Agilent HSDL-3220 IrDA® Data Compliant Low Power 4.0 Mbit/s Infrared Transceiver Data Sheet Features • Fully compliant to IrDA 1.4 physical layer low power specification from 9.6 kbit/s to 4.0 Mbit/s (FIR) • Miniature package – Height: 2.5 mm – Width: 8.0 mm – Depth: 3.0 mm • Typical link distance > 50 cm • Guaranteed temperature performance, -25o to 70oC Description The HSDL-3220 is a new generation low profile high speed infrared transceiver module that provides interface between logic and IR signals for through-air, serial, half-duplex IR data-link. The module is fully compliant to IrDA Physical Layer specification version 1.4 low power from 9.6kbit/s to 4.0 Mbit/s (FIR) and is IEC825-Class 1 Eye Safe. VCC The HSDL-3220 can be shutdown completely to achieve very low power consumption. In the shutdown mode, the PIN diode will be inactive and thus producing very little photocurrent even under very bright ambient light. It is also designed to interface to input/output logic circuits as low as 1.8V. These features are ideal for mobile devices that require low power consumption. GND (8) RECEIVER SHIELD TRANSMITTER LED A (1) CX3 Figure 1. Functional block diagram of HSDL-3220. 8 7 6 5 4 3 2 • Lead-free package • LED stuck-high protection Applications TXD (3) R1 • Interfacing with I/O logic circuits as low as 1.8 V • IEC 825-class 1 eye safe • Lead-free and RoHS Compliant HSDL-3220 Vled • Vcc supply 2.7 to 3.6 Volts CX1 SD (5) LED C (2) • Excellent EMI performance • Designed to accommodate light loss with cosmetic windows VCC (6) RXD (4) • Low power consumption – Low shutdown current – Complete shutdown of TXD, RXD, and PIN diode CX2 CX4 IOVCC (7) • Critical parameters are guaranteed over temperature and supply voltage 1 Figure 2. Rear view diagram with pinout. • Mobile telecom – Mobile phones – Smart phones – Pagers • Data communication – Pocket PC handheld products – Personal digital assistants – Portable printers • Digital imaging – Digital cameras – Photo-imaging printers • Electronic wallet • Small industrial & medical instrumentation – General data collection devices – Patient & pharmaceutical data collection devices Application Support Information The Application Engineering Group is available to assist you with the application design associated with the HSDL-3220 infrared transceiver module. You can contact them through your local sales representatives for additional details. Order Information Part Number Packaging Type Package Quantity HSDL-3220-021 Tape and Reel Front View 2500 HSDL-3220-001 Tape and Reel Front View 500 I/O Pins Configuration Table Pin Symbol Description I/O Type Notes 1 LED A LED Anode I 1 2 LED C LED Cathode 3 TXD Transmit Data. Active High. I 3 4 RXD Receive Data. Active Low. O 4 5 SD Shutdown. Active High. I 5 6 Vcc Supply Voltage 6 7 IOVcc Input/Output ASIC Vcc 7 8 GND Ground 8 - Shield EMI Shield 9 2 Recommended Application Circuit Components Component Recommended Value Notes R1 5.6Ω ± 5%, 0.25 watt for 2.7 ≤ Vled < 3.3V 10Ω ± 5%, 0.25 watt for 3.3 ≤ Vled < 4.2V 15Ω ± 5%, 0.25 watt for 4.2 ≤ Vled < 5.5V CX1, CX4 0.47 µF ± 20%, X7R Ceramic 10 CX2, CX3 6.8 µF ± 20%, Tantalum 11 Notes: 1. Tied through external series resistor, R1, to regulated Vled from 2.7 to 5.5V. Please refer to table above for recommended series resistor value. 2. Internally connected to LED driver. Leave this pin unconnected. 3. This pin is used to transmit serial data when SD pin is low. If this pin is held high for longer than 50 µs, the LED is turned off. Do NOT float this pin. 4. This pin is capable of driving a standard CMOS or TTL load. No external pull-up or pull-down resistor is required. The pin is in tri-state when the transceiver is in shutdown mode. The receiver output echoes transmitted signal. 