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NA555, NE555, SA555, SE555
SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
xx555 Precision Timers
1 Features
3 Description
•
•
•
•
These devices are precision timing circuits capable of
producing accurate time delays or oscillation. In the
time-delay or mono-stable mode of operation, the
timed interval is controlled by a single external
resistor and capacitor network. In the a-stable mode
of operation, the frequency and duty cycle can be
controlled independently with two external resistors
and a single external capacitor.
1
•
Timing From Microseconds to Hours
Astable or Monostable Operation
Adjustable Duty Cycle
TTL-Compatible Output Can Sink or Source
Up to 200 mA
On Products Compliant to MIL-PRF-38535,
All Parameters Are Tested Unless Otherwise
Noted. On All Other Products, Production
Processing Does Not Necessarily Include
Testing of All Parameters.
The threshold and trigger levels normally are twothirds 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 flipflop 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.
2 Applications
•
•
•
Fingerprint Biometrics
Iris Biometrics
RFID Reader
The output circuit is capable of sinking or sourcing
current up to 200 mA. Operation is specified for
supplies of 5 V to 15 V. With a 5-V supply, output
levels are compatible with TTL inputs.
Device Information(1)
PART NUMBER
xx555
PACKAGE
BODY SIZE (NOM)
PDIP (8)
9.81 mm × 6.35 mm
SOP (8)
6.20 mm × 5.30 mm
TSSOP (8)
3.00 mm × 4.40 mm
SOIC (8)
4.90 mm × 3.91 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
4 Simplified Schematic
VCC
8
6
THRES
2
TRIG
CONT
5
Î
Î
Î Î
Î Î
Î
Î Î
RESET
4
Î
Î
Î
Î
Î
Î
Î
R1
R
3
OUT
1
S
7
DISCH
1
GND
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
NA555, NE555, SA555, SE555
SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
www.ti.com
Table of Contents
1
2
3
4
5
6
7
8
Features ..................................................................
Applications ...........................................................
Description .............................................................
Simplified Schematic.............................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
1
2
3
4
7.1
7.2
7.3
7.4
7.5
7.6
4
4
4
5
6
7
Absolute Maximum Ratings .....................................
Handling Ratings.......................................................
Recommended Operating Conditions.......................
Electrical Characteristics...........................................
Operating Characteristics..........................................
Typical Characteristics ..............................................
Detailed Description .............................................. 9
8.1
8.2
8.3
8.4
9
Overview ................................................................... 9
Functional Block Diagram ......................................... 9
Feature Description................................................... 9
Device Functional Modes........................................ 12
Applications and Implementation ...................... 13
9.1 Application Information............................................ 13
9.2 Typical Applications ................................................ 13
10 Power Supply Recommendations ..................... 18
11 Device and Documentation Support ................. 19
11.1
11.2
11.3
11.4
Related Links ........................................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
19
19
19
19
12 Mechanical, Packaging, and Orderable
Information ........................................................... 19
5 Revision History
Changes from Revision H (June 2010) to Revision I
Page
•
Updated document to new TI enhanced data sheet format. .................................................................................................. 1
•
Deleted Ordering Information table. ...................................................................................................................................... 1
•
Added Military Disclaimer to Features list. ............................................................................................................................. 1
•
Added Applications. ................................................................................................................................................................ 1
•
Added Device Information table. ............................................................................................................................................ 1
•
Moved Tstg to Handling Ratings table. .................................................................................................................................... 4
•
Added DISCH switch on-state voltage parameter. ................................................................................................................. 5
•
Added Device and Documentation Support section............................................................................................................. 19
•
Added ESD warning. ............................................................................................................................................................ 19
•
Added Mechanical, Packaging, and Orderable Information section..................................................................................... 19
2
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Copyright © 1973–2014, Texas Instruments Incorporated
Product Folder Links: NA555 NE555 SA555 SE555
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SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
6 Pin Configuration and Functions
NA555...D OR P PACKAGE
NE555...D, P, PS, OR PW PACKAGE
SA555...D OR P PACKAGE
SE555...D, JG, OR P PACKAGE
(TOP VIEW)
1
8
2
7
3
6
4
5
VCC
DISCH
THRES
CONT
NC
GND
NC
VCC
NC
NC
TRIG
NC
OUT
NC
4
3 2 1 20 19
18
5
17
6
16
7
15
14
9 10 11 12 13
8
NC
DISCH
NC
THRES
NC
NC
RESET
NC
CONT
NC
GND
TRIG
OUT
RESET
SE555...FK PACKAGE
(TOP VIEW)
NC – No internal connection
Pin Functions
PIN
NAME
D, P, PS,
PW, JG
FK
I/O
DESCRIPTION
NO.
