SY88403BL 3.3V 4.25Gbps CML Low-Power Limiting Post Amplifier with TTL LOS General Description Features The SY88403BL is a low-power limiting post amplifier optimized for copper applications. The device connects to typical transimpedance amplifiers (TIAs). The linear signal output from TIAs can contain significant amounts of noise and may vary in amplitude over time. The SY88403BL quantizes these signals and outputs typically 800mVPP voltage-limited waveforms. The SY88403BL operates from a single +3.3V ±10% power supply, over an industrial temperature range of –40°C to +85°C. With its wide bandwidth and high gain, signals with data rates up to 4.25Gbps and as small as 5mVPP can be amplified to drive devices with CML inputs or AC-coupled PECL inputs. The SY88403BL incorporates a loss-of-signal (LOS) open-collector TTL output with internal 4.75kΩ pull-up resistor. A programmable loss-of-signal level set pin (LOSLVL) sets the sensitivity of the input amplitude detection. LOS asserts high if the input amplitude falls below the threshold set by LOSLVL and de-asserts low otherwise. LOS can be fed back to the enable bar (/EN) input to maintain output stability under a loss of signal condition. /EN de-asserts the true output signal without removing the input signal. Typically, 3.5dB LOS hysteresis is provided to prevent chattering. All support documentation can be found on Micrel’s web site at: www.micrel.com. • Multi-rate up to 4.25Gbps operation • 5mVPP input sensitivity • Low noise 50Ω CML data outputs – 800mVpp output swing Typical Performance – 60ps edge rates – 1psRMS typ. random jitter • • • • • • – 10psPP typ. deterministic jitter Chatter-free Loss-of-Signal (LOS) output – 3.5dB electrical hysteresis – OC-TTL output with internal 4.75kΩ pull-up resistor Programmable LOS sensitivity using single external resistor Internal 50Ω data input termination TTL /EN input allows feedback from LOS Wide operating range: – Single 3.3V ±10% power supply – Industrial temperature range: –40°C to +85°C Available in a 10-pin EPAD-MSOP and 16-pin QFN package Applications • 1.062Gbps, 2.125Gbps and 4.25Gbps Fibre Channel • Cable driver • Small form factor (SFF) and small form factor pluggable (SFP) transceivers • High-gain line driver and line receiver Markets • Copper interconnect • Datacom and telecom • Storage area network (SAN) Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com November 2008 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL Typical Application Functional Block Diagram November 2008 2 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL Ordering Information(1) Part Number SY88403BLEY (2) SY88403BLEYTR SY88403BLMG (2) SY88403BLMGTR Package Type Operating Range Package Marking Lead Finish K10-2 Industrial 403B with Pb-Free bar-line indicator Matte-Sn K10-2 Industrial 403B with Pb-Free bar-line indicator Matte-Sn QFN-16 Industrial 403B with Pb-Free bar-line indicator NiPdAu Pb-Free QFN-16 Industrial 403B with Pb-Free bar-line indicator NiPdAu Pb-Free Notes: 1. Contact factory for die availability. Dice are guaranteed at TA = 25°C, DC Electricals only. 2. Tape and Reel. Pin Configuration 16-Pin QFN 10-Pin EPAD-MSOP (K10-2) November 2008 3 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL Pin Description QFN Pin Number EPAD-MSOP Pin Number Pin Name Type 1, 4 2, 3 DIN, /DIN Differential data input 2, 3, 10, 11 Exposed Pad 6 Exposed Pad GND Ground Device ground. Exposed pad must be soldered (or equivalent) to the same potential as the ground pins. 5, 8, 13, 16 10 VCC Power supply Positive power supply. Bypass with 0.1µF||0.01µF low ESR capacitors. 0.01µF capacitors should be as close as possible to VCC pin. 6 4 VREF 7 7 LOS Open Collector TTL output with internal 4.75kΩ pullup resistor 9, 12 9, 8 DOUT, /DOUT Differential CML output 14 5 LOSLVL Input: Default is maximum sensitivity. 