ZHCSLS0B July 2022 – April 2024 TPS929240-Q1
PRODUCTION DATA
请参考 PDF 数据表获取器件具体的封装图。
The TPS929240-Q1 also integrates analog comparators to monitor all outputs with respect to two alternative threshold for single-LED short-circuit diagnostic in FAIL-SAFE state. Setting the register SLSEN to 1 enables the single-LED short-circuit detection.
The single-LED short-circuit detection is only effective during PWM-ON state with programmable minimal pulse width of t(BLANK) + t(SLS_deg). The t(BLANK) is programmable by register BLANK. If PWM on-time is less than t(BLANK) + t(SLS_deg), the device cannot report any single-LED short-circuit fault. When the device supply voltage V(SUPPLY) is below the threshold V(LOWSUPTH) set by register LOWSUPTH, the single-LED short-circuit is not detected nor reported.
When the voltage V(OUTXn) is below threshold V(SLSTHx) with duration longer than deglitch timer length of t(BLANK) + t(SLS_deg), and the device supply voltage V(SUPPLY) is above the threshold V(LOWSUPTH), the device pulls the ERR pin down with constant current sink to report fault and set flag registers including FLAG_SLSOUTXn, FLAG_OUT and FLAG_ERR. The TPS929240-Q1 provides two alternative threshold V(SLSTH0) and V(SLSTH1) for single-LED short-circuit detection selected by SLSTHOUTXn independently for each current output. The V(SLSTH0) is selected for current OUTXn when LSTHOUTXn is set to 0, however V(SLSTH1) is selected when SLSLTHOUTXn is set to 1. The actual voltage value for V(SLSTH0) and V(SLSTH1) is programmable by two 8-bit registers SLSTH0 and SLSTH1 from 2.5 V to 34.375 V at 125-mV interval. In FAIL-SAFE state, the TPS929240-Q1 shuts down the normal current regulation and PWM duty cycle for the faulty output, then the device sources a pulse current, I(OUTXn) programed by IOUTXn register to the faulty output every t(SLS_Retry), 10 ms for retrying. When the voltage V(OUTXn) of error output rises above threshold V(SLSTHx) + 275 mV with duration longer than t(BLANK) + t(SLS_deg) during retrying, or the supply voltage V(SUPPLY) is below the threshold V(LOWSUPTH), the device automatically resumes the normal current and PWM dutycycle setup and releases the ERR pin.
The fault is latched in flag registers. When the single-LED short-circuit fault is removed, the master controller must write 1 to register CLRFAULT to clear FLAG_SLSOUTXn, FLAG_OUT and FLAG_ERR. The CLRFAULT automatically returns to 0.