P r e li m i na r y D a t a S h ee t , M ay 20 0 1 F O A 23 2 2A 3 . 2 G b it / s L a s e r D r i v e r I C f o r T el ec o m a n d D a t a c o m Ap pl ic a t io ns IC s f or C om m u n i c a ti o n s N e v e r s t o p t h i n k i n g . Edition 2001-05 Published by Infineon Technologies AG, St.-Martin-Strasse 53, D-81541 München, Germany © Infineon Technologies AG 2001. All Rights Reserved. Attention please! The information herein is given to describe certain components and shall not be considered as warranted characteristics. Terms of delivery and rights to technical change reserved. We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts stated herein. Infineon Technologies is an approved CECC manufacturer. Information For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office in Germany or our Infineon Technologies Representatives worldwide. Warnings Due to technical requirements components may contain dangerous substances. For information on the types in question please contact your nearest Infineon Technologies Office. Infineon Technologies Components may only be used in life-support devices or systems 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. P r e li m i na r y D a t a S h ee t , M ay 20 0 1 F O A 23 2 2A 3 . 2 G b it / s L a s e r D r i v e r I C f o r T el ec o m a n d D a t a c o m Ap pl ic a t io ns IC s f or C om m u n i c a ti o n s N e v e r s t o p t h i n k i n g . FOA2322A Revision History: 2001-05 Previous Version: Page Subjects (major changes since last revision) For questions on technology, delivery and prices please contact the Infineon Technologies Offices in Germany or the Infineon Technologies Companies and Representatives worldwide: see our webpage at http://www.infineon.com FOA2322A Table of Contents Page 1 1.1 1.2 1.3 1.4 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.1 2.2 2.3 2.4 2.4.1 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 General Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Characteristics and Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Typical Characteristics of Temperature Compensation (Mode 1) . . . . . . . 14 Modulation Current Swing versus RMOD, RTC, Junction Temperature and Supply Voltage / High Current Drive . . . . . . 14 Modulation Current Swing versus RMOD, RTC, Junction Temperature and Supply Voltage / Low Current Drive . . . . . . 16 Principle of Modulation Current Control by Using a Pilot Signal (Mode 2) 18 Data / Clock Input Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Timing of Clock and Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Laser and VCC Supervising Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Input Signal Monitoring and Hardware Alarm (Consideration in absence of Laser Fault) . . . . . . . . . . . . . . . . . . . . . . . . . 21 2.4.2 2.5 2.6 2.7 2.8 2.9 2 2 2 2 2 3 3.1 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Pad Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4 Application Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Preliminary Data Sheet 1 2001-05 3.2 Gbit/s Laser Driver IC for Telecom and Datacom Applications FOA2322A FOA2322A 1 Overview 1.1 Features • • • • • Data rate up to 3.2 Gbit/s Supply range from +3.0 V to +5.5 V Modulation current adjustable up to 75 mA Bias current adjustable up to 80 mA Choice between temperature compensation and integrated Two-Loop-Control of bias and modulation current • Integrated laser supervisor • Monitor output for optical output power 1.2 Applications • Fiber optics telecom and data communication systems • SDH / SONET, Fiber Channel, Gigabit Ethernet 1.3 Technology • Bicmos B6HFC 1.4 General This document defines the ratings and characteristics of a laser driver circuit dedicated for applications within telecom and datacom modules with respect to various transmission standards and laser safety requirements. A block diagram of this circuit is shown in Figure 1. Modulation Control / Modulator / Input Stage The modulator is capable of driving modulation currents up to 75 mA. There are two modes for adjusting the modulation current: Mode 1: The modulation current is adjusted by an external resistor (RMOD). The IC has an internal temperature compensation circuit for compensating the temperature characteristic of laser diode slope efficiency. With the external resistor (RTC) the modulation current temperature coefficient is adjustable. The temperature input itself is derived from chip junction temperature. Preliminary Data Sheet 2 2001-05 FOA2322A Overview Mode 2: The modulation current is controlled by using a low frequency pilot signal. The controller cutoff frequency is adjustable by external capacitor (CMOD). Mode 2 is suitable for data rates 1.25 Gbit/s (depending on laser diode). There is an option for using data input latch. Input Signal Monitor An input signal monitor circuit