My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX3946ETG+
- Part No.:
- MAX3946ETG+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Laser Drivers
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
MAX3946ETG+.pdf
- Description:
- IC LASER DRV 11.3GB 3.63V 24TQFN
- Quantity:
- Payment:
- Shipping:
Inventory:750
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX3946ETG+ from Maxim Integrated is a +3.3V, multirate SFP+ laser driver IC optimized for 1Gbps to 11.3Gbps Ethernet and Fibre Channel optical transceivers. It drives differential TOSAs with 5Ω–25Ω loads, delivers up to 80mA modulation current and 80mA bias current, achieves 22ps edge speed (20%–80%), and supports unmatched FP/DFB lasers to reduce power and headroom constraints in compact SFP+ modules.
For engineers reviewing the MAX3946ETG+ datasheet, MAX3946ETG+ pinout, MAX3946ETG+ application, or MAX3946ETG+ equivalent, this page provides verified technical context, deterministic jitter performance (5–7psP-P), programmable equalization/deemphasis, integrated eye safety circuitry, and SFF-8431/SFF-8472 compliance - all critical for high-speed optical module design and qualification.
Technical Context
The MAX3946ETG+ implements a fully differential, high-bandwidth signal path with on-chip 25Ω back terminations at TOUT+ and TOUT−, enabling low deterministic jitter (5psP-P at 25Ω load) and tolerance to laser impedance mismatch. Its output stage supports 5Ω–50Ω differential loads without external matching networks.
A 3-wire digital interface controls nine key functions: input equalization (SET_TXEQ), pulse-width adjustment (SET_PWCTRL), Tx polarity, deemphasis (SET_TXDE), modulation current (SET_IMOD, 9-bit DAC), and bias current (SET_IBIAS, 9-bit DAC), all programmable without external components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Data Rate | 1Gbps to 11.3Gbps NRZ - supports full SFP+ MSA range including 10GBASE-LR/LRM and 4x/8x FC. |
| Modulation Current | 10mA to 80mAP-P into 25Ω load - digitally programmable via 9-bit DAC with ±1.5% stability over temp/VCC. |
| Bias Current | 5mA to 80mA - 9-bit DAC control with 190μA LSB; includes IBIASMAX limit register for laser protection. |
| Deterministic Jitter | 5psP-P (25Ω load), 7psP-P (5Ω load) - measured at 11.3Gbps with K28.5 pattern; enables tight eye opening in SFP+ modules. |
| Edge Speed | 22ps (20% to 80%) - consistent across 10–80mA IMOD range, critical for maintaining signal integrity at 10+ Gbps. |
| Power Dissipation | 225mW at 3.3V (IMOD = 40mA, IBIAS = 60mA, 25Ω load) - enables <1W total SFP+ module power budget. |
| Supply Voltage | +2.85V to +3.63V - single 3.3V rail operation with 100mVP-P noise tolerance (DC–10MHz). |
Pinout & Package
MAX3946ETG+ uses a 4mm × 4mm, 24-pin TQFN-EP package with exposed pad (EP) soldered to ground for thermal and electrical performance. Pin count and layout comply with SFP+ MSA mechanical requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC / VCCD / VCCT | Power supply domains | VCC powers core logic; VCCD powers digital interface; VCCT powers output stage - independent rails minimize noise coupling. |
| TIN+ / TIN− | Differential CML-compatible data input | On-chip 75Ω termination; supports 0.15–1.0VP-P input swing; programmable equalization compensates FR4 trace loss. |
| TOUT+ / TOUT− | Differential laser modulation outputs | 25Ω on-chip back termination to VCCT; deliver up to 80mAP-P into 5Ω–25Ω loads; symmetrical drive reduces common-mode noise. |
| BIAS / BMON / BMAX | Laser bias control & monitoring | BIAS sinks up to 80mA; BMON sources 1% of BIAS current for analog monitoring; BMAX sets max bias via voltage divider for eye-safety fault latching. |
| DISABLE / FAULT / CSEL / SDA / SCL | 3-wire interface & safety control | DISABLE disables both bias/modulation; FAULT is open-drain latched fault indicator; CSEL/SDA/SCL implement robust I²C-like serial control with collision protection. |
Key Features
| Feature | Design Value |
|---|---|
| SFP+ MSA Compliance | Fully supports SFF-8431 physical layer and SFF-8472 digital diagnostics - enables plug-and-play integration into standard SFP+ cages and host systems. |
