STMicroelectronics CLT3-4BT6 Current limited over-voltage protected quad digital termination Datasheet

CLT3-4BT6
®
CURRENT LIMITED OVER-VOLTAGE PROTECTED
QUAD DIGITAL TERMINATION
APPLICATIONS
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Industrial Automation
Programmable Logic Controller
Communication field bus nodes
Peripheral Input / Output modules
Machine tool interface
FEATURES
4 channels topology
Wide range input DC Voltage:
VI = - 0.3 to 30V with RI = 0
VI = - 30 to 35V with RI = 1.2kΩ
Low side configuration with common ground
Current limiter:
IGEN = 3mA
Input current limiter activation voltage < 5V
Temperature compensated operation
Opto-coupler drive:
No coupler activation below 1.5 mA input current
Input protection (RI = 1.2KΩ):
IEC61000-4-2 electrostatic discharge ESD, Class 3
In contact, ±6kV; in air, ±8kV
Level B: temporary disruption; no change of opto-coupler state
IEC61000-4-5 voltage surge, Class 3
± 1000V with 42Ω serial resistor in differential mode
Level B: temporary disruption
IEC61000-4-4 transient burst immunity
± 4kV peak voltage; 5kHz repetitive rate
Level A: fully functional
Operating ambient temperature: - 25 to 85°C
TSSOP20
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BENEFITS
Reduced overall dissipation
Compact with high integration
Enables input to meet type 1 characteristic of IEC61131-2 standard
Compatible operation with 2 and 3 wires proximity sensor according EN60947-5-2 standard
Insensitive to the on state sensor impedance
Surface Mount Package for highly automated assembly
Enhanced functional reliability
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August 2002 - Ed: 4A
1/10
CLT3-4BT6
IEC61000-4 STANDARD ROBUST APPLICATION DIAGRAM
VI
1
COM
COM
IN1
OUT1
VIN
2 wires sensor
RI
ESD12
24V
SUPPLY
COM12
RI
3 wires sensor
VC
VCC
IN2
OUT2
VC
COM
ESDC
COM
IN3
OUT3
RC
RI
Contact switch
ESD34
COM34
RI
2 wires sensor
IN4
OUT4
COM
COM
INPUT TERMINATION BLOCK DIAGRAM
Vc
BIASING
CIRCUIT
ESD
Volt Prot
TO COMPARATORS
COM
ESDC
OPTO COUPLER DRIVER
OUT1
IN1
I1
ESD
OVER
VOLTAGE
PROTECTION
0.75xILIM
I1
0.25xILIM
CURRENT LIMITER ILIM
1.5mA
ESD12
COM12
ESD
OVER
VOLTAGE
PROTECTION
CURRENT LIMITER ILIM
1.5mA
0.25xILIM
I2
0.75xILIM
I2
IN2
OUT2
OPTO COUPLER DRIVER
OPTO COUPLER DRIVER
IN3
OUT3
I3
0.75xILIM
I3
0.25xILIM
ESD
OVER
VOLTAGE
PROTECTION
CURRENT LIMITER ILIM
1.5mA
ESD34
COM34
ESD
OVER
VOLTAGE
PROTECTION
CURRENT LIMITER ILIM
I4
IN4
2/10
1.5mA
0.25xILIM
0.75xILIM
I4
OPTO COUPLER DRIVER
OUT4
CLT3-4BT6
FUNCTIONAL DESCRIPTION
The CLTx-4 is a quadruple input digital termination device designed for 24 V DC automation applications. It
achieves the front-end circuitry of a digital input module (I/O) in industrial automation, and drives an
isolating opto-coupler.
Available in a four channels configuration, it offers a high-density termination by minimizing the external
components count. It is housed in a TSSOP20 surface mount package to reduce the printed board size.
Made of an input voltage protection, a serial current limiting circuit and an opto-coupler driver, each
channel circuit terminates the connection between the logic input and the associated high side sensor or
switch.
The CLT3-4 is a 3 mA quad channel device compatible the type 1 characteristics of the IEC61131-2
standard.
Each input voltage clamping block protects the module input against electromagnetic interferences such
as those described in the IEC61131-2 standard and IEC61000-4-2 (ESD), 4-4 (transient burst), 4-5
(voltage surge) standards. The supply input is also designed with such a protection structure.
The current limiting circuit connected between the input and the output pins is compensated all over the
temperature range. Thanks to its low tolerance, the current limitation allows reducing drastically the
dissipation of the input compared to a resistive input: the overall module requires less cooling capability
and becomes smaller.
The output block of each termination channel controls the operation of an opto-coupler that is enabled by a
Light Emitting Diode.
