Texas LP395Z/LFT1-Power Transistor

LP395Z/LFT1 Description

The LP395 is a fast monolithic transistor with complete overload protection. This very high gain transistor has included on the chip, current limiting, power limiting, and thermal overload protection, making it difficult to destroy from almost any type of overload. Available in an epoxy TO-92 transistor package this device is specified to deliver 100 mA.

 

Thermal limiting at the chip level, a feature not available in discrete designs, provides comprehensive protection against overload. Excessive power dissipation or inadequate heat sinking causes the thermal limiting circuitry to turn off the device preventing excessive die temperature.

 

The LP395 offers a significant increase in reliability while simplifying protection circuitry. It is especially attractive as a small incandescent lamp or solenoid driver because of its low drive requirements and blowout-proof design.

 

The LP395 is easy to use and only a few precautions need be observed. Excessive collector to emitter voltage can destroy the LP395 as with any transistor. When the device is used as an emitter follower with a low source impedance, it is necessary to insert a 4.7 kΩ resistor in series with the base lead to prevent possible emitter follower oscillations. Also since it has good high frequency response, supply by-passing is recommended.

 

Areas where the LP395 differs from a standard NPN transistor are in saturation voltage, leakage (quiescent) current and in base current. Since the internal protection circuitry requires voltage and current to function, the minimum voltage across the device in the on condition (saturated) is typically 1.6 Volts, while in the off condition the quiescent (leakage) current is typically 200 μA. Base current in this device flows out of the base lead, rather than into the base as is the case with conventional NPN transistors. Also the base can be driven positive up to 36 Volts without damage, but will draw current if driven negative more than 0.6 Volts. Additionally, if the base lead is left open, the LP395 will turn on.

 

The LP395 is a low-power version of the 1-Amp LM195/LM295/LM395 Ultra Reliable Power Transistor.

 

The LP395 is rated for operation over a −40°C to +125°C range.

LP395Z/LFT1 Features

Internal Thermal Limiting

Internal Current and Power Limiting

Specified 100 mA Output Current

0.5 μA Typical Base Current

Directly Interfaces with TTL or CMOS

+36 Volts On Base Causes No Damage

2 μs Switching Time

 

LP395Z/LFT1 Simplified Circuit

One failure mode incandescent lamps may experience is one in which the filament resistance drops to a very low value before it actually blows out. This is especially rough on most solid-state lamp drivers and in most cases a lamp failure of this type will also cause the lamp driver to fail. Because of its high gain and blowout-proof design, the LP395 is an ideal candidate for reliably driving small incandescent lamps. Additionally, the current limiting characteristics of the LP395 are advantageous as it serves to limit the cold filament inrush current, thus increasing lamp life.

 

LP395Z/LFT1 Package Outline

LP395Z/LFT1 Product Parameter

Manufacturer	Texas	Manufacturer's Part #	LP395Z/LFT1
Categories	Discrete Semiconductor Products	Sub-Categories	Transistors - Bipolar (BJT) - Single
Part Status	Active	Transistor Type	NPN
Current - Collector (Ic) (Max)	-	Voltage - Collector Emitter Breakdown (Max)	36V
Vce Saturation (Max) @ Ib, Ic	-	Current - Collector Cutoff (Max)	-
DC Current Gain (hFE) (Min) @ Ic, Vce	-	Power - Max	-
Frequency - Transition	-	Operating Temperature	0°C~125°C TA
Mounting Type	Through Hole	Package / Case	TO-226-3, TO-92-3 (TO-226AA)
Supplier Device Package	TO-92-3	Factory Lead Time	6 Weeks
Lifecycle Status	ACTIVE (Last Updated: 4 days ago)	Number of Pins	3
Packaging	Tape & Reel (TR)	Pbfree Code	yes
Terminal Finish	Matte Tin (Sn)	Terminal Position	BOTTOM
Collector Emitter Breakdown Voltage	36V	RoHS Status	ROHS3 Compliant
Lead Free	Lead Free	Subcategory	Other Transistors
Base Part Number	LP395	Polarity/Channel Type	NPN
Radiation Hardening	No	Mount	Through Hole
Configuration	Single	Height	5.34mm
Length	4.3mm	Width	4.3mm
Thickness	3.6mm

 

LP395Z/LFT1 Manufacturer

Texas Instruments is a semiconductor multinational company in Texas, USA. It is famous for developing, manufacturing, and selling semiconductor and computer technology. It is mainly engaged in innovative digital signal processing and analog circuits. In addition to the semiconductor business, it also provides solutions including sensing and control, educational products and digital light source processing. Texas Instruments (TI) is headquartered in Dallas, Texas, USA, and has manufacturing, design or sales organizations in more than 25 countries.