NE555
NE555Precision Timers
1 Features
1
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.
The threshold and trigger levels normally are two-
thirds and one-third, respectively, of V
CC
. 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 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.
•
•
•
•
•
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.
2 Applications
•
•
•
Fingerprint Biometrics
Iris Biometrics
RFID Reader
4 Simplified Schematic
CONT
5
6
THRES
R1
R
S
1
2
TRIG
1
GND
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1
Î Î
Î Î
Î Î
Î
Î
Î
V
CC
8
RESET
4
Î
Î
Î
Î
Î
Î
Î
3
OUT
7
DISCH
2014 OCT
NE555
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)
SE555...FK PACKAGE
(TOP VIEW)
GND
TRIG
OUT
RESET
1
2
3
4
8
7
6
5
V
CC
DISCH
THRES
CONT
NC
GND
NC
V
CC
NC
NC
TRIG
NC
OUT
NC
4
5
6
7
3 2 1 20 19
18
17
16
15
14
8
9 10 11 12 13
NC
DISCH
NC
THRES
NC
NC – No internal connection
Pin Functions
PIN
NAME
D, P, PS,
PW, JG
NO.
CONT
DISCH
GND
NC
OUT
RESET
THRES
TRIG
V
CC
3
4
6
2
8
5
7
1
12
17
2
1, 3, 4, 6, 8,
9, 11, 13,
14, 16, 18,
19
7
10
15
5
20
I/O
O
–
–
O
I
I
I
–
Controls comparator thresholds, Outputs 2/3 VCC, allows bypass capacitor
connection
Open collector output to discharge timing capacitor
Ground
No internal connection
High current timer output signal
Active low reset input forces output and discharge low.
End of timing input. THRES > CONT sets output low and discharge low
Start of timing input. TRIG < ½ CONT sets output high and discharge open
Input supply voltage, 4.5 V to 16 V. (SE555 maximum is 18 V)
FK
I/O
DESCRIPTION
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2
NC
RESET
NC
CONT
NC
2014 OCT
NE555
7 Specifications
7.1 Absolute Maximum Ratings
(1)
over operating free-air temperature range (unless otherwise noted)
MIN
V
CC
V
I
I
O
Supply voltage
Input voltage
Output current
D package
θ
JA
Package thermal impedance
(3) (4)
P package
PS package
PW package
θ
JC
T
J
Package thermal impedance
(5) (6)
Operating virtual junction temperature
Case temperature for 60 s
Lead temperature 1,6 mm (1/16 in) from case for 60 s
(1)
(2)
(3)
(4)
(5)
(6)
FK package
JG package
FK package
JG package
(2)
MAX
18
V
CC
±225
97
85
95
149
5.61
14.5
150
260
300
UNIT
V
V
mA
CONT, RESET, THRES, TRIG
°C/W
°C/W
°C
°C
°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 T
J
(max),
θ
JA
, and T
A
. The maximum allowable power dissipation at any allowable ambient
temperature is P
D
= (T
J
(max) - T
A
) /
θ
JA.
Operating at the absolute maximum T
J
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 T
J
(max),
θ
JC
, and T
C
. The maximum allowable power dissipation at any allowable case
temperature is P
D
= (T
J
(max) - T
C
) /
θ
JC
. Operating at the absolute maximum T
J
of 150°C can affect reliability.
The package thermal impedance is calculated in accordance with MIL-STD-883.
