, Irrespective Of Load ■ Shutdown Current 10µA ■ Adjustable Output Version In 8-Pin 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 shutdown current is only 10µA. The device will enter shutdown mode when the ENABLE pin is pulled low. Thermal and 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 165°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 3-lead SOT223. A P P L I C AT I O N S ■ 3.3V & 2.5V Supplies For Memory, Microprocessors, Clock Circuits, Etc. ■ Portable Equipment NOTE: For current data & package dimensions, visit our web site: http://www.linfinity.com. PRODUCT HIGHLIGHT LX8610- X X B L O C K D I A G R A M V V IN C u rre n t L im it R e fe re n c e C u rre n t R O U T A A D J * C h a rg e P u m p R B 1 .2 5 V G N D E N A B L E R 1 .5 V R e v e rs e V o lta g e S e n s e T h e rm a l S h u td o w n A R B L X 8 6 1 0 -0 0 - - L X 8 6 1 0 -2 5 2 5 k 2 5 k L X 8 6 1 0 -3 3 4 1 k 2 5 k * L X 8 6 1 0 -0 0 V e r s io n O n ly . PA C K A G E O R D E R I N F O R M AT I O N Output SOT-223 DM Plastic SOIC TA (°C) ST Plastic Voltage 3-pin 8-pin 0 to 70 3.3 LX8610-33CST LX8610-33CDM 2.5 LX8610-25CST LX8610-25CDM ADJ (00) LX8610-00CDM Note: All surface-mount packages are available in Tape & Reel, append the letter "T" to part number. (i.e. LX8610-xxCDMT) Copyright © 2000 Rev. 0.5 1/00 LINFINITY MICROELECTRONICS INC. 11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570 1 PRODUCT DATABOOK 1996/1997 LX8610-xx 1 A B I C M O S V E RY L OW D R O P O U T R E G U L AT O R S P R E L I M I N A R Y A B S O L U T E M A X I M U M R AT I N G S D A T A S H E E T (Note 1) Input Voltage (VIN) ...................................................................................................... 6.5V Enable Pin .............................................................................................. -0.3V to VIN+0.3V Operating Junction Temperature Plastic (ST & DM Packages) ................................................................................. 125°C Storage Temperature Range ...................................................................... -65°C to 150°C Lead Temperature (Soldering, 10 seconds) ............................................................. 300°C PA C K A G E P I N O U T S TAB IS GND 3. VOUT 2. GND 1. VIN Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of the specified terminal. ST PACKAGE (Top View) T H E R M A L D ATA ST PACKAGE: THERMAL RESISTANCE-JUNCTION TO TAB, θJT THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 15°C/W *150°C/W DM PACKAGE: THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 165°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. VOUT GND/HEATSINK GND/HEATSINK ADJ 1 8 2 7 3 6 4 5 ENABLE GND/HEATSINK GND/HEATSINK VIN DM PACKAGE (Top View) * θJAcan be improved with package soldered to 0.5IN2 copper area over backside ground plane or internal power plane. θJAcan vary from 20ºC/W to > 40ºC/W depending on mounting technique. FUNCTIONAL PIN DESCRIPTION Pin Designator 2 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 its 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 Reference ground. The input and output decoupling 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 heatsinking 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+R2/R1) where R1 is the resistor connected between VOUT and ADJ, and R2 is the resistor connected between ADJ and GND pin. ENABLE Enable input. This pin has a threshold of about 1.5V, it should be actively pulled high to enable the regulator. This can be accomplished with a resistive pull-up or controlled by a logic gate. When low, it turns off the regulator and puts the device in a low current shutdown state. Copyright © 2000 Rev. 0.5 1/00 PRODUCT DATABOOK 1996/1997 LX8610-xx 1 A B I C M O S V E RY L OW D R O P O U T R E G U L AT O R S P R E L I M I N A R Y D A T A S H E E T R E C O M M E N D E D O P E R AT I N G C O N D I T I O N S Parameter Symbol Input Voltage Load Current (with adequate heatsinking) Input Capacitor (VIN to GND) Output Capacitor (VOUT to GND) VIN Recommended Operating Conditions Min. Typ. Max. 2.5 10 2.2 10 5.5 1000 Units V mA µF µF ELECTRICAL CHARACTERISTICS (Unless otherwise specified, these specifications apply over the operating ambient temperatures for the LX8610-xxC with 0°C ≤ TA ≤ 70°C; VIN = VOUT + 1.5V; IOUT = 10mA; CIN = 10µF; COUT = 22µF; TJ = TA. