SPX1086 1.5A Low Dropout Voltage Regulator Adjustable & Fixed Output, Fast Response FEATURES APPLICATIONS • Adjustable Output Down To 1.2V • Fixed Output Voltages 1.5, 2.5, 3.3, 5.0V • Output Current of 1.5A • Low Dropout Voltage 1.1V Typ. • Extremely Tight Load And Line Regulation • Current & Thermal Limiting • Standard 3-Terminal Low Cost TO-220, TO-263 & TO-252 • Similar To Industry Standard LT1086/LT1586 • Powering VGA & Sound Card • Power PC Supplies • SMPS Post-Regulator • High Efficiency “Green” Computer Systems • High Efficiency Linear Power Supplies • Portable Instrumentation • Constant Current Regulators • Adjustable Power Supplies • Battery charger PRODUCT DESCRIPTION The SPX1086 is a low power 1.5A adjustable and fixed voltage regulators that are very easy to use. It requires only 2 external resistors to set the output voltage for adjustable version. The SPX1086 is designed for low voltage applications that offer lower dropout voltage and faster transient response. This device is an excellent choice for use in powering low voltage microprocessor that require a lower dropout, faster transient response to regulate from +2.5V to 3.8V supplies and as a post regulator for switching supplies applications. The SPX1086 features low dropout of a maximum 1.2 volts. The SPX1086 offers full protection against over-current faults, reversed input polarity, reversed load insertion, and positive and negative transient voltage. On-Chip trimming adjusts the reference voltage to 1%. The IQ of this device flows into load which increases efficiency. The SPX1086 are offered in a 3-pin TO-220, TO-263 & TO-252 packages compatible with other 3 terminal regulators. For a 3A low dropout regulator refer to the SPX1587 data sheet. PIN CONNECTIONS TO-263-3 (T) SPX1086 1 2 TO-252 (R) TO-220-3 (U) SPX1086 3 1 2 3 SPX1086 1 2 3 ADJ/GND VOUT VIN ADJ/GND VOUT VIN Top View Front View ADJ/GND VOUT VIN Front View Rev. 11/2/00 SPX1086 ABSOLUTE MAXIMUM RATINGS Lead Temp. (Soldering, 10 Seconds) .............................. 300°C Storage Temperature Range ............................ -65° to +150°C Operating Junction Temperature Range ...................... SPX1086 Control Section.......................... -45°C +125°C SPX1086 Power Transistor.........................-45°C +150°C Input Voltage........................................................ 30V Input to Output Voltage Differential .................... 30V ELECTRICAL CHARACTERISTICS (NOTE 1) at IOUT = 10mA, Ta=25°C, unless otherwise specified. SPX1086A PARAMETER CONDITIONS Typ Min Max SPX1086 Min Max Units 1.5V Version Output Voltage (Note 2) SPX1086-1.5V, 0 ≤IOUT≤1.5A, 2.75V≤VIN ≤29V 1.5 1.5 1.485 1.470 1.515 1.530 1.470 1.455 1.530 1.545 V 2.5V Version Output Voltage (Note 2) SPX1086-2.5V,0 ≤IOUT≤1.5A, 4.0V≤VIN ≤29V 2.5 2.5 2.475 2.450 2.525 2.550 2.450 2.425 2.550 2.575 V 3.3V Version Output Voltage (Note 2) SPX1086-3.3V, 0 ≤IOUT≤1.5A, 4.75V≤VIN ≤29V 3.3 3.3 3.270 3.240 3.330 3.360 3.230 3.201 3.370 3.399 V 5.0V Version Output Voltage (Note 2) SPX1086-5.0V, 0 ≤IOUT≤1.5A, 6.5V≤VIN ≤29V 5.0 5.0 4.95 4.90 5.05 5.10 4.900 4.850 5.100 5.150 V VIN≤ 7V, P≤ PMAX 1.5V≤ (VIN -VOUT)≤5.75V, 10mA≤IOUT≤1.5A 1.5V≤ (VIN -VOUT)≤5.75V 1.250 5 1.225 1.270 10 1.225 1.270 10 mA 2.75V≤VIN ≤29V, IOUT=10mA, TJ=25°C (Note 3) 0.005 0.2 0.2 % VIN ≤29V, IOUT=0mA, TJ=25°C (Note 2) 0.005 0.2 0.2 % 10mA≤IOUT ≤1.5A, (VIN-VOUT)=3V, TJ=25°C (Note 3) 0.05 0.3 0.3 % 0≤IOUT ≤1.5A, VIN=7V, TJ=25°C (Note 2) 0.05 0.3 0.3 % Dropout Voltage ∆VREF=1% 1.1 1.2 1.2 V Current Limit IOUT(MAX) Long Term Stability VIN=7V 1.4V≤ (VIN- VOUT) (Note3) TA=125°C, 1000 Hrs. 0.3 (Note 2) 1 1 % Thermal Regulation (∆VOUT(Pwr)) Temperature Stability (∆VOUT(T)) Output Noise, RMS Thermal Resistance TA=25°C, 20 ms pulse 0.01 0.020 0.020 %/W All Voltage Options Reference Voltage (VREF) Min. Load Current (Note 3) Line Regulation (∆VREF(VIN)) Load Regulation(∆VREF(IOUT)) IOUT =1.5A (Note 3) IOUT≤ 1.5A (Note 2) V A 2.5 1.7 1.7 0.25 10Hz to 10khz TO-220 DD Package % 0.003 TA=25°C Junction to Tab Junction to Ambient Junction to Tab Junction to Ambient 3.0 60 3.0 60 % VO 3.0 60 3.0 60 3.0 60 3.0 60 °C/W °C/W The Bold specifications apply to the full operating temperature range. Note 1: Changes in output voltage due to heating effects are covered under the specification for thermal regulation. Note 2: Fixed Version Only Note 3: Adjustable Version Only Rev. 11/2/00 SPX1086 APPLICATION HINTS The SPX1086 incorporates protection against over-current faults, reversed load insertion, over temperature operation, and positive and negative transient voltage. However, the use of an output capacitor is required in order to insure the stability and the performances. Reducing parasitic resistance and inductance One solution to minimize parasitic resistance and inductance is to connect in parallel capacitors. This arrangement will improve the transient response of the power supply if your system requires rapidly changing current load condition. Stability The output capacitor is part of the regulator’s frequency compensation system. Either a 220µF aluminum electrolytic capacitor or a 47µF solid tantalum capacitor between the output terminal and ground guarantees stable operation for all operating conditions. However, in order to minimize overshoot and undershoot, and therefore optimize the design, please refer to the section ‘Ripple Rejection’. Thermal Consideration Although the SPX1086 offers some limiting circuitry for overload conditions, it is necessary not to exceed the maximum junction temperature, and therefore to be careful about thermal resistance. The heat flow will follow the lowest resistance path, which is the Junction-to-case thermal resistance. In order to insure the best thermal flow of the component, a proper mounting is required. Note that the case of the device is electrically connected to the output. In case the case has to be electrically isolated, a thermally conductive spacer can be used. However do not forget to consider its contribution to thermal resistance. Ripple Rejection Ripple rejection can be improved by adding a capacitor between the ADJ pin and ground. When ADJ pin bypassing is used, the value of the output capacitor required increases to its maximum (220µF for an aluminum electrolytic capacitor, or 47µF for a solid tantalum capacitor). If the ADJ pin is not bypass, the value of the output capacitor can be lowered to 100µF for an electrolytic aluminum capacitor or 15µF for a solid tantalum capacitor. However the value of the ADJ-bypass capacitor should be chosen with respect to the following equation: C = 1 / ( 6.28 * FR * R1 ) Where C = value of the capacitor in Farads (select an equal or larger standard value), FR = ripple frequency in Hz, R1 = value of resistor R1 in Ohms. Assuming: VIN = 10V, VOUT = 5V, IOUT = 1.5A, TA = 50°C/W, θHeatsink Case= 6°C/W, θHeatsink Case = 0.5°C/W, θ JC = 3°C/W Power dissipation under this condition PD = (VIN – VOUT) * IOUT = 7.5W Junction Temperature