The ic components LM317 and LM317 Electrical Characteristics follows:
Specifications with standard type face are for TJ = 25°C, and those with boldface type apply over full Operating Temperature
Range. Unless otherwise specified, VIN − VOUT = 5V, and IOUT = 10 mA.
The electronic components LM317 is capable of providing extremely good load regulation but a few precautions are needed to obtain maximum performance. The current set resistor connected between the
adjustment terminal and the output terminal (usually 240Ω) should be tied directly to the output (case) of the regulator rather than near the load. This eliminates line drops from appearing
effectively in series with the reference and degrading regulation. For example, a 15V regulator with 0.05Ω resistance between the regulator and load will have a load regulation due to line resistance of 0.05Ω × IL.
If the set resistor is connected near the load the effective line resistance will be 0.05Ω (1 + R2/R1) or in this case, 11.5 times worse.
Figure 2 shows the effect of resistance between the regulator and 240Ω set resistor.
No comments:
Post a Comment