LX8816 Dual Channel 1A Low Dropout Regulator ® TM P RODUCTION D ATA S HEET KEY FEATURES DESCRIPTION enabling precise output voltages, typically ±1% of it’s specified value, while the BiPolar output transistor has a low dropout voltage even at full output current (VDO < 1.2V typ. @ 1A). Thermal and Short Circuit Current Protection are integrated on-chip and operate independently for each regulator output. The LX8816 regulator is stable with a low-value output capacitor, typically 2.2µF on the outputs, allowing designers flexibility in external component selection. Microsemi’s S-PAK package enables maximum power dissipation and ease of assembly using surface mount technology. Two Independent Regulated Outputs Accurate Output Voltages Typical Dropout of 1.2V at 1A and 1.1V at 500mA Independent Thermal and Current Limit Protection Low Profile 5 Lead SMT Power Package Low Tolerance Load Regulation Wide DC Supply Voltage of 4.3V to 10V Loop Stability Independent of Output Capacitor Type WWW . Microsemi .C OM The LX8816 is a dual channel positive-voltage linear regulator. This dual regulator has one fixed output coupled with an adjustable output. Each channel features low-dropout and high accuracy. The LX8816 provides designers with a flexible power management solution, minimal printed circuit board area and shorter design cycles. Each channel can supply up to one amp independently with a regulator design optimized for system efficiency by consuming minimal ground current and directing quiescent current to the load. The LX8816 features on-chip trimming of the internal voltage APPLICATIONS/BENEFITS IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com 5V to 3.3V / ADJ Regulators Hard Disk Drives, CD-ROMs ADSL and Cable Modems Battery Charging Circuits Instrumentation PC Peripherals APPLICATION CIRCUITS VIN = 5V VIN V2 LX8816-04 22µF 3.3V @ 1.0A 10 µF V1 GND ADJ 10µF R2 499 LX8816 ⎛ R1 ⎞ *V1 = VREF ⎜⎜1 + ⎟ + I ADJ R1 R 2 ⎠ ⎝ 2.5V* @ 1.0A R1 499 PACKAGE ORDER INFO TJ (°C) OUTPUT V1 (PIN 4) OUTPUT V2 (PIN 5) 0 to 125 Adj. 3.3V DF Plastic S-PAK 5-PIN RoHS Compliant Transition DC: 0515 LX8816-04CDF Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX8816-04CDF-TR) Copyright © 2000 Rev. 1.2c, 2005-05-18 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX8816 ® TM Dual Channel 1A Low Dropout Regulator P RODUCTION D ATA S HEET PACKAGE PIN OUT Input Voltage (VBAT).................................................................................................. 13.5V Load Current (Internally Limited)................................................................................... 1A Power Dissipation ................................................................................... Internally Limited Short-Circuit Protection ........................................................................................Indefinite Operating Junction Temperature................................................................................ 150°C Storage Temperature Range........................................................................ -65°C to 150°C Peak Package Solder Reflow Temperature (40 seconds maximum exposure)..................................................................260°C (+0, -5) Tab is GND 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. V2 4 V1 3 GND 2 ADJ 1 VIN DF PACKAGE THERMAL DATA DF 5 WWW . Microsemi .C OM ABSOLUTE MAXIMUM RATINGS (Top View) RoHS 100% Matte Tin Lead Finish Plastic S-Pak 5-Pin THERMAL RESISTANCE-JUNCTION TO TAB, θJT 4.5°C/W THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 24.5°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 vary from 25°C/W to > 40°C/W depending on mounting technique. (See Application Notes Section: Thermal considerations) FUNCTIONAL PIN DESCRIPTION PIN NAME DESCRIPTION VIN Positive unregulated supply input for the regulator. Bypass to GND with at least 2.2µF capacitance having low ESR for good transient response. ADJ Adjustable Input. The output voltage can be set by two external resistors with the following relationship: V1 = VREF * (1 + R1 / R2) + IADJ * R1 where R1 is the resistor connected between V1 and ADJ, and R2 is the resistor connected between ADJ and GND. GND Common terminal for ground reference. The input and output bypass