delivers a logic signal HWA and an internal signal which is used for laser disabling if data input is constantly high or low. Bias Control / Bias Generator The bias controller controls the LD optical output power by adjusting the bias current. The controller cutoff frequency is adjustable by external capacitor (CBIAS). A min. cutoff frequency is integrated. The laser bias current will start at < 500 µA after laser enable. Laser Supervisor / VCC Supervisor The laser supervisor circuit monitors the laser output power by the means of monitor diode feedback. The voltage generated by monitor diode circuit is compared to a reference. If the input voltage deviates more than ±2 dB (optical power ±1 dB) from this reference the laser diode is switched off and a fault indication is generated. The VCC supervisor monitors the circuit power supply and switches off the laser if the VCC level is below the reset threshold. It is keeping the laser output down for the adjusted delay time (power on delay) after VCC has risen above the VCC reset threshold. Preliminary Data Sheet 3 2001-05 FOA2322A Overview CFDEL CISM CILM VCCD2 VCCD VCCA LDOFF LF LEN RST RSTN Laser Supervisor VCC Supervisor HWA Bias Enable VMOD Modulation Enable D DN Input Stage CLK CLKN Modulator VEE2 Latch VEE2 RBRIP RMRIP CMOD MX COSC CSELN Modul. Control Incl. Oscillator Mode Start Temperature Compensation RTC RMOD IBIAS MD Bias Generator Bias Control VEE VEE CBIAS Figure 1 O O ON ON RPOUT MPOUT VEE1 VBIAS ITB11326 General Circuit Block Diagram – Number of pins: 42 – IC available as die Preliminary Data Sheet 4 2001-05 FOA2322A Electrical Characteristics 2 Electrical Characteristics 2.1 Absolute Maximum Ratings Absolute Maximum Ratings which may not be exceeded to the device without causing permanent damage or degradation. Exposure to these values for extended periods may effect device reliability. If the device is operated beyond the range of Operating Conditions and Characteristics functionality is not guaranteed. All voltages given within this data sheet are referred to VEE if not otherwise mentioned. Table 1 Absolute Maximum Ratings Parameter SymLimit Values bol min. max. Supply Voltage -0.3 Output Voltage at O, ON V – VCC - 2.6 VCC + 0.3 -0.3 VCC + 0.3 -0.3 VCC + 0.3 -0.3 VCC + 0.3 -0.3 VCC + 0.3 V 1) V 1)2) V 1) V 1)2) V 1) Differential Data Input Voltage |VD - VDN| – 2.5 V – Differential Data Input Voltage |VCLK - VCLKN| – 2.5 V – Sink Current at Logic Output LF, HWA – 5 mA – Source Current at LDOFF -4 – mA – Source Current at RPOUT -2 – mA – Modulation Current at O, ON (both Outputs) – 80 mA – Bias Current at IBIAS – 95 mA – Modulation Control Sink Current at VMOD (Input Current for Current Mirror 1:10) – 9.6 mA – Bias Control Sink Current at VBIAS (Input Current for Current Mirror 1:25) – 4.8 mA – Modulation Current Adjust Resistor RMOD 800 – Ω – Output Voltage at MPOUT Output Voltage at Logic Output LF, HWA Output Voltage at IBIAS Input Voltage at Logic Inputs LEN, RST, RSTN, CSELN Preliminary Data Sheet 5 6 Unit Conditions 2001-05 FOA2322A Electrical Characteristics Table 1 Absolute Maximum Ratings (cont’d) Parameter SymLimit Values bol min. max. Unit Conditions Modulation Temperature Coefficient Resistor RTC 50 – Ω – Junction Temperature -40 125 °C – Storage Temperature -55 150 °C – Relative Humidity (non-condensing) – 95 % – Electrostatic Discharge Voltage Capability – 1 kV – 1) Maximum voltage is 6 V. 2) For applications with VCC + 5 V (please refer to Figure 13). Note: Stresses above the ones listed here may cause permanent damage to the device. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. 2.2 General Operating Conditions Under the below defined operating conditions all specified characteristics will be met unless otherwise noted. Table 2 General Operating Conditions Parameter SymLimit Values bol min. max. Unit Conditions Environmental Junction Temperature Relative Humidity (non-condensing) °C 1) -40 125 -40 110 – 95 % – 3 5.5 V 3) 2) Supply Voltage VCC Range 1) For modulation current IOH ≤ 50 mA 2) For modulation current 50 mA < IOH ≤ 75 mA 3) Valid for VCCA and VCCD; VCCA ≥ VCCD Preliminary Data Sheet 6 2001-05 FOA2322A Electrical Characteristics 2.3 Characteristics and Operating Conditions Table 3 Characteristics and Operating Conditions SP Parameter Symbol Limit Values min. typ. max. Unit Condition Modulator / Modulation Control 1 Data Transmission Rate DR 0 – 2.5 Gbit/s 1) 2 Supply Current ICC – 30 63 mA 2)3) 3 Modulation Current High at O/ON for VCC = 3.3 V for VCC = 5 V IOH IOL mA 4)5) Modulation Current Low at O/ON IOL mA 6) 5 Modulation Current at Laser Shut Down IOSD 6 O, ON Output Voltage Range for VCC = 3.3 V V O, VON 4 5 5 – – 65 75 0 – 2 Offset 0 – 200 µA 7) V 8) VCC - – VCC 1.65 V VCC 2.0 V – VCC 800 – Open Input Ω 9)10) RTC 50 – Open Input Ω 9)11) Data Input Voltage High