AN-EVAL 2x8-ISO1I813T ISOFACETM Evaluation Board for galvanically isolated 8-Channel Digital Input ICs with IEC61131-2 compatible characteristics for industrial applications ISO1I813T EVAL - Board Application Note V 1.0, 2011-09-09 Industrial & Multimarket Edition 2011-09-09 Published by Infineon Technologies AG 81726 Munich, Germany © 2011 Infineon Technologies AG All Rights Reserved. Legal Disclaimer The information given in this document shall in no event be regarded as a guarantee of conditions or characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights of any third party. Information For further information on technology, delivery terms and conditions and prices, please contact the nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements, components may contain dangerous substances. For information on the types in question, please contact the nearest Infineon Technologies Office. Infineon Technologies components may be used in life-support devices or systems only with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered. AN-EVAL 2x8-ISO1I813T Draft Version Table of Contents Table of Contents Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Board Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 3.1 3.2 3.3 3.3.1 3.4 3.5 3.6 3.7 3.8 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Parallel Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 μC Control Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Sensor Input Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Wire Break Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Filter Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 DC/DC Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4 Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 5 Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 6 PCB Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7 Bill of Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 8 Transformer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Application Note 3 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version Application Note Table of Contents 4 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version 1 Introduction Introduction Application This Application Note describes an Evaluation Board with two isolated 8 Channel IEC61131-2 compatible Digital Input ICs for a wide range of industrial applications. The board is designed to allow easy exploration of the features of the ISOFACETM Digital Input part. It contains two ISO1I813T as an electrically isolated 8 bit data input interface in TSSOP-48 package. These parts are used to detect the signal states of up to eight independent input lines according to IEC61131-2 Type 1/2/3 (e.g. twowire proximity switches) with a common ground. An 8 bit parallel/serial µC compatible interface allows to connect the IC directly to a µC system. The input interface supports also a direct control mode and is designed to operate with 3.3/5V CMOS compatible levels. The data transfer from input to output side across the galvanic isolation uses Infineon’s Coreless Transformer Technology. VBB VFI VCC TS 330n DC ENA SW1 WB 8 sensors IN0 12k I0H 2k I0L I7H IN7 12k 2k I7L S E R I A L I Z E D E S E R I A L I Z E SW2 digital filter /ERR L O G I C SYNC µC /CS parallel or serial interface digital filter e.g. XE166 Rosc GNDFI GND GNDBB ISO1I813T Figure 1 Typical Application Application Note 5 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version Board Characteristics ISO1I813T Figure 2 EVAL 2x8-ISO1I813T 2 Board Characteristics Table 1 Board Characteristics Parameter Symbol Values Unit Min. Typ. Max. – 35 V 35 V VBB Input Voltage VBB 9.6 VINx Input Voltage VINx -35 VCC Input Voltage VCC 3.0 – 5.5 V Logic Signals uC Interface VIL -0.3 – 0.3 x VCC V VIH 0.7 x VCC – VCC + 0.3 V V Oscillator Frequency 50 500 kHz Note / Test Condition set to 500kHz using ROSC 22k For a complete description of the characteristics of the ISO1I813T please consult respective Data Sheet available at: www.infineon.com/isoface Note: this board is intended to be used in the lab to explore the functionality of the ISO1I813T device. It is not designed to be used in professional applications! Application Note 6 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version 3 Functional Description Functional Description This board contains two ISO1I813T as an electrically isolated 8 bit data input interface in TSSOP-48 package. These parts are used to detect the signal states of up to eight independent input lines according to IEC61131-2 Type 1/2/3 (e.g. two-wire proximity switches) with a common ground. For operation in accordance with IEC61131-2, it is necessary for the ISO1I813T to be wired with resistors rated RIN and RLED. (it is recommended to use resistors with an accuracy of 2%, in any case < 5% - mandatory, temperature-coefficients < 200ppm are allowed) A parallel/serial µC compatible interface allows to connect the Board directly to a µC system. If the parallel interface is used, only IC1 can be operated. In serial mode either IC1 can be used with 8 Bit SPI or IC1 and IC2 can be put into a Daisy Chain configuration with 16 Bit SPI. The isolated data transfer from input to output side is realized by the integrated Coreless Transformer Technology. K1 VBB VBB K4 VCC VCC 470n TS Rosc WB /ERR I0H IN0 digital filter 2k 12k I0L S E R I A L I Z E I7H IN7 D E S E R I A L I Z E 2k 12k I7L L O G I C ALE /WR /RD /RD /CS /CS AD0 AD0 AD1 AD1 AD2 AD2 AD3 AD3 AD4 AD5 AD6 AD7 AD4 AD5 digital filter AD6 K9 AD7 K10 GND GNDBB GNDbb /ERR ALE /WR GND K11 ISO1I813T K8 K12 VBB K2 VBB 470n VCC TS WB IN0 IN0 12k Rosc I0H I0L S E R I A L I Z E 12k GNDbb Figure 3 I7H IN7 IN7 D E S E R I A L I Z E 2k GNDbb /ERR digital filter 2k I7L L O G I C /CS AD0 AD1 AD2 AD3 digital filter AD4 AD5 AD6 AD7 GND GNDBB ISO1I813T Block Diagram Application Note 7 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version 3.1 Functional Description Power Supply The IC contains 2 electrically isolated voltage domains that are independent from each other. The microcontroller interface is supplied via pin VCC and the input stage is supplied via pin VBB. The different voltage domains can be switched on at different time. If the VCC and VBB voltage have reached their operating range and the internal data transmission have been started successfully, the IC indicates the end of the Start-Up procedure by setting the pin /ERR to logic high. 3.2 Oscillator The frequency of the internal oscillator can be set by the resistor ROSC. This internal oscillator provides the clock for the data sampling and transmission as well as for the digital averaging filter. For adjusting the frequency of the oscillator the values of ROSC can be taken out of the diagram in the ISO1I813T datasheet. 3.3 Parallel Interface The ISO1I813T contains a parallel interface that can be selected by pulling the pin SEL to logic low state (see also Table 2). This interface can be directly controlled by the microcontroller output signals. Table 2 Mode Select Mode K13 K9 K10 K11 K12 K8 Parallel (IC1) 2-3 close open close open 1-2 Serial 8 Bit (IC1) 1-2 close open close open 1-2 Serial 16 Bit 1-2 open close open close 2-3 3.3.1 μC Control Mode CS - Chip select. The system microcontroller selects the ISO1I813T by means of the pin CS. Whenever the pin is in a logic low state, data can be transferred from or to the μC. RD, WR (Read / Write) By pulling one of these pins down, a read or write transaction is initiated on the AddressData bus and the data becomes valid. These pins have internal Pull-Up resistors. ALE (Address Latch Enable) the pin ALE is used to select between address (ALE is in a logic High state) or data (ALE is in a logic Low state). When ALE is pulled high, addresses are transferred and latched over the bit AD0 to AD7. During the Low State of ALE all read or write transactions hit the same adress. This pin has an internal PullDown resistor. The pins AD0 .. AD7 are the bidirectional input / outputs for data write