78xxSR Series
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 Specifications 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 regula-
tors that are installed with their metal tabs lying flat 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 con-
tact 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 flat on the
pc-board), it is recommended that a 0.020” (0.5mm) clearance be main-
tained 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.
3.3V/5V/12V Outputs High-Efficiency
Switching Regulators with LM78xx Pinouts
Performance/Functional Specifications
Typical at T
A
= +25°C
Input/Output
Models
Output Voltage
Rated Output Current
Output Voltage Accuracy
Input Voltage Range
➀
Line Regulation (100% load)
Load Regulation (0-100% load)
Quiescent Current
Input Current
Efficiency
Transient Response
Input & Output Noise
Short Circuit Protection
➁
Isolation
Overvoltage Protection
Undervoltage Protection
7803SR-C
+3.3Vdc
0.5A
±2%
+7.5-36Vdc
±0.3%
±0.2%
7805SR-C
+5.0Vdc
0.5A
±1.5%
+7.5-36Vdc
±0.3%
±0.2%
7812SR-C
+12.0Vdc
0.4A
±2%
+15-36Vdc
±0.3%
±0.2%
3mA typ., 5mA max.
See Performance Curves
See Performance Curves
See Performance Curves
See Performance Curves
Continuous
None
None
None
Environmental
Models
Operating Temperature
Storage Temperature
Cooling
Humidity (Non-condensing)
7803SR-C
7805SR-C
–40 to +70°C
–40 to +85°C
Free Air Convection
0 to 85%
7812SR-C
Physical
Mechanical
Package
Pins
See Mechanical Specifications
Open-frame SIP
0.025” (0.64mm) square,
tin-plated bronze
0.08 ounces (2.2g)
+260°C for 5 seconds
Typical Dropout Voltage
0% Load
7803SR-C
7805SR-C
7812SR-C
6.0V
6.3V
12.8V
25% Load
6.2V
6.2V
13.0V
50% Load
6.2V
6.2V
12.8V
100% Load
6.3V
6.8V
13.0V
Weight
Pin Soldering
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.
www.murata-ps.com
Technical enquiries
email: sales@murata-ps.com, tel:
+1 508 339 3000
MDC_78xxSR Series.B03
Page 2 of 6
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