DS3994应用电路
DS3994应用电路 Application with a single lamp per channel
In this application the internal DC bias voltage at the LCM and OVD pins allows for an AC-coupled input. This design can make the external circuitry very simple. A typical operating circuit for this application is shown in Figure 1.
In this application, the thresholds are referenced to VDCB. The values are listed in Table 2 and may be different for other parts.
Table 2. DS3994 LCM and OVD Thresholds (for Figure 1)
Parameter | Symbol | Min | Typ | Max | Units |
Lamp off threshold | VLOT | 0.30 | 0.40 | 0.50 | V |
Lamp overcurrent threshold | VLOC | 1.80 | 2.00 | 2.20 | V |
Lamp regulation threshold | VLRT | 0.94 | 1.00 | 1.06 | V |
OVD threshold | VOVDT | 0.90 | 1.00 | 1.10 | V |
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