VIHD – – VCCD V – 10 Data Input Voltage Low for VCCD = 3.3 V for VCCD = 5 V VILD V – 1.0 2.2 – – – – 11 Data Input Voltage Swing |VD VDN| 250 – 1600 mV – 12 Clock Input Voltage High VIHCLK – – VCCD - 0.65 V for VCC = 5 V 7 Modulation Current Adjust RMOD Resistor Range (MOD-Resistor) 8 Modulation Temperature Coefficient Resistor Range Serial Data/Clock Input 9 Preliminary Data Sheet 7 – 2001-05 FOA2322A Electrical Characteristics Table 3 Characteristics and Operating Conditions (cont’d) SP Parameter Symbol Limit Values min. typ. max. 1.0 2 – – – – 1100 13 Clock Input Voltage Low for VCCD = 3.3 V for VCCD = 5 V VILCLK 14 Clock Input Voltage Swing |VCLK VCLKN| 250 – 15 Bias Voltage at D/DN VBBD – 16 Bias Voltage at CLK/CLKN VBBC 17 Differential Data/Clock Input Termination Unit Condition V – mV – VCCD - 1.0 – V 12) – VCCD - 1.3 – V 12) RIN 80 100 120 Ω 12)13) 19 Input Capacitance D/DN/CLK/CLKN CIN – – 0.6 pF – 20 Setup Time (Data/Clock) tSETUP – 20 – ps – 21 Hold Time (Data/Clock) tHOLD – 20 – ps – 22 Eye Opening at 2.5 Gbit/s (w. Latch) tEO – 360 – ps – 23 Internal ISM cutoff frequency fISM 165 238 372 kHz 14) 24 Cutoff frequency of ISM with external CISM fISM (6.1 µs + 84 kΩ × CISM)-1 (4.2 µs + 70 kΩ × CISM)-1 (2.7 µs + 56 kΩ × CISM)-1 25 Internal ILM cutoff frequency fILM – 160 – kHz 14) 26 Cutoff frequency of ILM with external CILM = 1nF fILM – 73 – kHz 14)15) 27 Duty Cycle for laser enable 25 – 75 % – 28 Duty Cycle for laser disable 0 – 5 % Input low 29 Duty Cycle for laser disable 95 – 100 % Input high Input Signal Monitor (ISM) Preliminary Data Sheet 8 14)15) 2001-05 FOA2322A Electrical Characteristics Table 3 Characteristics and Operating Conditions (cont’d) SP Parameter Symbol Limit Values min. typ. max. Unit Condition 30 Bias Current IIBIASmax 0 – 80 mA – 31 Start Bias Current IIBIASmin – – 500 µA – 32 Bias Current at Laser Shut Down IIBIASSD – – 500 µA – 33 Output Voltage Range IBIAS VIBIAS 0.5 – VCC V – 34 Power Monitor Current IMPOUT 0 VMD RPOUT 1 mA 16) 35 Output Voltage Range MPOUT VMPOUT VRPOUT + – VCC V – 36 Resistor Range RPOUT RPOUT 2.4 – Open Input kΩ – 37 Output Voltage Range RPOUT VRPOUT 0 VMD VCC - 1.2 V – 38 Internal cutoff frequency of bias controller fBIAS 23 37 62 kHz 17) 39 Cutoff frequency of bias controller with external fBIAS (44 µs + 306 kΩ × CBIAS)-1 (27 µs + 204 kΩ × CBIAS)-1 (16 µs + 131 kΩ × CBIAS)-1 GBIAS – 100 – – VMDnom + VMDnom + 1.5 dB 2 dB VMDnom - VMDnom - – 2 dB 1.55 dB VMDnom - – Laser Power Control 0.5 CBIAS 40 Conversion gain of bias generator 15)17) mA/V – Laser Supervising Circuit 41 MD Failure Voltage High 42 MD Failure Voltage Low 43 MD Range without Failure Recognition 1.2 dB VMDnom + tFDEL 38 60 86 45 Additional Failure Recognition Time by external CFDEL tFDEL CFDEL × CFDEL × CFDEL × Preliminary Data Sheet 9 18) V 19) µs 17)20) 1.2 dB 44 Internal Failure Recognition Time 0.7 µs/pF 18) 1.0 µs/pF 15)17)20) 1.3 µs/pF 2001-05 FOA2322A Electrical Characteristics Table 3 Characteristics and Operating Conditions (cont’d) SP Parameter Symbol Limit Values min. typ. max. Unit Condition 46 Shut Off Time after LF tLDdis transition or Laser Disable 0 – 3 µs 21) 47 VCC Reset Threshold for Laser Enable/Disable 2.5 2.75 2.99 V 22) 333 480 µs 23) 48 Internal Power On Delay tPDEL 213 49 Additional Power On Delay by external COSC tPDEL 64 × COSC 64 × COSC 64 × COSC × 138 kΩ × 173 kΩ × 208 kΩ 15)23) 50 LDOFF low Output Current 1.5 – 4 mA sink current 51 LDOFF high Output Current – – 2 µA sink current 52 LDOFF high Output Voltage VCC - 0.1 – – V – 53 LDOFF low Output Voltage VCC - 2.0 – VCC - 1.2 V without external load Reference Voltage 54 MD Reference Value VMDR 1.12 – 1.32 V 24) 55 VMDR Drift over Temperature Range |∆VMDR/ VMDR| – – 5 % – 56 VMDR Drift over Supply Voltage Range 3 V … 5.5 V |∆VMDR/ VMDR| – – 10 % – 57 VMDR Drift over Temperature Range at Supply Voltage Range 3 V … 3.6 V |∆VMDR/ VMDR| – – 5 % – 58 VMDR Drift over Temperature Range at Supply Voltage Range 4.7 V … 5.3 V |∆VMDR/ VMDR| – – 5 % – Preliminary Data Sheet 10 2001-05 FOA2322A Electrical Characteristics Table 3 Characteristics and Operating Conditions (cont’d) SP Parameter Symbol Limit Values min. typ. max. Unit Condition Logic Inputs RSTN, RST, LEN 59 Input Voltage High VIHLOGIC 2.0 – VCC V 25) 60 Input Voltage Low VILLOGIC 0 – 0.8 V 25) 61 Input Current High IIHLOGIC – – 5 µA – 62 Input Current Low IILLOGIC -5 – – µA – 2.2 – VCC V – Logic Inputs CSELN 63 Input Voltage High for VIHLOGIC disabling data input latch (nonclocked mode) or let CSELN open 64 Input Voltage Low for enabling data input latch (clocked mode) VILLOGIC 0 – 0.8 V – 65 Internal Pull-Up-Resistor RCSELN 8 10 12 kΩ – Logic Outputs LF, HWA 66 Output Voltage Low VOLLOGIC – – 0.4 V – 67 Output Current High (Leakage Current) IOHLOGIC – – 100 µA open collector 68 Output Current Low IOLLOGIC 2 – – mA sink