7.2 Handling Ratings
PARAMETER
T
stg
Storage temperature range
DEFINITION
MIN
–65
MAX
150
UNIT
°C
7.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
V
CC
V
I
I
O
Supply voltage
Input voltage
Output current
NA555
T
A
Operating free-air temperature
NE555
SA555
SE555
–40
0
–40
–55
NA555, NE555, SA555
SE555
CONT, RESET, THRES, and TRIG
4.5
4.5
MAX
16
18
V
CC
±200
105
70
85
125
°C
UNIT
V
V
mA
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3
2014 OCT
NE555
7.4 Electrical Characteristics
V
CC
= 5 V to 15 V, T
A
= 25°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
THRES voltage level
THRES current
(1)
V
CC
= 15 V
TRIG voltage level
V
CC
= 5 V
TRIG current
RESET voltage level
RESET current
DISCH switch off-state
current
DISCH switch on-state
voltage
V
CC
= 5 V, I
O
= 8 mA
V
CC
= 15 V
CONT voltage
(open circuit)
V
CC
= 5 V
V
CC
= 15 V, I
OL
= 10 mA
V
CC
= 15 V, I
OL
= 50 mA
V
CC
= 15 V, I
OL
= 100 mA
V
CC
= 15 V, I
OL
= 200 mA
V
CC
= 5 V, I
OL
= 3.5 mA
V
CC
= 5 V, I
OL
= 5 mA
V
CC
= 5 V, I
OL
= 8 mA
V
CC
= 15 V, I
OH
= –100 mA
High-level output voltage
V
CC
= 15 V, I
OH
= –200 mA
V
CC
= 5 V, I
OH
= –100 mA
Output low, No load
Supply current
Output high, No load
(1)
3
T
A
= –55°C to 125°C
V
CC
= 15 V
V
CC
= 5 V
V
CC
= 15 V
V
CC
= 5 V
2
10
3
9
2
12
5
10
4
10
3
9
2
15
6
13
5
mA
13
T
A
= –55°C to 125°C
12
12.5
3.3
2.75
12.5
3.3
V
T
A
= –55°C to 125°C
0.1
T
A
= –55°C to 125°C
0.15
13.3
9.6
T
A
= –55°C to 125°C
T
A
= –55°C to 125°C
T
A
= –55°C to 125°C
0.4
T
A
= –55°C to 125°C
2
T
A
= –55°C to 125°C
2.5
0.35
0.2
0.8
0.25
12.75
0.15
13.3
0.4
0.1
0.35
9.6
2.9
2.9
0.1
3.3
10
10.4
10.4
3.8
3.8
0.15
0.2
0.5
1
2.2
2.7
2.5
2
2.5
V
0.4
0.75
0.1
0.25
2.6
3.3
4
9
TRIG at 0 V
0.3
T
A
= –55°C to 125°C
RESET at V
CC
RESET at 0 V
0.1
–0.4
20
4.8
T
A
= –55°C to 125°C
T
A
= –55°C to 125°C
0.5
0.7
3
1.45
1.67
V
CC
= 15 V
V
CC
= 5 V
9.4
2.7
SE555
TYP
10
3.3
30
5
MAX
10.6
4
250
5.2
6
1.9
1.9
0.9
1
1.1
0.4
–1
100
0.1
–0.4
20
0.15
10
0.4
–1.5
100
0.4
11
V
0.3
0.5
0.7
2
1
μA
V
mA
nA
V
1.1
1.67
2.2
4.5
MIN
8.8
2.4
NA555
NE555
SA555
TYP
10
3.3
30
5
MAX
11.2
4.2
250
5.6
V
V
nA
UNIT
Low-level output voltage
This parameter influences the maximum value of the timing resistors R
A
and R
B
in the circuit of
Figure 12.
For example,
when V
CC
= 5 V, the maximum value is R = R
A
+ R
B
≉
3.4 MΩ, and for V
CC
= 15 V, the maximum value is 10 MΩ.
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4
2014 OCT
NE555
7.5 Operating Characteristics
V
CC
= 5 V to 15 V, T
A
= 25°C (unless otherwise noted)
PARAMETER
(3)
TEST
CONDITIONS
(1)
MIN
T
A
= 25°C
T
A
= MIN to MAX
T
A
= 25°C
C
L
= 15 pF,
T
A
= 25°C
C
L
= 15 pF,
T
A
= 25°C
SE555
TYP
0.5
1.5
30
90
0.05
0.15
100
100
200
(4)
200
(4)
100
(4)
0.2
(4)
NA555
NE555
SA555
MAX
1.5
(4)
UNIT
MAX
3
%
ppm/
°C
0.5
%/V
ns
ns
MIN
TYP
1
2.25
50
150
0.1
0.3
100
100
Initial error of timing
interval
(2)
Temperature coefficient of
timing interval
Each timer, monostable
Each timer, astable
(5)
Each timer, monostable
(3)
Each timer, astable
(5)
(3)
Supply-voltage sensitivity of Each timer, monostable
timing interval
Each timer, astable
(5)
Output-pulse rise time
Output-pulse fall time
(1)
(2)
(3)
(4)
(5)
300
300
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: R
A
= 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: R
A
= 1 kΩ to 100 kΩ,
C = 0.1
μF.
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2014 OCT
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