Datenblatt-pdf.com


LM555 Schematic ( PDF Datasheet ) - Fairchild Semiconductor

Teilenummer LM555
Beschreibung Single Timer
Hersteller Fairchild Semiconductor
Logo Fairchild Semiconductor Logo 




Gesamt 13 Seiten
LM555 Datasheet, Funktion
January 2013
LM555
Single Timer
Features
• High-Current Drive Capability: 200 mA
• Adjustable Duty Cycle
• Temperature Stability of 0.005%/°C
• Timing From μs to Hours
• Turn off Time Less Than 2 μs
Applications
• Precision Timing
• Pulse Generation
• Delay Generation
• Sequential Timing
Description
The LM555 is a highly stable controller capable of pro-
ducing accurate timing pulses. With a monostable opera-
tion, the delay is controlled by one external resistor and
one capacitor. With astable operation, the frequency and
duty cycle are accurately controlled by two external
resistors and one capacitor.
8-DIP
1
8-SOIC
1
Ordering Information
Part Number
LM555CN
LM555CM
LM555CMX
Operating Temperature Range
0 ~ +70°C
Top Mark
LM555CN
LM555CM
LM555CM
Package
DIP 8L
SOIC 8L
SOIC 8L
Packing Method
Rail
Rail
Tape & Reel
© 2002 Fairchild Semiconductor Corporation
LM555 Rev. 1.1.0
1
www.fairchildsemi.com






LM555 Datasheet, Funktion
Figure 8. Waveforms of Astable Operation
An astable timer operation is achieved by adding resistor RB to Figure 2 and configuring as shown on Figure 6. In the
astable operation, the trigger terminal and the threshold terminal are connected so that a self-trigger is formed, operat-
ing as a multi-vibrator. When the timer output is high, its internal discharging transistor. turns off and the VC1 increases
by exponential function with the time constant (RA+RB)*C.
When the VC1, or the threshold voltage, reaches 2 VCC/3; the comparator output on the trigger terminal becomes
high, resetting the F/F and causing the timer output to become low. This turns on the discharging transistor and the C1
discharges through the discharging channel formed by RB and the discharging transistor. When the VC1 falls below
VCC/3, the comparator output on the trigger terminal becomes high and the timer output becomes high again. The dis-
charging transistor turns off and the VC1 rises again.
In the above process, the section where the timer output is high is the time it takes for the VC1 to rise from VCC/3 to 2
VCC/3, and the section where the timer output is low is the time it takes for the VC1 to drop from 2 VCC/3 to VCC/3.
When timer output is high, the equivalent circuit for charging capacitor C1 is as follows:
RA RB
Vcc C1 Vc1(0-)=Vcc/3
C1
d----v----c---1--
dt
=
V-----c---c---------V-----(--0--------)
RA + RB
VC1(0+) = VCC 3
(1)
(2)
VC1(t)
=
VC
C
1
2--
3
-
e
(---R-----A-----+-----Rt-----B----)--C-----1--

(3)
Since the duration of the timer output high state (tL) is the amount of time it takes for the VC1(t) to reach 2 VCC/3,
VC1(t)
=
2--
3
VC
C
=
V
C
C
1
2--
3
-
e
(---R-----A-----+---t--HR-----B----)--C-----1--


(4)
tH = C1(RA + RB)In2 = 0.693(RA + RB)C1
(5)
© 2002 Fairchild Semiconductor Corporation
LM555 Rev. 1.1.0
6
www.fairchildsemi.com

6 Page









LM555 pdf, datenblatt
Physical Dimensions (continued)
8-SOIC
Figure 17. 8-Lead, SOIC,JEDEC MS-012, 150" NARROW BODY
Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner
without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or
obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the
warranty therein, which covers Fairchild products.
Always visit Fairchild Semiconductor’s online packaging area for the most recent package drawings:
http://www.fairchildsemi.com/packaging/.
For current tape and reel specifications, visit Fairchild Semiconductor’s online packaging area:
http://www.fairchildsemi.com/dwg/M0/M08A.pdf.
© 2002 Fairchild Semiconductor Corporation
LM555 Rev. 1.1.0
12
www.fairchildsemi.com

12 Page





SeitenGesamt 13 Seiten
PDF Download[ LM555 Schematic.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
LM555TimerNational Semiconductor
National Semiconductor
LM555Single TimerFairchild Semiconductor
Fairchild Semiconductor
LM555LM555 Timer (Rev. D)Texas Instruments
Texas Instruments
LM555Timers for Timing Delays and Oscillator Application in CommercialHarris Corporation
Harris Corporation
LM555CTimers for Timing Delays and Oscillator Applications in Commercial/ Industrial and Military EquipmentIntersil Corporation
Intersil Corporation

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com       |      2020       |      Kontakt     |      Suche