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7812SRC
Datasheet
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MURATA POWER SOLUTIONS 7812SRC Datasheet

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78xxSR Series
3.3V/5V/12V Outputs High-Effi ciency
Switching Regulators with LM78xx Pinouts
FEATURES
3.3V/0.5A, 5V/0.5A or 12V/0.4A outputs; Pin and size-compatible with LM7805 & LM7812 regulators
Up to 95% effi ciency– no heat sinks or thermal derating required
Two SIP-packages fi t 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 fi lter 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 protection
Ordering Information
MPS Part No. Output Output Input Voltage Current Voltage
Standard Pin Package 7803SR-C +3.3Vdc 0.5A +7.5-36Vdc 7805SR-C +5.0Vdc 0.5A +7.5-36Vdc 7812SR-C +12.0Vdc 0.4A +15-36Vdc
Horizontal Pin Package 7803SRH-C +3.3Vdc 0.5A +7.5-36Vdc 7805SRH-C +5.0Vdc 0.5A +7.5-36Vdc 7812SRH-C +12.0Vdc 0.4A +15-36Vdc
Murata Power Solutions’ 7805SR-C (5V output), 7812SR-C (12V output) and 7803SR-C (3.3V output) step-down switching regulators are modern drop-in replacements for older, ineffi cient, LM7805 and LM7812 linear regulators. The 78XXSR's are pin- and size-compat­ible with industry-standard TO-220 SIP packages. A 260kHz switching frequency provides for effi ciencies 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 signifi cant improvements over their linear coun­terparts: lower quiescent current (3mA vs. 5 mA), higher input voltage (40V vs. 32V), and better output accuracy (±2% 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 Effi ciency 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-C and 7803SR-C, and to 0.3A for 7812SR-C. Under no circumstances should the input voltage be allowed to exceed 45Vdc.
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TECHNICAL NOTES (continued)
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 Specifi cations section for pin 1 orientation and recommended plated-through hole dimensions.
While 78SR regulators easily withstand a 2kV ESD discharge to any ter-
minal (using human body model), they should always be treated as ESD sensitive devices.
7. Horizontal-Pin Models (78XXSRH-C): 78XXSRH-C switching regulators are pin-compatible replacements for TO-220 style LM78XX linear regula­tors that are installed with their metal tabs lying fl at on the surface of the pc-board. However, because the surface of inductor L1 on 78XXSRH-C models is electrically conductive, it must not be allowed to come in con­tact with any exposed pc-board traces, other than power ground (GND).
While the 2-mil-thick (0.05mm) polyester label attached to L1 provides
some degree of electrical insulation (only if L1 sits perfectly fl at 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-C and 7805SR-C, and 15.0V for 7812SR-C). However, these devices will stay in regulation at lower input voltages if they are operated at less than their rated loads.
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.
78xxSR Series
3.3V/5V/12V Outputs High-Effi ciency
Switching Regulators with LM78xx Pinouts
Performance/Functional Specifi cations
Typical at TA = +25°C
Input/Output
Models 7803SR-C 7805SR-C 7812SR-C
Output Voltage +3.3Vdc +5.0Vdc +12.0Vdc
Rated Output Current 0.5A 0.5A 0.4A
Output Voltage Accuracy ±2% ±2% ±2%
Input Voltage Range ➀ +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%
Quiescent Current 3mA typ., 5mA max.
Input Current See Performance Curves
Effi ciency See Performance Curves
Transient Response See Performance Curves
Input & Output Noise See Performance Curves
Short Circuit Protection ➁ Continuous
Isolation None
Overvoltage Protection None
Undervoltage Protection None
Environmental
Models 7803SR-C 7805SR-C 7812SR-C
Operating Temperature –40 to +70°C
Storage Temperature –40 to +85°C
Cooling Free Air Convection
Humidity (Non-condensing) 0 to 85%
Typical Dropout Voltage
0% Load 25% Load 50% Load 100% Load
7803SR-C 6.0V 6.2V 6.2V 6.3V
7805SR-C 6.3V 6.2V 6.2V 6.8V
7812SR-C 12.8V 13.0V 12.8V 13.0V
Physical
Mechanical See Mechanical Specifi cations
Packag e 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 signifi cant temperature rise. Extended short-circuit operation will adversely affect the unit’s reliability.
