Rev 2.0 ©2010 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, CA 94089-1706 Tel: (408) 747-1155 Fax: (408) 747-1286

www.aldinc.com

SINGLE/DUAL PRECISION HIGH SPEED MICROPOWER TIMER

ALD1502/ALD2502

BLOCK DIAGRAM (EACH TIMER)

OUTPUT

(3)

DISCHARGE

(7)

RESET

(4)

R

S

R

R

R

TRIGGER

(2)

GND

(1)

CONTROL

(5)

THRESHOLD

(6)

V+

(8)

* Contact factory for leaded (non-RoHS) or high temperature versions.

Operating Temperature Range *

0°C to +70°C0°C to +70°C

-55°C to +125°C

8-Pin Small Outline

8-Pin Plastic

8-Pin CERDIP

Package (SOIC)

DIP Package

Package

ALD1502SAL

ALD1502PAL

ALD1502DA

14-Pin Small Outline

14-Pin Plastic

14-Pin CERDIP

Package (SOIC)

DIP Package

Package

ALD2502SBL

ALD2502PBL

ALD2502DB

ORDERING INFORMATION (“L” suffix denotes lead-free (RoHS))

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 oscilla-

tions 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 200KΩ

each) that set the threshold and trigger levels at two-thirds and one-third

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: 50µA typical for ALD1502

and100µA 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

PIN CONFIGURATION

SAL, PAL, DA PACKAGES

1

2

3

4

8

7

6

5

GND

TRIG

OUT

RST

DISC

THRES

CONT

ALD1502

SBL, PBL, DB PACKAGES

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

8

ALD2502