126.96.36.199.3 Setting the Current Limit
The current limit of the LM3409 is determined by the current draw of the IADJ pin of the TPS99000-Q1, which is controlled by an internal DAC and an external resistor connected to the R_IADJ pin of the TPS99000-Q1. The approximate peak current limit can be calculated by the following equation:
- VDAC is the voltage of the current control DAC.
- RADJ is the resistor attached to the R_IADJ pin of the LM3409. Do to the max current this circuit can output, it is recommended that this value be 1 kΩ or higher
- RSCP is the resistor attached to the CSP pin of the LM3409. Use the same value for RCSN.
- RHSS is the high side sense resistor of the LM3409 control circuit.
Figure 44. Current Limit Configuration Circuit