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient temperature.) LX8610-33 Fixed 3.3V, 1A Parameter Symbol Output Voltage VOUT Line Regulation Load Regulation Dropout Voltage (VDO = VIN - VOUT) VREG IREG VDO Current Limit Short Circuit Current Quiescent Current Reverse Leakage Current ICL ISC IQ Test Conditions TJ = 25°C Over Temperature 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 = VOUT - 1% VOUT = 0V IOUT = 10mA to 1A 0V < VIN < VOUT, VOUT < 3.4V (at VOUT) 0V < VIN < VOUT, VOUT < 3.4V (at VIN) Enable Threshold * Shutdown Current * Min. 3.25 3.22 1.1 1 -50 0.8 LX8610-33 Typ. Max. 3.3 4 5 0.25 0.15 0.05 1.3 1.25 400 400 0 1.5 10 3.35 3.38 8 10 0.4 0.25 0.15 1.8 1.7 600 650 25 Units V V mV mV V V V A A µA µA mA V µA LX8610-25 Fixed 2.5V, 1A Parameter Symbol Output Voltage VOUT Line Regulation Load Regulation Dropout Voltage (VDO = VIN - VOUT) VREG IREG VDO Current Limit Short Circuit Current Quiescent Current Reverse Leakage Current ICL ISC IQ Test Conditions TJ = 25°C Over Temperature 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 = VOUT - 1% VOUT = 0V IOUT = 10mA to 1A 0V < VIN < VOUT, VOUT < 2.6V (at VOUT) 0V < VIN < VOUT, VOUT < 2.6V (at VIN) Enable Threshold * Shutdown Current * Min. 2.46 2.44 1.1 1 -50 0.8 LX8610-25 Typ. Max. 2.5 2.5 3 5 0.25 0.15 0.05 1.3 1.25 300 400 0 1.5 10 2.54 2.56 6 10 0.4 0.25 0.1 1.8 1.7 600 650 25 Units V V mV mV V V V A A µA µA mA V µA * Enable Threshold and Shutdown Current apply only to 8-pin SOIC package outline versions. Copyright © 2000 Rev. 0.5 1/00 3 PRODUCT DATABOOK 1996/1997 LX8610-xx 1 A B I C M O S V E RY L OW D R O P O U T R E G U L AT O R S P R E L I M I N A R Y D A T A S H E E T E L E C T R I C A L C H A R A C T E R I S T I C S (Continued) LX8610-00 Adjustable Output, 1A Parameter Symbol Reference Voltage VREF Line Regulation Load Regulation Dropout Voltage (VDO = VOUT - VIN) VREG IREG VDO Current Limit Short Circuit Current Quiescent Current Reverse Leakage Current ICL ISC IQ Bias Current at ADJ Pin Enable Threshold Shutdown Current Test Conditions Min. 1.238 1.225 TJ = 25°C Over Temperature VIN = VOUT+150mV to 5.5V, IOUT = 10mA IOUT = 10mA to 1A IOUT = 1A, VIN > 4V IOUT = 0.5A, VIN > 3V IOUT = 10mA, VIN > 3V VOUT = VOUT - 1% VOUT = 0V IOUT = 10mA to 1A, VIN = 5.5V 0V < VIN < VOUT, VOUT < 5.5V (at VOUT) 0V < VIN < VOUT, VOUT < 5.5V (at VIN) 1.1 1 -50 0.8 Enable < 0.8V LX8610-00 Typ. Max. 1.25 1.25 2 7 0.25 0.15 0.05 1.3 1.25 400 400 0 100 1.5 10 1.262 1.270 4 15 0.4 0.25 0.15 1.8 1.7 600 650 250 25 Units V V mV mV V V V A A µA µA mA nA V µA T Y P I C A L A P P L I C AT I O N VIN LX8610-xx CIN VOUT 5 1 GND ADJ 2 ENABLE R1 4 3 COUT R2 VREF VOUT = VREF 1 + R2 R1 FIGURE 1 — Typical Application 4 Copyright © 2000 Rev. 0.5 1/00 PRODUCT DATABOOK 1996/1997 LX8610-xx 1 A B I C M O S V E RY L OW D R O P O U T R E G U L AT O R S P R E L I M I N A R Y D A T A S H E E T CHARACTERISTIC CURVES 300 DROPOUT (mV) 250 200 0 25 C 150 75 C 100 50 0 0.01 0.25 0.5 0.75 1 IOUT (A) FIGURE 2 — Dropout Voltage vs. Output Current (Typical - LX8610-25CST) PRELIMINARY DATA - Information contained in this document is pre-production data, and is proprietary to LinFinity. It may not modified in any way without the express written consent of LinFinity. Product referred to herein is offered in sample form only, and Linfinity reserves the right to change or discontinue this proposed product at any time. Copyright © 2000 Rev. 0.5 1/00 5