capacitors should be connected to this pin. In addition the tab on the S-Pak package and pin 3 are also used for heat sinking the device. V2 Fixed regulator output (Regulator #2). It is recommended to bypass to GND with at least 2.2µF. Size your output capacitor to meet the transient loading requirement. For dynamic loads, a lower ESR capacitor will improve the response to these load steps. Copyright © 2000 Rev. 1.2c, 2005-05-18 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 PACKAGE DATA V1 Adjustable regulator output (Regulator #1) It is recommended to bypass to GND with at least 2.2uF. Size your output capacitor to meet the transient loading requirement. If you have a very dynamic load, a lower ESR capacitor will improve the response to these load steps. LX8816 ® TM Dual Channel 1A Low Dropout Regulator P RODUCTION D ATA S HEET Parameter Symbol Input Voltage VIN Output Voltage (adjustable) Min LX8816-04 Typ 4.5 Load Current each output (with adequate heat sinking) Units Max 10 VOUT 0 WWW . Microsemi .C OM RECOMMENDED OPERATING CONDITIONS V 5.5 V 1000 mA Input Capacitor (VIN to GND) 2.2 20 µF Output Capacitor (VOUT to GND) 1.0 10* µF * Size your output capacitor to meet the transient loading requirement. If you have a very dynamic load, a lower ESR and larger value 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 and the following test conditions: VIN = 5V, IOUT = 10mA, C1= 10µF (Tantalum), C2= C3= 4.7µF (Tant.), & TJ = TA using low duty cycling methods. LX8816-04 Parameter Symbol Test Conditions Units Min Typ Max ` Adjustable Output (Output 1) Reference Voltage VREF ∆V1(VIN) Line Regulation 1.225 1.273 V 1.5 2.5 mV ∆V1(VIN) 4.50V < VIN < 10V, IOUT = 5mA 0.17 0.22 %V Load Regulation ∆VREF(I1) 5mA < I1 < 1A, VIN = 4.75V 0.04 0.15 %V Dropout Voltage ∆V ILOAD = 1A, ∆V1 = -2% 1.2 1.3 V IOUT (MAX) Minimum Load Current IL Adjust Pin Bias Current IADJ 1.0 Note 1, The external resistor divider current can be included in this requirement. Bias current flows into part. 1.4 A 2 3 mA 0.12 1 µA Fixed Output (Output 2) Output Voltage V2 3.30 3.3825 V Line Regulation ∆V2(VIN) 4.75V < VIN < 5.5V, IOUT = 5mA 6 8 mV Line Regulation ∆V2(VIN) 4.50V < VIN < 10V, IOUT = 5mA 0.17 0.22 %V Load Regulation ∆V2(I2) 5mA < I2 < 1A, VIN = 4.75V 2.6 6 mV Dropout Voltage ∆V ILOAD = 1A, ∆V2 = -2% 1.2 1.3 V Current Limit 5mA < I2 < 1A, 4.75V < VIN < 10V IOUT (MAX) Minimum Load Current IL 3.234 1.0 1.4 Note 1 A 0 mA Entire Regulator Quiescent Current IQ VIN < 10V, I1 = 5mA, I2 = 5mA 2.6 3.8 mA Quiescent Current IQ VIN < 10V, I1 = 1A, I2 = 1A 3.5 6 mA Ripple Rejection RMS Output Noise (% of VOUT) Thermal Shutdown PSRR f=120Hz, VIN = 5V VOUT (RMS) 10Hz < f < 10kHz TJSD 60 135 75 dB 0.003 %V 140 °C Note 1: Minimum load current is defined as the amount of output current required to maintain regulation. Copyright © 2000 Rev. 1.2c, 2005-05-18 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 ELECTRICALS ` 5mA < I1 < 1A, 4.75V < VIN < 10V Line Regulation Current Limit ` 1.25 4.75V < VIN < 5.5V, IOUT = 5mA LX8816 Dual Channel 1A Low Dropout Regulator ® TM P RODUCTION D ATA S HEET VIN WWW . Microsemi .C OM BLOCK DIAGRAM 1 VOUT2 5 C1 10µF (Fixed) BIAS C2 10µF + - VIN 1.25V VREF VOUT1 4 (Adjustable) R1 GND C3 10µF 2 + - R2 3 ⎛ VOUT1 = 1.25 × ⎜1 + ⎜ ⎝ Note: Application circuit above using ceramic capacitors. R1 and R2 used with adjustable version only. R1 R2 ⎞ ⎟+ I ×R ⎟ ADJ 1 ⎠ Figure 1 – Simplified Block Diagram BLOCK DIAGRAM Copyright © 2000 Rev. 1.2c, 2005-05-18 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 LX8816 Dual Channel 1A Low Dropout Regulator ® TM P RODUCTION D ATA S HEET LOAD TRANSIENT RESPONSE LOAD TRANSIENT RESPONSE VIN = 20µF Ceramic, ESR= 45mΩ; V1,V2 = 10µF Ceramic, ESR= 75mΩ VIN = 22µF Tantalum, ESR=232mΩ; V1,V2 = 10µF Tantalum, ESR=198mΩ VIN = 5V V1 = 1.5V 180Ω Load 50mV / DIV 50mV / DIV 50mV / DIV 50mV / DIV V2 = 3.3V 1A Step Load V1 = 1.5V V2 = 3.3V 1A Step Load 50mV / DIV WWW . Microsemi .C OM CHARACTERISTIC CURVES 1A 1A 0mA 1mA 2µs / DIV 2µs / DIV CURRENT LIMIT RESPONSE TURN ON CHARACTERISTICS 500mV / DIV V1 = 1.5V 20mV(A C) / DIV V2 = 3.3V 500mV / DIV 1.2A V2 = 3.3V VIN = 5V Rising Load On V2 V1 = 1.5V 500m V / DIV 200mA / DIV 100µs / DIV 100µs / DIV VOUT AND ICHIP VS. VIN RAMP 5 4.5 40 4 35 3.5 30 3 