A
DVANCED
L
INEAR
D
EVICES,
I
NC.
SINGLE/DUAL PRECISION HIGH SPEED MICROPOWER TIMER
GENERAL DESCRIPTION
The ALD1502/ALD2502 timers are high performance single/dual mono-
lithic timing circuits built with advanced silicon gate CMOS technology.
They offer the benefits of high input impedance, thereby allowing smaller
timing capacitors and a longer timing cycle; high speed, with typical cycle
time of 400ns; low power dissipation for battery operated environment;
reduced supply current spikes, allowing smaller and lower cost decoupling
capacitors.
Each timer is capable of producing accurate time delays and oscillations in
both monostable and astable operation, and operates in the one-shot
(monostable) 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 respec-
tively of V
+.
These levels can be adjusted by using the control terminal.
When the trigger input is below the trigger level, the output is in the high
state and sourcing 2mA. When the 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
High speed operation -- 2.5MHz typical oscillation at 5V
High discharge sinking current of 80mA at 5V
Guaranteed low operating supply voltage of 2V to 12V
Functional equivalent to and same pin-out as NE555/NE556
with greatly expanded high and low frequency ranges
High speed, low power, monolithic CMOS technology
Low supply current 50
A typical for ALD1502
and100
A typical for ALD2502
Extremely low trigger, threshold and reset currents 10pA typical
Operates in both monostable and astable modes
Fixed 50% duty cycle or adjustable duty cycle
CMOS, NMOS and TTL compatible input/output
Low supply current spikes
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
Synchronized timer
ALD1502/ALD2502
Operating Temperature Range *
-55
C to +125
C
0
C to +70
C
0
C to +70
C
8-Pin
8-Pin Small Outline
8-Pin Plastic Dip
CERDIP Package
Package (SOIC)
Package
ALD1502 DA
ALD1502 SA
ALD1502PA
14-Pin
14-Pin Small Outline 14-Pin Plastic Dip
CERDIP Package
Package (SOIC)
Package
ALD2502 DB
ALD2502 SB
ALD2502 PB
* Contact factory for industrial temperature range
PIN CONFIGURATION
BLOCK DIAGRAM (EACH TIMER)
ORDERING INFORMATION
DSC1
THRES1
CONT1
RST1
OUT1
TRIG1
GND
TRIG2
OUT2
RST2
CONT2
THRES2
DSC2
V+
2
3
4
5
6
7
9
10
11
12
13
14
1
1
2
3
4
8
7
6
5
TOP VIEW
DA, PA, SA PACKAGE
GND
TRIG
OUT
RST
V+
DISC
THRES
CONT
TOP VIEW
DB, PB, SB PACKAGE
8
OUTPUT
(3)
DISCHARGE
(7)
RESET
(4)
R
S
R
R
R
TRIGGER
(2)
GND
(1)
CONTROL
(5)
THRESHOLD
(6)
V+
(8)
1998 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, California 94089 -1706 Tel: (408) 747-1155 Fax: (408) 747-1286 http://www.aldinc.com
ALD1502/ALD2502
Advanced Linear Devices
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, PB, SA, SB package
0
C to + 70
C
DA, DB 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 ALD1502
I
S
50
90
A
Outputs Unloaded
Supply Current ALD2502
I
S
100
180
A
Timing error / Astable mode
t
err
1.0
2.2
%
C = 0.1
F
Initial Accuracy
Drift with Temperature
1
t/
T
10.0
ppm/
C
R
A
= 1K
Drift with Supply Voltage
1
t/
V+
0.2
%/V
R
B
= 1K
Threshold Voltage
V
TH
3.233
3.333
3.433
V
Trigger Voltage
V
TRIG
1.567
1.667
1.767
V
Trigger Current
2
I
TRIG
.01
0.4
nA
Reset Voltage
V
RST
0.4
0.7
1.0
V
Reset Current
2
I
RST
.01
0.4
nA
Threshold Current
2
I
TH
.01
0.4
nA
Control Voltage Level
V
CONT
3.233
3.333
3.433
V
Output Voltage Drop (Low)
V
OL
0.2
0.4
V
I
SINK
= 10mA
Output Voltage Drop (High)
V
OH
4.2
4.6
V
I
SOURCE
= -2mA
Rise Time of Output
1
t
r
10
20
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
1.5
2.5
MHz
R
B
= 200
C
T
=100pF
Minimum Trigger Pulse Width
1
t
TRIG
50
100
ns
Notes:
1
Sample tested parameters.
2
Consists of junction leakage currents with strong temperature dependence.
ALD1502/ALD2502
Advanced Linear Devices
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
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
DD
)
MINIMUM PULSE WIDTH (ns)
T
A
= 25
C
V
+
= 5V
V
+
=12V
V
+
= 2V
SUPPLY CURRENT AS A FUNCTION OF
SUPPLY VOLTAGE
0
2
4
6
8
10
12
100
60
50
40
30
20
10
0
70
80
90
TA = + 85
C
TA = + 20
C
TA = - 40
C
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (
A)
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
1 mF
100
F
10
F
1
F
10 nF
1 nF
100 pF
10
0.1
100
(
R
A
- 2R
B
)
TA = 25
C
100M
10M
1M
100K
10K
1K
ALD1502/ALD2502
Advanced Linear Devices
4
TYPICAL APPLICATIONS ( EACH TIMER )
TYPICAL PERFORMANCE CHARACTERISTICS
ASTABLE MODE OPERATION
50% DUTY CYCLE
1
2
3
4
8
7
6
5
R
C
0.1
F
Frequency f = 1/ (1.4 RC)
V
+
V
+
ASTABLE MODE OPERATION
(FREE RUNNING OSCILLATOR)
MONOSTABLE MODE OPERATION (ONE SHOT PULSE)
Pulse Delay t
d
= 1.1 R
C
1
2
3
4
8
7
6
5
C
0.1
F
R
A
V
+
V
+
R
B
Frequency f = 1.46 / (RA + 2RB)C
Duty Cycle DC = RB / (RA + 2RB)
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
+
= 5V
V
+
= 12V
TRIGGER
INPUT
DELAYED PULSE
OUTPUT
1
2
3
4
8
7
6
5
0.1
F
C
R
RESET
V
+
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