current 69 Mode 1 select VMODE VCC - 0.8 – VCC V – 70 Mode 2 select VMODE 0 – 0.8 V – 71 Internal pilot frequency fPILOT 7.7 12 17.3 kHz – 72 Pilot frequency with external COSC fPILOT (130 µs + (83 µs + (58 µs + 16 × COSC 16 × COSC 16 × COSC × 208 kΩ)-1 × 173 kΩ)-1 × 138 kΩ)-1 Modulation Control (Mode 2) 73 Effective pilot current amPILOT amplitude on modulation current high level (default) Preliminary Data Sheet – 3.5 11 – 15) % 26) 2001-05 FOA2322A Electrical Characteristics Table 3 Characteristics and Operating Conditions (cont’d) SP Parameter Symbol Limit Values min. typ. max. Unit Condition 74 Pilot current amplitude on abPILOT bias current (default) – 5.05 – % 75 Cutoff frequency of fMOD modulation controller with external CMOD (306 kΩ × CMOD)-1 (204 kΩ × CMOD)-1 (131 kΩ × CMOD)-1 26) 15)17) 1) Measured into 25 Ω . 2) The bias-, modulation-, the LF-, HWA- and MPOUT- output currents are not included. 3) The typical supply current is defined for driving a laser with about 20 mA bias current and about 20 mA modulation current and a IC junction temperature of about 50 °C and a VCC of 5 V. The maximum supply current is defined for driving the upper limits of bias current and modulation current with worst case junction temperature and with a VCC of 5.5 V (VCC = VCCA = VCCD). 4) This describes the AC modulation current (the DC component is the overall offset current). AC modulation current is drawn by O at VD > VDN, it is drawn by ON at VD < VDN. IOH refers to drawn modulation current (AC + DC). IOL refers to an inactive current output (DC current only). 5) See Table 2 for operating conditions junction temperature. 6) Inactive current output (see also 4)). 7) Modulation current when the laser diode is disabled. 8) Valid for VCC = VCCA = VCCD = 5 V. It is possible to increase the output voltage range for the VCC range of 5 V ± 0.5 V of about 0.85 V by using the Pad VCCD2 instead of VCCD (see Figure 14). The specified limits for data and clock inputs are valid for VCCD. 9) Adjustment of programmable parameter by resistor value within this range (see Chapter 2.4). 10) Adjusting the modulation current by RMOD notice that the decreasing of RMOD will increase the modulation current. RMOD in combination with RTC has to be adjusted that the modulation current is smaller than 50 mA or 75 mA respectively over specified temperature range. If RMOD-Pad is not connected (open input) there will be no modulation current at the output O/ON. 11) Modulation current adaptation within junction temperature range. Low junction temperature represents a low additional modulation current. High junction temperature represents a high additional modulation current. If RTC-Pad is not connected there will be no noteworthy modulation current adaptation. 12) Data/clock inputs are internally connected to VBBD/VBBC by resistor R1/R2 with a differential termination by RIN. See data input stage description (see Figure 9). 13) The resistance is guaranteed for junction temperature 25 °C. Preliminary Data Sheet 12 2001-05 FOA2322A Electrical Characteristics 14) If data input duty cycle falls below lower limit or exceeds upper limit the laser will be disabled by ISM circuit. On the other hand, the laser will be enabled whenever the data input duty cycle goes back to the allowed range. Data input duty cycle refers to the quotient given by number of ones divided by number of zeros within serial data stream. The ISM-circuit evaluates the mean value of the duty cycle (integrator). The cutoff frequency of ISM fISM is defined for data pattern 1010 …. In case of data frequency is to small the ISM circuit will disable the laser because of long High- or Low-series. The ISM-circuit can be deactivated by a 25 kΩ resistor from CISM to VEE. The ILM-circuit additionally is used for ac-coupled data inputs. It works as a peak detector. The laser will be disabled if data are set to a static state. The cutoff frequency of ILM fILM is defined for data pattern 1010 …. (Specified value is for data input voltage swing of 400 mV).The ILM-circuit is direct AC-coupled to the data input. So the cutoff frequency depends on data input swing. The ILM-circuit can be deactivated by a short from CILM to VCC. 15) A capacitor within this range programs the time (or frequency). 16) Open collector output for pulling up a resistor to monitor the current. 17) Difference and temperature drift of passive IC component parameters match to passive IC component parameters in other circuit parts. 18) The supervisor circuit will detect a failure condition if MD voltage exceeds VMDnom ± 2 dB range. VMDnom is given by nominal voltage level at MD which is set by VMDR. The deviation is calculated with 20lg(VMD/VMDnom). The deviation of optical power is calculated with 10lg(VMD/VMDnom). 