5. The transceiver is in shutdown mode if this pin is high for more than 400 µs. On falling edge of this signal, the state of the TXD pin sampled and used to set receiver low bandwidth (TXD=low) or high bandwidth (TXD=high) mode. Refer to the section ”Bandwidth selection timing” for programming information. Do NOT float this pin. 6. Regulated, 2.7 to 3.6 Volts. 7. Connect to ASIC logic controller Vcc voltage or supply voltage. The voltage at this pin must be equal to or less than supply voltage. 8. Connect to system ground. 9. Connect to system ground via a low inductance trace. For best performance, do not connect directly to the transceiver pin GND. 10. CX1 must be placed within 0.7 cm of the HSDL-3220 to obtain optimum noise immunity. 11. In environments with noisy power supplies, including CX2, as shown in Figure 1, can enhance supply ripple rejection performance. 2 Marking Information The unit is marked with the letter “G” and “YWWLL” on the shield where: Y is the last digit of the year WW is the work week LL is the lot information Bandwidth Selection Timing The transceiver is in default SIR/ MIR mode when powered on. User needs to apply the following programming sequence to both the SD and TXD inputs to enable the transceiver to operate at FIR mode. VIH VIH 50% SD/MODE 50% SD/MODE VIL VIL tS tS tH tH VIH TXD 50% TXD 50% 50% 50% VIL VIL Figure 3. Bandwidth selection timing at SIR/MIR mode. Setting the transceiver to SIR/MIR Mode (9.6 kbit/s to 1.152 Mbit/s) 1. Set SD/Mode input to logic HIGH 2. TXD input should remain at logic LOW 3. After waiting for tS ≥ 25 ns, set SD/Mode to logic LOW, the HIGH to LOW negative edge transition will determine the receiver bandwidth Figure 4. Bandwidth selection timing at FIR mode. 4. Ensure that TXD input remains low for tH ≥ 100 ns, the receiver is now in SIR/MIR mode 5. SD input pulse width for mode selection should be > 50 ns. Setting the transceiver to FIR (4.0 Mbit/s) Mode 1. Set SD/Mode input to logic HIGH 2. After SD/Mode input remains HIGH at > 25 ns, set TXD input to logic HIGH, wait tS ≥ 25 ns (from 50% of TXD rising edge till 50% of SD falling edge) 3. Then set SD/Mode to logic LOW, the HIGH to LOW negative edge transition will determine the receiver bandwidth 4. After waiting for tH ≥ 100 ns, set the TXD input to logic LOW 5. SD input pulse width mode selection should be > 50 ns. Transceiver I/O Truth Table Inputs Outputs TXD Light Input to Receiver SD LED RXD High Don’t Care Low On Not Valid Low High Low Off Low Low Low Low Off High Don’t Care Don’t Care High Off High Note 12,13 Notes: 12. In-band IrDA signals and data rates ≤ 4.0 Mbit/s 13. RXD logic low is a pulsed response. The condition is maintained for a duration dependent on pattern and strength of the incident intensity. 3 CAUTIONS: The BiCMOS inherent to the design of this component increases the component’s susceptibility to damage from electrostatic discharge (ESD). It is advised that normal static precautions be taken in handling and assembly of this component to prevent damage and/or degradation which may be induced by ESD. Absolute Maximum Ratings For implementations where case to ambient thermal resistance is ≤ 50°C/W. Parameter Symbol Min. Max. Units Storage Temperature TS -40 +100 °C Operating Temperature TA -25 +70 °C LED Anode Voltage VLEDA 0 6.5 V Supply Voltage VCC 0 6.5 V Input Voltage: TXD, SD/Mode VI 0 6.5 V Output Voltage: RXD VO 0 6.5 V DC LED Transmit Current