Lm3915 Calculator ~repack~ Now

Externally, the reference voltage ( V_\textref ) (typically 1.25 V) is set by a resistor divider between pin 7 (REF OUT) and pin 8 (REF ADJ). The full-scale range is determined by the voltage at pin 4 (RHI) and pin 5 (RLO).

Standard LEDs run safely at 10mA to 20mA. The LM3915 regulates current internally via a resistor from pin 7 to ground. The formula is ( I_LED = \frac12.5R_PROG ). A calculator will convert your desired mA (say, 15mA) into a standard resistor value (approx 820 ohms). LM3915 Calculator

...but that is the simplified version. In reality, the chip uses an internal 10-stage voltage divider. The calculator solves for two critical variables: Externally, the reference voltage ( V_\textref ) (typically

): This formula ensures your LEDs are bright enough without exceeding the IC's power limits. The LM3915 regulates current internally via a resistor

Cell A2 (VHI) Cell A3 (Steps = 10)