| Unmatched TOSA Support | Eliminates need for external impedance-matching networks by tolerating 5Ω–25Ω laser loads - reduces BOM cost and PCB area in space-constrained modules. |
| Integrated Eye Safety | Hardware-based fault detection (BMAX/BMON/BIAS thresholds) with latched FAULT output - meets Class 1 laser safety requirements without firmware intervention. |
| Programmable Deemphasis | 6-bit SET_TXDE register adjusts deemphasis from 0% to 40% - compensates SFP+ connector and PCB channel loss to restore high-frequency content. |
| Low-Power Operation | 225mW typical dissipation at 3.3V/40mA IMOD/60mA IBIAS - enables thermally constrained SFP+ modules to meet <1W total power envelope. |
Applications
| 10GBASE-LR SFP+ Transceivers | 10GBASE-LRM SFP+ Transceivers |
|---|---|
Use Scenario: 10km single-mode fiber links in enterprise data centers using standardized SFP+ pluggables. IC Role / Device Role / Timing Role: Laser driver providing precise modulation/bias control and deterministic jitter suppression for 10.3125Gbps NRZ signals. Use Value: Enables compliant eye mask margin at receiver after 10km SMF; 5psP-P DJ ensures BER <10−12 without forward error correction. |
Use Scenario: 220m multi-mode fiber links in legacy campus networks using OM1/OM2 cabling. IC Role / Device Role / Timing Role: High-swing, low-jitter driver compensating for modal dispersion and connector loss in MMF channels. Use Value: Programmable input equalization and output deemphasis restore signal integrity degraded by 220m OM2 fiber and SFP+ cage insertion loss. |
| 4x/8x Fibre Channel SFP+ | OC192-SR XFP/SFP+ SDH/SONET |
Use Scenario: Storage area network (SAN) interconnects operating at 8.5Gbps (8x FC) or 4.25Gbps (4x FC) with hot-pluggable optics. IC Role / Device Role / Timing Role: Multirate laser driver supporting both rates with identical pinout and register map - simplifies dual-speed module design. Use Value: Single hardware platform covers 4x and 8x FC; 22ps edge speed maintains rise/fall symmetry required for FC-PI-4 jitter compliance. |
Use Scenario: Metro optical transport nodes requiring SONET OC-192 (9.953Gbps) short-reach interfaces in XFP or SFP+ form factors. IC Role / Device Role / Timing Role: Precision laser driver meeting GR-253-CORE jitter and extinction ratio requirements for SDH/SONET. Use Value: 7psP-P DJ at 5Ω load ensures compliance with SONET OC-192 SR mask; integrated bias monitor supports real-time laser health reporting. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar laser driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX3947ETG+ | Same pinout and register map; adds integrated temperature sensor and enhanced diagnostic registers per SFF-8472 rev 10.2. | Required for SFP+ modules needing full digital diagnostics (DDM) compliance beyond basic monitoring. | Select MAX3947ETG+ when DDM feature set (real-time temp, voltage, TX bias/power) is mandatory for host system management. |
| SY88315BLEY | 5mm × 5mm 32-pin QFN; supports higher 12.5Gbps CPRI rate; no integrated BMAX/BMON safety circuitry; requires external bias monitor. | Targeted at wireless fronthaul (CPRI/OBSAI) where extended rate and external safety logic are acceptable trade-offs. | Choose SY88315BLEY only for CPRI 10.137Gbps/12.5Gbps applications; not drop-in for SFP+ due to different pin count, package, and safety architecture. |
Compared with MAX3947ETG+, the MAX3946ETG+ offers identical core laser driving performance but omits advanced DDM features - making it optimal for cost-sensitive, standards-compliant SFP+ modules where full digital diagnostics are not required. Versus SY88315BLEY, MAX3946ETG+ provides integrated eye safety and SFP+-optimized footprint at the expense of CPRI-rate support.
Availability
MAX3946ETG+ is available at Aetrix Electronics and suitable for 10GBASE-LR/LRM optical transceivers, Fibre Channel SFP+ modules, and OC192-SR SDH/SONET interfaces requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MAX3946ETG+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and high-speed communication ICs for demanding industrial, communications, and computing applications.
