® ® A SUBSIDIARY OF C&D TECHNOLOGIES 78SR Series NEW low-profile package Order online at www.datel.com Features • 3.3V/0.5A, 5V/0.5A or 12V/0.4A outputs; Pin and size-compatible with LM7805 & LM7812 regulators • Up to 95% efficiency – no heat sinks or thermal derating required! • Two SIP-packages fit existing TO-220 footprints: Vertical-pin models occupy less than 0.1 square in. Optional horizontal pins provide 0.350 in. installed height • +7.5-36Vdc operating input range; Low 3mA quiescent current • Built-in filter capacitors – no external components required • –40 to +70°C operation at full load; Short-circuit protection • Excellent load (±0.2%) and line (±0.3%) regulation • Ideal for powering instrumentation from 9V/12V/24V/28V supplies or batteries • Can be used with unregulated dc supplies 3.3V/5V/12V Outputs High-Efficiency Switching Regulators with LM78XX Pinouts DATEL’s 7805SR (5V output), 7812SR (12V output) and 7803SR (3.3V output) step-down switching regulators are modern drop-in replacements for older, inefficient, LM7805 and LM7812 linear regulators. The 78XXSR's are pin- and sizecompatible with industry-standard TO-220 SIP packages. A 260kHz switching frequency provides for efficiencies as high as 95%. Full-load (up to 0.5A) operation from 9V, 12V, 24V, or 36V supplies at ambient temperatures up to +70°C requires no heat sinks, no temperature derating, no forced-air cooling, and no external capacitors. 78SR switching regulators provide many significant improvements over their linear counterparts: lower quiescent current (3mA vs. 5 mA), higher input voltage (40V vs. 32V), and better output accuracy (±1.5% vs. ±5%). All these features combine to make 78SR regulators ideal for new or existing LM7805 & LM7812 applications requiring full-load operation at elevated voltages. Technical Notes 1. Input/Output (I/O) Filtering: As shown in the noise and ripple graphs, 78SR switching regulators exhibit excellent low-noise performance with no external I/O capacitors. However, if additional noise reduction is required, be sure to use low-ESR capacitors that are rated for continuous operation (with an additional 20% safety margin) at the highest system voltages and temperatures. Adding external output capacitors will also improve the unit’s load-transient response. Applications in which 78SR regulators are located more than 24 inches (61cm) from the input power supply should include an external 47uF/50V (or greater) aluminum electrolytic capacitor, connected as close as possible to the regulator’s +Vin and GND terminals (pins 1 and 2). An external input capacitor is particularly important if the input voltage is applied to the regulator via a mechanical switch or relay. Contact bounce at turn-on can produce large inductive current-spikes, and these current spikes can generate damaging voltage transients at the regulator’s input terminals. 2. Input Fusing: 78SR switching regulators are not internally fused. If fusing their input and/or output terminals is required, use the data shown in the Efficiency Curves as a guide to selecting an appropriate slow-blow fuse. 3. Input-Output Isolation: 78SR regulators’ internal input and output circuits share a common connection (GND, pin 2); there is no electrical isolation between the INPUT (pin 1) and OUTPUT (pin 3) terminals. 4. Overvoltage Protection: 78SR switching regulators do not provide input or output overvoltage protection. In the extremely rare situation in which a catastrophic failure occurs, the output voltage may rise to excessively high levels. If your load must be protected against all possible overvoltage situations, external voltage-limiting circuitry must be provided. 