MAX3967A 19-3629 Rev 0 3/05 270Mbps SFP LED Driver General Description Features The MAX3967A is a programmable LED driver for fiber TX DISABLE for SFP Compatibility optic transmitters operating at data rates up to Single +2.97V to +5.5V Power Supply 270Mbps. The circuit contains a high-speed current dri- ver with programmable temperature coefficient (temp- Adjustable Temperature Compensation co), adjustments for LED prebias voltage, and a disable Adjustable Modulation Current feature. The circuit accepts PECL data inputs, and operates from a single +2.97V to +5.5V power supply. Complementary Output Reduces Supply Noise The SFP LED driver can switch up to 100mA into typical Programmable LED Prebias Voltage high-speed light-emitting diodes. As temperature increases, the devices modulation current increases Available in 24-Pin Thin QFN or Die with a tempco that is programmable from 2500ppm/C to 12,000ppm/C. The modulation current is pro- grammed with a single external resistor. The MAX3967As LED prebias voltage is programmable Ordering Information from 400mV to 925mV. The prebias circuit produces peaking current, which improves the LED switching PART TEMP RANGE PIN-PACKAGE speed. MAX3967AETG -40C to +85C 24 Thin QFN Complementary current outputs help to maintain a con- MAX3967AE/D -40C to +85C Dice* stant supply current, reducing EMI and supply noise *Dice are tested and guaranteed only at T = +25C. A generated by the transmitter module. The MAX3967A is available in die form, or in a 4mm x 4mm, 24-pin thin QFN package. Applications Pin Configuration Multimode LED Transmitters TOP VIEW Fast Ethernet/FDDI 155Mbps LAN ATM Transceivers 18 17 16 15 14 13 ESCON Receivers SFP Transceivers V 19 N.C. CC 12 IN- 20 11 OUT- IN+ 21 10 OUT- MAX3967A TX DISABLE 22 OUT+ 9 Typical Operating Circuits appear at end of data sheet. V EE 23 8 OUT+ V TCMIN 24 7 EEOUT 123 456 THIN QFN (4mm x 4mm) THE EXPOSED PAD MUST BE CONNECTED TO GROUND FOR PROPER THERMAL AND ELECTRICAL PERFORMANCE Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. TCNOM MODSET TC MON PB1 N.C. PB2 V CC PB3 V CCOUT V V EEOUT CCOUT270Mbps SFP LED Driver ABSOLUTE MAXIMUM RATINGS Supply Voltage at V , V Continuous Power Dissipation (T = +85C) CC CCOUT A ( , = 0V) ..............................................-0.5V to +7V 24-Lead Thin QFN (derate 20.8mW/C VEE VEEOUT Current into OUT+, OUT-................................-40mA to +160mA above +85C).............................................................1354mW Differential Output Voltage (OUT+ to OUT-) .........-3.3V to +3.3V Operating Junction Temperature Range...........-40C to +150C Voltage at PB1, PB2, PB3, Die Attach Temperature...................................................+375C IN+, IN-, OUT+, OUT-, TX DISABLE......-0.5V to (V + 0.5V) Storage Temperature Range .............................-50C to +150C CC Voltage at TCMIN, TCNOM, TC, MODSET, MON ....-0.5V to +2V Lead Temperature (soldering, 10s) .................................+300C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. DC ELECTRICAL CHARACTERISTICS (Load as specified in Figure 1 V = +2.97V to +5.5V (at the V pins) V V = 0V T = -40C to +85C, unless otherwise CC CC EE, EEOUT A noted. Temperature coefficients are referenced to T = +25C. Typical values are at V = +3.3V, T = +25C, unless otherwise A CC A noted. Dice are tested at T = +25C only.) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Data Input High Voltage Referenced to V , DC-coupled input -1.165 -0.880 V CC Data Input Low Voltage Referenced to V , DC-coupled input -1.810 -1.475 V CC Supply Current I (Note 1) 30 39 mA CC Input Current at IN+ or IN- -50 +50 A T = -40C 109 A R = 698 MODSET T = +25C 112 126 140 A (Note 2) T = +85C 126 140 155 A T = -40C 15.3 A R = 3.0k MODSET Modulation Current T = +25C 17.5 19.8 25 mA A (Note 2) T = +85C 21.9 24 28.7 A 65 74 89 T = -40C A R = 1.0k MODSET T = +25C V 79 86 89 A CC = 3.3V (Note 2) 90 96 110 T = +85C A PB1, PB2, PB3 = (open, open, open) 0.368 0.400 0.451 Prebias Voltage PB1, PB2, PB3 = (V , V , open) 0.575 0.625 0.696 V EE EE PB1, PB2, PB3 = (V , V , V ) 0.848 0.925 1.026 EE EE EE Maximum tempco (TC open) 12,000 Temperature Coefficient of Nominal tempco (TC shorted to TCNOM) 3600 ppm/C Modulation Current Minimum tempco (TC shorted to TCMIN) 2500 Prebias Resistor R 66 78 90 PREBIAS TX DISABLE Resistance Resistance to V (Note 3) 50 65 100 k EE TX DISABLE High V 2.0 V IH TX DISABLE Low V 0.8 V IL I / I , V < 1.1V, MON MODSET MON Monitor Gain 0.92 1 1.08 A/A R = 1k , TC = TCMIN MODSET Note 1: R = 1k . Excludes I + and I -, TX DISABLE high or low. MODSET OUT OUT Note 2: TC connected to TCMIN, PB1 = PB2 = V , PB3 = open. EE Note 3: The TX DISABLE pin is internally pulled low. The driver is enabled when TX DISABLE is left open. 2 MAX3967A