When the input current is less than 1.5 mA, this output circuit derivates the input current to maintain the
opto-coupler off.
The original structure of the CLT limiter allows its activation threshold to be low and insensitive to the
output voltage up to a maximum value of 2.0 V.
When the CLT input voltage VIN is higher than 5 V, or the module input voltage Vi higher than 11 V with the
use of a reverse diode and a serial resistor RI = 1.2 kΩ, the output current that is a share of the input current
(3/4) is higher than 1.5 mA. The whole termination channel including the opto-coupler is on.
ABSOLUTE RATINGS (limiting values)
Symbol
VCC
VI
(1)
IIN
Pin
VC
IN
IN
Parameter name & conditions
Value
Unit
Supply steady state voltage, RC = 0kΩ
- 0.3 to 30
V
Supply steady state voltage, RC = 4.7kΩ
- 0.3 to 35
V
Input steady state voltage, RI = 0kΩ
- 0.3 to 30
V
Input steady state voltage, RI = 1.2kΩ
- 0.3 to 32
V
Input repetitive pulse voltage, RI = 1.2kΩ
- 0.3 to 35
V
Input repetitive pulse voltage,
RI = 1.2kΩ, RC = 4.7kΩ (2)
- 30 to 30
V
Input maximum forward current,
RI = 1.2kΩ, RC = 4.7kΩ
5
mA
Input maximum reverse current,
RI = 1.2kΩ, RC = 4.7kΩ (2)
20
mA
2.5
V
- 4 to 4
mA
VOM
OUT
Maximum output steady state voltage
IOM
OUT
Output current
AII
Operating ambient temperature
- 25 to 85
°C
Operating and storage junction temperature
- 25 to 150
°C
TAMB
TJ
Note 1: VI = VIN + RI x IIN; VIN = voltage at the input pin itself
Note 2: according to test diagram on figure 8, this case covers especially the reverse polarity operation of one input.
3/10
CLT3-4BT6
ELECTROMAGNETIC COMPATIBILITY RATINGS
RI = 1.2kΩ, RC = 4.7kΩ, reverse diode connected as shown on figure 6 (unless otherwise specified)
Symbol
VPP
Node
IN
Parameter name & conditions
Value
Unit
ESD protection, IEC61000-4-2, per input, in air
±8
kV
ESD protection, IEC61000-4-2, per input, in contact
±6
kV
ESD protection, IEC61000-4-2, per input, in air, RI = 0Ω
±3
kV
ESD protection, IEC61000-4-2, per input, in contact, RI = 0Ω
±3
kV
VPPB
VI
Total Peak Pulse Voltage Burst, IEC61000-4-4
CIN = 100pF, COUT = 22nF, F = 5kHz (3)
±4
kV
VPP
VI
Peak Pulse Voltage Surge, IEC61000-4-5, R = 42Ω, (4)
±1
kV
VPP
VCC
Peak Pulse Voltage Surge, IEC61000-4-5, R = 2Ω (4)
±1
kV
Value
Unit
90
°C/W
Note 3: test conditions of IEC standard applied to the application diagram page 2.
Note 4: see test circuit figure 6 or 7.
THERMAL RESISTANCE
Symbol
Parameter
TSSOP20 thermal resistance junction to ambient
Board copper surface = 2cm², copper thickness = 35µm
Rth (j-a)
ELECTRICAL CHARACTERISTICS
(TJ = 25°C, VCC = 24V and COM pin voltage referred unless otherwise specified)
Symbol
Pin
Name
Conditions
Min.
Typ.
Max.
Unit
2.1
3
3.7
mA
Current limitation
ILIM
IN
Input limiting current
VOUT = 0.9 to 2.0V
VIN = 5 to 27V
TAMB = - 25 to 85°C
VLOW
IN
Maximum off state voltage
IIN = 100µA
1.5
VTH
IN
Activation threshold
IIN = 2.1 mA
3.4
5
V
31
38
-
V
VI = 5V, (5)
-
10
40
µA
IIN = 1.5mA, (6)
-
10
40
µA
0.15
0.5
V
2
-
mA
V
Input & Supply Protection
VCL
IN
Clamping voltage
IIN = 7mA; tP = 1 ms
Opto-coupler driver operation
IOFF
OUT
Off state output current
VOFF
OUT
Off state output voltage
IIN = 1.5 mA
ION
OUT
On state output current
VIN = 5V
1.5
Supply & biasing circuit
VC
VC
Supply voltage
TAMB = - 25 to 85°C
IC
VC
Supply current
VIN = VC = 30V
10
V
550
800
µA
Note 5: According to application diagram on page 2 with use of a RI = 1.2kΩ resistor, an opto-coupler (RLED (0V) = 15kΩ, VF = 1.2V) and a reverse diode from COM to GND (VF = 0.7V)
Note 6: same as note 5 but RI = 0Ω.
