Microchip Technology ATR0981-TRUY

Overview

ATR0981-TRUY from Atmel is a monolithic SiGe front-end IC integrating a low-noise amplifier (LNA) and power amplifier (PA) for UHF 300–500 MHz transceivers. It delivers 29 dBm saturated output power, 1.5 dB noise figure, and 55% power-added efficiency at 466 MHz, enabling compact, high-performance RF front-ends in battery-powered wireless infrastructure.

For engineers reviewing the ATR0981-TRUY datasheet, ATR0981-TRUY pinout, ATR0981-TRUY application, or ATR0981-TRUY equivalent, key selection criteria include its dual-band LNA/PA integration, ±3 dB output power control range, 34 dB PA gain, 19 dB LNA gain, and PSSO20 thermal-enhanced package with down-set paddle for 150°C junction operation.

Technical Context

The ATR0981-TRUY implements a fully integrated transmit/receive front-end architecture: the LNA operates from 2.4–2.6 V with 2.5 mA supply current and 1.5 dB NF, while the PA runs from 3.0–4.5 V with 400–550 mA current and supports true CW operation under 10:1 load mismatch. Both sections share a common 300–500 MHz frequency band but are isolated by internal grounding and separate bias paths.

Control is implemented via analog voltage on POUT_CONTROL (pin 17), enabling continuous output power adjustment from 0.7 V (min) to 2.5 V (max), with full shutdown below 0.1 V drawing only 20 µA. Thermal management relies on the PSSO20's 19 K/W junction-to-ambient resistance and exposed paddle soldered to PCB ground.

Key Specifications

Pinout & Package

Packaged in PSSO20 plastic package with down-set paddle for enhanced thermal dissipation and mechanical stability. Exposed paddle must be soldered to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar UHF front-end applications.

Compared with RF5110 and QM11035, the ATR0981-TRUY offers superior noise figure (1.5 dB vs ≥2.2 dB), tighter output control (±3 dB vs fixed or digital-step), and optimized PSSO20 thermal performance for sustained 400 mA operation-making it preferred for compact, battery-sensitive UHF telemetry.

Availability

ATR0981-TRUY is available at Aetrix Electronics and suitable for UHF wireless telemetry, license-free utility metering, and industrial remote control requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for ATR0981-TRUY 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

Atmel Corporation (now part of Microchip Technology) is a semiconductor manufacturer specializing in microcontrollers, nonvolatile memory, and RF analog products for embedded and industrial applications.

The ATR0981-TRUY belongs to Atmel's UHF front-end IC product line, designed specifically for integrated, low-power, high-efficiency transceiver modules in 300–500 MHz license-free and telemetry bands.

FAQ

What is the maximum junction temperature specification for the ATR0981-TRUY?

The ATR0981-TRUY has an absolute maximum junction temperature of 150°C. This rating is supported by its PSSO20 package with down-set paddle and 19 K/W junction-to-ambient thermal resistance. For reliable operation at full 550 mA PA current, PCB layout must provide adequate copper area under the paddle and maintain ambient temperature ≤60°C. Derating curves in the datasheet confirm safe operation up to 150°C with proper thermal design.

Does the ATR0981-TRUY require external matching components for 433 MHz operation?

Yes, the ATR0981-TRUY requires external matching components for 433 MHz operation. Its LNA_IN and PA_IN pins are internally matched to 50 Ω but require external DC blocking capacitors and input/output filters. The typical application circuit (Figure 8-1) specifies discrete inductors (L1–L8) and capacitors (C1–C14) for impedance transformation and harmonic suppression. No internal matching is provided for the V3_PA_OUT pins-they connect directly to external PA output network.

Can the ATR0981-TRUY operate with a 2.5 V LNA supply and 3.3 V PA supply simultaneously?

Yes, the ATR0981-TRUY supports independent LNA and PA supplies: VS_LNA (pin 13) operates at 2.4–2.6 V, and VS_PA (pins 1,2,3,11,19) operates at 3.0–4.5 V. The datasheet confirms stable operation with 2.5 V on LNA_IN/LNA_OUT and 3.3 V on V2_PA and V3_PA_OUT. This dual-supply capability enables optimized noise performance and power efficiency without level-shifting circuitry.

What is the function of the NC pin (pin 6) on the ATR0981-TRUY?

The NC pin (pin 6) on the ATR0981-TRUY is Not Connected-no internal circuitry connects to this terminal. It must remain unconnected on the PCB; routing traces or vias to pin 6 may cause parasitic coupling or mechanical stress. The pin exists solely for mechanical symmetry in the PSSO20 package and does not require grounding, floating, or termination. All other ground pins (GND1–GND6) must be properly connected to the PCB ground plane.

How does the POUT_CONTROL pin (pin 17) affect PA operation in the ATR0981-TRUY?

The POUT_CONTROL pin (pin 17) provides analog voltage-based output power control for the ATR0981-TRUY PA stage. Applying 0.7–2.5 V adjusts output power continuously across ±3 dB range; voltages ≤0.1 V place the PA in shutdown mode, reducing supply current to 20 µA. The pin draws ≤400 µA and requires no external pull-up/down. This enables simple MCU GPIO or DAC-based power management without digital interface overhead.