The MAX3946 product line targets SFP+ optical transceiver manufacturers, delivering multirate laser drivers with integrated safety, low jitter, and MSA-compliant digital control to enable compact, reliable, and standards-certified pluggable optics.
FAQ
What is the maximum data rate supported by the MAX3946ETG+?
The MAX3946ETG+ supports data rates from 1Gbps up to 11.3Gbps NRZ, fully covering the SFP+ MSA specification including 10GBASE-LR (10.3125Gbps), 10GBASE-LRM (10.3125Gbps), and 8x Fibre Channel (8.5Gbps). This range is confirmed in the General Description and Electrical Characteristics sections of the datasheet, with deterministic jitter validated at 11.3Gbps using K28.5 and PRBS patterns.
Does the MAX3946ETG+ require external components for laser bias monitoring?
No, the MAX3946ETG+ integrates a dedicated BMON pin that sources current proportional to the BIAS pin current (typically 1/100th), enabling direct analog monitoring with a single external resistor to ground. The BMAX pin further allows setting a programmable laser bias current limit via a resistive divider - eliminating need for external op-amps or ADCs in basic safety and monitoring implementations.
How does the MAX3946ETG+ handle impedance mismatch between the driver and TOSA?
The MAX3946ETG+ tolerates laser impedance mismatch through its unique symmetrical output stage with integrated 25Ω back terminations at TOUT+ and TOUT−, and a design that relaxes headroom requirements. It operates reliably across 5Ω–25Ω differential loads without external matching networks - a key feature explicitly highlighted in the General Description and validated by DJ measurements down to 5Ω.
What digital interface does the MAX3946ETG+ use, and how many wires are required?
The MAX3946ETG+ uses a 3-wire digital interface (CSEL, SDA, SCL) compatible with I²C timing but implemented with open-drain CMOS logic and internal pull-up/down resistors. Only three signal wires plus ground are needed to configure all functions - including modulation/bias current, equalization, deemphasis, and pulse-width control - reducing PCB routing complexity versus parallel interfaces.
Is the MAX3946ETG+ RoHS-compliant and lead-free?
Yes, the MAX3946ETG+ is RoHS-compliant and lead-free, as indicated by the "+" suffix in the part number per Maxim's ordering information table. It is packaged in a lead(Pb)-free TQFN-EP with matte tin finish, qualified for reflow soldering at 260°C, and meets JEDEC J-STD-020 moisture sensitivity level 3 requirements.
MAX3946ETG+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- Laser Diode Driver
- Data Rate:
- 11.3Gbps
- Number of Channels:
- 1
- Voltage - Supply:
- 2.85V ~ 3.63V
- Current - Supply:
- 68 mA
- Current - Modulation:
- 80mA
- Current - Bias:
- 80 mA
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 24-TQFN (4x4)
- Mounting Type:
- Surface Mount
MAX3946ETG+ FAQ
1.How can I place an order for MAX3946ETG+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX3946ETG+ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MAX3946ETG+ reliable?
The price and inventory of MAX3946ETG+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX3946ETG+ is usually 5 days.
3.What payment methods are accepted for MAX3946ETG+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX3946ETG+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX3946ETG+?
MAX3946ETG+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX3946ETG+ order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MAX3946ETG+?
For technical support, including MAX3946ETG+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX3946ETG+ requirements.
6.How does Aetrix verify that MAX3946ETG+ is sourced from the original manufacturer or authorized distributors?
All MAX3946ETG+ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MAX3946ETG+ meets industry standards.
7.What is the process for return or replacement of MAX3946ETG+?
All MAX3946ETG+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX3946ETG+, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MAX3946ETG+ part is unused and in its original packaging.
Return procedure for MAX3946ETG+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX3946ETG+ Tags
-
EPC21701
EPC
-
EPC21601
EPC
-
MAX3799ETJ+T
Analog Devices Inc./Maxim Integrated
-
AD9665ACPZ-REEL7
Analog Devices Inc.
-
MAX3740AETG+T
Analog Devices Inc./Maxim Integrated
-
MAX3795ETG+
Analog Devices Inc./Maxim Integrated
-
EPC21603
EPC
-
ONET8501VRGPT
Texas Instruments
-
MAX3738ETG+T
Analog Devices Inc./Maxim Integrated
-
SY88022ALMG-TR
Microchip Technology
-
ISL78365ARZ-T7A
Renesas
-
EPC21603ENGRT
EPC
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