CONT
5
12
I/O
Controls comparator thresholds, Outputs 2/3 VCC, allows bypass capacitor
connection
DISCH
7
17
O
Open collector output to discharge timing capacitor
GND
1
2
–
Ground
1, 3, 4, 6, 8,
9, 11, 13,
14, 16, 18,
19
–
No internal connection
NC
OUT
3
7
O
High current timer output signal
RESET
4
10
I
Active low reset input forces output and discharge low.
THRES
6
15
I
End of timing input. THRES > CONT sets output low and discharge low
TRIG
2
5
I
Start of timing input. TRIG < ½ CONT sets output high and discharge open
VCC
8
20
–
Input supply voltage, 4.5 V to 16 V. (SE555 maximum is 18 V)
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SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
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7 Specifications
7.1 Absolute Maximum Ratings (1)
over operating free-air temperature range (unless otherwise noted)
MIN
VCC
Supply voltage (2)
VI
Input voltage
IO
Output current
θJA
18
CONT, RESET, THRES, TRIG
Package thermal impedance (3) (4)
θJC
Package thermal impedance (5) (6)
TJ
Operating virtual junction temperature
(1)
(2)
(3)
(4)
(5)
(6)
MAX
UNIT
V
VCC
V
±225
mA
D package
97
P package
85
PS package
95
PW package
149
FK package
5.61
JG package
14.5
°C/W
°C/W
150
°C
Case temperature for 60 s
FK package
260
°C
Lead temperature 1,6 mm (1/16 in) from case for 60 s
JG package
300
°C
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating
Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
All voltage values are with respect to GND.
Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable ambient
temperature is PD = (TJ(max) - TA) / θJA. Operating at the absolute maximum TJ of 150°C can affect reliability.
The package thermal impedance is calculated in accordance with JESD 51-7.
Maximum power dissipation is a function of TJ(max), θJC, and TC. The maximum allowable power dissipation at any allowable case
temperature is PD = (TJ(max) - TC) / θJC. Operating at the absolute maximum TJ of 150°C can affect reliability.
The package thermal impedance is calculated in accordance with MIL-STD-883.
7.2 Handling Ratings
PARAMETER
Tstg
DEFINITION
Storage temperature range
MIN
MAX
UNIT
–65
150
°C
UNIT
7.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
VCC
Supply voltage
VI
Input voltage
IO
Output current
TA
4
Operating free-air temperature
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MIN
MAX
NA555, NE555, SA555
4.5
16
SE555
4.5
18
CONT, RESET, THRES, and TRIG
V
VCC
V
±200
mA
NA555
–40
105
NE555
0
70
SA555
–40
85
SE555
–55
125
°C
Copyright © 1973–2014, Texas Instruments Incorporated
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SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
7.4 Electrical Characteristics
VCC = 5 V to 15 V, TA = 25°C (unless otherwise noted)
PARAMETER
THRES voltage level
TEST CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
9.4
10
10.6
8.8
10
11.2
VCC = 5 V
2.7
3.3
4
2.4
3.3
4.2
30
250
5
5.2
1.67
1.9
4.8
VCC = 15 V
TA = –55°C to 125°C
TRIG voltage level
RESET current
3
1.45
VCC = 5 V
RESET voltage level
0.3
5.6
1.1
1.67
2.2
0.5
2
0.7
1
nA
V
0.9
1
0.3
1.1
μA
V
RESET at VCC
0.1
