Philips Semiconductors Linear Products

Product specification

ICM7555

General purpose CMOS timer

August 31, 1994

338

EQUIVALENT BLOCK DIAGRAM

NOTE:

UNUSED INPUTS SHOULD BE CONNECTED TO APPROPRIATE VOLTAGE FROM TRUTH TABLE.

V

DD

8

R

6

5

2

R

1

R

COMPARATOR

A

COMPARATOR

B

FLIP–FLOP

RESET

4

OUTPUT

DRIVERS

3

OUTPUT

DISCHARGE

7

N

1

+

–

+

–

THRESHOLD

CONTROL

VOLTAGE

TRIGGER

TRUTH TABLE

THRESHOLD VOLTAGE

TRIGGER VOLTAGE

OUTPUT

DISCHARGE SWITCH

DON’T CARE

DON’T CARE

LOW

LOW

ON

>2/3(V+)

> 1/3(V+)

HIGH

LOW

ON

HIGH

STABLE

STABLE

DON’T CARE

<1/3(V+)

HIGH

HIGH

OFF

NOTES:

1. RESET will dominate all other inputs: TRIGGER will dominate over THRESHOLD.

SYMBOL

PARAMETER

RATING

UNITS

Supply voltage

+18

V

Trigger input voltage

Control voltage

> -0.3 to

Threshold input voltage

V

RESET input voltage

Output current

100

mA

N package

1160

mW

D package

780

mW

Storage temperature range

-65 to +150

Lead temperature (Soldering 60s)

300

NOTES:

1. Due to the SCR structure inherent in the CMOS process used to fabricate these devices, connecting any terminal to a voltage greater than

not operating from the same power supply be applied to the device before its power supply is established. In multiple systems, the supply of

the ICM7555 must be turned on first.

2. Derate above 25

°C, at the following rates:

N package at 9.3mW/

°C

D package at 6.2mW/

°C

3. See “Power Dissipation Considerations” section.