Bay Linear Inspire the Linear Power B1587 4.0A Low Dropout Voltage Regulator Adjustable & Fix Output Description Features The Bay Linear B1587 is Monolithic low power 4.0A Adjustable and fixed NPN voltage regulator that are easy to use with minimum external components. It is suitable for applications requiring a well-regulated positive output voltage with low input-output differential voltage requirements and output voltage 1.5V, 2.5V, 3.0V, 3.3V, or 5V. The B1587 Outstanding features include full power usage up to 4.0Amp of load current internal current limiting and thermal shutdown. Other fixed versions are also available consult with factory. The B1587 is offer in a new LPDD (Low Profile TO263) package from 4.47 mm (DD) thickness down to only 1.27 mm (LPDD) total thickness. The B1587 is offered in a 3-pin TO-220, TO-263 & TO-252 packages compatible with other 3 terminal regulators. For 5A Low dropout Regulator refer to the B1585 data sheet. • • • • • • • Adjustable Output Down to 1.2V Fixed Output Voltages 2.5V, 3.0V 3.3V, and 5.0V Output Current of 4.0A Low Dropout Voltage 1.1V Typ. Current & Thermal Limiting Standard 3-Terminal Low Cost TO-220, D2, D Packages Similar to industry Standard LT1085/LT1587/LT1585 Applications • • • • • • 3.3V to 2.5V for Pentium Processor SMPS Post Regulator High Efficiency “Green” Computer Systems High Efficiency Linear Power Supplies 5V to 3.XXV for Pentium Processor Battery Charger Ordering Information Pin Connection Devices B1587T B1587S B1587D B1587J TO-263-3 (S) ( Package Temp. TO-220 TO-263 TO-252 LPDD 0 °C to 70 °C 0 °C to 70 °C 0 °C to 70 °C 0 °C to 70 °C TO-252 (D) Bay Linear 1 2 3 1 ADJ/ GND Top View Bay Linear, Inc 2 3 V OU VIN T Front View LPDD (J) 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B1587 Absolute Maximum Rating Parameter Maximum Input Voltage Power Dissipation Thermal Resistance Junction to Case Thermal Resistance Junction to Ambient Operating Junction Temperature Range Control Section Power Transistor Storage Temperature Range Lead Temperature (Soldering 10 Sec.) Symbol Value Unit VIN PO θJC θJA 7 Internally Limited 3 50 V W °C/W °C TJ TSTG TLEAD 0 to 125 0 to 150 -65 to 150 260 Electrical Characteristics (VIN = 4.75V to 5.25V; IO = 10mA to 4.0Amp, unless otherwise specified) Parameter Symbol Conditions Output Voltage VO 0<IOUT<4A, 3.3V<VIN<7V, T= 25 °C 0<IOUT<4A, 3.3V<VIN<7V, Over Temp. 0<IOUT<4A, 4.0V<VIN<7V, T= 25 °C 0<IOUT<4A, 4.0V<VIN<7V, Over Temp. 0<IOUT<4A, 4.5V<VIN<7V, T= 25 °C 0<IOUT<4A, 4.5V<VIN<7V, Over Temp. 0<IOUT<4A, 4.8V<VIN<7V, T= 25 °C 0<IOUT<4A, 4.8V<VIN<7V, Over Temp. 0<IOUT<4A, 6.5V<VIN<7V, T= 25 °C 0<IOUT<4A, 6.5V<VIN<7V, Over Temp. VIN<7V, 1.5V<VIN<5.75, 10Ma<Iout<4Amp MIN TYP MAX UNIT 1.485 1.475 2.475 2.460 2.970 2.950 3.267 3.247 4.950 4.920 1.238 1.230 1.5 V Reference Voltage Vref Line Regulation (1) REG (line) IO = 10mA, VIN =5V, T= 25 °C 0.04 1.515 1.525 2.525 2.540 3.030 3.050 3.333 3.353 5.050 5.080 1.262 1.270 0.2 Load Regulation (1) REG (LOAD) IO = 10mA, VIN =5V, T= 25 °C 0.08 0.40 T= 25 °C, IOUT=3A T= 25 °C, IOUT=4A 1.0 1.1 5 5 5 0.5 0.003 75 3.0 60 3.0 60 1.1 1.3 10 Dropout Voltage VD Minimum load Current Current Limit Ground Pin Current Temperature Stability Thermal Regulation Ripple Rejection Thermal Resistance Imin IS IQ TS RA - (Vin-Vout)=3V VIN =5V IO = 10mA, VIN =5V T= 25 °C, 30ms pulse T= 25 °C, VIN =5V TO-220 Junction to Tab Junction to Ambient DD Package Junction to Tab Junction to Ambient 3 60 2.5 3.0 3.3 5.0 1.250 10 3.0 60 3.0 60 V % V mA A mA % %/W dB °C/W Note: Output Switch tests are performed under pulsed conditions to minimize power dissipation Bay Linear, Inc 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B1587 APPLICATION HINTS The Bay Linear B1587 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. 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’. 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. If an ADJ-bypass capacitor is use, the amplitude of the output ripple will be independent of the output voltage. If an ADJ-bypass 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. 