| State | PROT Pin Voltage | IC Outputs (PWM) | |---|---|---| | Normal | ~5V | Switching | | Fault detected (first few cycles) | ~5V (no change) | Switching | | Fault confirmed | 0V | Hi-Z (off) | | After ( V_CC ) reset | ~5V (rising edge) | Switching resumes |
: Short lamp detection features stay offline until the C_TO line climbs past 0.5V .
被锁存后的LX1692会彻底关断AOUT、BOUT、COUT、DOUT四个驱动输出端的PWM信号，同时20脚VDDP供电仍维持5V。ISNS引脚会降至接近0V（保护后电流反馈停止），OV_SNS可能在灯管开路时出现异常峰压但芯片不再对此响应。只有当ENABLE信号复位或VDDP完全掉电再上电后，才可重新尝试点火。 lx1692 protection pin
The LX1692 is engineered to protect hardware from dangerous conditions. When a fault is detected, the IC shuts down the inverter to prevent catastrophic hardware failure, such as transformer burnout or housing fires.
: Verify that the main supply rails ( VIN , typically 12V or 24V) to the inverter bridge are stable and free of ripple. | State | PROT Pin Voltage | IC
. It allows you to see if the lamps light up briefly, helping identify if the issue is a faulty bulb or the controller itself.
Common faults that trigger the protection mechanisms include: : Verify that the main supply rails (
Turn on the monitor. The backlight will remain continuously forced on, allowing you to visually inspect the CCFL tubes and pinpoint which lamp is flicking, dimming, or failing. Method 2: The ISNS / OLP Resistor Pull-Down
On the LX1692 IC architectural layout, the protection timing mechanism is heavily tied to the , which is typically Pin 5 on standard 20-pin TSSOP/SOIC configurations.
The protection system is designed around a . It continuously monitors the backlight's electrical characteristics for safety and to extend the lifespan of the CCFL tubes.