ILED (DC) 50 mA Average Transmit Current ILED (PK) 200 mA Conditions ≤ 90 µs pulse width ≤ 25% duty cycle Recommended Operating Conditions Parameter Symbol Min. Supply Voltage VCC Input/Output Voltage Logic Input Voltage for TXD, SD/Mode Typ. Max. Units 2.7 3.6 V IOVcc 1.8 Vcc V Logic High VIH IOVcc – 0.5 IOVcc V Logic Low VIL 0 0.4 V Logic High EIH, min 0.0081 mW/cm2 0.020 mW/cm2 EIH, max 500 mW/cm2 ≤ 4.0 Mbit/s [14] 9.6 kbit/s ≤ in-band signals ≤ 4.0 Mbit/s[14] EIL 0.3 µW/cm2 For in-band signals [14] Receiver Input Irradiance Logic Low LED (Logic High) Current Pulse Amplitude Receiver Data Rate ILEDA 150 0.0096 Conditions 9.6kbit/s ≤ in-band signals ≤1.152 Mbit/s [14] 1.152 Mbit/s < in-band signals mA 4.0 Mbit/s Note : 14. An in-band optical signal is a pulse/sequence where the peak wavelength, λp, is defined as 850 ≤ λp ≤ 900 nm, and the pulse characteristics are compliant with the IrDA Serial Infrared Physical Layer Link Specification v1.4. 4 Electrical and Optical Specifications Specifications (Min. and Max. values) hold over the recommended operating conditions unless otherwise noted. Unspecified test conditions may be anywhere in their operating range. All typical values (Typ.) are at 25°C, Vcc set to 3.0V and IOVcc set to 1.8V unless otherwise noted. Parameter Symbol Min. Viewing Angle 2θ 30 Peak Sensitivity Wavelength λp Typ. Max. Units Conditions Receiver ° 880 nm Logic High VOH IOVCC – 0.2 IOVCC V IOH = -200 µA, EI ≤ 0.3 µW/cm2 Logic Low VOL 0 0.4 V IOL = 200 µA, EI ≥ 8.1 µW/cm2 RXD Pulse Width (SIR)[15] tPW (SIR) 1 4.0 µs θ ≤ 15°, CL = 9 pF RXD Pulse Width (MIR)[16] tPW(MIR) 100 500 ns θ ≤ 15°, CL = 9 pF RXD Pulse Width (FIR) [16] tPW(FIR) 80 175 ns θ ≤ 15°, CL = 9 pF RXD Rise and Fall Times tr, tf 60 ns CL = 9 pF Receiver Latency Time[17] tL 25 50 µs Receiver Wake Up Time[18] tW 50 100 µs RXD Output Voltage Transmitter Radiant Intensity IEH 10 Viewing Angle 2θ 30 Peak Wavelength λp 875 nm Spectral Line Half Width ∆λ 35 nm TXD Input Current 45 mW/sr 60 ILEDA= 150 mA, θ ≤ 15°, VTXD ≥ VIH, VSD ≤ VIL, Ta=25°C ° High IH 10 µA VTXD ≥ VIH Low IL 10 µA 0 ≤ VTXD ≤ VIL mA VTXD ≥ VIH, R1=5.6ohm, Vled=3.0V LED ON Current ILEDA 150 TXD Pulse Width (SIR) tPW (SIR) 1.5 1.6 1.8 µs tPW (TXD) = 1.6 µs at 115.2 kbit/s TXD Pulse Width (MIR) tPW(MIR) 148 217 260 ns tPW (TXD) = 217 ns at 1.152 Mbit/s TXD Pulse Width (FIR) tPW(FIR) 115 125 135 ns tPW(TXD)=125 ns at 4.0 Mbit/s Maximum Optical PW[19] tPW(max.) 50 100 µs TXD Rise and fall Time (Optical) tr, tf 600 40 ns ns tPW(TXD) = 1.4 µs at 115.2 kbit/s tPW (TXD) = 125 ns at 4.0 Mbit/s LED Anode On-State Voltage VON(LEDA) 1.6 2.1 V ILEDA=150 mA, VTXD ≥VIH Shutdown ICC1 0.1 1 µA VSD ≥ VIH, Ta= 25°C Idle ICC2 1.8 3.0 mA VSD ≤ VIL, VTXD ≤ VIL, EI=0 Transceiver Supply Current Notes: 15. For in-band signals from 9.6 kbit/s to 115.2 kbit/s, where 9 µW/cm2 ≤ EI ≤ 500 mW/cm2. 16. For in-band signals from 0.576 Mbit/s to 4.0 Mbit/s, where 22.5 µW/cm2 ≤ EI ≤ 500 mW/cm2. 17. Latency time is defined as the time from the last TxD light output pulse until the receiver has recovered full sensitivity. 18. Receiver wake up time is measured from Vcc power on or SD pin high to low transition to a valid RXD output. 19. The maximum optical PW is the maximum time the LED remains on when the TXD is constantly high. This is to prevent long turn on time of the LED for eye safety protection. 5 tpw tpw VOH LED ON 90% 90% 50% 50% 10% VOL 10% LED OFF tf tr Figure 5. RxD output waveform. tr tf Figure 6. LED optical waveform. SD TXD RX LIGHT RXD LED tRW tpw (MAX.) Figure 7. TxD “Stuck On” protection waveform. Figure 8. Receiver wakeup time waveform. 