Texas Instruments ONET3301PARGTR

Overview

ONET3301PARGTR from Texas Instruments is a 3.3-Gbps high-speed limiting amplifier with integrated loss-of-signal (LOS) detection and received signal strength indicator (RSSI), delivering 50 dB gain, 3 mV_p−p input sensitivity, and CML differential outputs. It operates on a single 3.3-V supply in SONET OC48, Fibre Channel 2.125-Gbps, and Gigabit Ethernet receiver front-ends.

For engineers reviewing the ONET3301PARGTR datasheet, ONET3301PARGTR pinout, ONET3301PARGTR application, or ONET3301PARGTR equivalent, key selection criteria include input dynamic range (3–1200 mV_p−p), deterministic jitter (≤30 ps_p−p at 2.7 Gbps), RSSI linearity (±3% over 20-dB range), and QFN-16 thermal performance at −40°C to 85°C.

Technical Context

The ONET3301PARGTR implements a three-stage high-gain analog data path with on-chip 50-Ω input termination to VCC and 50-Ω CML output back-termination to VCCO, enabling stable 600–1200 mV_p−p differential swing. Offset cancellation uses internal COC1/COC2 filter nodes, supporting adjustable low-frequency cutoff from 45 kHz (open) down to 0.8 kHz (2.2 nF external).

LOS detection is programmable via external resistor to TH pin (2–40 mV_p−p threshold range), while RSSI provides linear analog voltage output (100–2800 mV) proportional to input amplitude. The device integrates bandgap-referenced bias generation and CMOS control logic for OUTPOL polarity inversion and DISABLE output gating.

Key Specifications

Pinout & Package

ONET3301PARGTR is housed in a 3 mm × 3 mm, 16-pin QFN package with 0.5-mm pitch and exposed thermal pad (EP) requiring PCB ground connection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed limiting amplifier applications.

Compared with MAX3748AETE+ and SY88303BLMG, the ONET3301PARGTR uniquely balances integrated monitoring (RSSI + LOS), low power (106 mW), and industry-standard QFN-16 packaging-making it optimal for cost-sensitive, space-constrained SFP and SONET OC48 designs where analog diagnostics are required.

Availability

ONET3301PARGTR is available at Aetrix Electronics and suitable for SONET OC48 receivers, Fibre Channel 2.125-Gbps systems, and Gigabit Ethernet optical interfaces requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for ONET3301PARGTR 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 company headquartered in Dallas, Texas, specializing in analog, embedded processing, and connectivity technologies for industrial, communications, and computing markets.

The ONET3301PARGTR belongs to TI's Optical Networking product line, engineered specifically for high-speed fiber-optic receiver front-ends in telecom and datacom infrastructure where low jitter, wide dynamic range, and integrated diagnostics are essential.

FAQ

What is the minimum input signal level supported by the ONET3301PARGTR?

The ONET3301PARGTR supports a minimum input signal level of 3 mV_p−p (typical) at BER <10⁻¹⁰, enabled by its 50-dB gain and on-chip offset cancellation. This sensitivity allows reliable operation with low-output photodiodes in long-haul optical links. The ONET3301PARGTR maintains this performance across its full −40°C to 85°C operating range without recalibration.

Does the ONET3301PARGTR require dual power supplies?

No, the ONET3301PARGTR operates from a single 3.3-V ±10% supply applied to VCC (pins 1, 4) and VCCO (pin 12). VCC powers the input stage and bias circuitry, while VCCO independently supplies the CML output stage-providing noise isolation without requiring separate regulators. The ONET3301PARGTR datasheet specifies 3.0 V to 3.6 V for both rails.

How is loss-of-signal (LOS) detection configured on the ONET3301PARGTR?

LOS detection on the ONET3301PARGTR is configured using an external resistor connected between the TH pin (pin 5) and GND. This sets the input amplitude threshold between 2 mV_p−p and 40 mV_p−p. The LOS output (pin 7) asserts high when the input falls below this threshold. The ONET3301PARGTR includes 2.5–4.5 dB hysteresis to prevent chatter during marginal signal conditions.

Can the ONET3301PARGTR output polarity be inverted dynamically?

Yes, the ONET3301PARGTR supports dynamic polarity inversion via the OUTPOL pin (pin 9). When pulled low, it inverts the DOUT+/DOUT− output pair relative to DIN+/DIN−; leaving it open or high selects normal polarity. This feature is implemented with internal CMOS logic and requires no external components, enabling real-time signal alignment in the ONET3301PARGTR without redesigning the data path.

What is the role of the COC1 and COC2 pins on the ONET3301PARGTR?

The COC1 (pin 14) and COC2 (pin 15) pins on the ONET3301PARGTR form the terminals of the internal offset cancellation loop filter. Connecting an external capacitor (e.g., 2.2 nF) between them extends the low-frequency −3-dB bandwidth from 45 kHz down to 0.8 kHz. Shorting COC1 and COC2 disables the loop entirely. This adjustment directly impacts baseline stability for low-frequency optical modulation schemes used in the ONET3301PARGTR.