The document discusses integrated circuit voltage regulators. It describes IC voltage regulators as circuits that supply constant voltage regardless of load current changes. It classifies regulators as multi-pin types like the LM 723C or 3-pin types like the 78/79XX series. The document lists common fixed positive voltage regulators like the 7805 and negative voltage regulators like the 7905. It also discusses the adjustable LM317 positive and LM337 negative regulators and their ability to output any voltage from 1.2V to 57V. Performance parameters like line and load regulation, temperature stability, ripple rejection and quiescent current are defined.
7. IC Voltage Regulators
7
It is a circuit that supplies constant voltage regardless of changes in the load
current.
Advantages – Inexpensive, versatile, provides current /voltage boosting,
internal short circuit current limiting, thermal shutdown, high voltage
applications.
Classification of IC voltage regulators:
There are basically two kinds of IC voltage regulators:
Multi-pin type, e.g. LM 723C
3-pin type, e.g. 78/79XX series
Multi-pin regulators are less popular but they provide the greatest flexibility
and produce the highest quality voltage regulation.
3-pin types make regulator circuit design simple.
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8. TYPES
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Fixed output voltage regulators: Positive fixed output regulator(78XX
series) and Negative fixed output regulator(79XX series)
Adjustable output voltage regulators: Positive (LM317) and
Negative(LM337)
Switching regulators: Motorola MC1723
General purpose regulator - used in many ways as a fixed positive or
negative output voltage regulator, variable output voltage regulator.
Standard type in the electronics industry due to its flexibility.
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10. PURPOSE
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Without stable potentials, circuit performance degrades and if
the variations are large enough the components may get
destroyed.
In order to avoid this, regulation is used.
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11. PERFORMANCE PARAMETERS
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Line or input regulation: defined as a change in output voltage for a change
in input voltage.
Load regulation: defined as the change in output voltage for a change in load
current.
Temperature stability or average temperature coefficient of output
voltage(TCVO): defined as the change in output voltage per unit change in
temperature and expressed in millivolts per degree Celsius.
Ripple rejection: is the measure of regulator’s ability to reject ripple voltages
and it is usually expressed in decibels.
Quiescent current Iq : current that flows into the regulator and does not include
current drawn by load or internal resistor networks.
The smaller the value of these performance parameters, the better the
regulator. Prof. Satheesh MB, Indian Navy
12. FIXED +ve VOLTAGE REGULATORS
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IC No Voltage
7805 5V
7806 6V
7808 8V
7809 9V
7810 10V
7812 12V
7815 15V
7818 18V
7824 24V
13. FEATURES
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3 terminal positive voltage regulator
• High Output Current - typically 1.5A
• Short circuit current limit - 750mA at 5v
• Internal thermal overload protection
• Low quiescent current - 6mA
• Max input voltage = 35v
• Minimum Input Voltage = Vout + 2.5
14. -ve VOLTAGE REGULATORS
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IC No Voltage
7902 -2V
7905 -5V
7905.2 -5.2V
7906 -6.2V
7908 -8V
7912 -12V
7915 -15V
7918 -18V
7924 -24V
15. Adjustable Regulator – LM 317 / 337
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Output voltage regulated at any setting over the
range of 1.2 V to 57 V.