2.4 100 2.2 80 VLEDA (V) RADIANT INTENSITY (mW/sr) 120 60 1.8 40 1.6 20 0 0.10 0.15 0.20 0.25 0.30 ILEDA (A) Figure 9. Radiant Intensity vs ILEDA. 6 2.0 0.35 1.4 0.10 0.15 0.20 0.25 ILEDA (A) Figure 10. VLEDA vs ILEDA. 0.30 0.35 HSDL-3220 Package Dimensions 2.0 0.8 0.4 7 HSDL-3220 Tape and Reel Dimensions 4.0 ± 0.1 Unit: mm 1.75 ± 0.1 1.5 ± 0.1 Ø1.5 +0.10 POLARITY Pin 8: VLED 7.5 ± 0.1 16.0 ± 0.2 Pin 1: GND 0.4 ± 0.05 8.4 ± 0.1 3.4 ± 0.1 2.8 ± 0.1 8.0 ± 0.1 Progressive Direction Empty Parts Mounted Leader (400 mm min) (40 mm min) Empty (40 mm min) Option # "B" "C" Quantity 001 178 60 500 021 330 80 2500 Unit: mm Detail A 2.0 ± 0.5 B C 13.0 ± 0.5 R1.0 LABEL 21 ± 0.8 Detail A 16.4 +2 0 2.0 ± 0.5 Note: The carrier tape is compliant to the packaging materials standards for ESD sensitive device, EIA-541 8 Moisture Proof Packaging All HSDL-3220 options are shipped in moisture proof package. Once opened, moisture absorption begins. This part is compliant to JEDEC Level 4. Baking Conditions If the parts are not stored in dry conditions, they must be baked before reflow to prevent damage to the parts. Package UNITS IN A SEALED MOISTURE-PROOF PACKAGE Temp. Time In reels 60°C ≥ 48 hours In bulk 100°C ≥ 4 hours 125°C ≥ 2 hours 150°C ≥ 1 hour Baking should only be done once. PACKAGE IS OPENED (UNSEALED) Recommended Storage Conditions ENVIRONMENT LESS THAN 30°C, AND LESS THAN 60% RH YES PACKAGE IS OPENED LESS THAN 72 HOURS NO PERFORM RECOMMENDED BAKING CONDITIONS Figure 11. Baking conditions chart. 9 10°C to 30°C Relative Humidity below 60% RH Time from Unsealing to Soldering After removal from the bag, the parts should be soldered within three days if stored at the recommended storage conditions. If times longer than three days are needed, the parts must be stored in a dry box. YES NO BAKING IS NECESSARY Storage Temperature NO Recommended Reflow Profile MAX. 260°C T – TEMPERATURE – (°C) 255 R4 R3 230 220 200 180 R2 60 sec. MAX. ABOVE 220°C 160 R1 120 R5 80 25 0 50 100 150 200 250 300 t-TIME (SECONDS) P1 HEAT UP P2 SOLDER PASTE DRY P3 SOLDER REFLOW P4 COOL DOWN Process Zone Symbol ∆T Maximum ∆T/∆time Heat Up P1, R1 25°C to 160°C 4°C/s Solder Paste Dry P2, R2 160°C to 200°C 0.5°C/s P3, R3 200°C to 255°C (260°C at 10 seconds max) 4°C/s P3, R4 255°C to 200°C -6°C/s P4, R5 200°C to 25°C -6°C/s Solder Reflow Cool Down The reflow profile is a straightline representation of a nominal temperature profile for a convective reflow solder process. The temperature profile is divided into four process zones, each with different ∆T/∆time temperature change rates. The ∆T/∆time rates are detailed in the above table. The temperatures are measured at the component to printed circuit board connections. In process zone P1, the PC board and HSDL-3220 castellation pins are heated to a temperature of 160°C to activate the flux in the solder paste. The temperature ramp up rate, R1, is limited to 4°C per second to allow for even heating of both the PC board and HSDL-3220 castellations. 10 Process zone P2 should be of sufficient time duration (60 to 120 seconds) to dry the solder paste. The temperature is raised to a level just below the liquidus point of the solder, usually 200° C (392° F). Process zone P3 is the solder reflow zone. In zone P3, the temperature is quickly raised above the liquidus point of solder to 255° C (491° F) for optimum results. The dwell time above the liquidus point of solder should be between 20 and 60 seconds. It usually takes about 20 seconds to assure proper coalescing of the solder balls into liquid solder and the formation of good solder