19) The supervisor circuit will detect no failure condition if MD input voltage ranges from VMDnom - 1.2 dB to VMDnom + 1.2 dB. VMDnom is given by nominal voltage level at MD which is set by VMDR. The deviation is calculated with 20lg(VMD/VMDnom). The deviation of optical power is calculated with 10lg(VMD/VMDnom). 20) A failure condition will be reported by LF = H if this condition lasts for tFDEL. Minimal capacitor on CFDEL has to be chosen that the failure recognition time is longer than the setting time of the bias controller. 21) Time between LF high (or LEN high) and LDOFF high. 22) At supply voltages below VCC threshold the laser diode bias and modulation current will be held disabled and LDOFF will be held high. Above the laser diode will be enabled after the Power On Delay. 23) The Power On Delay is the Reset time after VCC voltage has risen above the VCC reset threshold. During the Power On Delay the Laser diode bias and modulation current will be held disabled and LDOFF will be held high. 24) Temperature and voltage drift are included. 25) The minimal enable pulse width time for RST = L or RSTN = H or LEN = L has to be longer then tFDEL . 26) Out of amPILOT and abPILOT a factor K = abPILOT/amPILOT can be defined, which is an important factor for the pilot control (for definition of amPILOT and abPILOT see Figure 8). For most laser diodes the optimum value of K is 1.44 (default value). If K is set close to factor 2 the modulation current and jitter may increase. If K is set close to factor 1 the modulation current may decrease. In both cases a malfunction of laser control is possible. A resistor between VCC and RMRIP can be used for decreasing amPILOT. Further a resistor between VCC and RBRIP can be used for decreasing abPILOT. So the factor K can be adjusted. For default factor K let RBRIP and RMRIP connected to VCC (= VCCA). Preliminary Data Sheet 13 2001-05 FOA2322A Electrical Characteristics 2.4 Typical Characteristics of Temperature Compensation (Mode 1) 2.4.1 Modulation Current Swing versus RMOD, RTC, Junction Temperature and Supply Voltage / High Current Drive ITD11327 2.8 F 2.6 2.4 2 k Ω/5 V 4 k Ω/5 V 4 k Ω/3.3 V 2 k Ω/3.3 V 2.2 2.0 1.8 1.6 1.4 1.2 0 500 1000 kΩ 1500 2000 RTC Figure 2 F = I100 °C/I0 °C versus RTC, Parameter RMOD, VCC ITD11328 80 mA IO 70 60 2 kΩ/200 Ω 2 kΩ/700 Ω 2 kΩ/2 kΩ 4 kΩ/200 Ω 4 kΩ/700 Ω 4 kΩ/2 kΩ 50 40 30 20 10 -50 -30 -10 10 30 50 70 90 110 ˚C 130 t Figure 3 I0 versus Tj, Parameter RMOD, RTC (VCC = 3.3 V) Preliminary Data Sheet 14 2001-05 FOA2322A Electrical Characteristics ITD11329 100 mA IO 80 2 kΩ/200 Ω 2 kΩ/700 Ω 2 kΩ/2 kΩ 4 kΩ/200 Ω 4 kΩ/700 Ω 4 kΩ/2 kΩ 70 60 50 40 30 20 10 0 -50 -30 -10 10 30 50 70 90 110 ˚C 130 t Figure 4 I0 versus Tj, Parameter RMOD, RTC (VCC = 5.0 V) Preliminary Data Sheet 15 2001-05 FOA2322A Electrical Characteristics 2.4.2 Modulation Current Swing versus RMOD, RTC, Junction Temperature and Supply Voltage / Low Current Drive ITD11330 1.40 F 10 kΩ/3.3 V 10 kΩ/5 V 5 kΩ/5 V 5 kΩ/3.3 V 1.30 1.25 1.20 1.15 1.10 1.05 1.00 1800 2800 3800 4800 5800 6800 kΩ 7800 9800 RTC Figure 5 F = I100 °C/I0 °C versus RTC, Parameter RMOD, VCC ITD11331 18 mA 5 kΩ/2 kΩ 5 kΩ/5 kΩ 5 kΩ/9.5 kΩ IO 16 15 14 13 12 11 10 10 kΩ/2 kΩ 10 kΩ/5 kΩ 10 kΩ/9.5 kΩ 9 8 7 6 5 -50 -30 -10 10 30 50 70 90 110 ˚C 130 t Figure 6 I0 versus Tj, Parameter RMOD, RTC (VCC = 3.3 V) Preliminary Data Sheet 16 2001-05 FOA2322A Electrical Characteristics ITD11332 18 mA 5 kΩ/2 kΩ 5 kΩ/5 kΩ 5 kΩ/9.5 kΩ IO 16 15 14 13 12 11 10 10 kΩ/2 kΩ 10 kΩ/5 kΩ 10 kΩ/9.5 kΩ 9 8 7 6 5 -50 -30 -10 10 30 50 70 90 110 ˚C 130 Tj Figure 7 I0 versus Tj, Parameter RMOD, RTC (VCC = 5.0 V) Preliminary Data Sheet 17 2001-05 FOA2322A Electrical Characteristics 2.5 Principle of Modulation Current Control by Using a Pilot Signal (Mode 2) The DC-part of the monitor current controls the bias current. The difference of the optical low frequency AC-part ∆Ppp is used for the modulation current control. ∆Ppp is measured over the monitor current. The aim of the control is to settle ∆Ppp to Zero. (That means a part of the pilot current amplitude on bias current is modulated below laser current threshold. Therefore please take into account the laser characteristics, e.g. switch-on delay, for higher data rates.) Mode 2 can only be used for DC-coupled laser diodes. POpt ∆P1 P1 P ∆Ppp P0 ∆P0 abPILOT amPILOT ∆Ppp = ∆P0 - ∆P1 Figure 8 ILaser ITD11333 Modulation Current Control by Using a Pilot Signal Preliminary Data Sheet 18 2001-05 FOA2322A Electrical Characteristics 2.6 Data / Clock Input Stage Data and clock inputs are terminated with 100 Ω and are connected to a VBB reference by resistors R1/R2. (VBB for Clock input is VBBC, VBB for Data input is VBBD.) This easily provides the input reference voltage at AC coupling. A schematic of the input stage is shown below: P RIN N R1 R2 Reference Generator VBB R1, R2 = 5 kΩ RIN = 100 Ω ±20% Figure 9 2.7 ITS11334 Data/Clock