AC LINE FREQUENCY TIMER

June 2004

FEATURES:

• Selectable Timing Intervals

• Internal Voltage Regulator

• Schmitt Trigger on all inputs for high noise immunity

• Power-On-Reset

• Built-in discharge when power is removed

• Output to drive an SCR connected to load

• Output to flash an indicator when timeout has occurred

• LS6301 (DIP); LS6301-S (SOIC) - See Figure 1

DESCRIPTION:

The circuit operates by counting AC power line cycles. When the

selected timeout occurs, the circuit will switch an external power

device. Selectable timing intervals using 3 mode pins are indicated

in Table 1. The circuit contains a Power-On-Reset (POR) to zero

out all the timing counters upon power-up. A positive or negative

transition of any of the A, B or C timing mode input pins will cause

the timer to reset and begin again. Once time-out is achieved, it re-

mains latched until a mode pin transition occurs or POR occurs.

TABLE 1. TIMING INTERVALS (60 Hz INPUT)

A INPUT

B INPUT

C INPUT

TIMING I NTERVAL

Vss

Vss

Vss

15 Minutes

Vss

Vss

2 Minutes

Vss

Vss

30 Minutes

Vss

45 Minutes

Vss

Vss

30 Seconds

Vss

15 Minutes

Vss

1 Hour

2 Hours

1

2

3

4

5

6

7

8

B

A

OUT 1

AC IN

FIGURE 1

PIN ASSIGNMENT - TOP VIEW

OUT 2

C

6301-060804-1

LSI/CSI

LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 (631) 271-0400 FAX (631) 271-0405

LS6301

UL

®

A3800

The C input mode pin contains an internal pull up resistor for

directly connecting to a SPST switch. By tying either the A or B

input, or both, to the C input and using the C input as the time-

out selection, a maximum number of timeout combinations can

be achieved.

Output 1 is normally low and goes high at the end of the

selected timing interval. It produces a 1.85Hz output square

wave signal and is normally used to drive an SCR with a load

such as a thermal relay or a neon indicator lamp.

Output 2 is normally high and goes low at the end of the

selected timing interval. The output drives an SCR whose load

could be a relay, resistance heater or some other device. The

load would be turned off at the end of the timing interval.

ELECTRICAL CHARACTERISTICS:

Operating Temperature 0°C to 85°C

Min

Typical

Max

Unit

Power-On-Reset

-

3.0

-

V

Hysteresis

-

0.8

-

V

Regulating Voltage

-

5.5

-

V

Timing Mode Pins:

Pull-up current (Pin 5 only)

-

100

-

uA

-

-

4.9

V

0.7

-

-

V

AC Input Pin

Maximum frequency

1.0

-

-

MHz

Input Current

± 10

-

-

mA

-

-

4.9

V

0.7

-

-

V

Hysteresis

2.0

-

-

V

Output 1 (Pin 2); Output 2 (Pin 3)

150

-

950

uA

3.8

-

-

mA