LX8819 ® TM Dual Channel 1A Low Dropout Regulator D ATA S HEET KEY FEATURES DESCRIPTION Voltages (typically ±1% of its specified value) while the Bipolar output transistor has a low dropout voltage even at full output current (VDO < 1.25V typical @ 1A). Thermal and Short Circuit Current Protection are integrated on-chip and operate independently for each of the regulator output. The LX8819 regulator is stable with a low-value output capacitor (typically 2.2µF on the outputs) allowing the designers flexibility in external component selection. Microsemi’s S-PAK and D-PAK power packages enable maximum power dissipation and ease of assembly using surface mount technology. IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com Two Independent Regulated Outputs Accurate Output Voltages Typical Dropout of 1.25V 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 3.5V to 10V Loop Stability Independent of Output Capacitor Type WWW . Microsemi .C OM The LX8819 is a dual channel positive-voltage linear regulator. This dual regulator has one fixed output coupled with an adjustable output. Each channel features a low dropout and a high accuracy. The LX8819 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 while directing quiescent current to the load. The LX8819 features on-chip trimming of the internal voltage reference enabling precise output APPLICATIONS 5V to 3.3V / ADJ Regulators Hard Disk Drives, CD-ROMs ADSL and Cable Modems Battery Charging Circuits Instrumentation PC Peripherals PRODUCT HIGHLIGHT V IN = 5V VIN VOUT2 10 F 22 F VOUT2 = 3.3V/2.5V @ 1A 8819 GND VOUT1 = 1.8V @ 1A VOUT1 10 F ADJ 221 499 TJ (°C) 0 to 125 Output V1 Output V2 (Pin 5) (Pin 4) Adj. Adj. 3.3 2.5 DF Plastic S-PAK 5 pin DT LX8819 PACKAGE ORDER INFO Plastic D-PAK 5-Pin RoHS Compliant Transition DC: 0515 LX8819-33CDF LX8819-25CDF LX8819-33CDT LX8819-25CDT Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX8819-33CDT-TR) Copyright © 2003 Revision 1.0a, 4/29/2005 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 LX8819 ® TM Dual Channel 1A Low Dropout Regulator D ATA S HEET ABSOLUTE MAXIMUM RATINGS PACKAGE PIN OUT 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. WWW . Microsemi .C OM Input Voltage (VIN)......................................................................................13.5V Load Current (Internally Limited) .....................................................................1A Power Dissipation ......................................................................Internally Limited Short-Circuit Protection .......................................................................... Indefinite Operating Temperature Range ......................................................... 0°C to 150°C Maximum Operating Junction Temperature ................................................ 150°C Storage Temperature Range...........................................................-65°C to 150°C Lead Temperature (Soldering 180 seconds) ................................................ 235°C RoHS Peak Package Solder Reflow Temperature (40 second maximum exposure) ..................................................... 260°C (+0, -5) DF PACKAGE (Top View) RoHS 100% Matte Tin Lead Finish TAB is GND VOUT2 VOUT1 GND ADJ VIN THERMAL DATA DF Plastic S-PAK 5-Pin THERMAL RESISTANCE-JUNCTION TO CASE, θJC 5°C/W 30°C/W THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA DT DT PACKAGE (Top View) Plastic D-PAK 5-Pin THERMAL RESISTANCE-JUNCTION TO CASE, θJC 6°C/W 32°C/W THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 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 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. Adjustable regulator feedback input – The output voltage can be set by two external resistors with the following relationship: ⎛ VOUT1 = VREF ⋅ ⎜⎜ 1 + ADJ ⎝ R1 ⎞ ⎟ + I ADJ ⋅ R1 R 2 ⎟⎠ 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. VOUT1 Adjustable regulator output (Regulator #1) – It is recommended to bypass to GND with at least 2.2µF. 