Operating Temperature Range *
-55
C to +125
C
0
C to +70
C
0
C to +70
C
8-Pin
8-Pin
8-Pin
CERDIP
Small Outline
Plastic Dip
Package
Package (SOIC)
Package
ALD555 DA
ALD555 SA
ALD555 PA
APPLICATIONS
High speed one-shot (monostable)
pulse generation
Precision timing
Sequential timing
Long delay timer
Pulse width and pulse position
modulation
Missing pulse detector
Frequency divider
A
DVANCED
L
INEAR
D
EVICES,
I
NC.
ALD555
HIGH SPEED CMOS TIMER
GENERAL DESCRIPTION
The ALD555 timer is a high performance monolithic timing circuit built with
advanced silicon gate CMOS technology. It offers the benefits of high
input impedance, thereby allowing smaller timing capacitors and longer
timing cycle; high speed, with typical cycle time of 500ns; low power
dissipation for battery operated environment; reduced supply current
spikes, allowing smaller and lower cost decoupling capacitors. It is
capable of producing accurate time delays and oscillations in both
monostable and astable operation. It operates in the one-shot (mono-
stable) mode or 50% duty cycle free running oscillation mode with a single
resistor and one capacitor. The inputs and outputs are fully compatible
with CMOS, NMOS or TTL logic.
There are three matched internal resistors (approximately 200K
each)
that set the threshold and trigger levels at two-thirds and one-third
respectively of V+
.
These levels can be adjusted by using the control
terminal (pin 5). When the trigger input is below the trigger level, the
output is in the high state and sourcing 2mA. When threshold input is
above the threshold level at the same time the trigger input is above the
trigger level, the internal flip-flop is reset, the output goes to the low state
and sinks up to 10mA. The reset input overrides all other inputs and when
it is active (reset voltage less than 1V), the output is in the low state.
FEATURES
Functional equivalent to NE555 with greatly expanded high
and low frequency ranges
High speed, low power, monolithic CMOS technology
Low supply current 100
A typical
Extremely low trigger, threshold and reset currents -- 1pA typical
High speed operation -- 2MHz oscillation
Low operating supply voltage 2 to 12V
Operates in both monostable and astable modes
Fixed 50% duty cycle or adjustable duty cycle
CMOS, NMOS and TTL compatible input/output
High discharge sinking current (80mA)
Low supply current spikes
PIN CONFIGURATION
BLOCK DIAGRAM
GROUND
TRIGGER
OUTPUT
RESET
TOP VIEW
DA, PA, SA PACKAGE
DISCHARGE
THRESHOLD
7
CONTROL
3
1
2
4
6
8
5
V
+
OUTPUT
(3)
DISCHARGE
(7)
RESET
(4)
R
S
R
R
R
TRIGGER
(2)
GND
(1)
CONTROL
(5)
THRESHOLD
(6)
V+
(8)
ORDERING INFORMATION
* Contact factory for industrial temperature range
1998 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, California 94089 -1706 Tel: (408) 747-1155 Fax: (408) 747-1286 http://www.aldinc.com
ALD555
Advanced Linear Devices
9-2
ABSOLUTE MAXIMUM RATINGS
Supply voltage, V
+
13.2V
Input voltage range
-0.3V to V+
+0.3V
Power dissipation
600 mW
Operating temperature range
PA,SA package
0
C to +70
C
DA package
-55
C to +125
C
Storage temperature range
-65
C to +150
C
Lead temperature, 10 seconds
+260
C
OPERATING ELECTRICAL CHARACTERISTICS
T
A
= 25
o
C
V+
= +5V unless otherwise specified
Parameter
Symbol
Min
Typ
Max
Unit
Test Conditions
Supply Voltage
V+
2
12
V
Supply Current
I
S
100
180
A
Outputs Unloaded
Timing error / Astable mode
Initial Accuracy
t
err
1.0
2.2
%
C = 0.1
F
Drift with Temperature
1
t/
T
10.0
ppm/
C
R
A
= 1K
Drift with Supply Voltage
1
t/
V+
0.1
%/V
R
B
= 1K
Threshold Voltage
V
TH
3.273
3.333
3.393
V
Trigger Voltage
V
TRIG
1.607
1.667
1.737
V
Trigger Current
2
I
TRIG
.001
0.2
nA
Reset Voltage
V
RST
0.4
0.7
1.0
V
Reset Current
2
I
RST
.001
0.2
nA
Threshold Current
2
I
TH
.001
0.2
nA
Control Voltage Level
V
CONT
3.273
3.333
3.393
V
Output Voltage Drop (Low)
V
OL
0.2
0.4
V
I
SINK
= 10mA
Output Voltage Drop (High)
V
OH
4.2
V
I
SOURCE
= -2mA
Rise Time of Output
1
t
r
15
30
ns
R
L
= 10M
Fall Time of Output
1
t
f
10
20
ns
C
L
= 10pF
Discharge Transistor
I
DL
.01
nA
Leakage Current
Discharge Voltage Drop
V
DISC
0.5
1.0
V
I
DISCHARGE
= 80mA
0.2
0.4
V
I
DISCHARGE
= 30mA
Maximum Frequency
R
A
= 470
Astable Mode
f
MAX
1.4
2
MHz
R
B
= 200
C
T
= 200pF
Notes:
1
Sample tested parameters.
