Use the following instructions to observe the transient overload performance:
- The overcurrent blanking timer duration
(tTIMER) is 2.18 ms by default. The overcurrent blanking timer duration can
be programmed via PMBus using the OC_TIMER (E6h) register if another timer duration is
needed in the range of 0 ms to 27.8 ms.
- The reference voltage for overcurrent protection
and active current sharing is at 1 V by default. The reference voltage can also be
programmed via PMBus using the VIREF (E0h) register if another reference voltage is needed
in the range of 0.3 V to 1.2 V.
- Place jumper J6 in a good position to set
required circuit breaker threshold (IOCP) as per Table 4-3.
- Set the input supply voltage VIN to 12 V and current limit of 200 A.
- Connect the power supply between VIN (Connector T1) and PGND (Connector T3) and enable the power supply.
- Now apply an overload in the range of IOCP < ILOAD < 2 × IOCP between VOUT (Connector T2) and PGND (Connector T3) for a time duration less than tTIMER decided by using the OC_TIMER (E6h) register through PMBus.
- Observe the waveforms using an oscilloscope.
Figure 5-9 shows transient overload performance in TPS25990EVM with one TPS25990 eFuse and one
TPS25985 eFuse in parallel. Figure 5-10 presents the current sharing between two eFuses during the transient overload.
Figure 5-9 Transient Overload Performance in TPS25990EVM (VIN = 12 V, tITIMER = 20 ms, COUT = 470 μF, RIMON = 1.47 ∥ 1.1 kΩ, VIREF = 1 V, IOUT Ramped from 85 A to 140 A then 85 A within 15 ms) Figure 5-10 Transient Overload Performance in TPS25990EVM: Current Sharing between TPS25990 and TPS25985 eFuses (VIN = 12 V, tITIMER = 20 ms, COUT = 470 μF, RIMON = 1.47 ∥ 1.1 kΩ, VIREF = 1 V, IOUT Ramped from 85 A to 140 A then 85 A within 15 ms)