MAX3955 11.32Gbps Transceiver with Dual CDRs, Digital Monitors, and DC-Coupled Laser Driver0 pages

EVALUATION KIT AVAILABLE

MAX3955

11.32Gbps Transceiver with Dual CDRs,
Digital Monitors, and DC-Coupled Laser Driver

General Description

The MAX3955 is an 11.3Gbps, highly-integrated, lowpower transceiver with dual CDRs, and digital diagnostics monitoring (DDM) designed for next-generation
SONET transmission systems. The receiver incorporates
a limiting amplifier with loss-of-signal (LOS) circuit. The
limiting amplifier features an independent 9.95Gbps to
11.32Gbps CDR. The transmitter incorporates Maxim’s
proprietary DC-coupled laser driver interface, an independent 9.95Gbps to 11.32Gbps CDR, and closed-loop control
of average laser power.
The MAX3955 supports differential AC-coupled signaling
with integrated 50Ω terminations at Rx input, Rx output,
and Tx input. The Tx output is a DC-coupled 25Ω laser
diode interface with dedicated pins for the laser anode
(TOUTA) and the laser cathode (TOUTC).
An integrated 12-bit analog-to-digital converter (ADC)
is utilized to provide digital monitors of internal/external
temperature, VCC, and received signal strength indication
(RSSI). The MAX3955’s analog monitors and the use of
a 2-wire or 3-wire slave interface enables configuration
through either a digital-only microcontroller (µC) or
through the DS1978 SFP+ controller (future product).
The MAX3955 operates from single +3.3V supply and
over a -40°C to +95°C temperature range and is available
in a standard 5mm x 5mm, 32-pin TQFN-EP package.
Ordering Information appears at end of data sheet.

Benefits and Features

Performance
●● Dual CDRs Exceeding SONET Jitter Requirements
with PLL Bandwidth Setting of 7MHz
●● 540mW Typical IC Power Dissipation (ILD_MOD =
45mA, IBIAS = 45mA, Both CDRs Enabled)
Flexibility
●● Independent, Reference-less Tx and Rx CDRs
●● Pattern Generator for Receive and Transmit Paths
●● Signal Loop-Back Paths
●● Programmable Tx Input Equalization and Rx Output
Deemphasis
●● Pin-Compatible with MAX3956 11.3Gbps Transceiver
Safety and Monitoring
●● Integrated Eye Safety Features with Maskable Fault
and Interrupt Signal Generation
●● Analog Monitors with Integrated 12-Bit ADC, Fully
Supporting SFF-8472 DDM with Digital-Only µC
●● High-Accuracy Temperature, VCC, and RSSI
Monitors
●● Auxiliary ADC Input at BADC for General Use

Applications

●● OC-192 XFP and SFP+ Optical Transceivers
For related parts and recommended products to use with this part, refer
to www.maximintegrated.com/MAX3955.related.

Simplified Block Diagram
9.95 TO 11.32Gbps LIMITING AMPLIFIER WITH CDR
50Ω

50Ω

50Ω

50Ω

RIN+

ROUT+

MUX

RINLOS

ROUT-

PAT GEN

RX-CDR

RX-LOS

LFRX
CSEL
SDA
SCL

DDM

2-WIRE/3-WIRE

VCC

TEMP

BADC

TX-POWER

RSSI

RSSI

9.95 TO 11.32Gbps, DC-COUPLED LASER DRIVER WITH CDR
VCCTO
TOUTA
TOUTC

DC-COUPLED
LASER DRIVER

VOUT
APC

TX-LOS
MUX

EQUALIZER
PAT GEN

TX-CDR

50Ω

50Ω
TIN+
TINLFTX

19-6858; Rev 0; 12/13