and read. Depending on the state of the ALE, RD, WR pins, register addresses or data can be transferred between the internal registers and e.g. the microcontroller. The μC Control Mode can be operated by connecting a Processor Board to the corresponding Signals of Connector K4. The timing requirements for the μC Control Mode are shown in Figure 5. Application Note 8 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version Functional Description VCC VCC ALE /CS /RD /WR AD0 AD1 INx AD2 AD3 AD4 AD5 AD6 AD7 ISO1I813T Figure 4 MCU (e.g. XE166) or ASIC SEL parallel _interface_uc.vsd μC Control Mode /CS tCSD tRD_su ALE tRDlow tRD_hd tRDhigh /RD tAD_su tAD_hd AD[7:0] GLERR address (04h) tclrrdy tfloat tADvalid GLERR data GLERR data GLERR 00h Rd_timing_813T - Parallel _Timing_Read Figure 5 Timing Diagram μC Control Mode Read /CS tCSD tWR_su ALE tWRhigh tWR_hd /WR tWR_su tWR_hd tAD_su tAD_hd AD[7:0] COEFILx COEFILx address COEFILx data 0FH 00h tlat COEFILx data 0AH 0Fh Wr_timing_813T - Parallel _Timing_Write Figure 6 Timing Diagram μC Control Mode Write Application Note 9 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version 3.4 Functional Description Serial Interface The ISO1I813T contains two serial interfaces that can be activated by pulling the SEL pin to logic High state. The interface can be directly controlled by the microcontroller output ports. The output pins SDO and SSO are in state “Z” as long as CS=1. Otherwise, the bits are sampled with the falling edge of CS. With every falling edge of SCLK the bits are provided serially to the pin SDO and SSO, respectively. At the same time, the inputs to SDI, SSI are registered into input-FIFO buffers (sampled with the rising edge of SCLK). When all internally sampled bits have been transferred to SDO/SSO, the buffered bits from the inputs SDI/SSI are provided to these pins (daisy-chain support). The timing requirements for the serial interface are shown in Figure 8. The serial interface can be set to 8 Bit operation by using IC1 only or to 16 Bit operation by using IC1 and IC2 in daisy-chain mode. For this purpose the jumpers K8, K9, K10 have to be set in the according manner (see also Figure 7) IC1 SCLK INx SCLK SDI SDI SSI SSI SSO SDO /CS /CS K8 IC2 SCLK K10 K9 SDI SSI INx SSO K12 K11 SSO SDO SDO /CS Figure 7 SPI Configuration inactive /CS tSCLK_su active tCSD tSCLK receive edge SCLK tSU transmit edge tHD MSB SDI, SSI LSB tCS_valid SDO, SSO t CSH tSCLK_valid MSB t float LSB Serial_Bus_Timing Figure 8 Timing Diagram Serial Mode Application Note 10 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version 3.5 Functional Description Sensor Input Stage The sensor input structure is shown in Figure 9. Due to its active current a I-V-characteristic as shown in Figure 10 is maintained. This I-V-curve is well within the IEC 61131 standard requirements of Type 1 and Type 3 sensors, respectively. Type 2 sensors are supported as well with the restriction that 2 input channels have to be used in parallel i.e. only 4 channels are available. Additionally RIN and RLED has to be modified according Figure 9. It is recommended to choose for the external resistors RIN, RLED an accuracy of 2 % (< 5% is mandatory) otherwise the I/V-characteristic shown in Figure 10 cannot be attained. The Input Type 1, 2, 3 can be selected by modifying RTS according Table 3. Table 3 Type Select Input Characteristic Type 1 according IEC61131-2 33R RTS Type 2 Type 3 33k 330k VBB P24 TS RTS Inputx INx 12k (8.5k *) 0V 2k (1,5k *) IxH DATAx RIN RLED IxL GNDBB *) : for Type2 Figure 9 Sensor Input Application Note 11 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version Functional Description VFI=30V 15V/11V VINxDset VINxDhys VINxDclr active current sink 5V -3V 0.5mA Data Bit must be zero Figure 10 Sensor Input Characteristic 3.6 Wire Break Detection 2mA/3mA I INxsnkC,M 15mA Data Bit must be one The wire-break detection current can be adjusted by the RWB-resistor value connected to the pin WB (Figure 11). The minimum