Input Stage Timing of Clock and Data Daten D/DN 50% tSETUP Clock CLK tHOLD 50% ITT11335 Figure 10 Timing of Clock and Data Preliminary Data Sheet 19 2001-05 FOA2322A Electrical Characteristics 2.8 Laser and VCC Supervising Circuit If there is a laser fault (optical power deviates ±1 dB) this signal is stored and indicated by LF (logic high). The fault indication (LF) can be reset with low level at RSTN or with high level at RST or with power down (VCC < VCC Reset Threshold) only. After power up, LF will always be cleared. Disabling the laser by LEN does not influence a previous fault indication by LF. The laser fault generation can be switched off by connecting CFDEL to VCC. During RSTN is logic low or RST is logic high the circuit is in Reset state. In case of changing RST = H or RSTN = L after laser fault recognition LF = H (after tFDEL) there is an additional delay time implemented which has the same value as the Power On Delay. If the supply voltage is lower than the VCC reset threshold the indicator Hardware Alarm (HWA) is still at the low level and the circuit is in Reset state. During Power On Delay the circuit is in Reset state too. The Power On Delay is defined as the delay after VCC voltage has risen above the VCC reset threshold. This time can be adjusted by an external capacitor at COSC (Mode 1). The Reset N-Output of the MAX 809S Power Supervisor IC can be connected to RSTN to use the reset function of the MAX 809S. The laser control by RST and RSTN is fully redundant. This means only an AND combination of RST = 0 / RSTN = 1 can switch the laser on. The OR combination of RST = 1 / RSTN = 0 switches the laser off (see Table 4 for clarification). Table 4 Laser Diode Currents Enable / Disable Signals RST LEN RSTN In Case of VCC < Reset LDOFF Modulation Bias LF (high Laser Fault Threshold VCC Enable1) Enable1) active) X 1 X 0 X 1 0 0 0 1 X X X X 1 0 0 0 X X 0 X X 1 0 0 0 X X X X yes 1 0 0 0 0 0 1 1 no2) 13) 0 0 13) 0 0 1 0 no2) 04) 1 1 0 1) Internal signal 2) After Power On Delay 3) After tFDEL 4) Sink current enabled = Low Table 4 shows the static states of these signals. Dynamic changes or delays due to external delay capacitors are not shown. Preliminary Data Sheet 20 2001-05 FOA2322A Electrical Characteristics Bias current is disabled by setting Bias Enable low, modulation current is disabled by setting Modulation Enable low. LEN do not effect LF. This means LF can not be reset by LEN. 2.9 Input Signal Monitoring and Hardware Alarm (Consideration in absence of Laser Fault) Table 5 Function of ISM Circuit and Hardware Alarm Indicator (HWA) Data Level (after delay of ISM) VCC < Reset Constant High ISM Laser LDOFF HWA (low Enable1) active) Modulation Bias Enable1) Enable1) No 0 1 0 0 0 Constant Low No 0 1 0 0 0 Constant High Yes 0 1 0 0 0 Constant Low Yes 0 1 0 0 0 Duty Cycle ok Yes 1 1 0 0 0 Duty Cycle ok No 1 02) 1 1 1 Threshold of VCC /Circuit in Reset state 1) Internal signal 2) Sink current enabled = Low Preliminary Data Sheet 21 2001-05 FOA2322A Pin Description 3 Table 6 Pin Description Pin Definitions and Functions Signal Name Function Explanation D / DN Differential Input Differential data input. D corresponds to O and DN to ON current output. With a high level at D and a low level at DN modulation current is drawn by O and ON is inactive. With a low level at D and a high level at DN modulation current is drawn by ON and O is inactive. Both inputs are prebiased to internal VBBD. The input termination is 100 Ω. CLK / CLKN Differential Input Differential clock input for input data latch. The input termination is 100 Ω. CSELN Logic Input A low level at CSELN enables the data input latch (clocked mode), a high level or an open input disables the data input latch (nonclocked mode). It has an internal pull-up-resistor of about 10 kΩ. O / ON Differential Current These output signals drive the modulation current Output switched by D / DN data inputs. CMOD Control The modulation controller characteristic can be set to an i-controller with an external capacitor at CMOD to VEE and the time constants are adjustable in mode 2. Let open if mode 1 is used. VMOD Output Base of the output current mirror 1:10. For normal application it can be leave open if not used. CISM Control With an external capacitor at CISM to VCC the delay time for detection of a bad duty cycle data input situation can be increased. If the input signal monitor is not used CISM has to be pulled down by 25 kΩ resistor to VEE. CILM Control With an external capacitor at CILM to VCC the delay time for detection of static data input situation can be increased. If the peak detector is not used CILM has to short to VCC. HWA Logic Output HWA is an open collector output (indicator output). A low level is generated whenever a bad duty cycle data input situation is detected by the input signal monitor