A
L
D
DVANCED
INEAR
EVICES, INC.
ALD1502/ALD2502
SINGLE/DUAL PRECISION HIGH SPEED MICROPOWER TIMER
GENERAL DESCRIPTION
APPLICATIONS
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.
? 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
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.
PIN CONFIGURATION
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.
+
V
GND
TRIG
OUT
RST
1
2
3
8
7
6
5
+
DISC
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
levelatthesametimethetriggerinputisabovethetriggerlevel, theinternal
flip-flopisreset, theoutputgoestothelowstateandsinksupto10mA. The
resetinputoverridesallotherinputsandwhenitisactive(resetvoltageless
than 1V), the output is in the low state.
THRES
CONT
4
TOP VIEW
DA, PA, SA PACKAGE
+
1
14
V
DSC
1
1
1
FEATURES
THRES
2
3
4
13 DSC
2
? 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 50μA typical for ALD1502
and100μA typical for ALD2502
CONT
RST
12 THRES
2
11
10
9
CONT
1
2
5
6
7
OUT
RST
2
1
OUT
TRIG
2
1
8
GND
TRIG
2
TOP VIEW
DB, PB, SB PACKAGE
? 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
BLOCK DIAGRAM (EACH TIMER)
+
V
(8)
RESET
(4)
ORDERING INFORMATION
Operating Temperature Range *
THRESHOLD
(6)
R
S
R
R
-55°C to +125°C
0°C to +70°C
0°C to +70°C
CONTROL
(5)
OUTPUT
(3)
8-Pin
8-Pin Small Outline 8-Pin Plastic Dip
DISCHARGE
(7)
CERDIP Package
ALD1502 DA
Package (SOIC)
ALD1502 SA
Package
ALD1502PA
TRIGGER
(2)
R
14-Pin
14-Pin Small Outline 14-Pin Plastic Dip
CERDIP Package
ALD2502 DB
Package (SOIC)
ALD2502 SB
Package
ALD2502 PB
GND
(1)
* Contact factory for industrial temperature range
? 1998 Advanced Linear Devices, Inc. 415Tasman Drive, Sunnyvale, California 94089 -1706 Tel: (408) 747-1155 Fax: (408) 747-1286 http://www.aldinc.com
ALD [ ADVANCED LINEAR DEVICES ]