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CLT3-4BT6
SWITCHING ELECTRICAL CHARACTERISTICS
(TJ = 25°C, VCC = 24V and COM pin voltage referred unless otherwise specified)
Symbol
Pin
Name
Conditions
FMAX
IN-OUT
Input to output running frequency
tPLH
IN-OUT
Input activation propagation time
tPHL
IN-OUT
Input de-activation propagation
time
Min.
Typ.
Max.
Unit
200
Hz
COUT = 22nF
6
µs
COUT = 22nF
10
µs
INPUT CHARACTERISTICS OF CLT3-4
Fig. 1: Typical input characteristics of each CLT3-4 channel
VIN(V)
30
30
25
3.7
20
15
10
5
2.1
5
0
0
0.5
1
1.5
2
2.5
3
3.5
4
IIN(mA)
Fig. 2: Typical current limiter variation versus junction temperature 0.9V < VOUT < 2V
Fig. 3: Typical limiter threshold voltage variation
versus junction temperature for IIN = 2.1mA
IIim / IIim (25°C)
VTH (V)
3.6
102%
100%
VIN = 27 V
98%
3.5
96%
94%
3.4
92%
VIN = 5 V
90%
3.3
88%
86%
Tj (°C)
Tj (°C)
3.2
84%
-25
0
25
50
75
100
125
-25
0
25
50
75
100
125
5/10
CLT3-4BT6
CLT3-4 INPUT / OUTPUT TRANSFER CHARACTERISTICS (respect to common pin COM)
Fig. 4: Current tranfer characteristic
Fig. 5: Transconductance characteristic
IOUT (mA)
4
Transition zone
3.5
3
Forbidden
2.5
IOUT (mA)
4
ISOLATOR ON
ISOLATOR ON
3.5
3.7
3
2.1
2.5
2
2
1.5
1.5
1
1
Transition zone
0.04
0.5
0.5
0
0
0.5
1
ISOLATOR OFF
1.5
2
2.5
IIN (mA)
3
3.5
4
0
0
5
10
15
VI (V)
20
25
30
APPLICATION DESCRIPTION
The CLT device is used between the connector and the opto-coupler of an I/O module. To secure the
coupler off state and the non-conduction of its diode, the maximum CLT output current is 40µA with R opto
= 15kΩ. When the CLT input voltage VIN is higher than 5 V, a minimum CLT output current of 1.5 mA will
secure the opto-coupler on state.
The CLT limiter is insensitive to the output voltage up to 2.0V. Therefore, its output is able to drive any state
of the art opto-coupler. Some additional device can be added in series with the opto-coupler if the output
voltage remains within its functional limits.
A stand-alone sensor is normally connected on the CLT input. For a good off state control, its quiescent
current has to be less than 1.5 mA (EN60947-5-2 standard compatible) keeping then the opto-coupler off
thanks to the CLT device (IOUT < 40µA). And its maximum ON state voltage VS-ON will be lower than 8 V
(EN60947-5-2 standard compatible) corresponding to the difference between the minimum supply voltage
(VCC MIN = 19.2V) and the maximum current limitation activation voltage VCC MIN = VS-ON + VI; VI = VIN + RI x
IIN MAX + VD (VI = 11 V when VIN = 5 V, RI = 1.2 kΩ, IIN < 3.7 mA, VD = 1V).
SURGE VOLTAGE TEST CIRCUIT
The input and supply pins are designed to withstand electromagnetic interferences. As shown on the
device block diagram, each channel input is protected by a clamping diode that is connected to the
common pin COM. Combined with a serial input resistance RI = 1.2 kΩ, this clamping diode implements an
effective protection against transient voltage burst (±4 kV, IEC61000-4-4) and voltage surge (±1 kV,
IEC61000-4-5).
This combination allows the surge voltage to be applied from each input to other inputs, the ground and the
supply contacts in differential or common modes (see figure 6).
Thanks to its high resistance RC = 4.7 kΩ and the conventional power supply protection that uses a
clamping diode such as the SM15T39C Transil™, the supply pin VC withstands IEC61000-4-5 with +/1000 V surge voltage (see figure 7).
Finally, an external output capacitor may be placed in parallel with the opto-coupler diode to filter the
transient disturbances injected in the inputs of the module and secure the immunity of the opto-coupler
itself.
6/10
CLT3-4BT6
Fig. 6: Input pin IN voltage surge test circuit.
VPP = ± 100V with 42Ω
Fig. 7: Supply pin VC voltage surge test cicuit.
