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SRK2001A

Operation description

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7.6.1

EN pin remote on-off

During the run mode, the EN pin can be used as remote on-off input, using a small signal

transistor connected to the pin. When the switch is closed, the pin voltage goes below the

7.6.2

Burst-mode detection

Normally, at reduced loads, resonant converters enter the burst-mode operation in order to

increase converter efficiency. The SRK2001A detects that the primary controller has

stopped switching, and enters the low consumption state: this happens when both DVS1,2

7.6.3

Low consumption state exit

After the primary controller restarts switching or the EN pin goes back high, the controller

resumes the operation when it detects that the conduction duty-cycle has increased above

number of clock cycles needed to exit the burst-mode is proportional to the difference

allows a faster sleep-out in case of the heavy load transient low-to-high.

switching cycles (i.e. 24 clock cycles) are still needed before the SRK2001A restarts driving

the SR MOSFETs (in order to allow the settlement of the internal timers, lost during the low

consumption state, where most of internal circuitry was not supplied or turned off).

For the correct operation of the SRK2001A, the primary controller has to be programmed in

such a way that, when it enters the burst-mode operation, the minimum switching stop has

to be longer than 20 µs (necessary to the SRK2001A to detect that operating condition).

Table 6. Burst-mode exiting lookup table

80%

75%

65%

0%