circuit or if the supply voltage is lower than the VCC reset. Let open if not used. Preliminary Data Sheet 22 2001-05 FOA2322A Pin Description Table 6 Pin Definitions and Functions (cont’d) Signal Name Function Explanation IBIAS Bias Output A sink current drawn by IBIAS determines the laser diode bias current. CBIAS Control The bias controller characteristic is set to an i-controller. The cutoff frequency can be decreased by an external capacitor at CBIAS to VEE. MPOUT Monitor Output MPOUT is an open collector output for pulling up a resistor to monitor the deviation of the optical power over the monitor diode current. Let open if not used. RPOUT Control A resistor between RPOUT and VEE can adjust the relation of optical power measured over the monitor diode current to output current at MPOUT. Let open if the monitoring of the optical power is not used. VBIAS Bias Output This output can be connected to the base of an external bias current NPN transistor. It can be leave open if not used. It is dedicated for applications which can not use the internal bias transistor. Base of the output current mirror 1:25. MD Monitor Diode Input This is the controller feedback input. The voltage at this input represents the monitor diode current and by this the laser output power. The bias current will be controlled to an equal level of VMD and VMDR. LDOFF Laser Shut Down Output Whenever the laser diode is disabled LDOFF will deliver a high voltage level closed to VCC. If the laser diode is enabled there is a sink current to drive the base of an external pnp transistor to support a laser diode supply shut down. If not used this output can be leave open without Laser Driver performance restrictions. There is an internal pull up resistor between LDOFF and VCCA of 10k. RSTN Logic Input Low active reset input. This input resets the LF indication if present. Further the laser diode is held within shut down mode if this signal is at low level. For constant laser diode enable this signal can be tied to VCC. Preliminary Data Sheet 23 2001-05 FOA2322A Pin Description Table 6 Pin Definitions and Functions (cont’d) Signal Name Function Explanation RST Logic Input High active reset input. This input resets the LF indication if present. Further the laser diode is held within shut down mode if this signal is at low level. For constant laser diode enable this signal can be tied to VEE. LEN Logic Input A low level at LEN enables the laser diode, a high level disables the laser diode. For constant enable this input can be tied to VEE. LF Logic Output Fault Indicator. A high level is generated whenever a fault situation is detected by the supervisor circuit. Fault situations are laser power failures indicated by MD input voltage deviation from VMDnom. Let open if not used. CFDEL Control With an external capacitor at CFDEL to VEE the laser fault detection delay time can be increased. This means if a constant fault condition is present a laser fault indication will be generated and the laser will be shut down after this delay time. The laser safety circuit can be switched off if CFDEL is connected to VCC. COSC Control With an external capacitor at COSC to VEE the piloton frequency can be decreased (mode 2). COSC determines the power on delay. MODE Logic Input A high level at MODE sets the modulation control circuit to mode 1 (using temperature compensation circuit). A low level at MODE sets the modulation control circuit to mode 2 (using modulation control by pilot signal). RMOD Control An external resistor at RMOD to VEE sets the modulation current level (in mode 1). Let open if mode 2 is used. RTC Control An external resistor at RTC to VEE sets the modulation current temperature coefficient. The temperature information is derived from chip junction temperature (in mode 1). Let open if mode 2 is used. Preliminary Data Sheet 24 2001-05 FOA2322A Pin Description Table 6 Pin Definitions and Functions (cont’d) Signal Name Function Explanation RBRIP Control The pilot current amplitude on bias current (mode 2) can be decreased by connecting a resistor between RBRIP and VCC. For default values do connect to VCC. It has no influence if using mode 1. Let open if mode 1 is used. RMRIP Control The pilot current amplitude on modulation current high level (mode 2) can be decreased by connecting a resistor between RMRIP and VCC. For default values do connect to VCC. It has no influence if using mode 1. Let open if mode 1 is used. START – Do not connect. MX – Do not connect. VCCA VCCD VCCD2 Power Supply Positive power supply for analog circuit part. Power Supply Positive power supply for digital circuit part. Power Supply Positive power supply for digital circuit part with an additional serial diode to increase the modulation output voltage range of about 0.85 V for VCC range of 5 V ± 0.5 V. Let open if it is not