wirebreak-current can be choosen only when a LED- or Zener-Diode is connected to the pin IxL with a forward current in the range of few uA in the voltage range below 1 V. In the case of a connected resistor at IxL a great current is flowing across the external resistor Rext and the IxL-resistor (RLED). This part cannot be measured internally and has to be added to the internal current part. In this case the minimum adjustable current is 230uA (RLED = 2kOhm). The currently assembled WB resistor of 33kOhm leads to a WB detection limit of 80...160uA for Type 1/3 Sensor Interfaces. The WB bits in the status register have a sticky (latched) property and remains set as long as they are not cleared by a read access and the fault condition is not detected anymore. In case that a relay contact is connected to the input interface, the contact needs to be bypassed with a resistor to provide the needed WB current If the wire-break function is not needed, it can be switched off by setting the MWB bit in the registers COEFIL0-7. Application Note 12 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version Functional Description Wire-Break-Current Versus RWB 450 Wire-Break-Current[uA] 400 350 300 250 200 150 100 50 0 25 30 35 40 45 50 55 RWB[kOhm] WBmin_LED Figure 11 WBmax_LED WBmin_Rled WBmax_Rled Wire Break Detection for Type 1/3 (typ. @ 25°C) Wire-Break-Current Versus RWB 800 Wire-Break-Current[uA] 700 600 500 400 300 200 100 0 25 30 35 40 45 50 55 RWB[kOhm] WBmin_LED Figure 12 WBmax_LED WBmin_Rled WBmax_Rled Wire Break Detection for Type 2 (typ. @ 25°C) Application Note 13 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version Functional Description In the case of Type 2 two sense inputs need to be switched in parallel to achieve 2 * 3 mA (Figure 12). In each sense input a mimimum wirebreak current of 60 uA can be measured which means in sum a minimum wirebreak current of 120 uA. It is not recommended to use external resistors at the pins IxL in case of wirebreak measurements. The recommended value would be RLED = 1.2 kOhm which has been choosen in order not to produce a large voltage drop between IxL and GNDBB which in turn would limit the voltage drop across the sink. But the low value of RLED would cause a high external current in case of wirebreak-measurements which has to be multiplied by two due to the parallel circuitry of the sense inputs. 3.7 Filter Setting The sensor data bits can be filtered by a configurable digital input filter. If selected, the filter changes its output according to an averaging rule with a selectable average length. When the sensor state changes without any spikes and noise the change is delayed by the averaging length. Sensor spikes that are shorter than the averaging length are suppressed. The averaging length is selected for each channel individually using the configuration registers COEFIL0-7. The programmed filter time apply for both the data and the diagnostics of one channel. See ISO1I813T datasheet for the different setting options including filter bypass. The filters are dimensioned for the nominal internal sampling fscannom. The corresponding filter delays can be adjusted by changing the oscillator frequency i.e. by tuning the resistor at the pin ROSC. The filters are dimensioned for the nominal internal sampling fscannom. The corresponding filter delays can be adjusted by changing the oscillator frequency i.e. by tuning the resistor at the pin ROSC. Application Note 14 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version 3.8 Functional Description DC/DC Supply DC_ENA 21 uC Supply (5V / 3.3V) VCC 5 PP Output driver SW1 VBB 22 1uF 10uF Clk 100nF Temp. Sense :2 DCK SW2 23 GND 24 N1 N2 GNDBB Tr GND 1, 7, 18 uC Supply (GND) uC-Domain Figure 13 dcdc _typapp .vsd Sense-Domain Typical Circuitry for Self Powered Mode with Push-Pull Converter The IC can as well operate in self powered mode. In this case, the Process Side can be supplied at VBB with an isolated push-pull converter connected to the