CLT3-4BT6 ® CURRENT LIMITED OVER-VOLTAGE PROTECTED QUAD DIGITAL TERMINATION APPLICATIONS ■ ■ ■ ■ ■ 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 ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ❏ ❏ ■ ❏ ❏ ■ ❏ ❏ ■ 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 ■ ■ ■ ■ ■ ■ ■ 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. 4/10 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 ■ 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. The ST logo is a registered trademark of STMicroelectronics © 2002 STMicroelectronics - Printed in Italy - All rights reserved. STMicroelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - Finland - France - Germany Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Singapore Spain - Sweden - Switzerland - United Kingdom - United States. http://www.st.com 10/10