LM1084R-5.0 View Datasheet(PDF) - HTC Korea

Part Name

Description

Manufacturer

LM1084R-5.0

5A L.D.O. VOLTAGE REGULATOR (Adjustable & Fixed)

HTC Korea 

5A L.D.O. VOLTAGE REGULATOR (Adjustable & Fixed)

LM1084

APPLICATION INFORMATION

The LM1084 series of adjustable and fixed regulators are easy to use and have all the protection features

expected in high performance voltage regulators : short circuit protection and thermal shut-down.

Pin compatible with older three terminal adjustable regulators, these devices offer the advantage of a lower

dropout voltage, more precies reference tolerance and improved reference stability with temperature.

STABILITY

The circuit design used in the LM1084 series requires the use of an output capacitor as part of the device

frequency compensation.

The addition of 150uF aluminum electrolytic or a 22uF solid tantalum on the output will ensure stability for

all operating conditions. When the adjustment terminal is bypassed with a capacitor to improve the ripple

rejection, the requirement for an output capacitor increases. The value of 22uF tantalum or 150uF aluminum

covers all cases of bypassing the adjustment terminal. Without bypassing the adjustment terminal smaller

capacitors can be used with equally good results.

To ensure good transient response with heavy load current changes capacitor values on the order of 100uF

are used in the output of many regulators. To further improve stability and transient response of these devices

larger values of output capacitor can be used.

PROTECTION DIODES

Unlike older regulators, the LM1084 family does not need any

protection diodies between the adjustment pin and the output and

LM1084

from the output tu the input to prevent over-stressing the die.

Internal resistors are limiting the internal current paths on the

LM1084 adjustment pin, therfore even with capacitors on the

adjustment pin no protection diode is needed to ensure device

safety under short-circuit conditions.

Diodes between the input and output are not usually needed.

Figure 10.

Microsecond surge currents of 50A to 100A can be handled by

the internal diode between the input and output pins of the device. In norminal operations it is difficult to get

those values of surge currents even with the use of large output capacitances. If high value output capacitors

are used, such as 1000uF to 5000uF and the input pin is instantaneously shorted to ground, damage can occur.

A diode from output to input is recommended, when a crowbar circuit at the input of the LM1084 is used.

Normal power supply cycling or even plugging and unplugging in the system will not generate current large

enough to do any damage.

The adjustment pin can be driven on a transient basis ±25V, with respect to the output without any device

degradation. As with any IC regulator, none the protection circuitry will be functional and the internal

transistors will break diwn if the maximum inout to output voltage differential is exceeded.

HTC

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