NE555/SA555/NA555

Document number: DS35112 Rev. 5 - 2

1 of 14

www.diodes.com

February 2021

© Diodes Incorporated

NE555

PRECISION TIMER

Description

These devices are precision timing circuits capable of producing

accurate time delays or oscillation. In the time-delay or monostable

mode of operation, the timed interval is controlled by a single external

resistor and capacitor network. In the astable mode of operation, the

frequency and duty cycle can be controlled independently with two

external resistors and a single external capacitor.

The threshold and trigger levels normally are two-thirds and one-third,

respectively, of VCC. These levels can be altered by use of the

control-voltage terminal. When the trigger input falls below the trigger

level, the flip-flop is set, and the output goes high. If the trigger input

is above the trigger level and the threshold input is above the

threshold level, the flip-flop is reset and the output is low. The reset

(RESET) input can override all other inputs and can be used to

initiate a new timing cycle. When RESET goes low, the flip-flop is

reset, and the output goes low. When the output is low, a low-

impedance path is provided between discharge (DISCH) and ground.

The output circuit is capable of sinking or sourcing current up to

200mA. Operation is specified for supplies of 5V to 15V. With a 5-V

supply, output levels are compatible with TTL inputs.

Features

•

Timing from microseconds to hours

•

Astable or monostable operation

•

Adjustable duty cycle

•

TTL compatible output can source or sink up to 200mA

•

Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)

•

Halogen- and Antimony-Free. “Green” Device (Note 3)

•

For automotive applications requiring specific change

control (i.e. parts qualified to AEC-Q100/101/200, PPAP

capable, and manufactured in IATF 16949 certified

facilities), please contact us or your local Diodes

representative.

https://www.diodes.com/quality/product-definitions/

Pin Assignments

Notes:

1. No purposely added lead. FullyEU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3).compliant.

2. See https://www.diodes.com/quality/lead-free/ formore information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"

and Lead-free.

3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl)

and <1000ppm antimony compounds.

(Top View)

SO-8

VCC

DISCH

THRES

CONT

OUT

TRIG

GND

RESET