VOUT (Volts) 45 25 20 6 Ichip, ma 5 V2,(Rext=13K ohms) V1, adj(Rext=909 ohms) 4 2.5 3 2 2 1.5 15 1 1 10 0.5 5 0 100 0 0.5 0 1000 10000 100000 1 1.5 2 2.5 3 3.5 4 4.5 5 VIN (Volts) FREQUENCY (HZ) Copyright © 2000 Rev. 1.2c, 2005-05-18 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 CHARTS RIPPLE REJECTION (DB) RIPPLE REJECTION VS. FREQUENCY VIN = 5V, CIN = 22µF, COUT1,2 = 10µF, V2=3.3V, IOUT2=1A Ichip (mA) 1V / DIV LX8816 ® TM Dual Channel 1A Low Dropout Regulator P RODUCTION D ATA S HEET Description Temperature Protection The LX8816 is part of a family of Dual LDO (Low Drop-Out) linear regulators in Microsemi’s S-PAK power package, which offer maximum power dissipation in a low profile surface mount technology. The family includes combination fixed and adjustable versions. Each channel can supply up to one amp independently with a regulator design optimized for system efficiency by consuming minimal ground current and directing quiescent current to the load. The thermal protection shuts the LX8816 down when the junction temperature exceeds 1400C. Each output has independent thermal shutdown capability. Exposure to absolute maximum rated conditions for extended periods may affect device reliability, see Thermal Considerations below. Input Capacitor To improve load transient response and noise rejection a input bypass capacitor is of at least 2.2uF is required. Generally we recommend a 20uF ceramic or tantalum or 22uF electrolytic capacitor. Output Capacitor The regulator requires output capacitors connected between V1, V2 and GND to stabilize the internal control loop. Many types of capacitors are available, with different capacitance values tolerances, temperature coefficients and equivalent series resistance. We recommend a minimum of 4.7uF. To ensure good transient response from the power supply system under rapidly changing current load conditions, designers generally use additional output capacitors connected in parallel. Such an arrangement serves to minimize the effects of the parasitic resistance (ESR) and inductance (ESL) that are present in all capacitors. The regulator has been tested stable with capacitor ESR’s in the range of 0.05 to 2 ohms. We have found it best to use the same type of capacitor for both input and output bypass. Adjustable Output Voltage The LX8816 develops a 1.25V reference voltage between the adjust terminal and GND (See Figure 2). By placing a resistor, R2, between these two terminals, a constant current is caused to flow through R1 and down through R2 to set the overall output voltage. Because IADJ is very small and constant when compared with the current through R2, it represents a small error and can usually be ignored. VIN LX8816-04 The LX8816 includes over current protection, when the output load current exceeds typically 1.4A the circuit forces the regulator decrease in output. Thermal Considerations Thermal shutdown protects the integrated circuit from thermal overload caused from a rise in junction temperature during power dissipation. This means of protection is intended for fault protection only and not as a means of current or power limiting during normal application usage. Proper thermal evaluation should be done to ensure that the junction temperature dose not exceed it’s maximum rating. Operating at the maximum TJ of 150°C can impact reliability . Due to variation in individual device electrical characteristics and thermal resistance , the built in thermal overload protection may be activated at power levels slightly above or below the rated dissipation. Also peak output power should be considered for each individual output. Power dissipation for regulator can be calculated using the following equation: PD = (VIN(MAX)-V1) * I1 + (VIN(MAX)-V2 ) * I2 (Note: power dissipation resulting from quiescent (ground) current is negligible) For the S-PAK package, thermal resistance, θTAB-AMB is 25-450C/W depending on mounting technique when mounted on a FR4 copper clad PCB. Junction temperature of the integrated circuit can be calculated using: TJUNCTION = TJUNCTION-TAB RISE _+ TTAB-AMB RISE + TAMB V2 TTAB = PD MAX * θJT V1 An example: Given conditions: TA = 50°C, VIN= 5.0V, V1= 2.5V, I1= 210mA, V2= 3.3V I2= 1A. TTAB-AMB = (PD REG1 + PD REG2) * θPCB TJ-TAB REG1 = (5V-2.5V) * (210mA) * 4.5°C/W = (0.525) * 4.5°C/W = 2.4°C VREF TJ-TAB REG2 R2 = (5V-3.3V) * (1.0A) * 4.5°C/W = (1.7) * 4.5°C/W = 7.7°C TTAB-AMB RISE = ( 0.525W + 1.7W ) * 30°C/W = 66.8°C TJUNCTION = 10.1°C + 66.8°C + 50°C = 126.9°C FIGURE 2 - BASIC ADJUSTABLE REGULATOR Minimum Load Requirement The LX8816 has a minimum load is requirement for proper output regulation. This minimum current is specified at 0mA for the fixed output and 2ma for the adjustable output regulators. It is important to note that although each output of the regulator will produce up to 1A in current, the individual or total power dissipation may limit the useful total current draw. The junction temperature should be calculated for each individual output as well as the combined outputs to insure the maximum junction temperature in not exceeded. Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 APPLICATION IADJ 1µA Copyright © 2000 Rev. 1.2c, 2005-05-18 ; Calculated values: R1 ADJ ⎛ R1 ⎞ V1 = VREF ⎜⎜1 + ⎟ + I ADJ R1 ⎝ R2 ⎠ Current Limit Protection WWW . Microsemi .C OM APPLICATION INFORMATION LX8816 Dual Channel 1A Low Dropout Regulator ® TM P RODUCTION D ATA S HEET APPLICATION INFORMATION Heatsink Consideration The layout must be done with low impedance paths for VIN, V1, V2 and Ground by using sufficiently wide traces to avoid voltage drops and noise pick up. The output capacitors must be placed as close as possible to the voltage regulator output pins. To allow the same voltage reference for all circuits, use a star configuration from the output capacitors to the different loads. The input capacitor should be connected between VIN and ground with short leads. Although it may not be immediately obvious, best load regulation for the adjustable output is obtained when the top of the resistor divider, (R1), is connected as close as possible to the case of the regulator, not to the load. The PCB copper can be used as a heatsink for the surface mounted S-Pak. Using the minimum size as shown in the recommended pad layout limits the usable power to about 1W for ambient temperature of 50°C. Since most applications require greater than 2W there is the need to provide additional heat sinking. This can be accomplished by using additional copper area both on the PCB surface as shown in the possible heat sink layout below, or to an embedded ground plane. Since the die pad (copper tab) is in electrical contact with ground, the designer can use thermal vias on the surface of the PCB taking advantage of the heat-spreading (Cu) layer of an internal ground plane. WWW . Microsemi .C OM Layout Consideration HEAT SINK LAYOUT G ro u n d P la n e B o a rd L e ve l Com ponent T ra ce B Component A Component Trace B VIAS A Ground Plane Inner Power Plane Backside Trace Figure 3 - Heatsink RECOMMENDED MINIMUM PCB FOOTPRINT 9.75mm 11.56mm 9.98mm APPLICATION 8.84mm 7.92mm 8.89mm 3.28mm 1.37mm 0mm .86mm 4.39mm 1.83mm 5.36mm Copyright © 2000 Rev. 1.2c, 2005-05-18 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 LX8816 Dual Channel 1A Low Dropout Regulator ® TM P RODUCTION D ATA S HEET DF WWW . Microsemi .C OM PACKAGE DIMENSIONS 5-Pin Plastic S-Pak A M C L B K H J F G E I D Dim Note: INCHES MIN MAX 0.365 0.375 0.310 0.320 0.070 0.080 0.316 BSC 0.010 BSC 0.025 0.031 0.067 BSC 0.031 0.041 0.256 BSC 0.001 0.005 0.410 0.420 0.01 BSC 0.03 0.05 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. 1.2c, 2005-05-18 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8 MECHANICALS A B C D E F G H I J K L M MILLIMETERS MIN MAX 9.27 9.52 7.87 8.13 1.78 2.03 8.03 BSC 0.25 BSC 0.63 0.79 1.70 BSC 0.79 1.04 6.50 BSC 0.03 0.13 10.41 10.67 0.25 BSC 0.76 1.27 LX8816 TM ® Dual Channel 1A Low Dropout Regulator P RODUCTION D ATA S HEET WWW . Microsemi .C OM NOTES NOTES PRODUCTION DATA – Information contained in this document is proprietary to Microsemi and is current as of publication date. This document may not be modified in any way without the express written consent of Microsemi. Product processing does not necessarily include testing of all parameters. Microsemi reserves the right to change the configuration and performance of the product and to discontinue product at any time. Copyright © 2000 Rev. 1.2c, 2005-05-18 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 9