Functional Description for Evaluation Module E931.98 AN 0137

Functional Description for Evaluation Module E931.98 AN 0137
Functional Description for Evaluation Module E931.98
AN 0137
Jun 26, 2015
1 Description
The E931.98 is well suited for motion sensor lights.
The requirements for this application are
ƒƒ Good range (>10m)
ƒƒ Responsive detection of humans
ƒƒ Adjustable detection range
ƒƒ Adjustable timing
ƒƒ Daylight sensor
ƒƒ Reliable operation
The unit can be used indoors or outdoors. It should not face direct sunlight as the material of the Fresnel lens may lose efficiency over time. Exposure to sudden temperature changes, hot and cold air movement and moving objects in the field of view
may result in switching the light on in the absence of human movement / presence.
The type of lens, the mounting height, the enclosure and the insulation against temperature changes of the detector have the
most influence on the usable detection range.
2 Functions and Implementations
For details referring to components, see Figure 1.
3 Motion Detection
The E931.98 contains a second order band pass filter for the signal processing. Together with the circuitry required to operate
the analog PIR detector, a 3rd order high pass filter function and a second order low pass filter function is achieved. The filter
removes unwanted out of band signals.
In order to switch the REL output (load on), the circuit must observe a signal pulse above the threshold within a time window
of 4s. The E931.98 ensures, that the load is only switched on during mains voltage zero crossing.
The LED output indicates whenever the trigger threshold is exceeded. The REL output becomes active, once movement has
been detected (load on). The REL output remains active, until no further movement is detected and the user defined On Time
has lapsed. The On Time is calculated from the moment, where no further motion is detected.
4 Relay Switching
The unit is configured for normally open relays. Motion will cause the load to be switched on. The zero cross switch function
prevents early relay failure due to excessive contact wear when switching capacitive loads such as compact fluorescent lights.
5 Connection of PIR Detector
The PIR detector contains a pyro ceramic, which is connected to the gate of a JFET. The drain terminal needs to be connected to
a positive supply voltage (2V to 12V) and the source requires a resistor to ground. The JFET provides the impedance conversion
from the internal pyro ceramic to the external load. The DC voltage on the source can be between 0.1V and >1V, depending on
detector type, supplier and operating conditions – specifically the temperature.
The PIR detector generates a relatively small signal of some 100uV as a result of movement. The signal value depends to a large
extend on the lens, the size and temperature of the moving object and the distance of the object to the detector.
Resistor R9 is the source resistor for the detector. The supplier recommends values between 50k and 150k. For very low power
applications, many users choose much higher resistor values.
Capacitor C6 reduces any RF signal coupled from the environment onto the source of the detector as it would result in noise
due to the demodulation across the source gate diode inside the detector. Some detector manufacturers have this capacitor
already integrated.
Elmos Semiconductor AG
Application Note 1/5
QM-No.: 25AN0137E.00
Functional Description for Evaluation Module E931.98
AN 0137
Jun 26, 2015
Capacitor C5 in conjunction with resistor R8 removes any DC content from the detector output signal. The CR combination
is selected to act as a first order HP filter to remove unwanted lower frequency content. The value for resistor R8 should be a
few times higher than resistor R9 to avoid any attenuation of the signal. The inverting PIR input (NPIRIN) is connected to GND.
It is important, that the noise on the drain voltage of the PIR detector is below 1mV as the drain source voltage attenuation is
only 30 dB in the frequency band of interest.
6 Supply voltage regulation
The unit is supplied with mains voltage. The capacitor C1 generates the required voltage drop from the mains voltage to the
voltage on the bridge rectifier. Resistor R2 is for surge protection. The voltage on the bridge rectifier is defined by the Zener diode Z1 voltage behind the bridge rectifier and the voltage drop across the diodes in the bridge rectifier.
The poorly stabilized DC voltage (VREL) on the Zener diode supplies the PIR controller through R3. The integrated shunt regulator on the E931.98 limits the supply voltage to 3V on the IC and the PIR detector. The maximum shunt current can be 5mA.
The voltage range for the unregulated
supply is primarily defined by the value and the power rating of the resistor R3 and the total current consumption of the circuitry connected to the regulated supply. Capacitors C3 and C4 are supply bypass capacitors to eliminate transients on the
supply voltage of the E931.98 and the PIR detector.
7 Range / Sensitivity Adjustment
The DC voltage on the SENS input defines the threshold of the comparators. 0V results in 50µV peak, >0.25*VDD results in
460µV. The range is covered with a resolution of 127 equal steps. RV3 in conjunction with R5 is provided for adjustment.
8 Relay Switching Time
The time, how long the relay output is active after no further motion is detected, can be adjustedthe same way as the sensitivity.
A range of 8s to approx. 2048s is provided. RV2 is provided for adjustment.
Fixed resistors in place of POTs may be used if no adjustment is required, footprints R14 and R13 are on the PCB for that purpose.
9 Calculation of component values
R6, R5, RV2 and RV3:
1 / (1+ R6/RV2) must yield slightly more that 0.25 to ensure full range for On Time.
