PIR SENSOR INTERFACE

June 2009

6506R-060209-1

LSI/CSI

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

LS6506R

LS6507R

UL

®

A3800

DESCRIPTION

The

LS6506R is a CMOS integrated circuit designed for room oc-

cupancy detection and can be used for switching power on to all types

of AC loads. The circuit drives a two-coil latching relay (Figure 2). When

the latching relay is engaged, full AC power is connected to the load.

The

LS6506R draws its power from the AC hot line and the house-

ground connection that is located in a standard wall box. The maximum

current draw from the ground line is 500µA RMS. The

LS6507R draws

its power from the AC HOT and AC NEUTRAL lines. All timing is gener-

ated from the AC input.

The circuit contains a two stage PIR amplifier. The sensitivity can be ad-

justed by replacing R5 in

Figure 2 with a potentiometer. Upon power up

all inputs are disabled for a period of 56 seconds (60Hz operation) or 67

seconds (50Hz operation) in order for the PIR amplifier to reach its

quiescent operating state. The circuit contains two operating modes. Re-

fer to

Figure 5 for State Diagrams.

Operation for Mode 1 is as follows:

Refer to Figure 2. The IC will power up in the Off-State, S0. A mo-

mentary pressing of the pushbutton switch SW1, or occupancy de-

tection, will cause a negative-going output pulse, LR1, to occur and turn

on the light and place the IC in the

On-State, S1. If occupancy is not de-

tected, a negative-going output pulse, LR2, will cause the lights to turn

off after a time-out of 5, 10, 20 or 30 minutes, or 30 seconds, as se-

lected by a potentiometer control at the Timer Control input. If oc-

cupancy is detected before time-out occurs, the selected time-out be-

gins again. If time-out occurs and the lights switch off, then occupancy

detection, or pressing the pushbutton switch, will switch the lights back

on again. Once the unit is in

S1, pressing the On/Off push-button switch

places the unit in the

Off-State, S2, and turns the lights off and keeps

them off as long as motion is detected, or if motion is not detected the

lights will stay off for the time-out period. At the end of the time-out pe-

riod, the unit will revert to

S0. Whether the lights are on or off, detected

motion will cause the LED indicator light to blink.

FEATURES:

• Latching relay drive (LS6506R)

•

LS6506R is suitable for incandescent and fluorescent lights,

electronic and magnetic ballasts, motors and heaters, etc.

• Triac drive (

LS6507R)

• Sensitivity adjustment

• Push-button for manual on/off control

• Ambient light override adjustment

• Selectable time-out adjustments

•

3 Operating Modes:

1. Manual On or Auto On / (Manual Off and Delayed Auto On) or

(Manual Off and Manual On)

or Auto Off

2. Manual On / Manual Off or Auto Off

3. Manual On or Auto On / Manual Off or Auto Off

• LED indicator light for motion detection

• Controls 115VAC and 220VAC applications

•

LS6506R (DIP), LS6506R-S (SOIC);

LS6507R (DIP), LS6507R-S (SOIC) - See Figures 1A & 1B

Operation for Mode 2 is as follows:

In this mode, lights can only be turned on by pressing the On/Off push-

button. Lights will remain on if occupancy is detected. Lights will turn

off automatically when occupancy no longer exists and the time-out

occurs. Lights can also be turned off by pressing the On/Off push-

button.

Operation for Mode 3 is as follows:

In this mode, Pins 10 and 12 are connected together. One momentary

switch is used instead of the two as shown in Figures 2 and 3. Lights

can be turned on by pressing the momentary pushbutton or by oc-

cupancy detection. Lights will remain on if occupancy is detected.

Lights will turn off automatically when occupancy no longer exists and

the time-out occurs. Lights can also be turned off by pressing the mo-

mentary pushbutton.

Refer to the application schematic of Figure 2: Whenever the mo-

mentary switch SW1 is pressed, a 7 second delay period (60Hz opera-

tion) or an 8.4 second delay period (50Hz operation) occurs in which

the momentary switch operation is disabled. This enables capacitor C9

to be recharged so that the next operation of SW1 will be properly rec-

ognized.

An additional control potentiometer at the LDR input is used to adjust

the amount of ambient light required to prevent occupancy detection

from turning the lights on (Mode 1 only) and from resetting the time-out

counter. The occurrence of an ambient light condition will not affect a

timeout already in progress.

The

LS6506R can operate using a 12V latching relay. Figure 2 shows

typical resistor and capacitor values for a 12V relay. Z1 is specified as

a 15V zener diode. The chip generates its own 5V regulator to power

its internal circuits and a separate 5V regulator to power the two stage

PIR amplifier and external PIR. The

LS6506R generates 16ms pulses

on two outputs for setting/resetting the latching relay. Upon power up,

the

LS6506R generates a reset pulse as soon as its supply voltage

reaches the relay coil’s set/reset voltage. This ensures that the relay

comes up in the off position and occurs 20 seconds (60Hz operation)

or 24 seconds (50Hz operation) after power is applied.

For triac operation, the

LS6507R is shown in the Figure 3 application

schematic. The

LS6507R has the same features as the LS6506R.

This circuit is intended for driving lamps, motors and heaters. The

LS6507R has a single output that generates a 50µs negative pulse to

drive the gate of a triac. The pulse output is delayed from the AC zero-

crossover point by 1.2ms. This delay still enables 99% power to be de-

livered to the load while allowing circuit power to be derived from the

connection to the load. The

LS6507R application schematic does not

require connection to the house-ground.

For calibration purposes in either mode, connecting the Timer Control

to set the desired sensitivity. Note also that a two- position switch may

be used instead of a potentiometer for time-out control. In that case,

either 5 minutes or 30 seconds is available for time-out. The circuit

also has a built-in 2 second dead time at the end of the time-out to pre-

vent false turn-ons from occurring.