0.4
0.1
0.4
RESET at 0 V
–0.4
–1
–0.4
–1.5
20
100
20
100
nA
0.15
0.4
V
9
10
11
2.6
3.3
4
0.1
0.25
0.4
0.75
2
2.5
VCC = 5 V, IO = 8 mA
9.6
TA = –55°C to 125°C
TA = –55°C to 125°C
VCC = 15 V, IOL = 10 mA
VCC = 15 V, IOL = 50 mA
VCC = 15 V, IOL = 100 mA
VCC = 5 V, IOL = 5 mA
Output low, No load
Supply current
Output high, No load
3.8
0.1
0.15
0.5
1
2
TA = –55°C to 125°C
2.2
2.7
V
2.5
TA = –55°C to 125°C
2.5
0.35
0.1
TA = –55°C to 125°C
0.2
0.1
0.35
0.15
0.4
0.8
0.15
13
0.25
13.3
12.75
13.3
12
12.5
3
TA = –55°C to 125°C
V
0.2
TA = –55°C to 125°C
TA = –55°C to 125°C
mA
3.8
0.4
VCC = 15 V, IOH = –200 mA
VCC = 5 V, IOH = –100 mA
3.3
TA = –55°C to 125°C
VCC = 5 V, IOL = 8 mA
VCC = 15 V, IOH = –100 mA
10.4
10.4
2.9
VCC = 15 V, IOL = 200 mA
VCC = 5 V, IOL = 3.5 mA
10
9.6
2.9
VCC = 5 V
(1)
0.7
TA = –55°C to 125°C
CONT voltage
(open circuit)
High-level output voltage
250
5
V
1.9
0.5
VCC = 15 V
Low-level output voltage
30
4.5
6
TA = –55°C to 125°C
TRIG at 0 V
DISCH switch off-state
current
DISCH switch on-state
voltage
UNIT
VCC = 15 V
THRES current (1)
TRIG current
NA555
NE555
SA555
SE555
12.5
3.3
2.75
V
3.3
2
VCC = 15 V
10
12
10
15
VCC = 5 V
3
5
3
6
VCC = 15 V
9
10
9
13
VCC = 5 V
2
4
2
5
mA
This parameter influences the maximum value of the timing resistors RA and RB in the circuit of Figure 12. For example,
when VCC = 5 V, the maximum value is R = RA + RB ≉ 3.4 MΩ, and for VCC = 15 V, the maximum value is 10 MΩ.
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SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
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7.5 Operating Characteristics
VCC = 5 V to 15 V, TA = 25°C (unless otherwise noted)
PARAMETER
MIN
Initial error of timing
interval (2)
Each timer, monostable (3)
Temperature coefficient of
timing interval
Each timer, monostable (3)
Each timer, astable
Each timer, astable
TA = 25°C
(5)
TYP
MAX
0.5
1.5 (4)
1.5
TA = MIN to MAX
(5)
(3)
Supply-voltage sensitivity of Each timer, monostable
(5)
timing interval
Each timer, astable
NA555
NE555
SA555
SE555
TEST
CONDITIONS (1)
30
0.05
TYP
MAX
1
3
2.25
100 (4)
90
TA = 25°C
MIN
UNIT
50
ppm/
°C
150
0.2 (4)
0.15
0.1
%
0.5
0.3
%/V
Output-pulse rise time
CL = 15 pF,
TA = 25°C
100
200 (4)
100
300
ns
Output-pulse fall time
CL = 15 pF,
TA = 25°C
100
200 (4)
100
300
ns
(1)
(2)
(3)
(4)
(5)
6
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
Timing interval error is defined as the difference between the measured value and the average value of a random sample from each
process run.
Values specified are for a device in a monostable circuit similar to Figure 9, with the following component values: RA = 2 kΩ to 100 kΩ,
C = 0.1 μF.
On products compliant to MIL-PRF-38535, this parameter is not production tested.
Values specified are for a device in an astable circuit similar to Figure 12, with the following component values: RA = 1 kΩ to 100 kΩ,
C = 0.1 μF.
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SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
7.6 Typical Characteristics
Data for temperatures below –40°C and above 105°C are applicable for SE555 circuits only.
