Ver11 1 Jul 262015
Features
Output Current of 500mA
Thermal Overload Protection
Short Circuit Protection
Output transistor safe area protection
No external components
Package:TO252
Output voltage accuracy tolerance ±5
General Description
HE78MXX is threeterminal positive regulators
One of these regulators can deliver up to 500mA
of output current The internal limiting and thermal
shutdown features of the regulator make them
essentially immune to overload When used as
a
replacement for a zener dioderesistor
Combination an effective improvement in output
impedance can be obtained together with lower
quiescent current
Pin ConfigurationVer11 2 Jul 262015
Selection Table
Part No Output Voltage Package Marking
HE78M05 50V
TO252
HE78M06 60V
HE78M08 80V
HE78M09 90V
HE78M12 12V
Block Diagram
Absolute Maximum Ratings(Ta25℃)
Parameter Rating Unit
Input supply voltage VIN 35 V
MAX Output currentIout 500 mA
MAX PowerPmax 05 W
Maximum junction temperatureTj 25~125 ℃
Storage temperatureTstr 55~125 ℃
Soldering temperature and time +260(Recommended 10S) ℃
Note The absolute maximum ratings are rated values exceeding which the product could suffer physical
damage These values must therefore not be exceeded under any conditions
HE78MXXVer11 3 Jul 262015
Electrical Characteristics
(Cin033uF Co01uF 0≤Tj≤125℃unless otherwise noted)
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage Vout
Io40mA VIN10V 0964vout vout 1036vout
V
Io1mA~40mA
VIN7V~18V
096vout vout 104vout
Io1mA~10mA
VIN10V
095vout vout 105vout
Line Regulation LNR
VIN7V~18V Io40mA 150 150
mV
VIN8V~18V Io40mA 100 100
Load Regulation LDR
VIN10V
Io1mA~100mA
60 60
mV
VIN10V
Io1mA~40mA
30 30
Dropout Voltage VDIF Tj25℃Io100mA 2 V
Output noise
Voltage
VN F10Hz to 100KHz 40 uVVo
Ripple Rejection PSRR
Tj25℃f120Hz
Io40mA VIN8V~20V
80 dB
Quiescent Current IQ VIN10V IOUT40mA 55 mA
Quiescent Current
Change
△IQ
VIN8V~18V IO40mA 15 15
mAVIN10V
IOUT1mA~40mA
01 01
LNR Line Regulation The change in output voltage for a change in the input voltage The measurement
is made under conditions of low dissipation or by using pulse techniques such that the average chip
temperature is not significantly affected
LDR Load RegulationThe change in output voltage for a change in load current at constant chip
temperature
HE78MXXVer11 4 Jul 262015
Typical Performance Characteristics
HE78MXXVer11 5 Jul 262015
Operation Description
HE78MXX is designed with Thermal Overload Protection that shuts down the circuit when subjected to
an excessive power overload condition Internal Short Circuit Protection that limits the maximum current
the circuit will pass and Output Transistor SafeArea Compensation that reduces the output short
circuit current as the voltage across the pass transistor is increased
In many low current applications compensation capacitors are not required However it is recommended
that the regulator input be bypassed with a capacitor if the regulator is connected to the power supply
filter with long wire lengths or if the output load capacitance is large An input bypass capacitor should be
selected to provide good high frequency characteristics to insure stable operation under all load
conditions A 033μFor larger tantalum mylar or other capacitor having low internal impedance at high
frequencies should be chosen The bypass capacitor should be mounted with the shortest possible leads
directly across the regulator’s input terminals Normally good construction techniques should be used to
minimize ground loops and lead resistance drops since the regulator has no external sense lead
Typical Application
HE78MXX
A common ground is required between the input and the output voltages The input voltage must remain
typically 20 V above the output voltage even during the low point on the input ripple voltage
●Cin is required if regulator is located an appreciable distance from power supply filter
●Co is not needed for stability however it does improve transient response
HE78MXX
TheHE78MXX regulator can also be used as a current source when connected as Fig2 In order to
minimize dissipation the HE78MXX is chosen in this application Resistor R determines the current
as
follows
HE78MXXVer11 6 Jul 262015
HE78MXX
HE78MXXVer11 7 Jul 262015
Package Information
3pin TO252 Outline Dimensions
HE78MXX
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