SNVSAC2A March 2015 – June 2020 LM317A
PRODUCTION DATA.
Using the LM195 power transistor in parallel with the LM317A can increase the maximum possible output load current (see Figure 24). Sense resistor R1 provides the 0.6 V across base to emitter to turn on the PNP. This on switch allows current to flow, and the voltage drop across R3 drives three LM195 power transistors designed to carry an excess of 1 A each.
NOTE
The selection of R1 determines a minimum load current for the PNP to turn on. The higher the resistor value, the lower the load current must be before the transistors turn on.
NOTE:
‡Optional—improves ripple rejection