Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - laser controller Laser diode driver (LWL) VQFN 24 Surface-mount

FEATURES APPLICATIONS

DESCRIPTION

ONET4211LD

SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007

www.ti.com

155 Mbps to 4.25 Gbps LASER DRIVER

• SONET/SDH Transmission Systems

• Multirate Operation From 155 Mbps up to

4.25 Gbps

• Fibre Channel Optical Modules

• Fiber Optic Data Links

• Bias Current Programmable From 1 mA

to 100 mA

• Digital Cross-Connects

• Optical Transmitters

• Modulation Current Programmable From 5 mA

to 85 mA

• APC and Fault Detection

• Fault Mode Selection The ONET4211LD is a laser driver for multiple fiber

optic applications up to 4.25 Gbps. The device

• Bias and Photodiode Current Monitors

accepts CML input data and provides bias and

• CML Data Inputs

modulation currents for driving a laser diode. Also

• Temperature Compensation of Modulation

provided are automatic power control (APC),

temperature compensation of modulation current,

Current

fault detection, and current monitor features.

• Single 3.3-V Supply

The device is available in a small-footprint, 4 mm × 4

• Surface-Mount, Small-Footprint, 4 mm × 4 mm

mm 24-pin QFN package. The circuit requires a

24-Lead QFN Package

single 3.3-V supply.

This power-efficient laser driver is characterized for

operation from – 40 ° C to 85 ° C.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (29 pages)