10
7
VCC = 5 V
4
2
VOL − Low-Level Output Voltage − V
VOL − Low-Level Output Voltage − V
10
7
TA = −55°C
1
0.7
TA = 25°C
0.4
TA = 125°C
0.2
0.1
0.07
0.04
VCC = 10 V
4
2
TA = 25°C
1
0.7
TA= −55°C
0.4
TA = 125°C
0.2
0.1
0.07
0.04
0.02
0.02
0.01
0.01
1
2
4
7
10
20
40
1
70 100
Figure 1. Low-Level Output Voltage
vs Low-Level Output Current
7
10
20
40
70 100
Figure 2. Low-Level Output Voltage
vs Low-Level Output Current
TA = −55°C
VCC = 15 V
1.8
4
TA = −55°C
( VCC − VOH) − Voltage Drop − V
VOL − Low-Level Output Voltage − V
4
2.0
10
7
2
1
0.7
0.4
TA = 25°C
0.2
TA = 125°C
0.1
0.07
0.04
0.02
1.6
TA = 25°C
1.4
1.2
TA = 125°C
1
0.8
0.6
0.4
0.2
0.01
1
2
4
7
10
20
40
0
70 100
VCC = 5 V to 15 V
1
2
4
7 10
20
40
70 100
IOH − High-Level Output Current − mA
IOL − Low-Level Output Current − mA
Figure 3. Low-Level Output Voltage
vs Low-Level Output Current
Output Low,
No Load
9
8
TA = 25°C
7
6
5
TA = −55°C
4
Figure 4. Drop Between Supply Voltage and Output
vs High-Level Output Current
Pulse Duration Relative to Value at VCC = 10 V
10
I CC − Supply Current − mA
2
IOL − Low-Level Output Current − mA
IOL − Low-Level Output Current − mA
TA = 125°C
3
2
1
1.015
1.010
1.005
1
0.995
0.990
8
0.985
0
5
6
7
8
9
10
11
12
13
14
15
0
5
10
15
20
VCC − Supply Voltage − V
VCC − Supply Voltage − V
Figure 5. Supply Current
vs Supply Voltage
Figure 6. Normalized Output Pulse Duration
(Monostable Operation)
vs Supply Voltage
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Typical Characteristics (continued)
Data for temperatures below –40°C and above 105°C are applicable for SE555 circuits only.
1000
VCC = 10 V
900
TA = 125°C
1.010
t PD – Propagation Delay Time – ns
Pulse Duration Relative to Value at TA = 25 C
1.015
1.005
1
0.995
0.990
8
700
TA = 70°C
600
500
TA = 25°C
400
300
T A = 0° C
200
TA = –55°C
100
0.985
−75
8
−50
−25
0
25
50
75
100 125
TA − Free-Air Temperature − °C
Figure 7. Normalized Output Pulse Duration
(Monostable Operation)
vs
Free-Air Temperature
8
800
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0
0
0.05 0.1 0.15
0.2 0.25 0.3 0.35
Lowest Level of Trigger Pulse – ×VCC
0.4
Figure 8. Propagation Delay Time
vs
Lowest Voltage Level of Trigger Pulse
Copyright © 1973–2014, Texas Instruments Incorporated
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SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
8 Detailed Description
8.1 Overview
The xx555 timer is a popular and easy to use for general purpose timing applications from 10 µs to hours or from
< 1mHz to 100 kHz. In the time-delay or mono-stable mode of operation, the timed interval is controlled by a
single external resistor and capacitor network. In the a-stable mode of operation, the frequency and duty cycle
can be controlled independently with two external resistors and a single external capacitor. Maximum output sink
and discharge sink current is greater for higher VCC and less for lower VCC.
8.2 Functional Block Diagram
VCC
8
6
THRES
2
TRIG
CONT
5
Î
Î
Î Î
Î
Î Î
Î Î
RESET
4
Î
Î
Î
Î
Î
Î
Î
R1
R
3
OUT
1
S
7
DISCH
1
GND
A.
Pin numbers shown are for the D, JG, P, PS, and PW packages.
B.
RESET can override TRIG, which can override THRES.
8.3 Feature Description
8.3.1 Mono-stable Operation
For mono-stable operation, any of these timers can be connected as shown in Figure 9. If the output is low,
application of a negative-going pulse to the trigger (TRIG) sets the flip-flop (Q goes low), drives the output high,
and turns off Q1. Capacitor C then is charged through RA until the voltage across the capacitor reaches the
threshold voltage of the threshold (THRES) input. If TRIG has returned to a high level, the output of the threshold
comparator resets the flip-flop (Q goes high), drives the output low, and discharges C through Q1.
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Feature Description (continued)
VCC
(5 V to 15 V)
RA
Î
Î
Î
4
7
6
Input
2
5
8
CONT
VCC
RL
RESET
DISCH
OUT
3
Output
THRES
TRIG
GND
1
Pin numbers shown are for the D, JG, P, PS, and PW packages.
Figure 9. Circuit for Monostable Operation
Monostable operation is initiated when TRIG voltage falls below the trigger threshold. Once initiated, the
sequence ends only if TRIG is high for at least 10 µs before the end of the timing interval. When the trigger is
grounded, the comparator storage time can be as long as 10 µs, which limits the minimum monostable pulse
width to 10 µs. Because of the threshold level and saturation voltage of Q1, the output pulse duration is
approximately tw = 1.1RAC. Figure 11 is a plot of the time constant for various values of RA and C. The threshold
levels and charge rates both are directly proportional to the supply voltage, VCC. The timing interval is, therefore,
independent of the supply voltage, so long as the supply voltage is constant during the time interval.