15 1 /EN TTL input: Default is high. November 2008 Pin Function Differential data input. Each pin internally terminates to REF through 50Ω. Reference Voltage. Bypass with 0.01µF low ESR capacitor from VREF to VCC to stabilize LOSLVL and VREF. Loss-of-Signal: Asserts high when the data input amplitude falls below the threshold set by LOSLVL. Differential data output. Loss-of-Signal level set: A resistor from this pin to VCC sets the threshold for the data input amplitude at which the LOS output will be asserted. Enable bar: De-asserts true data output when high. Incorporates 25kΩ pull-up to VCC. 4 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VCC) ............................... 0V to +7.0V /EN, LOSLVL Voltage.................................... 0 to VCC REF Current ...................................................... ±1mA LOS Current ...................................................... ±5mA DOUT, /DOUT Current .................................... ±25mA DIN, /DIN Current ............................................ ±10mA Lead Temperature (soldering, 20sec.) ............. 260°C Storage Temperature (Ts) ............... –65°C to +150°C Supply Voltage (VCC)...........................+3.0V to +3.6V Ambient Temperature (TA) ................ –40°C to +85°C Junction Temperature (TA) .............. –40°C to +120°C (3) Package Thermal Resistance QFN θJA (Still-Air) .......................................... 61°C/W ψJB ........................................................ 38°C/W EPAD-MSOP θJA (Still-Air) .......................................... 38°C/W ψJB ........................................................ 22°C/W DC Electrical Characteristics VCC = +3.0V to +3.6V; TA = –40°C to +85°C; typical values at VCC = +3.3V, TA = 25°C. Symbol Parameter Condition ICC Power Supply Current Min Typ Max Units 3.3V, Note 4 25 42 mA 3.3V, Note 5 41 62 mA VREF REF Voltage VCC –1.3 VLOSLVL LOSLVL Voltage Range VCC V VOH DOUT, /DOUT HIGH Voltage Note 6 VCC –0.020 VCC –0.005 VCC V VOL DOUT, /DOUT LOW Voltage 3.3V, Note 6 VCC –0.475 VCC –0.400 VCC –0.350 V VOD_DC DC Differential Output Voltage Note 6 700 800 950 mV VOFFSET Differential Output Offset ±80 mV ZO Single-Ended Output Impedance 40 50 60 Ω ZI Single-Ended Input Impedance 40 50 60 Ω Typ Max Units VCC V 0.5 V VREF V TTL DC Electrical Characteristics VCC = +3.0V to +3.6V; TA = –40°C to +85°C. Symbol Parameter Condition Min VOH LOS Output HIGH Level Sourcing 100µA 2.4 VOL LOS Output LOW Level Sinking 2mA VIH /EN Input HIGH Voltage VIL /EN Input LOW Voltage IIH /EN Input HIGH Current VIN = 2.7V VIN = VCC IIL /EN Input LOW Current VIN = 0.5V 2.0 –0.3 V 0.8 V 20 100 µA µA mA Notes: 1. Permanent device damage may occur if ratings in the absolute maximum ratings section are exceeded. This is a stress rating only and functional operation is not implied for conditions other than those detailed in the operational sections of this data sheet. Exposure to absolute maximum ratings conditions for extended periods may affect device reliability. 2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings. 3. Thermal performance assumes are of 4-layer PCB. Exposed pad must be soldered (or equivalent) to the device's most negative potential on the PCB. 4. Excludes current of CML output stage. See “Detailed Description.” 5. Total device current with no output load. 6. Output levels are based on a 50Ω to VCC load impedance. If the load impedance is different, the output level will be changed. Amplifier is in limiting mode. Measured at 155Mbps with 20mVpp input and PRBS-23 data pattern and 50Ω load. November 2008 5 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL AC Electrical Characteristics VCC = +3.0V to +3.6V; TA = –40°C to +85°C; RL = 50 Ω to VCC; typical values at VCC = +3.3V, TA = 25°C. Symbol Parameter Condition tr, tf Output Rise/Fall Time (20% to 80%) tJITTER Min Typ Max Units Note 7 60 120 ps Deterministic Random Note 8 Note 9 10 1 VID Differential Input Voltage Swing See Figure 1 VOD_AC AC