Datasheet MLX90721S Datasheet (MELEXIS)

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MLX902xx Name of Sensor Rev Y.X 22/Aug/98 Page 1
MLX90721
Auto Shut Off Timer
MLX90721 Auto Shut Off Timer Page 1 Rev 1.0 22/Jun/00
Featur es an d Ben efits
Low cost – minimal external components Small package ( to92 for the 3 pins version,
cost 12V relays and most custom made
relays. Low power consumption (low dissipation)
Applications
Househ ol d ap pl i an ces Heater Hand-dryer
Ordering Information
Part No. Temperature Suffix Package option Temperature Range MLX90721 S TA -x 0C to 85C MLX90721 S A -x 0C to 85C MLX90721 S L -x 0C to 85C
The customer speci fi c option code is indicated with 1 character at the end of the ordering number. For cob assembly, please contact Melexis directly.
Description
The chip is intended to be used for switching on and off a mains powered device, with the added f eature of automatic switch off after a well-defined amount of time. Such device can replace conventional switches in all appliances that might be left on inadvertently. Besides saving energy, the main goal is to prevent all hazards due to appliances left on unattended. The chip can be used in its 3-pin version, where applying the supply to the chi p does switching on. In the 4-pin version switching on and off is done with a single push-button. As an alternative the fourth pin can also be used as a reset pin, where the auto- shut-off tim e counter i s reset when pushi ng this button. The auto-shut-off time is mask programmable and can be almost anyt hing between 2. 5 minutes and 32 hours. The duty cycle of the relay driver can also be adjusted by mask to adapt to almost any kind of relay construction.
Functional Diagram
Use Template :
block.vst
POR
Vreg
options
OSC
90721
logic
VDDA
VSS
BUT OUT
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MLX90721
Auto Shut Off Timer
MLX90721 Auto Shut Off Timer Page 2 Rev 1.0 22/Jun/00
General Description
The chip is intended to be used for switching on and off a mains powered device, with the added f eature of automatic switch off after a fixed amount of time. Such device can replace conventional switches in all appliances that might be left on inadvertently. Besides saving energy, the main goal is to prevent all hazards due to appliances left on unattended. The c hi p is of f er ed i n a 3-pin v er s io n , w her e a p pl yi n g the supply is switching the chip on. In its 4-pin version, switching on and off is done with a single push-button. As an alternative the fourth pin can also be used as a reset pin, where the auto- shut-off tim e counter i s reset when pushi ng this button. The chip application version (3 or 4 pins) and aut o­shut-off time are mask programmable. The auto­shut-off time can be almost any value between 2.5 minutes and 32 hours. The duty cycle of the relay driver can also be adjusted by the same mask to adapt to all types of relay cons truction.
Power-On-Reset.
The Po w er -O n - Res et of th e ASI C i s a com bi n at i on o f a digi tal power-on-reset with hysteresi s DPOR, and an analog APOR. DPOR is used to initialize the logic on the chip. The APOR is characterized by a low level – APL signal and a high level – APH signal, which are debounced as follows: low level debouncing – appr ox. 25mS high level debouncing – approx. 3.5mS The digital signal APOR is a logic combination of the debounced signal s APLd and APHd. APOR is set to High when APHd = high and APOR i s reset to Low when APLd = low. A transition to the active state is indicated by the digital signal
APOR=1
in c as e of ap p li c at i on 1 an d 2 ,
or
APOR=1
and
START=1
in case of application 3. The result is that the transistor at the pin OUT is activated after a delay time Td , and starts switching ON and OFF with the specified frequency F1 and duty cycle
DC1
.
The digital signal
APOR=0
immediately brings the logi c back to the INACTIV E stat e, i.e. the out put is disabled and the state of the digital output signal from the start-stop/reset button (if present in the particular application) is initialized to non-pressed (released) state.
Button Input.
The Button Input can have three different functions, which determine the three different applications: APPL.1, APPL.2 and APPL.3. The function of the input is defined by the options mask.