connections. Beyond a dwell time of 60 seconds, the intermetallic growth within the solder connections becomes excessive, resulting in the formation of weak and unreliable connections. The temperature is then rapidly reduced to a point below the solidus temperature of the solder, usually 200° C (392° F), to allow the solder within the connections to freeze solid. Process zone P4 is the cool down after solder freeze. The cool down rate, R5, from the liquidus point of the solder to 25° C (77° F) should not exceed 6° C per second maximum. This limitation is necessary to allow the PC board and HSDL-3220 castellations to change dimensions evenly, putting minimal stresses on the HSDL-3220 transceiver. Appendix A: SMT Assembly Application Note Solder Pad, Mask and Metal Stencil Aperture METAL STENCIL FOR SOLDER PASTE PRINTING STENCIL APERTURE LAND PATTERN SOLDER MASK PCB Figure 12. Stencil and PCBA. Recommended Land Pattern SHIELD SOLDER PAD CL 1.35 MOUNTING CENTER 1.25 2.05 0.10 0.775 1.75 FIDUCIAL 0.60 0.475 1.425 UNIT: mm 2.375 3.325 Figure 13. Stencil and PCBA. 11 Recommended Metal Solder Stencil Aperture It is recommended that only a 0.152 mm (0.006 inches) or a 0.127 mm (0.005 inches) thick stencil be used for solder paste printing. This is to ensure adequate printed solder paste volume and no shorting. See the table below the drawing for combinations of metal stencil aperture and metal stencil thickness that should be used. Aperture opening for shield pad is 2.7 mm x 1.25 mm as per land pattern. Adjacent Land Keepout and Solder Mask Areas Adjacent land keep-out is the maximum space occupied by the unit relative to the land pattern. There should be no other SMD components within this area. APERTURES AS PER LAND DIMENSIONS t w l Figure 14. Solder stencil aperature. Stencil thickness, t (mm) Aperture size (mm) length, l width, w 0.152 mm 2.60 ± 0.05 0.55 ± 0.05 0.127 mm 3.00 ± 0.05 0.55 ± 0.05 10.1 0.2 3.85 The minimum solder resist strip width required to avoid solder bridging adjacent pads is 0.2 mm. It is recommended that two fiducial crosses be place at midlength of the pads for unit alignment. SOLDER MASK 3.0 UNITS: mm Note: Wet/Liquid PhotoImageable solder resist/mask is recommended. 12 Figure 15. Adjacent land keepout and solder mask areas. Appendix B: PCB Layout Suggestion The following PCB layout guidelines should be followed to obtain a good PSRR and EM immunity resulting in good electrical performance. Things to note: 4. Preferably a multi-layered board should be used to provide sufficient ground plane. Use the layer underneath and near the transceiver 1. The ground plane should be continuous under the part, but should not extend under the shield trace. TOP LAYER CONNECT THE METAL SHIELD AND MODULE GROUND PIN TO BOTTOM GROUND LAYER. 2. The shield trace is a wide, low inductance trace back to the system ground. CX1, CX2, CX3, and CX4 are optional supply filter capacitors; they may be left out if a clean power supply is used. 3. Vled can be connected to either unfiltered or unregulated power supply. If Vled and Vcc share the same power supply, CX3 need not be used and the connections for CX1 and CX2 should be before the current limiting resistor R1. In a noisy environment, including capacitor CX2 can enhance supply rejection. CX1 is generally a ceramic capacitor of low inductance providing a wide frequency response while CX2 and CX3 are tantalum capacitors of big volume and fast frequency response. The use of a tantalum capacitor is more critical on the Vled line, which carries a high current. CX4 is an optional ceramic capacitor, similar to CX1, for the IOVcc line. LAYER 2 CRITICAL GROUND PLANE ZONE. DO NOT CONNECT DIRECTLY TO THE MODULE GROUND PIN. LAYER 3 KEEP DATA BUS AWAY FROM CRITICAL GROUND PLANE ZONE. BOTTOM LAYER (GND) The area underneath the module at the second layer, and 3 cm in all directions around the module is defined as the critical ground plane zone. The ground plane should be maximized in this Figure 16. PCB layout suggestion. 