All models with adjustable output can be substituted for fixed output. LM1117 has adjustable voltage output and fixed voltage output, fixed voltage output has 5 specifications: 1.8V,2.5V.2.85V.3.3V.5V, its label suffix such as LM1117-1.8, LM1117-2.5, etc., and so on. The adjustable voltage output model is LM1117T-ADJ, and the adjustable voltage output range is 1.25V-13.8V. So the suffix of the fixed output must be the same. The output voltage has two meanings: the net output without load, that is, the open pressure difference at both ends of the circuit; Is the pressure difference between the output ends with load. The two are different, and the output value is different. A three-terminal voltage regulator is a semiconductor device with high resistance up to the critical reverse breakdown voltage. In the reverse breakdown of the voltage regulator, in a certain current range (or in a certain power loss range), the end voltage is almost unchanged, showing the voltage regulator characteristics, so it is widely used in the voltage regulator power supply and limiting circuit.
Because the fixed three-terminal voltage regulator belongs to a series voltage regulator circuit, its principle is equivalent to a series voltage regulator circuit. In the working process of the series regulated power supply circuit, the regulating tube is always required to be in the amplified state.
The current through the adjustment tube is equal to the load current, so it is necessary to choose the appropriate high-power tube as the adjustment tube, and install the heat dissipation device according to the regulations.
In order to prevent short circuit or long-term overload burning out the regulation tube, there are generally short circuit protection and overload protection circuits in the DC regulator.
LM1117 has adjustable voltage output and fixed voltage output, fixed voltage output has 5 specifications: 1.8V,2.5V.2.85V.3.3V.5V, its label suffix such as LM1117-1.8, LM1117-2.5, etc., and so on.