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. Thermal Consideration Although the B1587 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. Assuming: VIN = 10V, VOUT = 5V, IOUT = 4A, TA = 90°C, θCASE= 1°C/W (no external heat sink, no wind) Power dissipation under these conditions PD = (VIN – VOUT) * IOUT = 15W Junction Temperature TJ = TA + PD * (θCASE+ θJC) For the Control Section TJ = 90°C + 15W*(1°C/W + 0.6°C/W) = 114°C 114°C < TJUNCTION MAX for the control section. For the Power Section TJ = 90°C + 15W*(1°C/W + 1.6°C/W) = 129°C 129°C < TJUNCTION MAX for the power transistor. In both case reliable operation is insured by adequate junction temperature. VREF = Reference Voltage Bay Linear, Inc 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B1587 Basic Adjustable Regulator BAY B1587 V OU T V OU T V REF I R1 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 ADJ 50µA R2 VOUT = V REF * ( 1 + R2/R1) + IADJ * R2 Fig.2 Basic Adjustable Regulator 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. Output Voltage Output Voltage Output Voltage VOUT Consider Figure 2. The resistance R1 generates a constant current flow, normally the specified load current of 10mA BAY B1587 RP Parasitic Line Resistance Connect R1 to Case of Regulator R1 RL R2 Connect R2 to Load Fig.3 Basic Adjustable Regulator Bay Linear, Inc 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B1587 VIN BAY B1587 IN OUT VIN C1 BAY B1587 IN ADJ VOUT OUT C2 C1 R1 ADJ R1 LOAD R2 VOUT = VREF (1 + R2) + IADJ R2 R1 Fig 5. Typical Adjustable Regulator Fig.4 4A Current Output Regulator (Note A) VIN IN + 10µF BAY B1587 5V OUT VOUT VIN ADJ BAY B1587 R1 R2 + 121Ω 1% + + 10µF 150µF 365Ω 1% 5V OUT ADJ 121Ω 1% *C1 improves ripple rejection. XC should be ~ R1 at ripple frequency. IN (Note A) C1 10µF* TTL Output 100µF 1k 2N3904 1k 365Ω 1% Note A: VIN (MIN) = ( Intended VOUT ) + ( V DROPOUT (MAX) ) Note A: VIN (MIN) = ( Intended VOUT ) + ( V DROPOUT (MAX) ) Fig. 6 Bay Linear, Inc Improving Ripple Rejection Fig.7 5V Regulator with Shutdown 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B1587 TYPICAL CHARACTERISTICS Bay Linear, Inc 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com B1587 -B- -A- E b2 A A1 C1 L2 A 4 SEATING PLANE D 1 2 L3 L1 3 H L -C- b .010 M A M c b1 3 PLCS C A 8 e e1 NOTES D1 1. 2. 3. 4. Refer To Applicable Symbol List. Dimensions And Tolerancing Per Ansi Y14.5m - 1982. Lead Dimension Uncontrolled in 3L. Tab Contour Optional Within Dim. 2b& L2 And E1 & D1 5. D1 & E1 Establishes A Minimum Mounting Surface for Terminal 4. 6. L is the Termal Length for Soldering. 7. Controlling Dimension: Inch 8. 2 Mils Suggested For Postive Contact At Mounting. E1 TERM 4 BACK VIEW A-A Bay Linear, Inc S Y M B O L MIN MAX MIN MAX A 0.086 0.094 2.184 2.3876 A1 0.035 0.045 0.889 1.143 MM INCHES b 0.025 0.035 0.635 0.889 b1 0.300 0.045 7.620 1.143 b2 0.205 0.215 5.207 5.461 c 0.018 0.023 0.457 0.5842 c1 0.018 0.023 0.457 0.5842 D 0.235 0.245 5.969 6.223 D1 0.170 - 4.318 - E 0.250 0.265 6.350 6.731 E1 0.170 - 4.318 - e 0.098 e1 0.180 N O T E 4 4,5 4,5 2.489 4.572 H 0.370 0.410 9.398 10.414 L 0.020 - 0.508 - L1 0.025 0.040 0.635 1.016 L2 0.035 0.050 0.889 1.270 4 L3 0.045 0.060 1.143 1.524 3 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 6 www.baylinear.com B1587 0.405 (10.287 ± ± 0.005 0.127) 0.176 ± 0.005 (4.470 0.050 ± 0.002 (1.270 0.055 (1.397) 0.356 (9.042 ± ± ± ± 0.127) 0.051) 0.005 0.127) 0.600 +- 0.025 (15.24 ± 0.635) 0.100 ± 0.010 (2.540 ± 0.254) 0.103 BSC (2.616) 0.050 (1.270) 0.032 +- 0.001 (0.813 +- 0.025) 0.015 (0.381 ++- 0.003 0.074) 0° 8° Advance Information- These data sheets contain descriptions of products that are in development. The specifications are based on the engineering calculations, computer simulations and/ or initial prototype evaluation. Preliminary Information- These data sheets contain minimum and maximum specifications that are based on the initial device characterizations. These limits are subject to change upon the completion of the full characterization over the specified temperature and supply voltage ranges. The application circuit examples are only to explain the representative applications of the devices and are not intended to guarantee any circuit design or permit any industrial property right to other rights to execute. Bay Linear takes no responsibility for any problems related to any industrial property right resulting from the use of the contents shown in the data book. Typical parameters can and do vary in different applications. Customer’s technical experts must validate all operating parameters including “ Typical” for each customer application. LIFE SUPPORT AND NUCLEAR POLICY Bay Linear products are not authorized for and should not be used within life support systems which are intended for surgical implants into the body to support or sustain life, in aircraft, space equipment, submarine, or nuclear facility applications without the specific written consent of Bay Linear President. Bay Linear, Inc 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 606-5950, Fax: (925) 940-9556 www.baylinear.com