13 module as Vcc, and sandwich that layer between ground connected board layers. Refer to the diagram below for an example of a 4 layer board. zone. Refer to application note AN1114 or the Agilent IrDA Data Link Design Guide for details. The layout below is based on a 2-layer PCB. Appendix C: General Application Guide for the HSDL-3220 Description The HSDL-3220, a low-cost and small form factor infrared transceiver, is designed to address the mobile computing market such as PDAs, as well as small-embedded mobile products such as digital cameras and cellular phones. It is fully compliant to IrDA 1.4 low power specification from 9.6 kbit/s to 4.0 Mbit/s, and supports HP-SIR and TV Remote modes. The design of the HSDL3220 also includes the following unique features: • Low passive component count. • Shutdown mode for low power consumption requirement. • Interface to input/output logic circuits as low as 1.8V Interface to Recommended I/O chips The HSDL-3220’s TXD data input is buffered to allow for CMOS drive levels. No peaking circuit or capacitor is required. Data rate from 9.6 kbit/s up to 4.0 Mbit/s is available at the RXD pin. The block diagram below shows how the IR port fits into a mobile phone and PDA platform. Selection of Resistor R1 Resistor R1 should be selected to provide the appropriate peak pulse LED current over different ranges of Vcc as shown in the table below. Recommended R1 Vcc Intensity Minimum Peak Pulse LED Current 5.6Ω 3.0 V 45 mW/sr 150 mA SPEAKER AUDIO INTERFACE DSP CORE MICROPHONE ASIC CONTROLLER RF INTERFACE TRANSCEIVER MOD/ DE-MODULATOR IR MICROCONTROLLER USER INTERFACE Figure 17. Mobile phone platform. 14 HSDL-3220 LCD Panel ROM IR RAM CPU for embedded application Touch Panel PCMCIA Controller RS232C Driver Figure 18. PDA platform. The link distance testing was done using typical HSDL-3220 units with SMC’s FDC37C669 and FDC37N769 Super I/O controllers. An IR link distance of up to 50 cm was demonstrated for SIR and FIR speeds. 15 HSDL-3220 COM Port Appendix D: Window Designs for HSDL-3220 Optical port dimensions for HSDL-3220 To ensure IrDA compliance, some constraints on the height and width of the window exist. The minimum dimensions ensure that the IrDA cone angles are met without vignetting. The maximum dimensions minimize the effects of stray light. The minimum size corresponds to a cone angle of 30° and the maximum size corresponds to a cone angle of 60° . In the figure below, X is the width of the window, Y is the OPAQUE MATERIAL height of the window and Z is the distance from the HSDL-3220 to the back of the window. The distance from the center of the LED lens to the center of the photodiode lens, K, is 5.1mm. The equations for computing the window dimensions are as follows: X = K + 2*(Z+D)*tanA Y = 2*(Z+D)*tanA The above equations assume that the thickness of the window is negligible compared to the distance of the module from the back of the window (Z). If they are IR TRANSPARENT WINDOW Y X IR TRANSPARENT WINDOW K Z A D Figure 19. Window design diagram. 