APPL.1-
No Function
. The BUT input is not used and therefore not connected externally. BUT is an internally pulled up digital input. In this case, the transitions INACTIVE > ACTIVE state and vice versa are defined only by the APOR signal.
APPL.2-
Auto Shut-OFF Time Reset
. The input BUT can be connected to GND via an external button. The input is an internally pulled up, active Low, inverting digital input. In this case, the transitions INACTIVE state > ACTIVE state and vice versa are again defined only by the APOR signal. Each time the button is pressed a Reset signal is generated and the count down for the Auto Shut-Off Time starts from 0 again. The state of this input ( pressed or not ) is checked each 3.5mS. The high level (button pressed) at the digital output is debounced for approx. 3.5mS.
90721
LED (optional)
N
L
Load
VDD
GND
OUT
Appl.1 ASO without button
90721
LED (optional)
N
L
Load
VDD
GND
OUT
Appl.1 ASO with time reset button
BUT
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MLX90721
Auto Shut Off Timer
MLX90721 Auto Shut Off Timer Page 3 Rev 1.0 22/Jun/00
APPL.3-
Start/Stop Toggle Function
. The input BUT is now an acti ve High, zero cross input wi th internal pull down. The input is connected via a button and external resistor to the mains. Each time this button is pr essed , the i nter nal S TART si gnal toggl es and i n com bi n ati o n wi t h th e A PO R si g nal it def i nes t he l o gi c transitions in the following way: APOR=1 and START=1 –> transition to ACTIVE state APOR=1 and START=0 –> transition to INACTIVE state APOR=0 – defines the INACTIVE state and initialization of a start signal START= 0 The digital output of the BUT input is debounced as follows: High level debouncing (button pressed) – approx.
3.5mS Low level debouncing (button released) – approx. 100mS The first time the button is pressed after initialization sets START=1. Once the logic has found that the button is pressed, it has to detect a released button in order to interpret correctly consecutive activations of the button. Each next pressing toggles the START signal.
Auto Shut-OFF Function.
When the ASIC is in the ACTIVE state and when the delay period Td has elapsed, the output is activated (wi th a wel l d efi ned dut y cycl e) for a pr edef i ned Au t o Shut-OFF Time Ta. At the end of that period Ta, the output is switched OFF, the ASIC is brought to the INACTIVE state and the state of the digital output si gnal fr om th e st art-st op/r eset b utton (if p resent ) is initialized.
Internal Oscillator.
The ASIC has a calibrated free running, RC oscillator, which is used to generate a frequency and a duty cycle for the relay output, and the different delays and Auto Shut-Off times.
Relay Output.
When the coil is not activated, the open drain output transistor is in the OFF state constantly. When the coil is activated, the output transistor starts switching ON and OFF with the specified frequency
F1
and with a duty cycle
DC1
. Optionally, there could be doubled duty cycle during the first few msec -
Tdub
. This option is usef ul to provide th e extra energy needed for t he mechanical movement when act ivating a relay.
Supply.
The c hip is di rectl y suppl ied fr om the mai ns, vi a a diode and resistor. To limit the supply voltage VDDA, a zener with a voltage of
Vzen
is integrated. To supply the analog and digital functions, an on chip voltage regulator and the required biasing ci r cuits are f oreseen.
Doubled Duty cycle
Mechanical relays normally need a higher mag­netic field (and thus a higher coil current) to move the c ontac t away from his norm al posi tion, t hen to keep the contact in that position. Therefore it is possible to increase t he current supplied to the coi l during the first 6 msec. After activation of the out­put driver. This is done by doubling the duty cycle which has been selected by mask option. With a proper dimensioning of the external compo­nents the power consumption of the module can be optimized in this way.
