The starting order of the old light or damaged light

When an old lamp is connected to the ballast, the impact voltage is higher than the nominal value voltage and may be higher than the safety threshold. In this case, the lights may be longer than the ignition time or no time. In these two cases, during the ignition, due to the decrease in the frequency, the voltage at the output end of the ballast can easily reach the risk value. If the lamp is ruptured, the same situation will occur: the light cannot be ignited, and the lamp voltage must be limited. During the ignition, the L6585DE connects to the HBCS pin through the sensor sensor inflow into the light. If the HBCS pin voltage reaches 1.6 V, a small amount of current sinks from the EOI pin, causing the frequency to increase slightly. From a macro perspective, the result of the modification is the frequency adjustment, so the current adjustment and light voltage limit generates. Once the HBCS pin voltage reaches 1.6 V, the TCH pin starts to charge CD: When the TCH voltage reaches 4.63V, the TCH pin is no longer free (such as during the preheating period), but the sink of 26UA will cause the CD to release faster. When the TCH voltage reaches 1.5 V, pull down and check the HBCS voltage. If the voltage is higher than 1.05 V, the IC stops working. If the lights ignite within this shortened TCH cycle, the EOI pin stops the sinking current. If it reaches 1.9 V, the IC enters the operating mode, and the TCH pin will be pulled down immediately.

It is worth noting that the short TCH cycle time depends only on the CD value. It is recommended to start with CD to obtain protection time, and then continue to choose RD to obtain the required TPRE

Old light management in the operation mode

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[ 123] In the operating mode, there may be three different abnormal behaviors in the old lamp:

Rectifier effect

overcurrent

Hard exchange event

The rectification effect

The difference between the difference between the rectification effect and the two Om resistance between the two is related to the cathode. Therefore, when the light current flows in, the equivalent resistance of the lights is higher than the other direction. The current of the current waveform distortion is no longer zero. The offline pin is the input of the internal window comparator. It can be triggered by the voltage change caused by the rectification effect. The benchmark of this comparator and the amplitude of the window can be set to set the appropriate resistor of the EOLP pin shown in the table below:

The reference voltage of the comparator can be set. For fixed voltage or sales with the center. When connecting lights, you can use a fixed reference configuration (see Figure 12) ground. The average voltage of two Zina diode to move the lights is needed to be 2.5V. The symmetrical protection of the two Qina values u200bu200baffect interference: Choose two differences equal to two times reference voltage:

vup u003d vREF+VZ2+VF1+W/2

VDOWNu003dVREF–（VZ1+VF2）–W/2

VUPu003d-V下

2 VREFu003dVZ1 VZ2[ 123]

Among them, VUP and VDOWN are the maximum allowable values u200bu200bof VK. When the lights are connected to the clutch circle and the lock capacitor uses a block capacitor to configure the ground. The voltage on this configuration blocks the voltage on the capacitor is affected by the voltage ripples and superimposed on the PFC output. Use the reference to the same wave of patterns to help reject it and avoid premature triggers of comparators. Once the comparator is triggered, the TCH cycle begins to improve noise immunity.

Over current protection

The emergence of overcurrent and hard switching events increases the two cathode ohm resistors. Essence The overall effect will lead to an equivalent resistance of the lights and the resonance curve of the resonance network (see Figure 14).

The increase in resonance peaks will lead to the same current and ignition mode managed by L6585DE, but the limit threshold and inspection threshold are 1.05 volts and 0.82 volts, respectively.

Hard switch protection

When the FRUN is equal to the peak of the resonance curve, the load of the half bridge is pure resistor. In this case, the zero voltage switch no longer exists, and the high -current peak will appear when MOSFET is opened. The voltage at the HBCS pin shows that these peaks can be greater than 3V, and the duration depends on the resonance frequency and operating frequency. The typical value is about 40 nan seconds 200 nan seconds. These peaks may cause the MOSFET to overheat, but if it is detected correctly, it can prevent risks (capacitive mode) working below the resonance frequency. The L6585DE can detect these peaks through the 2.75 V threshold on the HBCS pin to detect the peak of 350 (typical) (typical) subsequent peaks, then the counter of the IC is turned off. This protection is blank during the preheating and ignition process.

The saturation protection of the choice circle

The saturation of the stiffened circle of the town of the town means that the very high current flows into the resonance network and the resonance curve almost instantly at the working point and is in a capacitive mode immediately. The stable operation in the capacitor mode is severely damaged.

Therefore, in the ignition and running mode, the comparator activation threshold connected to the HBCS pin is equal to 2.75 V and 1.6 V. It induced the sensor sensor resistance and immediately locks the IC of the low consumption mode. The width trigger peak is above 200ns. This ensures that switching events (typical duration between 40 ns and 100 ns) cannot be triggered in the operation mode. However, hard switch protection and anti -saturation protection is not perfectly independentof.Regarding the pulse width, we can point out four different areas:

(a) peaks that last less than 40ns: (noise zone) without protection triggers.

(B) The peak between the duration between 40 nan seconds and 100 nan seconds: (HSW area) Only hard switch protection will be activated after about 420 events.

(C) The peak between 100ns and 200NS duration: (uncertain area) hard switch protection action can also be anti -saturated protection activation, which may cause early activation or delay of the hard switch protection to start resistanceSaturation protection (the blocking will not be too deep in this case).

(D) Peak peaks that last more than 200NS: (ASP zone) Anti -saturation protection will definitely be activated during the first activity.