5. Operation at 40Vdc: Operating with inputs up to 40Vdc is permissible if, for inputs between 36 and 40Vdc, the maximum load current is reduced to 0.35A for 7805SR and 7803SR, and to 0.3A for 7812SR. Under no circumstances should the input voltage be allowed to exceed 45Vdc. 6. Soldering & Handling Precautions: All units are designed to be hand soldered to pc-boards using no-clean solders (+260°C, 5 seconds max.). Water-soluble solders can also be used, but the units must be washed and dried using processes appropriate to the type of solder employed. See the Mechanical Specifications section for pin 1 orientation and recommended plated-through hole dimensions. While 78SR regulators easily withstand a 2kV ESD discharge to any terminal (using human body model), they should always be treated as ESD sensitive devices. 7. Horizontal-Pin Models (78XXSRH): 78XXSRH switching regulators are pin-compatible replacements for TO-220 style LM78XX linear regulators that are installed with their metal tabs lying flat on the surface DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 • E–mail: firstname.lastname@example.org • Internet: www.datel.com 78SR Series H I G H - E F F I C I E N C Y S W I T C H I N G R E G U L ATO R S Technical Notes (continued) Performance/Functional Specifications Typical at TA = +25°C of the pc-board. However, because the surface of inductor L1 on 78XXSRH models is electrically conductive, it must not be allowed to come in contact with any exposed pc-board traces, other than power ground (GND). Input/Output While the 2-mil-thick (0.05mm) polyester label attached to L1 provides some degree of electrical insulation (only if L1 sits perfectly flat on the pc-board), it is recommended that a 0.020” (0.5mm) clearance be maintained between L1 and all exposed pc-board traces. 8. Dropout Voltage: 78SR series regulators described in this data sheet specify a minimum input voltage at which full-load accuracy and output regulation are guaranteed (7.5V for 7803SR and 7805SR, and 15.0V for 7812SR). However, these devices will stay in regulation at lower input voltages if they are operated at less than their rated loads. 7803SR 7805SR +3.3Vdc +5.0Vdc +12.0Vdc Rated Output Current 0.5A 0.5A 0.4A Output Voltage Accuracy ±2% ±1.5% ±2% +7.5-36Vdc +7.5-36Vdc +15-36Vdc Line Regulation (100% load) ±0.3% ±0.3% ±0.3% Load Regulation (0-100% load) ±0.2% ±0.2% ±0.2% 3mA typ., 5mA max. Input Current See Performance Curves Efficiency See Performance Curves Transient Response See Performance Curves Input & Output Noise See Performance Curves Short Circuit Protection ➁ Isolation None Overvoltage Protection None Undervoltage Protection None Models 7803SR Operating Temperature 0% Load 25% Load 50% Load 100% Load 6.0V 6.2V 6.2V 6.3V Cooling Humidity (Non-condensing) 6.3V 6.2V 6.2V 6.8V 7812SR 12.8V 13.0V 12.8V 13.0V Continuous Environmental Typical Dropout Voltage 7805SR 7812SR Input Voltage Range ➀ Quiescent Current The following dropout-voltage data, derived from sample testing performed at an ambient temperature of +25°C with resistive loads, should be used for information purposes only. For these tests, a unit was considered to be out of regulation when its output changed by more +/-0.005Vdc from its nominal value. All voltages were measured directly at the regulator’s I/O pins. 7803SR Models Output Voltage Storage Temperature 7805SR 7812SR –40 to +70°C –40 to +85°C Free Air Convection 0 to 85% Physical Mechanical See Mechanical Specifications Package Open-frame SIP Pins 0.025” (0.64mm) square, tin-plated bronze Weight 0.08 ounces (2.2g) Pin Soldering +260°C for 5 seconds ➀ See Technical Note 5. ➁ While these regulators can withstand a continuous short-circuit across their output terminals, they will experience a significant temperature rise. Extended short-circuit operation will adversely affect the unit’s reliability. Ordering