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. VOUT2 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 © 2003 Revision 1.0a, 4/29/2005 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 PACKAGE DATA where R1 is the resistor connected between VOUT1 and ADJ, and R2 is the resistor connected between ADJ and GND. LX8819 ® TM Dual Channel 1A Low Dropout Regulator D ATA S HEET RECOMMENDED OPERATING CONDITIONS Symbol Input Voltage - 3.3V Input Voltage - 2.5V < 200mA Load Output Voltage (Adjustable) Load Current (Each Output)1 Input Capacitor (VIN to GND) Output Capacitor (VOUTx to GND)2 Note VIN VOUT IOUT CIN COUT Min 4.5 3.5 LX8819 Typ 0 2.2 1.0 Max 10 10 5 1000 20 10 Units V V V mA µF µF 1: Care should be taken so as to not exceed the thermal dissipation capability of the package 2: 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. WWW . Microsemi .C OM Parameter ELECTRICAL CHARACTERISTICS Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C ≤ TA ≤ 125°C except where otherwise noted and with the following test conditions: VIN = 5V, IOUT = 10mA, CIN= 10µF (Tantalum), COUT = 4.7µF (Tant.), and TJ = TA using low duty cycling methods. Parameter ` Min LX8819 Typ Max Units VREF ∆VREF(VIN) ∆VREF(IOUT) ∆V IOUT (MAX) IL IADJ 5mA < IOUT1 < 1A, 4.75V < VIN < 5.5V 3.75V < VIN < 5.5V, IOUT1 = 5mA 5mA < IOUT1 < 1A, VIN = 4.75V 1.225 IOUT1 = 1A, ∆V1 = -1% 1.0 Note 3 1.25 1.5 0.18 1.3 1.4 2 -0.12 1.275 V 6 mV 0.36 %VOUT 1.46 V A 3 mA -1 µA 3.30 2.5 6 6 1.25 3.383 2.562 8 12 1.41 1.25 FIXED OUTPUT (OUTPUT 2) Output Voltage – LX8819-33 Output Voltage – LX8819-25 Line Regulation Load Regulation Dropout Voltage Current Limit Minimum Load Current ` Test Conditions ADJUSTABLE OUTPUT (VOUT1) Reference Voltage Line Regulation Load Regulation Dropout Voltage Current Limit Minimum Load Current Adjust Pin Bias Current ` Symbol 5mA < IOUT2 < 1A, 4.75V < VIN < 5.5V 5mA < IOUT2 < 0.2A, 3.75V < VIN < 5.5V ∆VOUT(VIN) 4.75V < VIN < 5.5V, IOUT2 = 5mA ∆VOUT(IOUT) 5mA < IOUT2 < 1A, VIN = 4.75V IOUT2 = 1A, ∆V2 = -1% ∆V IOUT2 = 0.2A, ∆V2 = -1% IOUT (MAX) IOUT VOUT 3.217 2.437 1.0 1.4 0 V mV mV V V A mA ENTIRE REGULATOR IQ VIN Under Voltage Lockout Threshold VOUT Rise Time for VIN Switched On Ripple Rejection RMS Output Noise Thermal Shutdown Note UVLO VIN < 5.5V, IOUT1 = 5mA, IOUT2 = 5mA VIN < 5.5V, IOUT1 = 1A, IOUT2 = 1A -3.3 Voltage Rising -2.5 Voltage Rising @ 25 °C VOUT(tR) PSRR VOUT (RMS) TJSD f=120Hz, VIN = 5V 10Hz < f < 10kHz 2.6 3.5 2.5 2.5 4.2 5 4.5 3.6 80 300 60 150 75 0.003 165 mA V µs dB %VOUT °C 3: Minimum load current is defined as the amount of output current required to maintain regulation. , The external resistor divider current can be included in this requirement. Copyright © 2003 Revision 1.0a, 4/29/2005 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 PACKAGE DATA Quiescent Current LX8819 ® TM Dual Channel 1A Low Dropout Regulator D ATA S HEET SIMPLIFIED BLOCK DIAGRAM WWW . Microsemi .C OM VIN 1 V 5 C1 10 F OUT2 (Fi x e d ) BIAS C2 10 F + - VIN 1.25V VREF V 4 OUT1 (Ad j u s ta b l e ) R1 GND C3 10 F 2 + - R2 3 ⎛ R ⎞ VOUT1 = VREF ⋅ ⎜⎜1 + 1 ⎟⎟ + IADJ ⋅ R1 ⎝ R2 ⎠ No te : Ap p l i c a ti o n c i rc u i t a b o v e u s i n g c e ra m i c c a p a c .i to rs R1 a n d R2 u s e d wi th a d j u s ta b l e v e rs i o n o n l y . Figure 1 – Simplified Block Diagram ELECTRICALS