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78SR 2 Amp Series
2 Amp, 3.3V, 5.0V, & 5.2V Output, High
Effi ciency, Synchronous Switching Regulators
MPM_78SR-2A.C01 Page 2 of 6
TECHNICAL NOTES (continued)
3. Input-Output Isolation: 78SR regulators’ internal input and output
circuits share a common connection (GND, pin 2), there is no
electrical isolation between their 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
where a catastrophic failure occurs, the output voltage may rise to
excessively high levels. If the load circuit must be protected against
all possible overvoltage situations, voltage-limiting circuitry must be
provided externally.
5. Soldering & Handling Precautions: All units are designed to be
hand soldered to pc-boards, using lead-free no-clean solders
(+260°C, 5 seconds max.). See the Mechanical Specifi cations sec-
tion for pin 1 orientation and recommended pc-board hole dimen-
sions.
78SR series regulators have limited built-in ESD protection; there-
fore they should always be treated as ESD susceptible devices.
6. Horizontal-Pin Models (78SRH): 78SRH switching regulators are
pin-compatible replacements for TO-220 style LM78xx linear regula-
tors which are installed with their metal tabs or heat sinks laying fl at
on the surface of the pc-board. In replacement applications, 78SRH
units must be soldered to the pc-board such that the insulating body
of diode D1 lies fl at and in contact with the pc-board’s surface.
Input/Output
Models 78SR-3.3/2-C 78SR-5/2-C 78SR-5.2/2-C
Output Voltage 3.3Vdc 5.0Vdc 5.25Vdc
Rated Output Current 2.0A 2.0A 2.0A
Output Voltage Accuracy ±2% ±2% ±2%
Input Voltage Range 8.0-32Vdc 8.0-32Vdc 8.0-32Vdc
Line Regulation (100% load) ±0.35% ±0.35% ±0.35%
Load Regulation (0-100% load) ±0.2% ±0.2% ±0.2%
Quiescent Current (mAdc) 25 typ., 30 max 20 typ., 35max 20 typ., 35max
Input Current vs. Input Voltage See Effi ciency Curves
Effi ciency See Effi ciency Curves
Transient Response See Performance Curves
Input & Output Noise See Performance Curves
Output Short Circuit Protection ➀
Continuous
Input/Output Isolation None
Overvoltage Protection None
Undervoltage Protection None
Environmental
Models 78SR-3.3/2-C 78SR-5/2-C 78SR-5.2/2-C
Operating Temperature –40 to +70°C
Storage Temperature –40 to +85°C
Cooling ➂
Free Air Convection
Humidity (Non-condensing) 0 to 85%
Physical
Mechanical See Mechanical Specifi cations
Package Open-frame SIP
Pins 0.025" (0.64mm) square, tin-plated bronze
Weight 0.15 ounces (4.2g)
Pin Soldering +260°C for 5 seconds
Absolute Maximum Ratings ➁
Input Voltage: +36Vdc
Operating Temperature +85°C
Output Current 3.0 Amps
➀ 78SR Series regulators can withstand a continuous short-circuit across their output
terminals. However, extended short-circuit operation will decrease the unit’s long-term
reliability.
➁ These are stress ratings only; Exposure of devices to any of these conditions may ad-
versely affect long-term reliability. Proper operation under conditions other than those
listed in the Performance/Functional Specifi cations Table is not implied.
③ See derating chart for more information.
Performance/Functional Specifi cations
Typical at TA = +25°C & VIN = 12V, unless otherwise noted