16 OPAQUE MATERIAL comparable, Z' replaces Z in the above equation. Z' is defined as Z' = Z + t/n where ‘t’ is the thickness of the window and ‘n’ is the refractive index of the window material. The depth of the LED image inside the HSDL-3220, D, is 3.17 mm. ‘A’ is the required half angle for viewing. For IrDA compliance, the minimum is 15° and the maximum is 30° . Assuming the thickness of the window to be negligible, the equations result in the following tables and graphs. Aperture Width (x, mm) Max. Min. Aperture Height (y, mm) Max. Min. 0 8.76 6.80 3.66 1.70 1 9.92 7.33 4.82 2.33 2 11.07 7.87 5.97 2.77 3 12.22 8.41 7.12 3.31 4 13.38 8.94 8.28 3.84 5 14.53 9.48 9.43 4.38 6 15.69 10.01 10.59 4.91 7 16.84 10.55 11.74 5.45 8 18.00 11.09 12.90 5.99 9 19.15 11.62 14.05 6.52 APERTURE WIDTH (X) vs. MODULE DEPTH APERTURE HEIGHT (Y) vs. MODULE DEPTH 25 16 20 15 10 X MAX. X MIN. 5 0 0 1 2 3 4 59 6 7 8 MODULE DEPTH (Z) – mm Figure 20. Aperture width (X) vs. module depth. 17 APERTURE HEIGHT (Y) – mm APERTURE WIDTH (X) – mm Module Depth (z) mm 14 12 10 8 6 4 Y MAX. Y MIN. 2 0 0 1 2 3 4 59 6 7 8 MODULE DEPTH (Z) – mm Figure 21. Aperture height (Y) vs. module depth. Window Material Almost any plastic material will work as a window material. Polycarbonate is recommended. The surface finish of the plastic should be smooth, without any texture. An IR filter dye may be used in the window to make it look black to the eye, but the total optical loss of the window should be 10% or less for best optical performance. Light loss should be measured at 875 nm. The recommended plastic materials for use as a cosmetic window are available from General Electric Plastics. Shape of the Window From an optics standpoint, the window should be flat. This ensures that the window will not alter either the radiation pattern of the LED, or the receive pattern of the photodiode. If the window must be curved for mechanical or industrial design reasons, place the same curve on the back side of the window that has an identical radius as the front side. While this will not completely eliminate the lens effect of the front curved surface, it will significantly reduce the effects. The amount of change in the radiation pattern is dependent upon the material chosen for the window, the radius of the front and back curves, and the distance from the back surface to the transceiver. Once these items are known, a lens design can be made which will eliminate the effect of the front surface curve. The following drawings show the effects of a curved window on the radiation pattern. In all cases, the center thickness of the window is 1.5 mm, the window is made of polycarbonate plastic, and the distance from the transceiver to the back surface of the window is 3 mm. Recommended Plastic Materials: Material # Light Transmission Haze Refractive Index Lexan 141 88% 1% 1.586 Lexan 920A 85% 1% 1.586 Lexan 940A 85% 1% 1.586 Note: 920A and 940A are more flame retardant than 141. Flat Window (First Choice) Figure 22. Shape of windows. 18 Curved Front and Back (Second Choice) Curved Front, Flat Back (Do Not Use) www.agilent.com/semiconductors For product information and a complete list of distributors, please go to our web site. For technical assistance call: Americas/Canada: +1 (800) 235-0312 or (916) 788-6763 Europe: +49 (0) 6441 92460 China: 10800 650 0017 Hong Kong: (+65) 6756 2394 India, Australia, New Zealand: (+65) 6755 1939 Japan: (+81 3) 3335-8152(Domestic/International), or 0120-61-1280(Domestic Only) Korea: (+65) 6755 1989 Singapore, Malaysia, Vietnam, Thailand, Philippines, Indonesia: (+65) 6755 2044 Taiwan: (+65) 6755 1843 Data subject to change. Copyright © 2003-2005 Agilent Technologies, Inc. Obsoletes 5989-3140EN August 18, 2005 5989-3640EN