JAJSJM2B July 2022 – April 2024 TPS929240-Q1
PRODUCTION DATA
デバイスごとのパッケージ図は、PDF版データシートをご参照ください。
The TPS929240-Q1 continuously monitors the SUPPLY voltage and compares the results with internal threshold V(LOWSUPTH) set by LOWSUPTH for low-supply voltage warning.
If the supply voltage is lower than threshold, the device sets flag registers including FLAG_LOWSUP and FLAG_ERR to 1.
The fault is latched in flag registers. When the supply voltage rises above low-supply warning threshold, the master controller must write register CLRFAULT to 1 to reset FLAG_LOWSUP and FLAG_ERR. The CLRFAULT bit automatically returns to 0.
The low-supply warning is also used to disable the LED open-circuit detection and single-LED short-circuit detection. When the voltage applied on SUPPLY pin is higher than the threshold V(LOWSUPTH), the TPS929240-Q1 enables LED open-circuit and single-LED short-circuit diagnosis. When V(SUPPLY) is lower than the threshold V(LOWSUPTH), the device disables LED-open-circuit detection and single-LED short-circuit diagnosis. Because when V(SUPPLY) drops below the maximum total LED forward voltage plus required V(OUT_drop) at required current, the TPS929240-Q1 is not able to deliver sufficient current output to pull the voltage of each output channel as close as possible to the V(SUPPLY). In this condition, the LED open-circuit fault or single-LED short-circuit fault might be detected and reported by mistake. Setting the low-supply warning threshold high enough can avoid the LED open-circuit and single LED short-circuit fault being detected when V(SUPPLY) drops to low. The V(LOWSUPTH) is programmable from 4 V to 35 V at 1-V interval.