SMS64 datasheet(16/24 Pages) SUMMIT

16 / 24 page

SMS64

Preliminary

Summit Microelectronics, Inc

2060 2.22 10/09/03

Applications Example

A simple application example is shown in Figure 8.

Three voltages are provided by a motherboard, +5V,

+3.3V, and +1.8V. The +5V and +3.3V supplies are

switched on through series MOSFETS and applied to

the application circuit. The +1.8V supply will drive an

LDO, supplying +1.2V to the application circuit. The

application requires that the power supplies sequence

in the following order: +1.2V, +3.3V, +5.0V. As these

supplies are sequenced on, RST_A# is cleared after

the +1.2V supply has reached its under-voltage

threshold. RST_B# is not cleared until the +3.3V and

+5.0V supplies have reached their under-voltage

threshold. After the supplies have sequenced on, a

10% under-voltage on the +1.2V supply will trigger

RSTA#. Similarly, a 10% under-voltage on the +3.3V

supply will trigger RSTB#. The devices driven by the

application circuit require that if a 10% under-voltage

occurs on the +5.0V supply, the SMS64 will generate

an IRQ#.

A 10% over-voltage on any supply will

trigger both RSTA# and RSTB#. This application also

requires that the power supplies are sequenced off in

the reverse order that they were sequenced on. The

power supply sequencing is controlled by toggling the

PWR_ON/OFF pin.

With these requirements, the

SMS64 is configured as follows:

Channel A

Sequenced; Sequence Position 2; Power-On

Delay(tDPONA) = 50ms; Power-Off Delay(tDPOFFA) =

50ms;

Under-voltage; Programmable Threshold(VPTHA) =

4.50V

Channel B

Sequenced; Sequence Position 1; Power-On

Delay(tDPONB) = 25ms; Power-Off Delay(tDPOFFB) =

25ms;

Under-voltage; Programmable Threshold(VPTHB) =

2.96V

Channel C

Sequenced; Sequence Position 0; Power-On

Delay(tDPONC) = 50ms; Power-Off Delay(tDPOFFC) =

100ms;

Under-voltage; Programmable Threshold(VPTHC) =

1.06V

Channel D

Not Sequenced; Sequence Position null (7);

Over-voltage; Programmable Threshold(VPTHD) =

5.50V

+5.0V

SMS64

+3.3V

IRQ#

RSTA#

RSTB#

GND

V+

OUT

SET

ON/OFF

+1.8V

+1.2V

+5.0V

+3.3V

Figure 8 – Simple Applications Example

APPLICATIONS INFORMATION (CONTINUED)

SMS64 датащи(PDF) 16 Page - Summit Microelectronics, Inc.

SMS64 датащи(HTML) 16 Page - Summit Microelectronics, Inc.

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

датащи скачать

ссылки URL