Differential Output Voltage Note 10 tOFF LOS Release Time tON LOS Assert Time 5 600 psPP psRMS 1800 mVpp 800 950 mVpp 2 10 µs 2 10 µs LOSAL Low LOS Assert Level RLOSLVL = 15kΩ, Note 11 LOSDL Low LOS De-assert Level RLOSLVL = 15kΩ, Note 11 HSYL Low LOS Hysteresis RLOSLVL = 15kΩ, Note 12 2 LOSAM Medium LOS Assert Level RLOSLVL = 5kΩ, Note 11 12 LOSDM Medium LOS De-assert Level RLOSLVL = 5kΩ, Note 11 HSYM Medium LOS Hysteresis RLOSLVL = 5kΩ, Note 12 LOSAH High LOS Assert Level RLOSLVL = 100Ω, Note 11 LOSDH High LOS De-assert Level RLOSLVL = 100Ω, Note 11 HSYH High LOS Hysteresis RLOSLVL = 100Ω, Note 12 VSR LOS Sensitivity Range 20 AV(Diff) Differential Voltage Gain 32 38 dB S21 Single-Ended Small-Signal Gain 26 32 dB 8 mVPP 12 mVPP 3.5 4.5 17 dB mVPP 25 33 mVPP 2 3.5 4.5 dB 34 47 70 83 mVPP 2 3.5 4.5 dB 35 mVPP mVPP Notes: 7. Amplifier in limiting mode. Input is a 200MHz square wave. 8. Deterministic jitter measured using 4.25Gbps K28.5 pattern, VID = 20mVPP. 9. Random jitter measured using 4.25Gbps K28.7 pattern, VID = 20mVPP. 10. Differential output swing measured at 4.25Gbps with 20mVpp input and PRBS-23 data pattern and 50Ω load. 11. See “Typical Operating Characteristics” for a graph showing how to choose a particular RLOSLVL for a particular LOS assert and its associated de-assert amplitude. 12. This specification defines electrical hysteresis as 20log(LOS De-assert/LOS Assert). The ratio between optical hysteresis and electrical hysteresis is found to vary between 1.5 and 2 depending on the level of received optical power and ROSA characteristics. Based on that ratio, the optical hysteresis corresponding to the electrical hysteresis range 2dB-4.5 dB shown in the AC characteristics table will be 0.5dB3dB Optical Hysteresis. November 2008 6 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL Typical Operating Characteristics 60 Power Supply Current vs. Temperature 55 50 45 40 35 30 RLOSLVL (kΩ) RLOSLVL (kΩ) Differential Output Voltage Swing vs. Temperature (Amplifier in Limiting Mode) 900 880 860 840 820 800 780 760 740 720 700 -40 25 -40 -15 10 35 60 TEMPERATURE (°C) 85 Differential Output Voltage Swing vs. Differential Input Voltage Swing 900 800 700 600 500 400 300 200 100 0 -15 10 35 60 TEMPERATURE (°C) November 2008 85 0 5 10 15 20 25 30 35 40 45 50 VID (mVpp) 7 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL Detailed Description Loss-of-Signal The SY88403BL incorporates a chatter-free loss-ofsignal (LOS) open-collector TTL output with internal 4.75kΩ pull-up resistor as shown in Figure 5. LOS is used to determine that the input amplitude is too small to be considered a valid input. LOS asserts high if the input amplitude falls below the threshold set by LOSLVL and de-asserts low otherwise. LOS can be fed back to the enable (/EN) input to maintain output stability under a loss of signal condition. /EN deasserts low the true output signal without removing the input signals. Typically 3.5dB LOS hysteresis is provided to prevent chattering. The SY88403BL low-power limiting post amplifier operates from a single +3.3V power supply, over temperatures from –40°C to +85°C. Signals with data rates up to 4.25Gbps and as small as 5mVPP can be amplified. Figure 1 shows the allowed input voltage swing. The SY88403BL generates an LOS output, allowing feedback to /EN for output stability. LOSLVL sets the sensitivity of the input amplitude detection. Input Amplifier/Buffer The SY88403BL’s inputs are internally terminated with 50Ω to REF. If not affected by this internal termination scheme, upstream devices need to be AC-coupled to the SY88403BL's inputs. Figure 2 shows a simplified schematic of the input stage. The high-sensitivity of the input amplifier allows signals as small as 5mVPP to be detected and amplified. The input amplifier allows input signals as large as 1800mVPP. Input signals are linearly amplified with a typically 38dB differential voltage gain. Since