Test Mode
The test mode aims full verification of the above specified logic functions and electrical characteris­tics, both on wafer and packaged device. The test mode is defined under the following condi­tions:
V(O UT) = 0V for appr ox. 5m sec
. The ASIC enters
test mode when on pin
OUT
is detected a short­circuit to GND. This detection is done after a digital debouncing for a per iod of ~ 5mS, and the result is latched and saved in a test status flip-flop. When in test mode, pin
OUT
is used as an i nput for the test clock sequence, as well as an output for the IC reaction. This is achieved by appropriate definition of input/output signal level s.
V(OUT) < 9V
. Thi s r es tri c t i on ai m s to mak e a cl ea r
distinction between normal mode operation, when
V(OUT)=
VDDA, and test mode. This feature also ensures that if by mistake test mode is activated during Normal Mode operation, and at the same time on pin
OUT
is found a potential higher than 9V, follows immediate reset of test mode, and the IC is brought back to normal mode.
Disclaimer
Melexis reserves the right to periodically make modifications to product specifications. The infor­mation included herein is believed to be accurate and reliable. However, Melexis assumes no re­sponsibility for its use; nor for any infringements of patents or other rights of third parties which may
90721
LED (optional)
N
L
Load
VDD
GND
OUT
Appl.1 ASO with start/stop button
BUT
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Auto Shut Off Timer
MLX90721 Auto Shut Off Timer Page 4 Rev 1.0 22/Jun/00
MLX90721 Electrical Specifications
DC Operating Parameters TA = 0oC to 85oC
Operating Ranges
Parameter Symbol Test Conditions Min Typ Max Units
Max. junction temperature Tjm 125 °C Ambient temperature Ta 0 85 °C
Supply Current
Parameter Symbol Test Conditions Min Typ Max Units
Supply current at VDDA=48V
Idd1 VDDA=48V, OUT open BUT not active 170 270 370 µA
Supply current at VDDA=55V
Idd2 VDDA=55V, OUT open BUT not active 200 300 400 µA
Integrated Zener
Parameter Symbol Test Conditions Min Typ Max Units
Zener voltage at VDDA Vzen 62 66 70 V Maximum sink current Izm 10 mA
Power On Reset
Parameter Symbol Test Conditions Min Typ Max Units
DPOR high level Vdh 2.8 V DPOR hysteresis Vdhys 0.9 V APOR high level VAPH 32 42 V APOR hysteresis VHYS 7 12 V
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Auto Shut Off Timer
MLX90721 Auto Shut Off Timer Page 5 Rev 1.0 22/Jun/00
Relay Driver Output
Parameter Symbol Test Conditions Min Typ Max Units
Maximum current in ON state
Ion 50 mA
Output voltage in ON state Von Iout = 50mA 0.4 3 V Leakage current in OFF
state
Ioff V(OUT)=Vzen 1 50 mA
Over voltage protection Vprot 90 V
Rise / fall time s Trf Iout = 25mA 0.7 1.0 1.3 µs Frequency of the relay
driver
F1 21.8 kHz
Duty cycle of the relay driver
DC1 See options Var. %
Internal Oscillator
Parameter Symbol Test Conditions Min Typ Max Units
Nominal frequency Fosc VDDA = 60V, Tamb 437 kHz Frequency tolerance Df 20V < VDDA < 70V -6 6 % Temp. coefficient of oscilla-
tor frequency
TCf T=0°-100°C 1000 ppm
Integrated Zener
Parameter Symbol Test Conditions Min Typ Max Units
Zener voltage at VDDA Vzen 62 66 70 V Maximum sink current Izm 10 mA
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Auto Shut Off Timer
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Button Input
Parameter Symbol Test Conditions Min Typ Max Units
Threshold voltage Vtr Valid for APPL.1 and APL.2 2.5 V Threshold current Itr
