The LM195/LM395 are fast, monolithic power transistors
with complete overload protection. These devices, which act
as high gain power transistors, have included on the chip,
current limiting, power limiting, and thermal overload protection making them virtually impossible to destroy from any
type ofoverload.In the standard TO-3transistor power package, the LM195 will deliver load currents in excess of 1.0A
and can switch 40V in 500 ns.
The inclusion of thermal limiting, a feature not easily available in discrete designs, provides virtually absolute protection against overload. Excessive power dissipation or inadequate heat sinking causes the thermal limiting circuitry to
turn off the device preventing excessive heating.
The LM195 offers a significant increase in reliability as well
as simplifying power circuitry. In some applications, where
protection is unusually difficult, such as switching regulators,
lamp or solenoid drivers where normal power dissipation is
low, the LM195 is especially advantageous.
The LM195 is easy to use and only a few precautions need
be observed. Excessive collector to emitter voltage can destroy the LM195 as with any power transistor. When the device is used as an emitter follower with low source imped-
ance, it is necessary to insert a 5.0k resistor in series with
the base lead to prevent possible emitter follower oscillations. Although the device is usually stable as an emitter follower,the resistor eliminates the possibility of trouble without
degrading performance. Finally, since it has good high frequency response, supply bypassing is recommended.
For low-power applications (under 100 mA), refer to the
LP395 Ultra Reliable Power Transistor.
The LM195/LM395 are available in standard TO-3 power
packages and solid Kovar TO-5. The LM195 is rated for operation from −55˚C to +150˚C and the LM395 from 0˚C to
+125˚C.
Features
n Internal thermal limiting
n Greater than 1.0A output current
n 3.0 µA typical base current
n 500 ns switching time
n 2.0V saturation
n Base can be driven up to 40V without damage
n Directly interfaces with CMOS or TTL
n 100%electrical burn-in
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Collector to Emitter Voltage
LM19542V
LM39536V
Collector to Base Voltage
LM19542V
Base to Emitter Voltage (Reverse)20V
Collector CurrentInternally Limited
Power DissipationInternally Limited
Operating Temperature Range
LM195−55˚C to +150˚C
LM3950˚C to +125˚C
Storage Temperature Range−65˚C to +150˚C
Lead Temperature
Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits.
Note 2: Unless otherwise specified, these specifications apply for −55˚C ≤ T
Note 3: Without a heat sink, the thermal resistance of the TO-5 package is about +150˚C/W, while that of the TO-3 package is +35˚C/W.
Note 4: Selected devices with higher breakdown available.
Note 5: Refer to RETS195H and RETS195K drawings of military LM195H and LM195K versions for specifications.
≤ +150˚C for the LM195 and 0˚C ≤ +125˚C for the LM395.
j
4236V
3.05.03.010µA
2.05.02.010mA
500500ns
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Page 4
Typical Performance Characteristics (for K and T Packages)
Collector Characteristics
Quiescent Current
Saturation Voltage
DS006009-33
DS006009-36
Short Circuit Current
Base Emitter Voltage
Response Time
DS006009-34
DS006009-37
Bias Current
DS006009-35
Base Current
DS006009-38
Response Time
DS006009-39
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DS006009-40
DS006009-41
Page 5
Typical Performance Characteristics (for K and T Packages) (Continued)
10V Transfer Function
Transconductance
DS006009-7
DS006009-9
36V Transfer Function
DS006009-8
Small Signal Frequency
Response
DS006009-10
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Page 6
Schematic Diagram
DS006009-11
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Page 7
Typical Applications
1.0 Amp Voltage Follower
*
Solid Tantalum
Power PNP
*
Protects against excessive base drive
**
Needed for stability
1.0 MHz Oscillator
DS006009-12
Time Delay
DS006009-13
DS006009-14
1.0 Amp Lamp Flasher
DS006009-15
DS006009-16
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Page 8
Typical Applications (Continued)
1.0 Amp Negative Regulator
†
Solid Tantalum
†
Solid Tantalum
DS006009-17
1.0 Amp Positive Voltage Regulator
DS006009-18
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Page 9
Typical Applications (Continued)
Fast Optically Isolated Switch
CMOS or TTL Lamp Interface
DS006009-21
6.0V Shunt Regulator with Crowbar
Optically Isolated Power Transistor
DS006009-19
Two Terminal Current Limiter
DS006009-22
Two Terminal 100 mA Current Regulator
DS006009-20
40V Switch
*
Drive Voltage 0V to ≥ 10V ≤ 42V
DS006009-23
DS006009-24
DS006009-25
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Page 10
Typical Applications (Continued)
Turn ON=350 mV
Turn OFF=200 mV
Low Level Power Switch
Emitter Follower
DS006009-26
Power One-Shot
T=R1C
R2=3R1
R2 ≤ 82k
High Input Impedance AC Emitter Follower
DS006009-27
*
Need for Stability
DS006009-28
Fast Follower
*
Prevents storage with fast fall time square wave drive
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.
labeling, can be reasonably expected to result in a
significant injury to the user.
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.