LS6511N Datasheet, PDF (1/5 Pages) LSI Computer Systems – Direct Interface with PIR Sensor

LSI/CSI
LS6511N LS6512
LS6513
U_{® L LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 [phone] FAX [phone]}
A3800
PIR SENSOR INTERFACE
September 2009
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
• 75µA Typical Supply Current
• Undervoltage Detection
• LS6511N(DIP); LS6511N-S (SOIC) - See Figure 1A
LS6512(DIP); LS6512-S (SOIC) - See Figure 1A
LS6513(DIP); LS6513-S (SOIC) - See Figure 1B
APPLICATIONS:
Security system intrusion detection, automatic doors, motion
triggered events such as remote animal photography, etc.
PROGRAMMABLE RETRIGGERABLE ONE-SHOTS
Positive and negative input signals at the digital filter outputs will gener-
ate 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 program-
mable using an external RC network. Typical windows are between
1 and 5 seconds.
ENABLE Input
A low on the Enable input for LS6513 allows the LED / Relay and
LED / Relay outputs to respond to the PIR input detection. If the Enable
input is high, then the two outputs remain in their dormant state. The
LED / Relay and LED / Relay outputs on LS6511N and LS6512 are
always enabled.
DESCRIPTION (See Figure 5)
The LS6511N, LS6512 and LS6513 are CMOS integrated circuits
designed for detecting motion from a PIR Sensor and initiating appro-
priate responses.
SEL UDV Input
For the LS6513, a low on this input allows undervoltage to be detected.
If left floating, undervoltage detection will not occur.
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.
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.
OUTPUTS
The LED / RELAY Output is an open drain output that will sink current
when an input signal is detected and processed. The LS6511N will also
sink current when the Power Supply drops below 3.5V (Typical) (Under-
voltage Detection). The Undervoltage Detection will be removed when
the Power Supply rises above 3.7V (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 15V
maximum). The LS6512 will not respond to an undervoltage detection.
The LS6513 can be selected to respond or not respond to a power
supply undervoltage.
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.
Single Pulse (SP) Mode is when detection from either a positive or
negative input signal at the Digital Filter outputs will cause an
LED / RELAY output to occur. Concurrent Pulse (CP) Mode is when
detection from a positive and negative input signal must occur within
a specific time before an output will occur. Dual Pulse (DP) mode is
when any two detections within a specific time will cause an output to
occur. SP Mode = 0; CP Mode = Open; DP Mode = 1.
6511N-092509-1
The undervoltage detection feature in the LS6511N assures that in
security systems tampering with the power supply by loading it and
causing it to be reduced in value will be quickly detected.
In battery operated non-security systems applications the undervoltage
feature is not desireable because it produces unwanted outputs as the
batteries age. The LS6512 should be selected for these applications.
SHUNT REGULATOR
The LS6511N includes a 5V Shunt Regulator Output which can be tied
to the V DD Pin so that the circuit can be powered from a higher voltage
power supply.
Note: See Figures 2, 3 and 4 for application schematics.