Valid for APPL.3
+12 mA
Max. source current Im1 -350 mA Max. sink current Im2 350 mA Clamp voltage 1 Vc1 APPL.3; Ibut = +4mA 5 V Clamp voltage 2 Vc2 APPL.3; Ibut = -4mA 0 V
Timings
Parameter Symbol Test Conditions Min Typ Max Units
Switch ON delay time Td 47 mS Auto Shut-OFF time Ta See options Increased Duty Cycle pe-
riod
Tdub In case this option is enabled 6 mS
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Auto Shut Off Timer
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Duty Cycle and Auto Shut-OFF Options
The function of input BUT as well as the doubled duty cycle function can be define by mask option. Also following options can be defined by mask option:
Parameter Symbol Test Conditions Min Typ Max Units
Relay Frequency Duty Cy­cle
DC In steps of 2.5% 5 37.5 %
Interval
0 – 1 H
2.5 5 7.5 10 12.5 15 17.5 20
22.5 25 30 35 37.5 40 45 50
52.5 min 1 – 2 H 1h 1h10m 1h15m 1h20m 1h30m 1h40m 1h45m 2 – 3 H 2h 2h20m 2h30m 2h40m 3 – 4 H 3h 3h20m 3h30m 4 – 5 H 4h 4h40m 5 – 6 H 5h 5h20m 6 – 7 H 6h 6h40m 7 – 9 H 7h 8h 9 – 10 H 9h 9h20m 10 – 11 H 10h 10h40 12 – 32 H 12h 14h 16h 20h 24h 28h 32h
AUTO SHUT-OFF TIMES
ESD Precautions
Electronic sem iconductor products are sensitive to Electro Static Discharge (ESD). Always observe Electro Static Discharge control procedures whenever handling semiconductor products.
Pin Name Type Description
1 VDDA Input supply 2 GND Input ground 3 OUT output relay driver output
4 (opt.) BUT input Button input
Pinout
Standard package f or the 3 pins version is a 3-pin TO 92 package, and PDIP8 or PSOP8 for the 4 pins version.
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MLX90721
Auto Shut Off Timer
MLX90721 Auto Shut Off Timer Page 8 Rev 1.0 22/Jun/00
“A” Package Dimensions
9.02
10.16
Min Max
18.67
19.68
18.67
19.68
22.35
23.67
24.89
26.92
31.24
32.51
0.20
0.38
2.54 BSC
1.1 5
1.7 7
0.35
0.55
0.39 Min
Dimension 8 Leads 16 Leads 18 Leads 20 Leads14 Leads 24 Leads
A
6.10
7.11
5.33 MAX
2.93
4.06
7.62
BSC
10.92 Max
A
Notes: 1-All measurements in mm
2-Body dimensions do not include mold flash or protrusion - not to exceed
0.15mm
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Auto Shut Off Timer
MLX90721 Auto Shut Off Timer Page 9 Rev 1.0 22/Jun/00
“L” Package Dimensions
0.40
1.27
0o to 8
o
2.35
2.65
0.010 min.
0.33
0.51
A
Dimension 8 Leads 14 Leads
A
4.80
5.00
Min Max
8.55
8.75
16 Leads
9.80
10.00
3.80
4.00
5.80
6.20
1.27
Notes:
1-All nominal measurements in millimeters 2-Body dimensions do not include mold flash or protrusion - not to exceed
0.15mm
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Auto Shut Off Timer
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“TA” Package Dimensions
Dimensions in millimeters Di m ensions in inches
MIN NOM MAX MIN NOM MAX
A 3.45 3.56 3.66 0.136 0.140 0.144 A1 1.22 1.30 1.37 0.048 0.051 0.054 b - 0.38 - - 0.015 ­C - 0.38 - - 0.015 ­D 4.27 4.52 4.78 0.168 0.178 0.188 D1 4.14 4.29 4.45 0.163 0.169 0.175 E 4.32 4.57 4.83 0.170 0.180 0.190 L 12.98 13.49 14.00 0.511 0.531 0.551 e - 1.27 - - 0.050 ­q - - - ­q - - - -
symbols
Note: All dimensions in inches.
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Auto Shut Off Timer
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For the lat est ver s i on of this docu m ent, Go to our website at:
www.melexis.com
Or for additional inf or m ati on contact Melexis Direct:
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