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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 155 Mbps to 4.25 Gbps LASER DRIVER FEATURES APPLICATIONS • • • • • • 1 • • • • • • • • • Multirate Operation From 155 Mbps up to 4.25 Gbps Bias Current Programmable From 1 mA to 100 mA Modulation Current Programmable From 5 mA to 85 mA APC and Fault Detection Fault Mode Selection Bias and Photodiode Current Monitors CML Data Inputs Temperature Compensation of Modulation Current Single 3.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. DETAILED DESCRIPTION BLOCK DIAGRAM A simplified block diagram of the ONET4211LD is shown in Figure 1. This compact, low-power, 4.25-Gbps laser driver circuit consists of a high-speed data path and a bias-and-control block.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 HIGH-SPEED DATA PATH The high-speed data path consists of an input buffer stage and a current modulator. The input buffer stage takes CML-compatible differential signals. It provides on-chip, 50-Ω termination to VCC. AC-coupling may be used at the DIN+ and DIN- inputs. The laser diode current modulator consists mainly of two common-emitter output transistors and the required driver circuitry.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 As with any negative-feedback system design, care must be taken to ensure stability of the loop. The loop bandwidth must not be too high, in order to minimize pattern-dependent jitter. The dominant pole is determined by the capacitor CAPC. The recommended value for CAPC is 200 nF. The capacitance of the monitor photodiode CPD adds another pole to the system, and thus it must be small enough to maintain stability.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 TRES Counter DISABLE IMODEN START RES IBEN Inverter Comparator VCC Inverter Flipflop + Q R + - IPD S 2.8 V Q MUX CMOS Buffer I0 Q I1 SDOWN MUX IBIAS/68 I1 Q Comparator MONB I0 + Q - Comparator MONP + Q + - MODTC SHORT MODTC MODSET MODSET APCSET APCSET IBMAX 1.25 V Short Circuit to VCC or GND Detect IBMAX FLTMODE B0093-01 Figure 2.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 Table 1.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 PD CAPC IBMAX OUTPOL APCSET DISABLE RGE PACKAGE (TOP VIEW) 17 VCC 3 16 MOD– DIN– 4 15 MOD+ VCC 5 14 VCC GND 6 13 12 BIAS 8 9 10 11 MODSET 7 MODTC VCC DIN+ SDOWN GND 2 FLTMODE 24 23 22 21 20 19 18 MONB 1 MONP GND P0024-03 Figure 3. Pinout of the ONET4211LD in a 4-mm × 4-mm, 24-Lead QFN Package (Top View) TERMINAL FUNCTIONS TERMINAL NAME NO.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 ABSOLUTE MAXIMUM RATINGS over operating free-air temperature range (unless otherwise noted) (1) VCC Supply voltage (2) –0.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range (unless otherwise noted) VCC Supply voltage TA Operating free-air temperature MIN NOM MAX 3 3.3 3.6 V 85 °C –40 UNIT DC ELECTRICAL CHARACTERISTICS over recommended operating conditions (unless otherwise noted) PARAMETER VCC TEST CONDITIONS MIN TYP MAX 3 3.3 3.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 AC ELECTRICAL CHARACTERISTICS (continued) Typical operating condition is at VCC = 3.3 V, IMOD = 30 mA, IBIAS = 20 mA and TA = 25°C. over recommended operating conditions (unless otherwise noted) PARAMETER Modulation current temperature compensation TEST CONDITIONS MIN RMODTC = 3.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 VHIGH SDOWN VLOW t VHIGH DISABLE VLOW t IMOD IMOD IMOD-OFF t IBIAS IBIAS IBIAS-OFF t tOFF T0102-01 Figure 4.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 VHIGH SDOWN VLOW t VHIGH DISABLE VLOW t IMOD IMOD IMOD-OFF t IBIAS IBIAS IBIAS-OFF t tON T0103-01 Figure 5.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 VHIGH SDOWN VLOW t VHIGH DISABLE VLOW t IMOD IMOD IMOD-OFF t IBIAS IBIAS IBIAS-OFF t tRESET tRESET tON T0104-01 Figure 6.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 TYPICAL CHARACTERISTICS Typical operating condition is at VCC = 3.3 V, IMOD = 30 mA, IBIAS = 20 mA and TA = 25°C (unless otherwise noted) ELECTRICAL EYE-DIAGRAM AT 2.125 Gbps WITH K28.5 PATTERN Single-Ended Output Voltage [50 mV/Div] Single-Ended Output Voltage [50 mV/Div] ELECTRICAL EYE-DIAGRAM AT 4.25 Gbps WITH K28.5 PATTERN Time [50 ps/Div] Time [100 ps/Div] G001 G002 Figure 8. ELECTRICAL EYE-DIAGRAM AT 1.0625 Gbps WITH K28.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 TYPICAL CHARACTERISTICS (continued) Typical operating condition is at VCC = 3.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 TYPICAL CHARACTERISTICS (continued) Typical operating condition is at VCC = 3.3 V, IMOD = 30 mA, IBIAS = 20 mA and TA = 25°C (unless otherwise noted) BIAS CURRENT MONITOR GAIN IMONB/IBIAS vs TEMPERATURE SUPPLY CURRENT (excl.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 APPLICATION INFORMATION CAPC RAPCSET RBIASMAX Figure 25 shows the ONET4211LD connected with a dc-coupled interface to the laser diode; alternatively, the ONET4211LD laser driver can be ac-coupled.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 SELECT A LASER In the design example according to Figure 25, the ONET4211LD is dc-coupled to a typical communication-grade laser diode capable of operating at 4.25 Gb/s with the following specifications shown in Table 2. Table 2. Laser Diode Specifications PARAMETER VALUE UNITS 1310 nm Average Optical Output Power 5 mW Threshold current 10 mA Laser-to-monitor transfer 0.05 mA/mW Laser slope efficiency 0.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 R MODSET[W] + 265 V I MOD[A] ǒ1 ) TC ǒT[ C] * T0[ C]ǓǓ o o (13) If 4000 ppm/°C is the desired temperature coefficient and the modulation current from the preceding example, 36.3 mA, is required at a temperature of 25°C, the MODSET resistor RMODSET is given by Equation 14. 4000 ppm (25 oC * 60 oC) + 6.3 kW R MODSET[W] + 265 V 1) oC 36.
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ONET4211LD SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 R BIASMAX + 343 V + 8.6 kW 40 mA www.ti.com (21) SELECT VMONB AND VMONP RANGE Monitoring the bias current is achieved by taking the fractional (1/68) bias current and developing a voltage across an external resistor to ground. Equation 22 provides the value for VMONB for a resistor value equal to 768 Ω. R [W] I [A] 768 W I [A] BIAS BIAS V [V] + MONB + + 11.
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ONET4211LD www.ti.com SLLS688A – NOVEMBER 2005 – REVISED SEPTEMBER 2007 Revision History Changes from Original (November 2006) to Revision A ................................................................................................ Page • • • • Changed Disable negate time From: Typ = 200 To: Typ = 80 ............................................................................................ Changed Time to initialize From: Typ = 200 To: Typ = 80 ....................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant ONET4211LDRGER VQFN RGE 24 3000 330.0 12.4 4.3 4.3 1.5 8.0 12.0 Q2 ONET4211LDRGET VQFN RGE 24 250 180.0 12.4 4.3 4.3 1.5 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-Apr-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) ONET4211LDRGER VQFN RGE 24 3000 338.1 338.1 20.6 ONET4211LDRGET VQFN RGE 24 250 210.0 185.0 35.
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