SP703 datasheet(10/16 Pages) SIPEX

Part #	SP703

Description	Low Power Microprocessor Supervisory with Battery Switch-Over

Download	16 Pages

Scroll/Zoom	100%

Manufacturer	SIPEX [Sipex Corporation]

Direct Link	http://www.sipex.com

Logo

10 / 16 page

SP703/704DS/07

SP703/704 Low Power Microprocessor Supervisory

10

Power-Fail Comparator

The Power-Fail Comparator can be used as an

under-voltage detector to signal the failing of a

power supply (it is completely separate from the

rest of the circuitry and does not need to be

dedicated to this function). The PFI input is

compared to an internal 1.25V reference. If PFI

is less than 1.25V, PFO goes low. The external

voltage divider drives PFI to sense the unregu-

lated DC input to the +5V regulator. The volt-

age-divider ratio can be chosen such that the

voltage at PFI falls below 1.25V just before the

+5V regulator drops out. PFO then triggers an

interrupt which signals the

µP to prepare for

power-down.

When V

BATT connects to VOUT, the power-fail

comparator is turned off and PFO is forced low

to conserve backup-battery power.

Backup-Battery Switchover

In the event of a brownout or power failure, it

may be necessary to preserve the contents of

RAM. With a backup battery installed at V

BATT,

the RAM is assured to have power if V

CC fails.

As long as V

CC exceeds the reset threshold,

V

OUT connects to VCC through a 0.6Ω PMOS

power switch. Once V

CC falls below the reset

threshold, V

CC or VBATT, whichever is higher,

switches to V

OUT.

V

BATT connects to VOUT

through a 5

Ω switch only when V

CC is below the

reset threshold and V

BATT is greater than VCC.

When V

CC exceeds the reset threshold, it is

connected to V

OUT, regardless of the voltage

applied to V

BATT Figure 9. During this time,

the diode (D1) between V

BATT and VOUT will

conduct current from V

BATT to VOUT if VBATT is

more than .6V above V

OUT.

When V

BATT connects to VOUT, backup mode is

activated and the internal circuitry will be

powered from the battery Figure 10. When V

CC

is just below V

BATT, in the backup mode the

current drawn from V

BATT will be typically

30

µA. When V

CC drops to more than 1V below

V

BATT, the internal switchover comparator shuts

off and the supply current falls to less than 0.6

µA.

Reset Threshold = 4.65V in SP703

Reset Threshold = 4.40V in SP704

Figure 9. BACKUP-BATTERY Switchover Block Diagram

SW1

D1

D2

D3

SW2

VBATT

VCC

GND

VOUT

N

O

I

T

I

D

N

O

C1

W

S2

W

S

V

C

d

l

o

h

s

e

r

h

T

t

e

s

e

R

>n

e

p

Od

e

s

o

l

C

V

C

d

n

a

d

l

o

h

s

e

r

h

T

t

e

s

e

R

<

V

C

V

>

T

A

B

n

e

p

Od

e

s

o

l

C

V

C

d

n

a

d

l

o

h

s

e

r

h

T

t

e

s

e

R

<

V

C

V

<

T

A

B

d

e

s

o

l

Cn

e

p

O

Similar Part No. - SP703

Manufacturer	Part #	Datasheet	Description
Sipex Corporation	SP703	216Kb / 16P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP703CN	216Kb / 16P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP703CP	216Kb / 16P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP703EN	216Kb / 16P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP703EP	216Kb / 16P	Low Power Microprocessor Supervisory with Battery Switch-Over

More results

Similar Description - SP703

Manufacturer	Part #	Datasheet	Description
Sipex Corporation	SP690A	631Kb / 16P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP703	216Kb / 16P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP791	202Kb / 19P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP691A	196Kb / 24P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP791CN-L	219Kb / 19P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP791	202Kb / 19P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP690A	631Kb / 16P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP691A	242Kb / 24P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP690A	411Kb / 16P	Low Power Microprocessor Supervisory with Battery Switch-Over
	SP690T	233Kb / 20P	3.0V/3.3V Low Power Microprocessor Supervisory with Battery Switch-Over

More results

SP703 Datasheet(PDF) 10 Page - Sipex Corporation

SP703 Datasheet(HTML) 10 Page - Sipex Corporation

Similar Part No. - SP703

Similar Description - SP703

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Datasheet Download

Link URL