1 / (1+ R5/RV3) must yield slightly more that 0.25 to ensure full range for Sensitivity.
Choose preferred value for RV3 and RV2 first.
R7 < R(relay coil) * ß(Q1)
RV1 depends on CDS1
R4 to avoid excessive current, when RV1 adjusted to 0 and full daylight.
R2 = 47k to 150k, power consumption is uncritical in this application.
R8 > 5 * R9
C5 > 1/(2*π*fo*R8), fo = cut off frequency (0.2Hz)
R1 < (47V-3V)/Imax
Imax = I(U1)+I(RV1)+I(R5)+I(R6)+I(R7)+100µA
Elmos Semiconductor AG
Application Note 2/5
QM-No.: 25AN0137E.00
Functional Description for Evaluation Module E931.98
AN 0137
Jun 26, 2015
LDR Ambient light sensor
Sensitivity voltage Test pin
OEN Test pin, Output enable
Sensitivity: CW=minimum
Dark level adjust:
CW=less dark
On-time: CCW=minimum
VREL Test pin,
Unregulated DC voltage,
48V for relay
On time voltage Test pin
PIR Sensor
REL Output Test pin
L
N
230V
Figure 1. Description of module M947
Notes:
1. For quick demo purposes: set the trim pots to the positions indicated in bold. Wait about 30s for the circuit to settle. Slowly turn the
sensitivity trim pot CCW until the desired sensitivity level is reached.
2. CW=Clock-Wise CCW=Counter-Clock-Wise
Figure 2. Photo of Module M947
Elmos Semiconductor AG
Application Note 3/5
QM-No.: 25AN0137E.00
Elmos Semiconductor AG
NE UT R AL
LO AD
LI VE
V1
S10
10M
1k/ 1W
VL
R10
220k
D1
DB 104S
150n/ 275V
C1
R1
R2
RW -SS -148D M
RE 1A
Q1
BC 849B
D2
1N4148
4/5
47V
Z1
Application Note R11b
4. 7M
R12b
Z C NN
R12
4. 7M
4. 7M
Z C LL
4. 7M
R11
CD S1
CD S
10k
RV 2
220k
ZC L
ZC N
RV 3
220k
11
12
9
7
6
10
SE NS
LED
RE L
O EN
VS S
C2
100u/ 64V
22k
R5
680k
8
R7
2. 2M
R6
680k
O NT I M E
R4
R3
56k
+
RV 1
VR EL
E931. 98A
ZC N
ZC L
SE NS
VS S
VS S
NP IR IN
PI RI N
EN VRE G
VD D
VD D
10u/ 6V
+ C4
O NT I M E
LED
RE L
O EN
U1
C3
470n
PI RI N
VS S
3
14
2
1
4
5
13
R8
2. 2M
470n
C5
R9
100k
PI RO
VD D
C6
10n
LHI 968
PI R1
Functional Description for Evaluation Module E931.98
Jun 26, 2015
AN 0137
Figure 3. Schematic of module
QM-No.: 25AN0137E.00
Functional Description for Evaluation Module E931.98
AN 0137
Jun 26, 2015
Usage Restrictions
Elmos Semiconductor AG provide the E931.98 Demonstration Board simply and solely for IC evaluation purposes in laboratory.
The Kit or any part of the Kit must not be used for other purposes or within non laboratory environments. Especially the use or
the integration in production systems, appliances or other installations is prohibited.
The pcb´s are delivered to customer are for the temporary purpose of testing, evaluation and development of the Elmos IC´s only.
Elmos will not assume any liability for additional applications of the pcb.
Disclaimer
Elmos Semiconductor AG shall not be liable for any damages arising out of defects resulting from (1) delivered hardware or software, (2) non observance of instructions contained in this document, or (3) misuse, abuse, use under abnormal conditions or
alteration by anyone other than Elmos Semiconductor AG. To the extend permitted by law Elmos Semiconductor AG hereby expressively disclaims and user expressively waives any and all warranties of merchantability and of fitness for a particular purpose,
statutory warranty of non-infringement and any other warranty or product liability that may arise by reason of usage of trade,
custom or course of dealing.
Elmos Semiconductor AG – Headquarters
Heinrich-Hertz-Str. 1 | 44227 Dortmund | Germany
Phone + 49 (0) 231 - 75 49 - 100 | Fax + 49 (0) 231 - 75 49 - 159
sales-germany@elmos.com | www.elmos.com
Note Elmos Semiconductor AG (below Elmos) reserves the right to make changes to the product contained in this publication without notice. Elmos assumes no responsibility for the use of any circuits described herein, conveys no licence under any patent or other right, and makes no representation that the circuits are free of patent infringement. While the information in this publication has been checked,
no responsibility, however, is assumed for inaccuracies. Elmos does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be
expected to cause failure of a life-support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications.
Copyright © 2015 Elmos Reproduction, in part or whole, without the prior written consent of Elmos, is prohibited.
Elmos Semiconductor AG
Application Note 5/5
QM-No.: 25AN0137E.00
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