AN3290 datasheet(13/34 Pages) STMICROELECTRONICS

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AN3290

Typical board waveforms

Doc ID 18038 Rev 1

13/34

Typical board waveforms

Typical waveforms during TX mode and different input voltages are shown in this section. In

this condition the load on output 1 changes from 35 to 550 mA with 1 Hz of repetition rate

and 60% duty cycle. Output 2 is loaded at 100 mA.

Figures Figure 10, 11, 12 and 13 show the drain voltage and drain current waveforms at

different input voltage values.

Note that the maximum drain peak voltage at maximum input voltage is 576 V (Figure 13),

ensuring a reliable operation of the MOSFET with good margin against its maximum

BVDSS.

During PLM operations it is important that the output voltage remains regulated within

specification limits, to ensure correct operations for the PLM power amplifier. In order to test

such conditions, output 1 has been submitted to a dynamic step load according to the

specifications of Table 1 and output 2 has been loaded with different output currents, in

order to simulate the widest possible operative conditions.

Results are shown in figures 13 to 21; the output voltage is quite stable and clean with no

abnormal oscillation during load changes and the steady-state values are within

specification with very good margin.

Figure 10.

Normal operations in TX mode at 85 VAC

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