TJ = TA + PD * (θ Case – HS + θ HS + θ JC) For the Control Sections TJ = 50 + 7.5*(0.5+6=3) = 121.25°C 121.25°C < TJ(max) for the Control & Power Sections. In both case reliable operation is insured by adequate junction temperature. If an ADJ-bypass capacitor is use, the amplitude of the output ripple will be independent of the output voltage. If an ADJbypass capacitor is not used, the output ripple will be proportional to the ratio of the output voltage to the reference voltage: M = VOUT / VREF Where M = multiplier for the ripple seen when the ADJ pin is optimally bypassed. VREF = Reference Voltage Rev. 11/2/00 SPX1086 Basic Adjustable Regulator V IN VOUT SPX1086 VREF I R1 ADJ 50µA R2 VOUT = VREF * ( 1 + R2/R1) + IADJ * R2 Fig.2 Basic Adjustable Regulator Output Voltage Consider Figure 2. The resistance R1 generates a constant current flow, normally the specified load current of 10mA. This current will go through the resistance R2 to set the overall output voltage. The current IADJ is very small and constant. Therefore its contribution to the overall output voltage is very small and can generally be ignored Load Regulation Parasitic line resistance can degrade load regulation. In order not to affect the behavior of the regulator, it is best to connect directly the R1 resistance from the resistor divider to the case, and not to the load. For the same reason, it is best to connect the resistor R2 to the Negative side of the load. VIN R P Parasitic Line Resistance SPX1086 Connect R 1 to Case of Regulator R1 RL R2 Connect R 2 to Load Fig.3 Basic Adjustable Regulator Rev. 11/2/00 SPX1086 TYPICAL APPLICATIONS VIN IN SPX1086 VIN OUT IN Fig. 5 Typical Adjustable Regulator Fig. 4 1.5A Current output Regulator (Note A) 5V + 10µF SPX1086 *C 1 improves ripple rejection. Xc should be ~ R 1 at ripple frequency. VOUT OUT ADJ R2 VOUT = VREF (1 + R2 ) + IADJ R2 R1 LOAD IN C2 R1 ADJ R1 ADJ VOUT OUT C1 C1 VIN SPX1086 VIN + 150µF + C1 10µF* SPX1086 TTL Input 5V OUT 121Ω 1% ADJ R1 121Ω 1% R2 365Ω 1% IN (Note A) + 10µF 100µF 1k 2N3904 1k 365Ω 1% Note A: VIN(MIN) = (Intended VOUT) + (VDROPOUT (MAX)) Note A: VIN(MIN)= (Intended VOUT) + (VDROPOUT (MAX)) Fig. 6 Improving Ripple Rejection Fig.7 5V Regulator with Shutdown Rev. 11/2/00 SPX1086 TYPICAL CHARACTERISTICS Rev. 11/2/00 SPX1086 ORDERING INFORMATION Ordering No. Precision Output Voltage SPX1086U SPX1086U-1.5 SPX1086U-2.5 SPX1086U-3.3 SPX1086U-5.0 SPX1086AU SPX1086AU-1.5 SPX1086AU-2.5 SPX1086AU-3.3 SPX1086AU-5.0 SPX1086T SPX1086T-1.5 SPX1086T-2.5 SPX1086T-3.3 SPX1086T-5.0 SPX1086AT SPX1086AT-1.5 SPX1086AT-2.5 SPX1086AT-3.3 SPX1086AT-5.0 SPX1086R SPX1086R-1.5 SPX1086R-2.5 SPX1086R-3.3 SPX1086R-5.0 SPX1086AR SPX1086AR-1.5 SPX1086AR-2.5 SPX1086AR-3.3 SPX1086AR-5.0 2% 2% 2% 2% 2% 1% 1% 1% 1% 1% 2% 2% 2% 2% 2% 1% 1% 1% 1% 1% 2% 2% 2% 2% 2% 1% 1% 1% 1% 1% Adj 1.5V 2.5V 3.0V 5.0V Adj 1.5V 2.5V 3.0V 5.0V Adj 1.5V 2.5V 3.0V 5.0V Adj 1.5V 2.5V 3.0V 5.0V Adj 1.5V 2.5V 3.0V 5.0V Adj 1.5V 2.5V 3.0V 5.0V Packages 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-220 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-263 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 3 Lead TO-252 Corporation SIGNAL PROCESSING EXCELLENCE Sipex Corporation Headquarters and Main Offices: 22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: [email protected] 233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 935-7600 FAX: (408) 934-7500 Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others. Rev. 11/2/00