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Typical Performance Curves TA = +25°C, VIN as indicated
Noise and Ripple - 10% and 100% Load, 20MHz Bandwidth
78xxSR Series
3.3V/5V/12V Outputs High-Effi ciency
Switching Regulators with LM78xx Pinouts
7803SR-C Vin = 12V, ILOAD = 50mA
7803SR-C Vin = 12V, I
LOAD = 500mA
7805SR-C Vin = 12V, ILOAD = 50mA
7805SR-C Vin = 12V, ILOAD = 500mA
7812SR-C Vin = 24V, I
7812SR-C Vin = 24V, I
LOAD = 40mA
LOAD = 400mA
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Switching Regulators with LM78xx Pinouts
Transient Response - 90% Load Step
78xxSR Series
3.3V/5V/12V Outputs High-Effi ciency
7803SR-C 10% to 100% Load Step
IN = 9V
V
7803SR-C 100% to 10% Load Step
7805SR-C 10% to 100% Load Step
IN = 9V
V
7805SR-C 100% to 10% Load Step
7812SR-C 10% to 100% Load Step
IN = 18V
V
7812SR-C 100% to 10% Load Step
V
IN = 9V
V
IN = 9V
V
IN = 18V
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78xxSR Series
50
55
60
65
70
75
80
85
90
8 1012141618202224262830323436
INPUT VOLTAGE
EFFICIENCY
0.00
0.05
0.10
0.15
0.20
0.25
8 1012141618202224262830323436
INPUT VOLTAGE
60
65
70
75
80
85
90
95
8 1012141618202224262830323436
INPUT VOLTAGE
EFFICIENCY
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
8 10 1214 1618 202224 2628 3032 3436
INPUT VOLTAGE
70
75
80
85
90
95
100
14 16 18 20 22 24 26 28 30 32 34 36
INPUT VOLTAGE
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
14 16 18 20 22 24 26 28 30 32 34 36
INPUT VOLTAGE
INPUT CURRENT (AMPS)
3.3V/5V/12V Outputs High-Effi ciency
Switching Regulators with LM78xx Pinouts
Effi cience Curves
7803SR-C Effi ciency 7803SR-C Input Current
100% LOAD
50% LOAD
25% LOAD
100% LOAD
50% LOAD
25% LOAD
7805SR-C Effi ciency
100% LOAD
50% LOAD
25% LOAD
25% LOAD
7805SR-C Input Current
100% LOAD
50% LOAD
7812SR-C Effi ciency 7812SR-C Input Current
100% LOAD
50% LOAD
25% LOAD
100% LOAD
50% LOAD
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25% LOAD
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SHIPPING TRAYS AND BOXES
78xxSR Series
3.3V/5V/12V Outputs High-Effi ciency
Switching Regulators with LM78xx Pinouts
EACH FOAM TRAY (2300276) CONTAINS 50 UNITS IN FULL MPQ QUANTITIES, TWO TRAYS EQUAL TO A TOTAL OF 100(2x50) UNITS PER CARTON.
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30 Oct 2015 MDC_78xxSR Series.B07 Page 6 of 7
Page 7
MECHANICAL DIMENSIONS: Inches (mm)
TOLERANCES: 2 PL DEC ±0.02 (±0.51) 3 PL DEC ±0.010 (±0.254)
0.19 (4.8)
L1
0.23 (5.7)
Standard Package
Pins: 0.025 (0.64) sq.
0.100 (2.54) centers
PC-Board Hole:
0.037 - 0.043 (0.94 - 1.09) Dia.
78xxSR Series
3.3V/5V/12V Outputs High-Effi ciency
Switching Regulators with LM78xx Pinouts
0.41
(10.4)
0.75
(19.1)
1
1
123
0.15
(3.8) Min.
OUTPUT (+VOUT)
GND
INPUT (+V
low-profi le package
(9.3) max.
0.37
0.15
(3.8) min.
0.07 (1.8)
L1
Horizontal Package
(H Pin Option)
1 2 3
GND
INPUT (+V
IN)
OUTPUT (+VOUT)
IN)
Pins: 0.025 (0.64) sq.
0.100 (2.54) centers
PC-Board Hole:
0.037 - 0.043 (0.94 - 1.09) Dia.
Murata Power Solutions, Inc. 11 Cabot Boulevard, Mansfi eld, MA 02048-1151 U.S.A.
ISO 9001 and 14001 REGISTERED
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This product is subject to the following operating requirements and the Life and Safety Critical Application Sales Policy: Refer to: http://www.murata-ps.com/requirements/
Murata Power Solutions, Inc. 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. Specifi cations are subject to change without notice. © 2015 Murata Power Solutions, Inc.
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