Micro-controller Side and driven by the pins SW1 and SW2 . The internal driver stage at SW1 and SW2 is designed to power up two ISO1I813T parts. The DC/DC-Converter is driven by the internal clock. Parameters are calculated with the internal clock = 500 kHz. By setting the bit DCK in the GLCFG register a prescaler by 2 can be activated. This may be useful to improve the EMI behaviour. Should the user adjusts another different frequency the transformer has to be adjusted accordingly. The built in short-circuit protection uses a temperature sensor located close to the drivers (Figure 13) and disables the driver stages when a predefined temperature is reached. That means that the drivers are switched off at a temperature of 160 °C and switched on at a temperature of <=150°C The transformer will be offered by EPCOS as a dedicated product for this ISO1I813T part. Order number for 3.3V to 12V @ 500kHz: DS-T7389-51-02 (see also Chapter 8). Special effort have to be spent on a proper layout, in order to minimize the noise caused by the DC/DC converter. As it can be seen in Figure 13 the current path of the DC/DC converter has to be layouted separately, using the ground pin 24. Please Note: the transformer as well as the necessary diode and capacitors are not assebled on the board. The recommended parts can be seen in the bill of material (Chapter 7). Application Note 15 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version Connectors 4 Connectors Table 4 K1, K2 Connector Pin Number K1 (IC1) K3 (IC2) 1 VBB VBB 2 Input0 Input0 3 Input1 Input1 4 Input2 Input2 5 Input3 Input3 6 Input4 Input4 7 Input5 Input5 8 Input6 Input6 9 Input7 Input7 10 GNDBB GNDBB Table 5 K4 Connector Pin Number Serial Mode Parallel Mode 1 VCC VCC 2 ERR ERR 3 SYNC SYNC 4 RD 5 DS0 WR 6 DS1 ALE 7 CS CS 8 SDI D0 9 SSO D1 10 D2 11 D3 12 CRCERR D4 13 SCLK D5 14 SSI D6 15 SDO D7 16 GND GND Application Note 16 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version Connectors 1 1 1 2 3 1 2 3 ISO1I813T 1 Figure 14 Board Assembly Application Note 17 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version 5 Schematic Figure 15 Schematic Page 1 Application Note Schematic 18 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version Figure 16 Schematic Schematic Page 2 Application Note 19 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version PCB Layout 6 PCB Layout Figure 17 Board Layout - Component Side Figure 18 Board Layout - Bottom Side (mirror view) Application Note 20 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version 7 Bill of Material Bill of Material Nr 1 2 3 4 5 6 Count 2 1 2 0 0 4 7 16 8 2 9 10 11 12 0 2 2 4 13 7 14 15 2 1 16 16 17 18 19 20 21 2 2 2 2 2 22 16 23 0 24 5 Application Note Pos. Value 470nF, 50V 10uF,10V 100nF, 50V 1uF, 50V 10uF, 10V 4,7nF, 500V C1, C7 C11 C2, C8 C3 C4 C5, C6, C9, C10 D1, D2, D3, D4, D5, D6, D7, D8, D10, D11, D12, LED, gn KPHCMD13, D14, D15, D16, 2012CGCK D17 LED, rt KPHCMD18, D19 2012EC-T D9 BAS70-05 IC1, IC2 ISO1I813T K1, K3 MKDS 1/10-3,81 K9, K10, K11, K12 Connector 2pol K6, K7, K8, K13, K14, Connector 3pol K15, K16 K17, K18 Connector 1pol K4 Connector 16pol R1, R2, R3, R4, R5, R6, R7, R8, R24, R25, R26, 2k, 1% R27, R28, R29, R30, R31 R17, R40 1k R18, R41 33k R19, R42 33R R20, R43 100R R21, R44 22k R9, R10, R11, R12, R13, R14, R15, R16, 12k, 1% R32, R33, R34, R35, R36, R37, R38, R39 T1 DS-T7389-51-02 Spacer D8mm , H2,8mm 21 Package 805 C_AL_B 805 805 805 1206 0805-DIODE 0805-DIODE SOT-23 TSSOP48 KLEMME_10_3,81 1X02 1X03 1X01 1X16-90 1206 805 805 805 1206 805 1206 E6,3 SMD V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version 8 Transformer Transformer In corporation by courtesy of EPCOS Application Note 22 V 1.0, 2011-09-09 AN-EVAL 2x8-ISO1I813T Draft Version References References [1] ISO1I813T, Isolated 8 Channel Digital Input with IEC61131-2 Type 1/2/3 Characteristics, Data Sheet, Infineon Technologies Application Note 23 V 1.0, 2011-09-09 w w w . i n f i n e o n . c o m Published by Infineon Technologies AG