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏ
Applying a negative-going trigger pulse simultaneously to RESET and TRIG during the timing interval discharges
C and reinitiates the cycle, commencing on the positive edge of the reset pulse. The output is held low as long
as the reset pulse is low. To prevent false triggering, when RESET is not used, it should be connected to VCC.
10
RA = 10 MΩ
1
Input Voltage
ÏÏÏÏÏÏ
ÏÏÏÏÏÏ
ÏÏÏÏÏÏ
ÏÏÏÏÏÏ
Output Voltage
Capacitor Voltage
tw − Output Pulse Duration − s
Voltage − 2 V/div
RA = 9.1 kΩ
CL = 0.01 µF
RL = 1 kΩ
See Figure 9
RA = 1 MΩ
10−1
10−2
10−3
RA = 100 kΩ
RA = 10 kΩ
10−4
RA = 1 kΩ
10−5
0.001
0.01
Figure 10. Typical Monostable Waveforms
10
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0.1
1
10
100
C − Capacitance − µF
Time − 0.1 ms/div
Figure 11. Output Pulse Duration vs Capacitance
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Feature Description (continued)
8.3.2 A-stable Operation
As shown in Figure 12, adding a second resistor, RB, to the circuit of Figure 9 and connecting the trigger input to
the threshold input causes the timer to self-trigger and run as a multi-vibrator. The capacitor C charges through
RA and RB and then discharges through RB only. Therefore, the duty cycle is controlled by the values of RA and
RB.
ÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎÎÎÎ
This astable connection results in capacitor C charging and discharging between the threshold-voltage level (≈
0.67 × VCC) and the trigger-voltage level (≈ 0.33 × VCC). As in the mono-stable circuit, charge and discharge
times (and, therefore, the frequency and duty cycle) are independent of the supply voltage.
VCC
(5 V to 15 V)
Î
Î
Î
0.01 µF
Open
(see Note A) 5
8
VCC
CONT
4
7
RB
6
2
RL
RESET
DISCH
3
OUT
Output
THRES
t
H
TRIG
GND
C
RL = 1 kW
See Figure 12
Voltage − 1 V/div
RA
RA = 5 kW
RB = 3 kW
C = 0.15 µF
tL
Output Voltage
1
Pin numbers shown are for the D, JG, P, PS, and PW packages.
NOTE A: Decoupling CONT voltage to ground with a capacitor can
improve operation. This should be evaluated for individual
applications.
Figure 12. Circuit for Astable Operation
Capacitor Voltage
Time − 0.5 ms/div
Figure 13. Typical Astable Waveforms
Figure 12 shows typical waveforms generated during astable operation. The output high-level duration tH and
low-level duration tL can be calculated as follows:
tH = 0.693 (R A + RB )C
(1)
tL = 0.693 (RB )C
(2)
Other useful relationships are shown below:
period = tH + tL = 0.693 (R A + 2RB )C
(3)
1.44
frequency »
(R A +2RB )C
(4)
tL
RB
Output driver duty cycle =
=
tH + tL R A + 2RB
(5)
Output waveform duty cycle =
Low-to-high ratio =
tH
RB
= 1tH + tL
R A + 2RB
(6)
tL
RB
=
tH R A + RB
Copyright © 1973–2014, Texas Instruments Incorporated
Product Folder Links: NA555 NE555 SA555 SE555
(7)
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11
NA555, NE555, SA555, SE555
SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
www.ti.com
Feature Description (continued)
100 k
RA + 2 RB = 1 kΩ
f − Free-Running Frequency − Hz
RA + 2 RB = 10 kΩ
10 k
RA + 2 RB = 100 kΩ
1k
100
10
1
RA + 2 RB = 1 MΩ
RA + 2 RB = 10 MΩ
0.1
0.001
0.01
0.1
1
10
100
C − Capacitance − µF
Figure 14. Free-Running Frequency
8.3.3 Frequency Divider
By adjusting the length of the timing cycle, the basic circuit of Figure 9 can be made to operate as a frequency
divider. Figure 15 shows a divide-by-three circuit that makes use of the fact that re-triggering cannot occur during
the timing cycle.