Copyright © 2003 Revision 1.0a, 4/29/2005 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 4 LX8819 TM ® Dual Channel 1A Low Dropout Regulator D ATA S HEET APPLICATION INFORMATION INPUT CAPACITOR To improve load transient response and noise rejection an input bypass capacitor of at least 2.2µF is required. Generally it is recommended that a 20µF ceramic/tantalum or 22µF electrolytic capacitor be used. OUTPUT CAPACITOR The LX8819 regulator requires output capacitors connected between each voltage output and ground to stabilize the internal control loop. Many types of capacitors, with different capacitance values, tolerances, temperature coefficients, and equivalent series resistance are available for use with the LX8819. It is recommended that a minimum of 4.7µF be used at each voltage output. 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 50mΩ to 2Ω. It is generally best to use the same type of capacitors for both input and output bypassing. MINIMUM LOAD REQUIREMENT The LX8819 has a minimum load requirement for proper output regulation. This minimum current is specified at 0mA for the fixed output and 2mA for the adjustable output regulator. Copyright © 2003 Revision 1.0a, 4/29/2005 VOUT2 LX8819 VOUT1 R1 ADJ IADJ 1 A ⎛ R ⎞ VOUT1 = VREF ⋅ ⎜⎜1 + 1 ⎟⎟ + IADJ ⋅ R 1 ⎝ R2 ⎠ VREF R2 Figure 2 – Basic Regulator Circuit TEMPERATURE PROTECTION The thermal protection shuts the LX8819 down when the junction temperature exceeds 140°C. Each output has independent thermal shutdown capability. Exposure to absolute maximum rated conditions for extended periods may affect device reliability (See Thermal Considerations below). CURRENT LIMIT PROTECTION The LX8819 includes over current protection. When the output load current exceeds 1.4A (typical) the current limit protection circuit forces the regulator to decrease the output current in order to maintain safe levels. THERMAL CONSIDERATIONS Thermal shutdown protection circuitry protects the integrated circuit from thermal overload caused from a rise in junction temperature during excessive power dissipation conditions. 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 (TJ) does not exceed its maximum rating. Continuous operation 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. Total power dissipation for the regulator can be calculated using the following equation: PD = (VIN(MAX) − VOUT1 ) ⋅ IOUT1 + (VIN(MAX) − VOUT2 ) ⋅ IOUT2 (Note: Power dissipation resulting from quiescent (ground) current is negligible and ignored) Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 APPLICATIONS ADJUSTABLE OUTPUT VOLTAGE The LX8819 develops a 1.25V reference voltage between the adjust terminal and ground (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 WWW . Microsemi .C OM DESCRIPTION The LX8819 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 a combination of 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. LX8819 ® TM Dual Channel 1A Low Dropout Regulator D ATA S HEET APPLICATION INFORMATION THERMAL CALCULATION EXAMPLE Given the following application parameters: TA = 50°C VIN(MAX) = 5V + 5% VOUT1 = 1.5V VOUT2 = 2.5V IOUT1(MAX) = IOUT2(MAX) = 500mA The maximum junction temperature of the LX8819 can be calculated using the following equation: TJ = TA + (PD(REG1) + PREG2 ) ⋅ θJA with: PD(REG1) = (VIN(MAX) − VOUT1 ) ⋅ IOUT1 and PD(REG2 ) = (V IN(MAX ) − VOUT 2 ) ⋅ IOUT 2 Substituting the known values yields a maximum junction temperature of: PD(REG1) = (5.25V − 1.5V ) ⋅ 0.5A = 1.75W LAYOUT CONSIDERATION The layout must be done with low impedance paths for VIN, VOUT1, VOUT2 and GND 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. The input capacitor should be connected between VIN and the ground plane with short leads. Although it may not be immediately obvious, best load regulation for the adjustable output is obtained when the top of the voltage feedback 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 package. Using the minimum size as shown in the recommended pad layout (Figure 3), limits the usable power to about 1W for an ambient temperature of 50°C. Since most applications require greater than 2W there is the need to provide additional heatsinking. 