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 supports independent channel brightness control through the FlexWire interface. The brightness of each channel is adjustable according to its DC current register IOUTXn, PWM duty cycle register PWMOUTXn/PWMLOWOUTXn and channel enable register ENOUTXn setting. The brightness of each channel reflects to its register setting value immediately after register is successfully updated through the FlexWire interface by master unit. However, the master unit loses the control for all current channels if the FlexWire communication fails between master unit and the TPS929240-Q1. For example, the interface cable is broken by accident. As a consequence, the brightness for all output channels of the TPS929240-Q1 are stuck and the ON and OFF control for all output channels are missed too. To keep the basic ON and OFF control for each output channels, the TPS929240-Q1 provides a FAIL-SAFE state when the communication to master is lost. For detailed description for FAIL-SAFE state entering and quitting criteria, refer to Device Functional Modes.
When the TPS929240-Q1 is entering FAIL-SAFE state, all the registers are set to default value or reloaded from EEPROM including IOUTXn, PWMOUTXn, PWMLOWOUTXn and ENOUTXn. The pre-programmed settings in the EEPROM are loaded and the corresponding registers are reset to the default values. The TPS929240-Q1 provides two hardware input pins, FS0 and FS1 to turn on or off corresponding current output channels in FAIL-SAFE state. Each current output channel has its own register, FSOUTXn to set the mapping to FS0 or FS1. When FSOUTXn is set to 0, the corresponding current output channel is controlled by FS0 input, otherwise it is controlled by FS1 input. If the voltage of FSx input is higher than its high threshold, VIH(IO), all current output channels mapped to FSx input are turned on. When the voltage of FSx input drops below low threshold, VIL(IO), all current out channels mapped to FSx input are turned off. The flag register FLAG_EXTFSx shows the FSx input level at real-time. If FSx pin input voltage is logic high, the FLAG_EXTFSx is set to 1. All FSOUTXn registers load their corresponding EEPROM data when the TPS929240-Q1 enters FAIL-SAFE state.
The PWM generator and phase shift dimming are both supported in FAIL-SAFE state. Figure 6-6 is the signal path diagram for PWM generator in FAIL-SAFE state.
The FAIL-SAFE state also allows the TPS929240-Q1 operating as a standalone device without master controlling in the system. The ERR pin is used as a fault indicator to achieve one-fails-all-fail or one-fails-others-on diagnostics requirement. When low quiescent current in fault mode is required, the device must be set as one-fails-all-fail. In this case, if fault is triggered, the device goes into low current fault mode.