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏ
Voltage − 2 V/div
VCC = 5 V
RA = 1250 Ω
C = 0.02 µF
See Figure 9
Input Voltage
Output Voltage
Capacitor Voltage
Time − 0.1 ms/div
Figure 15. Divide-by-Three Circuit Waveforms
8.4 Device Functional Modes
Table 1. Function Table
(1)
12
RESET
TRIGGER VOLTAGE (1)
THRESHOLD VOLTAGE (1)
OUTPUT
DISCHARGE SWITCH
Low
Irrelevant
Irrelevant
Low
On
High
1/3 VCC
>2/3 VCC
Low
High
>1/3 VCC
[maximum normal input high time]. RL improves VOH, but it is not required for
TTL compatibility.
Copyright © 1973–2014, Texas Instruments Incorporated
Product Folder Links: NA555 NE555 SA555 SE555
Submit Documentation Feedback
13
NA555, NE555, SA555, SE555
SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
www.ti.com
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
Typical Applications (continued)
9.2.1.3 Application Curves
Voltage − 2 V/div
VCC = 5 V
RA = 1 kΩ
C = 0.1 µF
See Figure 15
Input Voltage
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
Output Voltage
Capacitor Voltage
Time − 0.1 ms/div
Figure 17. Completed Timing Waveforms for Missing-Pulse Detector
9.2.2 Pulse-Width Modulation
The operation of the timer can be modified by modulating the internal threshold and trigger voltages, which is
accomplished by applying an external voltage (or current) to CONT. Figure 18 shows a circuit for pulse-width
modulation. A continuous input pulse train triggers the monostable circuit, and a control signal modulates the
threshold voltage. Figure 19 shows the resulting output pulse-width modulation. While a sine-wave modulation
signal is shown, any wave shape could be used.
VCC (5 V to 15 V)
4
RESET
Clock
Input
2
RL
8
VCC
OUT
TRIG
RA
3
Output
7
DISCH
Modulation
5
Input
(see Note A)
CONT
THRES
6
GND
C
1
Pin numbers shown are for the D, JG, P, PS, and PW packages.
NOTE A: The modulating signal can be direct or capacitively coupled
to CONT. For direct coupling, the effects of modulation source
voltage and impedance on the bias of the timer should be
considered.
Figure 18. Circuit for Pulse-Width Modulation
14
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Copyright © 1973–2014, Texas Instruments Incorporated
Product Folder Links: NA555 NE555 SA555 SE555
NA555, NE555, SA555, SE555
www.ti.com
SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
Typical Applications (continued)
9.2.2.1 Design Requirements
Clock input must have VOL and VOH levels that are less than and greater than 1/3 VCC. Modulation input can
vary from ground to VCC. The application must be tolerant of a nonlinear transfer function; the relationship
between modulation input and pulse width is not linear because the capacitor charge is based RC on an negative
exponential curve.
9.2.2.2 Detailed Design Procedure
Choose RA and C so that RA × C = 1/4 [clock input period]. RL improves VOH, but it is not required for TTL
compatibility.
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏÏÏÏÏÏÏÏ
ÏÏÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏÏÏ
ÏÏÏÏÏÏ
ÏÏÏÏÏÏ
ÏÏÏÏÏÏ
ÏÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏÏÏ
ÏÏÏÏÏÏ
9.2.2.3 Application Curves
RA = 3 kΩ
C = 0.02 µF
RL = 1 kΩ
See Figure 18
Voltage − 2 V/div
Modulation Input Voltage
Clock Input Voltage
Output Voltage
Capacitor Voltage
Time − 0.5 ms/div
Figure 19. Pulse-Width-Modulation Waveforms
9.2.3 Pulse-Position Modulation
As shown in Figure 20, any of these timers can be used as a pulse-position modulator. This application
modulates the threshold voltage and, thereby, the time delay, of a free-running oscillator. Figure 21 shows a
triangular-wave modulation signal for such a circuit; however, any wave shape could be used.
Copyright © 1973–2014, Texas Instruments Incorporated
Product Folder Links: NA555 NE555 SA555 SE555
Submit Documentation Feedback
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NA555, NE555, SA555, SE555
SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
www.ti.com
Typical Applications (continued)
VCC (5 V to 15 V)
4
8
RESET
2
VCC
OUT
RA
3
Output
TRIG
DISCH
Modulation
Input 5
(see Note A)
RL
CONT
THRES
7
6
RB
GND
C
Pin numbers shown are for the D, JG, P, PS, and PW packages.
