SLUSFA1 September 2024 TPS1214-Q1
ADVANCE INFORMATION
TPS1214-Q1 features an accurate analog load current monitor output (IMON) with adjustable gain. The current source at IMON terminal is configured to be proportional to the current flowing through the RSNS current sense resistor. This current can be converted to a voltage using a resistor RIMON from IMON terminal to GND pins.
This voltage, computed using following equation, can be used as a means of monitoring current flow through the system.
Use Equation to calculate the V(IMON).
Where,
VSNS = ILOAD × RSNS,
V(OS_SET) is the input referred offset (±150µV) of the current sense amplifier (VSNS to V(IMON) scaling),
0.9 is the current mirror factor between the current sense amplifier and the IMON pass FET.
The maximum voltage range for monitoring the current (V(IMONmax)) is limited to minimum([V(VS) – 0.5V], 5.5V)
to ensure linear output. This puts limitation on maximum value of RIMON resistor. The IMON pin has an internal clamp of 6.5V (typical).
Accuracy of the current mirror factor is < ±1%. Use the following equation to calculate the overall accuracy of V(IMON).