it is a limiting amplifier, the SY88403BL outputs typically 800mVPP voltage-limited waveforms for input signals that are greater than 20mVPP. Applications requiring the SY88403BL to operate with high-gain should have the upstream TIA placed as close as possible to the SY88403BL’s input pins to ensure the best performance of the device. Loss-of-Signal Level Set A programmable loss-of-signal level set pin (LOSLVL) sets the threshold of the input amplitude detection. Connecting an external resistor between VCC and LOSLVL sets the voltage at LOSLVL. This voltage ranges from VCC to VREF. The external resistor creates a voltage divider between VCC and VREF as shown in Figure 6. If desired, an appropriate external voltage may be applied rather than using a resistor. The relationship between VLOSLVL and RLOSLVL is given by: RLOSLVL VLOSLVL = VCC − 1.3 R LOSLVL + 2.8 where voltages are in volts and resistances are in kΩ. The smaller the external resistor, implying a smaller voltage difference from LOSLVL to VCC, lowers the LOS sensitivity. Hence, larger input amplitude is required to de-assert LOS. “Typical Operating Characteristics” contains graphs showing the relationship between the input amplitude detection sensitivity and RLOSLVL. Output Buffer The SY88403BL’s CML output buffer is designed to drive 50Ω lines. The output buffer requires appropriate termination for proper operation. An external Ω 50 resistor to VCC or equivalent for each output pin provides this. Figure 3 shows a simplified schematic of the output stage and includes an appropriate termination method. Of course, driving a downstream device with a CML input that is internally terminated with 50Ω to V CC eliminates the need for external termination. As noted in the previous section, the amplifier outputs typically 800mVPP waveforms across 25Ω total loads. The output buffer thus switches typically 16mA tail-current. Figure 4 shows the power supply current measurement, which excludes the 16mA tail-current. November 2008 Hysteresis The SY88403BL provides typically 3.5dB LOS electrical hysteresis. By definition, a power ratio measured in dB is 10log (power ratio). Power is 2 calculated as VIN /R for an electrical signal. Hence the same ratio can be stated as 20log (voltage ratio). While in linear mode, the electrical voltage input changes linearly with the optical power and hence the ratios change linearly. Therefore, the optical hysteresis in dB is half the electrical hysteresis in dB given in the datasheet. The SY88403BL provides typically 1.75dB LOS optical hysteresis. As the SY88403BL is an electrical device, this datasheet refers to hysteresis in electrical terms. With 3.5dB LOS hysteresis, a voltage factor of 1.5 is required to de-assert LOS. 8 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL Figure 1. VIS and VID Definition Figure 2. Input Structure November 2008 Figure 3. Output Structure 9 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL Figure 5. LOS Output Structure Figure 6. LOSLVL Setting Circuit Figure 4. Power Supply Current Measurement Related Product and Support Documentation Part Number Function Data Sheet Link Application Notes Notes on Sensitivity and Hysteresis in Micrel Post Amplifier www.micrel.com/product-info/app_hints+notes.shtml November 2008 10 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL Package Information 16-Pin QFN PCB Thermal Consideration for 16-Pin QFN Package (Always solder, or equivalent, the exposed pad to the PCB) Package Notes: 1. Package meets Level 2 qualification. 2. All parts are dry-packaged before shipment. 3. Exposed pads must be soldered to a ground for proper thermal management. November 2008 11 M9999-111808-F [email protected] or (408) 955-1690 Micrel, Inc. SY88403BL 10-Pin EPAD-MSOP (K10-2) MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2005 Micrel, Incorporated. November 2008 12 M9999-111808-F [email protected] or (408) 955-1690