CLT3-4
RC
VC
VCC
RI
VPP
RI
IN1
I
IN1
RI
RI
IN2
IN2
± 1kV
2Ω
RI
SM15T39C
RI
IN3
VPP
IN3
± 1kV
42Ω
RI
IN4
RI
IN4
GND
GND
CLT3-4
RC
VCC
VC
COM
COM
5 nF
5 nF
PE/FE
PE/FE
INPUT REVERSE POLARITY ROBUSTNESS
Each input of the CLT device may be biased to a reverse polarity. This case corresponds to a connection
mistake or a reverse biasing that is generated by the demagnetization of a monitored inductive solenoid.
The involved input withstands the high reverse current up to 20 mA; its opto-coupler is OFF and protected
by the conducting input diode. The other inputs remain operational, and some extra dissipation is
generated in their clamping protections.
Considering the supply operation, a reverse blocking diode can be connected between the module ground
and the common pin COM to protect the CLT device against any spurious reverse supply connection.
Then, the whole module supply voltage rating is extended to ± 30V.
Fig. 8: Current sharing in the CLT device when IN4 is biased at - 30V and the others at + 30V
1.1 mA
4.7kΩ
VC
Vcc = + 30V
IREG N
INN
IN= + 30V
N = 1,2 or 3
OUTN
VCL= 38 V
4.3 mA
1.2kΩ
OPTON
1N4007
GND (0V)
COM
OPTO4
1.2kΩ
I4 = -30V
14 mA
IN4
IREG4
OUT4
CLT3-4
7/10
CLT3-4BT6
Fig. 9: Typical junction to ambient thermal resistance versus copper surface under common pad
(FR4 epoxy; copper thickness is 35µm).
Rth(j-a)(°C/W)
160
140
120
100
80
60
40
20
0
0.0
S(cm²)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
PIN-OUT CONNECTION
COM
1
20
COM
IN
2
19
OUT1
ESD12
3
18
COM12
IN2
4
17
OUT2
VC
5
16
COM
ESDC
6
15
COM
IN3
7
14
OUT3
ESD34
8
13
COM34
IN4
9
12
OUT4
10
11
COM
COM
The pins ESD, COMIJ, COM (pins # 1, 3, 6, 8, 10, 11, 13, 15, 16, 18, 20) must be connected together
externally. This common pad COM is enlarged to reduce the thermal resistance and improve the device
cooling. The COM and IN pins are designed to minimize the EMI effects on the circuit.
8/10
CLT3-4BT6
TSSOP20 PRINTED BOARD EXAMPLE
COMMON PAD
COM
COM
IN1
OUT1
COM12
ESD12
IN2
OUT2
VC
COM
ESDC
COM
IN3
OUT3
ESD34
COM34
IN4
OUT4
COM
COM
GND
COOLING PAD
ORDERING INFORMATION
CLT
X
-
4
B
T6
Typical limited current
value, 3 = 3mA
Package
T6 = TSSOP20
EMC level
1000V according to IEC61000-4-5
Number of integrated channel
4 channels
OTHER INFORMATION
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Ordering code
Marking
Package
Weight
Base qty
Delivery mode
CLT3-4BT6
CLT3-4B
TSSOP20
0.074 g
74
Tube
CLT3-4BT6-TR
CLT3-4B
TSSOP20
0.074 g
2500
Tape & reel
Epoxy moulding resine meets UL 94,V0
9/10
CLT3-4BT6
PACKAGE MECHANICAL DATA
TSSOP20
DIMENSIONS
REF.
Millimeters
Min.
Typ. Max. Min.
A
A2 A
e
aaa
b
D
L1
L
20
11
E1
1
10
A1
k
c
Inches
Typ. Max.
1.200
0.047
0.150 0.002
0.006
A1
0.050
A2
0.800 1.000 1.050 0.031 0.039 0.041
b
0.190
0.300 0.007
0.012
c
0.090
0.200 0.003
0.007
D
6.400 6.500 6.600 0.252 0.256 0.259
E
6.200 6.400 6.600 0.244 0.252 0.256
E1
4.300 4.400 4.500 0.169 0.173 0.177
E
e
L
0.65
0.026
0.450 0.600 0.750 0.017 0.023 0.029
L1
k
aaa
1.000
0°
0.039
8°
0°
0.100
8°
0.004
TSSOP20 FOOTPRINT (in millimeters)
6.25
4.40
0.40
7.10
0.65
1.35
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of
use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by
implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to
change without notice. This publication supersedes and replaces all information previously supplied.
STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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© 2002 STMicroelectronics - Printed in Italy - All rights reserved.
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10/10
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