Information DATEL Part No. Output Voltage Standard Pin Package 7803SR +3.3Vdc 7805SR +5.0Vdc 7812SR +12.0Vdc Horizontal Pin Package 7803SRH +3.3Vdc 7805SRH +5.0Vdc 7812SRH +12.0Vdc Output Current Input Voltage 0.5A 0.5A 0.4A +7.5-36Vdc +7.5-36Vdc +15-36Vdc 0.5A 0.5A 0.4A +7.5-36Vdc +7.5-36Vdc +15-36Vdc DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 • E–mail: email@example.com • Internet: www.datel.com 2 78SR Series H I G H - E F F I C I E N C Y S W I T C H I N G R E G U L ATO R S Typical Performance Curves TA = +25°C, VIN as indicated Noise and Ripple - 10% and 100% Load, 20MHz Bandwidth 7803SR Vin = 12V, ILOAD = 50mA 7805SR Vin = 12V, ILOAD = 50mA 7812SR Vin = 24V, ILOAD = 40mA 7803SR Vin = 12V, ILOAD = 500mA 7805SR Vin = 12V, ILOAD = 500mA 7812SR Vin = 24V, ILOAD = 400mA 7812SR 10% to 100% Load Step Transient Response - 90% Load Step 7803SR 10% to 100% Load Step 7805SR 10% to 100% Load Step Vin = 9V 7803SR 100% to 10% Load Step Vin = 9V 7805SR 100% to 10% Load Step Vin = 9V Vin = 9V Vin = 18V 7812SR 100% to 10% Load Step Vin = 18V DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 • E–mail: firstname.lastname@example.org • Internet: www.datel.com 3 78SR Series H I G H - E F F I C I E N C Y S W I T C H I N G R E G U L ATO R S 7803SR Efficiency 7803SR Input Current 90 0.25 80 100% LOAD 75 EFFICIENCY INPUT CURRENT (AMPS) 85 50% LOAD 70 25% LOAD 65 60 55 0.20 100% LOAD 0.15 0.10 50% LOAD 0.05 25% LOAD 0.00 50 8 10 12 14 16 18 20 22 24 26 28 30 32 34 8 36 10 12 14 16 18 7805SR Efficiency 0.35 90 0.30 EFFICIENCY 85 NPUT CURRENT (AMPS) 95 100% LOAD 50% LOAD 80 75 25% LOAD 70 16 18 20 22 24 30 32 34 36 26 28 30 32 34 36 50% LOAD 25% LOAD 8 10 12 14 16 INPUT VOLTAGE 18 20 22 24 26 28 30 32 34 36 INPUT VOLTAGE 7812SR Efficiency 7812SR Input Current 0.40 100 INPUT CURRENT (AMPS) 0.35 95 EFFICIENCY 28 100% LOAD 0.10 0.00 14 26 0.15 60 12 24 7805SR Input Current 0.20 0.05 10 22 0.25 65 8 20 INPUT VOLTAGE INPUT VOLTAGE 100% LOAD 90 50% LOAD 85 25% LOAD 80 75 0.30 100% LOAD 0.25 0.20 50% LOAD 0.15 0.10 25% LOAD 0.05 0.00 70 14 16 18 20 22 24 26 28 30 32 34 14 36 16 18 20 22 24 26 28 30 32 34 36 INPUT VOLTAGE INPUT VOLTAGE DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: (508)339-3000, (800)233-2765 Fax: (508)339-6356 • E–mail: email@example.com • Internet: www.datel.com 4 78SR Series H I G H E F F I C I E N C Y S W I T C H I N G R E G U L ATO R S Mechanical Specifications MECHANICAL DIMENSIONS: Inches (mm) TOLERANCES: Standard Package 2 PL DEC ±0.02 (±0.51) 3 PL DEC ±0.010 (±0.254) 0.41 (10.4) 0.19 (4.8) L1 0.75 (19.1) 1 1 2 3 Pins: 0.025 (0.64) sq. 0.100 (2.54) centers 0.15 (3.8) Min. OUTPUT (+VOUT) GND INPUT (+VIN) PC-Board Hole: 0.037 - 0.043 (0.94 - 1.09) Dia. 0.21 (5.3) Horizontal Package (H Pin Option) 0.35 (8.9) max. L1 1 2 3 0.15 (3.8) min. PC-Board Hole: 0.037 - 0.043 (0.94 - 1.09) Dia. DATEL (UK) LTD. Tadley, England Tel: (01256)-880444 Internet: www.datel-europe.com E-mail: firstname.lastname@example.org DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 01-34-60-01-01 Internet: www.datel-europe.com E-mail: email@example.com A SUBSIDIARY OF C&D TECHNOLOGIES DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356 ww.datel.com E-mail: firstname.lastname@example.org www.cdpowerelectronics.com ISO 9001:2000 REGISTERED OUTPUT (+VOUT) ® GND INPUT (+VIN) ® Pins: 0.025 (0.64) sq. 0.100 (2.54) centers DS-0540D 11/04 DATEL GmbH München, Germany Tel: 89-544334-0 Internet: www.datel-europe.com E-mail: email@example.com DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-6354-2025 Internet: www.datel-co.jp E-mail: firstname.lastname@example.org, email@example.com DATEL China Shanghai, China Tel: 011-86-51317131 E-mail: firstname.lastname@example.org DATEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.