Texas Instruments ONET8551TYS9

Overview

ONET8551TYS9 from Texas Instruments is a 11.3-Gbps limiting transimpedance amplifier (TIA) optimized for optical receiver front-ends in high-speed fiber communication systems. It delivers 9-GHz bandwidth, –20-dBm sensitivity at 10.3125 Gbps, and 10-kΩ differential small-signal transimpedance, with integrated RSSI for signal strength monitoring in PIN/APD-based receivers.

For engineers reviewing the ONET8551TYS9 datasheet, ONET8551TYS9 pinout, ONET8551TYS9 application, or ONET8551TYS9 equivalent, key selection criteria include input-referred noise (0.9–1.4 μA_RMS), CML output compliance (on-chip 50-Ω back-termination), dual RSSI outputs (RSSI_IB/RSSI_EB), bandwidth configurability via BW0/BW1 pins, and die-level packaging for TO-can integration.

Technical Context

The ONET8551TYS9 implements a three-stage signal path: a photodiode-current-to-voltage transimpedance amplifier (TIA), a limiting voltage amplifier with automatic gain control (AGC), and a CML output buffer with on-chip 50-Ω termination to VCC. Its AGC dynamically adjusts gain to maintain limiting behavior across input currents from 25 μA_P-P to 2.5 mA_P-P.

Dual supply domains isolate VCC_IN (2.8–3.63 V for TIA stage) from VCC_OUT (same range for AGC/CML stages), while internal supply filtering eliminates need for external bypass capacitors. Bandwidth tuning is achieved via two digital inputs (BW0/BW1), enabling discrete adjustment between 7–9 GHz depending on grounding configuration.

Key Specifications

Pinout & Package

The ONET8551TYS9 is supplied as a bare die (WAFERSALE package type) with dimensions 870 μm × 1036 μm and thickness 203 ±13 μm. It requires conductive epoxy attachment to ground for back-side thermal and electrical connection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar limiting transimpedance amplifier applications.

Compared with MAX3748AETE+ and LMH6525MA/NOPB, the ONET8551TYS9 uniquely combines 9-GHz bandwidth, integrated RSSI, dual-supply isolation, and TO-can-optimized die packaging-making it the only option qualified for 10G+ optical standards like SONET OC-192 and 10G-EPON without external support circuitry.

Availability

ONET8551TYS9 is available at Aetrix Electronics and suitable for 10-Gigabit Ethernet transceivers, SONET OC-192 line cards, and CPRI fronthaul modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ONET8551TYS9 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and high-speed interface solutions, with decades of expertise in optical communications ICs.

The ONET8551TYS9 belongs to TI's ONET family of high-speed optical receiver ICs, designed specifically for 10G-class fiber infrastructure where sensitivity, jitter, and integration density are critical.

FAQ

What is the primary function of the ONET8551TYS9 in optical receiver designs?

The ONET8551TYS9 serves as a limiting transimpedance amplifier that converts photodiode current into a clean, differential CML data stream. It provides 10-kΩ transimpedance gain, 9-GHz bandwidth, –20-dBm sensitivity, and integrated RSSI for optical power monitoring - all within a die-level package optimized for TO-can integration. The ONET8551TYS9 enables compact, high-performance front-ends for 10G+ protocols including 10G-EPON and SONET OC-192.

Does the ONET8551TYS9 support both PIN and APD photodiodes?

Yes, the ONET8551TYS9 supports both PIN and APD photodiodes through dual biasing and RSSI configurations. For PIN diodes, use FILTER1/FILTER2 outputs and RSSI_IB; for APDs with external bias, use RSSI_EB and omit internal FILTER connections. The device includes dedicated circuitry to maintain RSSI accuracy under both bias schemes, though TI recommends RSSI_IB for highest precision when internal bias is employed. This flexibility makes the ONET8551TYS9 suitable across multiple optical receiver topologies.

How does bandwidth adjustment work on the ONET8551TYS9?

Bandwidth adjustment on the ONET8551TYS9 is controlled by two digital inputs: BW0 and BW1. Grounding either pin increases bandwidth; grounding both achieves the maximum 9-GHz specification. Leaving both open reduces bandwidth to ~7 GHz, lowering noise for lower-data-rate or higher-sensitivity applications. These pins are internally pulled up to VCC, so no external pull-ups are needed. The ONET8551TYS9 datasheet specifies exact bandwidth vs. temperature and process corner under each configuration, ensuring predictable performance across manufacturing lots.

What are the supply voltage requirements for the ONET8551TYS9?

The ONET8551TYS9 requires two independent 2.8–3.63-V supplies: VCC_IN powers the transimpedance amplifier stage, and VCC_OUT powers the AGC, RSSI, and CML output buffer. This separation prevents noise coupling from output switching into the sensitive TIA input. Both rails must be regulated and low-noise; the device includes on-chip supply filtering, eliminating need for external bulk capacitors. Total typical power dissipation is 92 mW, making the ONET8551TYS9 suitable for thermally constrained TO-can packages.

Can the ONET8551TYS9 be used without connecting the RSSI outputs?

Yes, the ONET8551TYS9 operates fully without RSSI connections. RSSI_IB and RSSI_EB are optional current-output pins; leaving them open disables RSSI functionality with no impact on TIA or CML performance. If RSSI is unused, TI recommends leaving the pads unconnected (not tied to ground or VCC) to avoid unintended loading or leakage paths. The ONET8551TYS9 maintains its specified –20-dBm sensitivity, 9-GHz bandwidth, and 2.5-mA_P-P overload capability regardless of RSSI usage - ensuring design flexibility across cost- and feature-sensitive applications.