used. VEE1 Power Supply Negative power supply, only connected to the output current mirror stage of bias generator, normally GND. VEE2 Power Supply Negative power supply, only connected to the output stage, normally GND. VEE Power Supply Negative power supply of the rest of circuit, normally GND. Preliminary Data Sheet 25 2001-05 FOA2322A Pin Description VEE2 O O ON ON VEE2 IBIAS VBIAS VEE1 32 VCCD2 33 VMOD Pad Layout VCCD 3.1 31 30 29 28 27 26 25 24 23 22 LDOFF 34 21 VEE HWA 35 20 MX LF 36 19 MODE RBRIP 37 18 COSC START 38 17 VEE RMRIP 39 16 MD CMOD 40 15 CBIAS RMOD 41 14 MPOUT VCCA 42 13 RPOUT 2 3 4 5 6 7 8 9 10 11 12 x CSELN CLKN CLK LEN DN D RST CILM RSTN CFDEL RTC S1048 1 CISM y ITP11336 Figure 11 The pad center x/y positions are given in Table 7 (related to the chip origin 0/0 excl. Seal ring): Preliminary Data Sheet 26 2001-05 FOA2322A Pin Description Table 7 Pad Positions Bottom: 1-12 Right: 13-21 Top: 33-22 Left: 42-34 x / µm y / µm x / µm y / µm x / µm y / µm x / µm y / µm 271 137 1777 267 271 1498 141 267 396 137 1777 391 396 1498 141 391 521 137 1777 516 521 1498 141 516 646 137 1777 693 646 1498 141 693 771 137 1777 818 771 1498 141 818 896 137 1777 943 896 1498 141 943 1021 137 1777 1119 1021 1498 141 1119 1146 137 1777 1244 1146 1498 141 1244 1271 137 1777 1369 1271 1498 141 1369 1396 137 – – 1396 1498 – – 1521 137 – – 1521 1498 – – 1646 137 – – 1646 1498 – – – – – – – – Die size: 1.92 mm × 1.64 mm (excl. seal ring) Chip thickness: 300 µm Frame grid: 2.024 mm × 1.75 mm Bondpad window: 80 µm × 80 µm Bondpad material: Aluminium Substrate: VEE Preliminary Data Sheet 27 2001-05 FOA2322A Application Examples 4 Application Examples VCC CFDEL CISM CILM VCCD2 VCC VCCD VCCA LDOFF LF LEN RST RSTN Laser Supervisor VCC Supervisor Bias Enable HWA VMOD Modulation Enable D DN Input Stage Modulator O O ON ON VEE2 CLK CLKN Latch VEE2 RBRIP RMRIP CMOD MX COSC CSELN VCC VCC Mode Start Modul. Control Incl. Oscillator Optional RTC Temperature Compensation RMOD IBIAS MD Bias Generator Bias Control VEE VEE CBIAS RPOUT MPOUT VBIAS VEE1 Optional Optional ITS11337 Figure 12 Application Example A: Using Mode 1 Preliminary Data Sheet 28 2001-05 FOA2322A Application Examples -5 V CFDEL CISM CILM VCCD2 VCCD VCCA LDOFF LF LEN RST RSTN Laser Supervisor VCC Supervisor Bias Enable X2 VMOD Modulation Enable D DN Input Stage CLK CLKN HWA Modulator Latch CSELN -5 V Mode Start Modul. Control Incl. Oscillator O O ON ON VEE2 -5 V VEE2 -5 V RBRIP RMRIP CMOD MX COSC -5 V -5 V Optional RTC Temperature Compensation RMOD IBIAS Bias Generator Bias Control VEE VEE CBIAS RPOUT MPOUT VEE1 Optional X1 -5 V -5 V -5 V -5 V VBIAS -5 V Current outputs pulled up to +5 V (e.g. 2 × BCX68) X1 Figure 13 X2 ITS11338 Application Example B: Power Supply with +5 V … 0 V (GND) … -5 V Using Mode 2 Preliminary Data Sheet 29 2001-05 FOA2322A Application Examples VCC CFDEL CISM CILM VCC VCCD2 VCCD VCCA LDOFF LF LEN RST RSTN Laser Supervisor VCC Supervisor Bias Enable HWA VMOD Modulation Enable D DN Input Stage Modulator O O ON ON VEE2 CLK CLKN Latch VEE2 RBRIP RMRIP CMOD MX COSC CSELN VCC VCC Mode Start Modul. Control Incl. Oscillator Optional RTC Temperature Compensation RMOD IBIAS MD Bias Generator Bias Control VEE VEE CBIAS RPOUT MPOUT VBIAS VEE1 Optional Optional ITS11344 Figure 14 Application Example C: Using VCCD2 for increasing the Modulation Output Voltage Range for the VCC Range of 5 V ± 0.5 V (here mode 1) Preliminary Data Sheet 30 2001-05 FOA2322A Application Examples VCC VCC 50 Ω 50 Ω 100 nF 20 Ω 50 Ω 220 nH ON 16.7 Ω ON CComp [x pF] CComp [x pF] RComp [xx Ω] RComp [xx Ω] 20 Ω 20 Ω O O 100 nF 100 nF 220 nH IBIAS 220 nH IBIAS ITS11339 VCC ITS11340 VCC 15 Ω 220 nH 10 Ω ON ON CComp [x pF] CComp [x pF] RComp [xx Ω] RComp [xx Ω] 10 Ω 10 Ω O O 220 nH IBIAS Figure 15 220 nH IBIAS ITS11341 ITS11342 Application Example D: Several Kinds for Connecting Laser Diode (1300 nm-FP-laser, 5 Ω); Resistor values are proposed values. They depend on used laser diodes, currents and mechanical and PCB design. Preliminary Data Sheet 31 2001-05 FOA2322A Application Examples VCC LLarge 100 Ω LLarge 100 Ω L = 5.6 nH L = 5.6 nH ON CComp [x pF] RComp [xx Ω] 20 Ω O 100 nF 220 nH IBIAS Figure 16 ITS11343 Application Example D: Several Kinds for Connecting Laser Diode (1300 nm-FP-laser, 5 Ω) (cont’d); Preliminary Data Sheet 32 2001-05 Infineon goes for Business Excellence “Business excellence means intelligent approaches and clearly defined processes, which are both constantly under review and ultimately lead to good operating results. Better operating results and business excellence mean less idleness and wastefulness for all of us, more professional success, more accurate information, a better overview and, thereby, less frustration and more satisfaction.” Dr. Ulrich Schumacher http://www.infineon.com Published by Infineon Technologies AG