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. PD(REG2) = (5.25V − 2.5V ) ⋅ 0.5A = 1.375W TJ = 50°C + (1.75W + 1.375W ) ⋅ 30 Ground Plane Board Level TJ = TA + (PD(REG1) + PD(REG2) ) ⋅ θJA WWW . Microsemi .C OM Using the calculated total power dissipation, the maximum junction temperature can be calculated using the given temperature coefficients (See Thermal Data) for the selected package. Component Trace A B °C W TJ = 140°C Figure 3 – Recommended Layout APPLICATIONS This value is within the safe operating range of the device under worst case conditions 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 that maximum junction temperature in not exceeded. Component Component Trace B VIAS A Ground Plane Inner Power Plane Backside Trace Figure 4 – Ground Plane Heatsink Copyright © 2003 Revision 1.0a, 4/29/2005 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 LX8819 ® TM Dual Channel 1A Low Dropout Regulator D ATA S HEET TRANSIENT RESPONSE-CERAMIC CAP TRANSIENT RESPONSE-TANT CAP WWW . Microsemi .C OM VIN = 5V VOUT1 = 1.5V 180 50mV / DIV Load 50mV / DIV V1 = 1.5V 50mV / DIV 50mV / DIV V2 = 3.3V 1A Step Load 50mV / DIV VOUT2 = 3.3V 1A Step Load 1A 1A 1mA 0mA CIN = 20µF Ceramic (ESR= 45mΩ) COUT(VOUT1) = COUT(VOUT2) = 10µF Ceramic (ESR= 75mΩ) CIN = 22µF Tantalum (ESR= 232mΩ) COUT(VOUT1) = COUT(VOUT2) = 10µF Tantalum (ESR= 198mΩ) TURN ON CHARACTERISTICS CURRENT LIMIT 500mV / DIV 20mV(A C) / DIV VOUT2 = 3.3V 500mV / DIV VOUT1 = 1.5V 1.2A VOUT2 = 3.3V VIN = 5V 1V / DIV Rising Load On V2 VOUT1 = 1.5V 500m V/ DIV 200mA / DIV RIPPLE REJECTION 45 35 30 25 CHARTS RIPPLE REJECTION (DB) 40 20 15 10 5 0 100 1000 10000 100000 FREQUENCY (HZ) VIN = 5V, CIN = 22µF, COUT1,2 = 10µF, VOUT2=3.3V, IOUT2=1A Copyright © 2003 Revision 1.0a, 4/29/2005 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 LX8819 ® TM Dual Channel 1A Low Dropout Regulator D ATA S HEET PACKAGE DIMENSIONS 5-Pin S-PAK A M C Dim A B C D E F G H I J K L MILLIMETERS MIN MAX 9.27 9.52 7.87 8.13 1.78 2.03 2.80 3.10 1.50 1.75 0.63 0.79 1.70 BSC 0.79 1.04 6.50 BSC 0.03 0.13 10.41 10.67 0.76 1.27 INCHES MIN MAX 0.365 0.375 0.310 0.320 0.070 0.080 0.110 0.122 0.059 0.069 0.025 0.031 0.067 BSC 0.031 0.041 0.256 BSC 0.001 0.005 0.410 0.420 0.030 0.050 Dim A B C D E F G H I J K L M N MILLIMETERS MIN MAX 5.96 6.22 6.47 6.73 5.00 5.22 2.18 2.38 0.45 0.55 0.63 0.78 1.27 BSC 1.08 1.29 1.01 1.11 0.76 0.86 9.70 10.08 1.52 1.62 0.03 0.13 1.27 REF INCHES MIN MAX 0.234 0.244 0.254 0.264 0.196 0.205 0.085 0.093 0.017 0.021 0.024 0.030 0.050 BSC 0.042 0.050 0.039 0.043 0.029 0.033 0.381 0.396 0.059 0.063 0.001 0.005 .05 REF L B K H J F G E I D DT WWW . Microsemi .C OM DF 5-Pin TO-252 (D-PAK) B C D J I A K L M H G E F MECHANICALS N 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. Note: Copyright © 2003 Revision 1.0a, 4/29/2005 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8 LX8819 TM ® Dual Channel 1A Low Dropout Regulator D ATA S HEET NOTES WWW . Microsemi .C OM 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 © 2003 Revision 1.0a, 4/29/2005 Microsemi Integrated Products Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 9