DS12978 Rev 1

13/28

VIPer26K

General description

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4

General description

4.1

Block diagram

Figure 19. Block diagram

4.2

Typical power capability

4.3

Primary MOSFET

The power section is implemented with an N-channel power MOSFET with a breakdown

voltage of 1050 V min. and a maximum RDS(ON) of 7 Ω. It includes a sense-FET structure to

allow a virtually lossless current sensing and the thermal sensor.

The gate driver of the power MOSFET is designed to supply a controlled gate current during

both turn-ON and turn-OFF in order to minimize common mode EMI. During UVLO

conditions, an internal pull-down circuit holds the gate low in order to ensure that the power

MOSFET cannot be turned ON accidentally.

Table 8. Typical power

Vin: 230 Vac

Vin: 85-265Vac

Vin: 85-440Vac

Adapter(1)

Open frame(2)

Adapter(1)

Open frame(2)

Adapter(1)

Open frame(2)

16W

20W

10W

12W

10W

12W

1. Typical continuous power in non-ventilated enclosed adapter measured at 50 °C ambient.

2. Maximum practical continuous power in an open frame design at 50 °C ambient, with adequate heatsinking.