2
Consists of junction leakage currents with strong temperature dependence.
ALD555
Advanced Linear Devices
9-3
TYPICAL PERFORMANCE CHARACTERISTICS
TIME DELAY IN THE MONOSTABLE MODE
AS A FUNCTION OF R
A
AND C
TIME DELAY
100ns 1
s
1ms
1s
10s
CAPACITANCE
1G
10M
100M
1M
100K
10K
1K
10 mF
100 nF
1 mF
100
F
10
F
1
F
10 nF
1 nF
100 pF
T
A
= 25
C
10
s 100
s
10ms 100ms
100s
R
A
2
SUPPLY CURRENT AS A FUNCTION OF
SUPPLY VOLTAGE
0
4
6
8
10
12
200
120
100
80
60
40
20
0
140
160
180
T
A
= - 40
C
T
A
= + 20
C
T
A
= + 85
C
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (uA)
0
10
20
30
40
MINIMUM PULSE WIDTH
REQUIRED FOR TRIGGERING
800
600
500
400
300
200
100
0
700
LOWEST VOLTAGE LEVEL OF TRIGGER
PULSE ( % V
+
)
MINIMUM PULSE WIDTH (ns)
T
A
= 25
C
V
+
= 2V
V
+
= 5V
V
+
= 12V
DISCHARGE SINK CURRENT (mA)
DISCHARGE OUTPUT SINK CURRENT AS A
FUNCTION OF DISCHARGE LOW VOLTAGE
DISCHARGE LOW VOLTAGE (V)
0.01
0.02
0.05
0.1
1.0
0.5
0.2
100
50
20
5.0
2.0
1.0
0.5
0.2
0.1
10
T
A
= 25
C
V
+
= 5V
V
+
= 12V
V
+
= 2V
FREQUENCY CHANGE IN THE ASTABLE MODE
AS A FUNCTION OF SUPPLY VOLTAGE
SUPPLY VOLTAGE (V)
0
2
4
6
12
10
8
+4
+3
+2
+1
0
-1
-2
-3
FREQUENCY CHANGE (%)
-4
FREE RUNNING FREQUENCY AS A
FUNCTION OF R
A,
R
B
AND C
FREQUENCY (Hz)
1.0
1K
10K 100K
10M 100M
1M
10 mF
100 nF
CAPACITANCE
100M
10M
1M
100K
10K
1K
1 mF
100
F
10
F
1
F
10 nF
1 nF
100 pF
10
0.1
100
T
A
= 25
C
( R
A
- 2R
B
)
ALD555
Advanced Linear Devices
9-4
TYPICAL PERFORMANCE CHARACTERISTICS
OUTPUT SINK CURRENT (mA)
OUTPUT SINK CURRENT AS A
FUNCTION OF OUTPUT VOLTAGE
OUTPUT VOLTAGE (V)
0.01
0.02
0.05
0.1
1.0
0.5
0.2
100
50
20
5.0
2.0
1.0
0.5
0.2
0.1
10
V
+
= 12V
V
+
= 2V
TA = 25
C
V
+
= 5V
OUTPUT SOURCE CURRENT AS A
FUNCTION OF OUTPUT VOLTAGE
-1.0
-2.0
-5.0
-10
-20
-50
-100
-0.5
-0.5
-0.2
-0.1
-0.05
-0.02
-0.01
-0.2
-0.1
-1.0
OUTPUT VOLTAGE (V)
(REFERENCED TO V
+
)
OUTPUT SOURCE CURRENT (mA)
V+ = 2V
V+ = 12V
V+ = 5V
TYPICAL APPLICATIONS
ASTABLE MODE OPERATION
(FREE RUNNING OSCILLATOR)
MONOSTABLE MODE OPERATION (ONE SHOT PULSE)
Pulse Delay td = 1.1 R
C
ASTABLE MODE OPERATION
50% DUTY CYCLE
1
2
3
4
8
7
6
5
R
C
0.1
F
Frequency f = 1/ (1.4 R
C
)
V
+
V
+
1
2
3
4
8
7
6
5
C
0.1
F
R
A
V
+
V
+
R
B
Frequency f = 1.46 / (R
A
+ 2R
B
)C
Duty Cycle DC = R
B
/ (R
A
+ 2R
B
)
TRIGGER
INPUT
DELAYED PULSE
OUTPUT
1
2
3
4
8
7
6
5
0.1
F
C
R
RESET
V
+
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