NOTE A: The modulating signal can be direct or capacitively coupled
to CONT. For direct coupling, the effects of modulation
source voltage and impedance on the bias of the timer
should be considered.
Figure 20. Circuit for Pulse-Position Modulation
9.2.3.1 Design Requirements
Both DC and AC coupled modulation input will change the upper and lower voltage thresholds for the timing
capacitor. Both frequency and duty cycle will vary with the modulation voltage.
9.2.3.2 Detailed Design Procedure
The nominal output frequency and duty cycle can be determined using formulas in A-stable Operation section. RL
improves VOH, but it is not required for TTL compatibility.
16
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Copyright © 1973–2014, Texas Instruments Incorporated
Product Folder Links: NA555 NE555 SA555 SE555
NA555, NE555, SA555, SE555
www.ti.com
SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
Typical Applications (continued)
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎ
ÎÎÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
ÎÎÎÎÎÎ
9.2.3.3 Application Curves
Voltage − 2 V/div
RA = 3 kΩ
RB = 500 Ω
RL = 1 kΩ
See Figure 20
Modulation Input Voltage
Output Voltage
Capacitor Voltage
Time − 0.1 ms/div
Figure 21. Pulse-Position-Modulation Waveforms
9.2.4 Sequential Timer
Many applications, such as computers, require signals for initializing conditions during start-up. Other
applications, such as test equipment, require activation of test signals in sequence. These timing circuits can be
connected to provide such sequential control. The timers can be used in various combinations of astable or
monostable circuit connections, with or without modulation, for extremely flexible waveform control. Figure 22
shows a sequencer circuit with possible applications in many systems, and Figure 23 shows the output
waveforms.
VCC
4
RESET
2
8
VCC
3
OUT
TRIG
S
DISCH
5
0.01
µF
CONT
4
RESET
RA 33 kΩ
2
0.001
µF
7
1
CA = 10 µF
RA = 100 kΩ
6
0.01
µF
CA
RB
Output A
CONT
THRES
GND
1
CB
CB = 4.7 µF
RB = 100 kΩ
4
RESET
33 kΩ
2
0.001
µF
DISCH 7
5
THRES
GND
TRIG
8
VCC
3
OUT
DISCH
5
6
0.01
µF
Output B
TRIG
8
VCC
3
OUT
CONT
THRES
GND
1
CC
CC = 14.7 µF
RC = 100 kΩ
RC
7
6
Output C
Pin numbers shown are for the D, JG, P, PS, and PW packages.
NOTE A: S closes momentarily at t = 0.
Figure 22. Sequential Timer Circuit
Copyright © 1973–2014, Texas Instruments Incorporated
Product Folder Links: NA555 NE555 SA555 SE555
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NA555, NE555, SA555, SE555
SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
www.ti.com
Typical Applications (continued)
9.2.4.1 Design Requirements
The sequential timer application chains together multiple mono-stable timers. The joining components are the 33kΩ resistors and 0.001-µF capacitors. The output high to low edge passes a 10-µs start pulse to the next
monostable.
9.2.4.2 Detailed Design Procedure
The timing resistors and capacitors can be chosen using this formula. tw = 1.1 × R × C.
ÏÏÏÏÏ
ÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏ
ÏÏÏ
ÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏ
ÏÏÏ
ÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏ
ÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏ
ÏÏÏÏ
ÏÏÏÏÏ
ÏÏÏÏ
ÏÏÏÏ
ÏÏ
ÏÏÏÏÏ
ÏÏÏÏ
ÏÏ ÏÏÏÏÏ
ÏÏÏÏ
ÏÏ ÏÏÏÏÏ
ÏÏÏ
ÏÏÏ
ÏÏÏ
ÏÏÏ
9.2.4.3 Application Curves
See Figure 22
Voltage − 5 V/div
Output A
twA
twA = 1.1 RACA
twB
Output B
twB = 1.1 RBCB
Output C
twC
twC = 1.1 RCCC
t=0
t − Time − 1 s/div
Figure 23. Sequential Timer Waveforms
10 Power Supply Recommendations
The devices are designed to operate from an input voltage supply range between 4.5 V and 16 V. (18 V for
SE555). A bypass capacitor is highly recommended from VCC to ground pin; ceramic 0.1 µF capacitor is
sufficient.
