USDIGITAL LS6511 Datasheet

DIGITAL FILTER RC

LSI/CSI

LS6511

U

A3800

LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 [phone] FAX [phone]

®

L

PIR MOTION DETECTOR

FEATURES:

• Direct Interface with PIR Sensor

• Two-Stage Differential Amplifier

• Amplifier Gain and Bandwidth externally controlled

• True and Complementary Output Drives

• Separate digital filters for processing positive and
negative input signals

• Single Pulse/Dual Pulse/ Concurrent Pulse Detection

• Adjustable Output Pulse Width

• Optional 5V Shunt Regulator Output

• 50 µA Typical Supply Current

• Undervoltage Detection

• 14-Pin DIP or 14-Pin SOIC - See Figure 1

DESCRIPTION:

The LS6511 is a CMOS Silicon Gate integrated circuit, designed
for detecting motion from a PIR Sensor and initiating appropriate
responses. Referring to Figure 2, the detailed description of the
functional blocks are as follows:

DIFFERENTIAL AMPLIFIER

Each stage of the two stage Differential Amplifier can be set to
have its own amplification and bandwidth. The two inputs to the
first stage allow for single-ended or differential connection to PIR
Sensors. This stage can be biased anywhere in its dynamic
range. The second stage is internally biased so that the Window
Comparator’s lower and higher thresholds can be fixed relative to
this bias. Signal levels as low as 100µV can be detected.

WINDOW COMPARATOR

The Window Comparator provides noise filtering by enabling only
those signals equal to or greater than a fixed threshold at the out­put of the Differential Amplifier to appear at the 2 outputs of the
Window Comparator. One output detects positive input signals
while the other output detects negative input signals.

April 2000

PIN ASSIGNMENT - TOP VIEW

DIFF. AMP. 1 OUTPUT

DIFF. AMP. 2 INPUT (-)

DIFF. AMP. 2 OUTPUT

ONE-SHOT/WINDOW TIMER RC

DURATION TIMER RC LED/RELAY OUTPUT

MODE SELECT

PROGRAMMABLE RETRIGGERABLE ONE-SHOTS

Positive and negative input signals at the digital filter outputs will
generate retriggerable one-shot pulses. In the Concurrent Pulse
Mode, outputs from each one-shot must occur together at some
point in time to cause an output to occur. The one-shot pulse
width is programmable using an external RC network. Typical
pulse widths used vary between 1 and 12 seconds.

WINDOW TIMER

In the Dual Pulse Mode any two detections must occur within a
timing window to cause an output to occur. The timing window is
programmable using an external RC network. Typical windows
are between 1 and 5 seconds.

OUTPUT DURATION TIMER

The duration timer is retriggerable and programmable using an
external RC network. Typical duration times are between 0.5 and
15 seconds. Successive input detections will restart the timer.

1

2

3

4

5

6

7

LSI

LS6511

FIGURE 1

DIFF. AMP 1 INPUT (-)

14

DIFF. AMP 1 INPUT (+)

13

5V REGULATOR OUTPUT

12

VDD

11

10

9

8

(+V)

VSS

(-V)

LED/RELAY OUTPUT

COMPARATOR DIGITAL FILTER

The outputs of the Window Comparator are filtered so that mo­tion must be present for a certain duration before it can be rec­ognized and appear as pulses at the Digital Filter outputs. An ex­ternal RC network sets the duration time. Nominal duration is
50ms.

MODE SELECT

A tristate input pin selects how the detected signals are pro­cessed. When the input is a logic 0, detection from either a pos­itive or negative input signal at the Digital Filter outputs will cause
an LED/RELAY output to occur (Single Pulse Mode). When the
input is floating, detection from a positive and negative input sig­nal must occur within a specific time before an output will occur
(Concurrent Pulse Mode). When the input is a logic 1, any two
detections within a specific time will cause an output to occur
(Dual Pulse Mode).

6511-040400-1

OUTPUTS

The LED/RELAY Output is an open drain output that will sink cur­rent when an input signal is detected and processed and when
the Power Supply drops below 3.7V (Typical) (Undervoltage De­tection). The Undervoltage Detection will be removed when the
Power Supply rises above 3.9V (Typical). The LED/RELAY Out­put performs identically but is opposite in polarity. The output can
sink current from a relay coil returned to a positive voltage (VDD
to 9.5V maximum).

SHUNT REGULATOR

The LS6511 includes a 5V Shunt Regulator Output which can be
tied to the VDD Pin so that the circuit can be powered from a
higher voltage power supply.

DIFF AMP 2

5

OUTPUT

DIFF AMP 2
INPUT (-)

DIFF AMP 1
OUTPUT

DIFF AMP 1
INPUT (-)

DIFF AMP 1
INPUT (+)

3

2

1

14

13

-

AMP

+

VDD

-

AMP

+

WINDOW

COMPARATOR

+

COMP

-

+

COMP

-

DIGITAL FILTER RC

4

DIGITAL
FILTER

DIGITAL
FILTER

DURATION
TIMER RC

6

OUTPUT
DURATION
TIMER

WINDOW
TIMER

MODE
SELECT

7

M
U
X

DRIVER

9

LED/RELAY
OUTPUT

VDD

11

VSS

10

5 V REGULATOR
OUTPUT

ONE-SHOT/
WINDOW TIMER RC

(+V)

(-V)

12

SHUNT

REGULATOR

UNDERVOLTAGE
DETECTOR

PROGRAMMABLE
RETRIGGERABLE
ONE-SHOT

PROGRAMMABLE
RETRIGGERABLE
ONE-SHOT

FIGURE 2. LS6511 BLOCK DIAGRAM

DRIVER

LED/RELAY

8

OUTPUT