HIP6501 datasheet(12/14 Pages) INTERSIL

12 / 14 page

If a P-Channel MOSFET is used to switch the 5VSB output

of the ATX supply into the 5VDUAL output during S3 and

S4/S5 states (as dictated by EN5VDL status), then, similar

to the situation where Q1 is a MOSFET, the selection criteria

of this device is also proper voltage budgeting. The

maximum rDS(ON), however, has to be achieved with only

4.5V of VGS, so a logic level MOSFET needs to be selected.

If a PNP device is chosen to perform this function, it has to

have a low saturation voltage while providing the maximum

sleep-state current and have a current gain sufﬁciently high

to be saturated using the minimum drive current (typically

20mA; 4mA during soft-start).

Q3, Q5

The two N-Channel MOSFETs are used to switch the 3.3V

and 5V inputs provided by the ATX supply into the

3.3VDUAL and 5VDUAL outputs, respectively, while in active

(S0, S1) states. Similar rDS(ON) criteria apply in these cases

as well, unlike the PMOS, however, these NMOS transistors

get the beneﬁt of an increased VGS drive (approximately 8V

and 7V, respectively).

The NPN transistor used as sleep-state pass element on the

3.3VDUAL output must have a minimum current gain of 100

at VCE = 1.5V, and ICE = 500mA throughout the in-circuit

operating temperature range.

HIP6501A

HIP6501 Scheda tecnica(PDF) 12 Page - Intersil Corporation