18
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Copyright © 1973–2014, Texas Instruments Incorporated
Product Folder Links: NA555 NE555 SA555 SE555
NA555, NE555, SA555, SE555
www.ti.com
SLFS022I – SEPTEMBER 1973 – REVISED SEPTEMBER 2014
11 Device and Documentation Support
11.1 Related Links
The table below lists quick access links. Categories include technical documents, support and community
resources, tools and software, and quick access to sample or buy.
Table 2. Related Links
PARTS
PRODUCT FOLDER
SAMPLE & BUY
TECHNICAL
DOCUMENTS
TOOLS &
SOFTWARE
SUPPORT &
COMMUNITY
NA555
Click here
Click here
Click here
Click here
Click here
NE555
Click here
Click here
Click here
Click here
Click here
SA555
Click here
Click here
Click here
Click here
Click here
SE555
Click here
Click here
Click here
Click here
Click here
11.2 Trademarks
All trademarks are the property of their respective owners.
11.3 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
11.4 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms and definitions.
12 Mechanical, Packaging, and Orderable Information
The following pages include mechanical packaging and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser based versions of this data sheet, refer to the left hand navigation.
Copyright © 1973–2014, Texas Instruments Incorporated
Product Folder Links: NA555 NE555 SA555 SE555
Submit Documentation Feedback
19
PACKAGE OPTION ADDENDUM
www.ti.com
10-Jun-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
JM38510/10901BPA
ACTIVE
CDIP
JG
8
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
JM38510
/10901BPA
Samples
M38510/10901BPA
ACTIVE
CDIP
JG
8
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
JM38510
/10901BPA
Samples
NA555D
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 105
NA555
Samples
NA555DG4
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 105
NA555
Samples
NA555DR
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 105
NA555
Samples
NA555P
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU | SN
N / A for Pkg Type
-40 to 105
NA555P
Samples
NA555PE4
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
-40 to 105
NA555P
Samples
NE555D
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
NE555
Samples
NE555DG4
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
NE555
Samples
NE555DR
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU | SN
Level-1-260C-UNLIM
0 to 70
NE555
Samples
NE555DRE4
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
NE555
Samples
NE555DRG4
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
NE555
Samples
NE555P
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU | SN
N / A for Pkg Type
0 to 70
NE555P
Samples
NE555PE4
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
0 to 70
NE555P
Samples
NE555PS
ACTIVE
SO
PS
8
80
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
N555
Samples
NE555PSR
ACTIVE
SO
PS
8
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
N555
Samples
NE555PSRE4
ACTIVE
SO
PS
8
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
N555
Samples
NE555PSRG4
ACTIVE
SO
PS
8
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
N555
Samples
NE555PW
ACTIVE
TSSOP
PW
8
150
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
N555
Samples
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com
10-Jun-2022
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
NE555PWG4
ACTIVE
TSSOP
PW
8
150
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
N555
Samples
NE555PWR
ACTIVE
TSSOP
PW
8
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
N555
Samples
NE555PWRE4
ACTIVE
TSSOP
PW
8
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
N555
Samples
NE555PWRG4
ACTIVE
TSSOP
PW
8
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
N555
Samples
SA555D
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
SA555
Samples
SA555DE4
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
SA555
Samples
SA555DG4
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
SA555
Samples
SA555DR
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU | SN
Level-1-260C-UNLIM
-40 to 85
SA555
Samples
SA555DRE4
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
SA555
Samples
SA555DRG4
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 85
SA555
Samples
SA555P
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
-40 to 85
SA555P
Samples
SA555PE4
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
-40 to 85
SA555P
Samples
SE555D
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-55 to 125
SE555
Samples
SE555DG4
ACTIVE
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-55 to 125
SE555
Samples
SE555DR
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-55 to 125
SE555
Samples
SE555DRG4
ACTIVE
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-55 to 125
SE555
Samples
SE555FKB
ACTIVE
LCCC
FK
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
SE555FKB
Samples
SE555JG
ACTIVE
CDIP
JG
8
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
SE555JG
Samples
SE555JGB
ACTIVE
CDIP
JG
8
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
SE555JGB
Samples
SE555P
ACTIVE
PDIP
P
8
50
RoHS & Green
NIPDAU
N / A for Pkg Type
-55 to 125
SE555P
Samples
Addendum-Page 2
PACKAGE OPTION ADDENDUM
www.ti.com
10-Jun-2022
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of