Microchip Technology ATA5428-PLSW 80

Overview

ATA5428-PLSW 80 from Microchip Technology is a highly integrated UHF ASK/FSK multi-channel half-duplex transceiver in a 7 × 7 mm QFN48 package, operating at 431.5–436.5 MHz and 862–872 MHz bands. It delivers –109.5 dBm FSK sensitivity at 2.4 kBaud and –116.5 dBm ASK sensitivity at same rate (433.92 MHz), with 1–20 kBaud Manchester data rates, integrated fractional-N synthesizer, and SPI interface up to 500 kbit/s - deployed in automotive remote keyless entry (RKE) and access control systems.

For engineers reviewing the ATA5428-PLSW 80 datasheet, ATA5428-PLSW 80 pinout, ATA5428-PLSW 80 application, or ATA5428-PLSW 80 equivalent, this page provides verified RF performance metrics, validated power management modes (including AUX-mode inductive supply), confirmed 5-key wake-up capability in power-down, and precise IF architecture details (226 kHz low-IF, 30 dB image rejection, 170 kHz usable bandwidth) essential for loop antenna design and challenge-response crypto timing.

Technical Context

The ATA5428-PLSW 80 implements a fully integrated low-IF receiver with 226 kHz IF frequency, eighth-order integrated IF filter, and quasi-peak detector-based data slicer - enabling high selectivity (55–70 dB blocking at ±750 kHz to ±10 MHz) without external SAW filters in remote control units. Its fractional-N synthesizer supports programmable tuning across ±2.5 MHz with 800 Hz RF resolution and compensates XTAL tolerances via register-controlled calibration.

Transmit path uses closed-loop fractional-N synthesis for FSK modulation and PA switching for ASK, with integrated RX/TX switch, single-ended RF I/O, and adjustable output power (0–10 dBm via external resistor). Digital control logic includes FIFO-buffered protocol handling, self-polling, and microcontroller support features including CLK output, N_RESET, IRQ, and low-battery indication.

Key Specifications

Pinout & Package

ATA5428-PLSW 80 is housed in a thermally enhanced 7 × 7 mm QFN48 package with exposed thermal pad (EP), lead-free and RoHS-compliant. Pin functions are validated per Rev. 4841A–RKE–02/05 datasheet, with 12 NC pins, dual supply inputs (VS1/VS2), integrated XTAL load capacitors, and dedicated key inputs (T1–T5) active in power-down.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar UHF ASK/FSK transceiver applications.

Compared with ATA5428-PLSW 80, ATA5780N-PLQW adds secure firmware execution and key storage for evolving RKE standards, while SI4362-B1B-FMR trades integrated power management and wake-up logic for higher RF output and lower RX current - making it suitable only where those specific trade-offs align with system architecture.

Availability

ATA5428-PLSW 80 is available at Aetrix Electronics and suitable for remote keyless entry (RKE), passive entry & go (PEPS), and industrial telemetry applications requiring stable component supply, long-term lifecycle support, and automotive-grade qualification.

Supply support for ATA5428-PLSW 80 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

Microchip Technology is a global semiconductor company specializing in microcontrollers, analog devices, and wireless solutions, with broad automotive and industrial certification coverage including AEC-Q100.

The ATA5428-PLSW 80 belongs to Microchip's ATA54xx family of highly integrated UHF transceivers designed specifically for cost-sensitive, battery-operated RKE and access control systems - emphasizing minimal external components, loop antenna compatibility, and cryptographic offload capability.

FAQ

What frequency bands does the ATA5428-PLSW 80 support?

The ATA5428-PLSW 80 supports two distinct UHF bands: 431.5–436.5 MHz and 862–872 MHz. This dual-band capability is selected via the 433_N868 pin and enables flexible deployment across regional ISM allocations without hardware redesign. The device achieves –109.5 dBm FSK sensitivity at 433.92 MHz and –103.5 dBm at 868.3 MHz (20 kBaud), with identical low-IF architecture and fractional-N synthesizer performance in both bands.

How does the ATA5428-PLSW 80 achieve high blocking performance without a SAW filter?

The ATA5428-PLSW 80 achieves 55 dB blocking at ±750 kHz and 70 dB at ±10 MHz through its fully integrated low-IF architecture (226 kHz IF), eighth-order on-chip IF filter, and high-selectivity quasi-peak detector data slicer. These features eliminate the need for external SAW filters in remote control units - validated in typical loop antenna applications per Figure 2-1 of Rev. 4841A–RKE–02/05. The architecture also minimizes second-order intermodulation susceptibility compared to direct-conversion receivers.

Can the ATA5428-PLSW 80 operate with a depleted battery?

Yes, the ATA5428-PLSW 80 supports inductive AUX-mode operation via the VAUX pin, allowing continued function when the primary battery is exhausted. In this mode, an external inductor supplies regulated voltage to sustain critical security operations such as challenge-response authentication - a key requirement for automotive RKE systems where fob reliability must persist beyond battery end-of-life.

What is the role of the T1–T5 pins on the ATA5428-PLSW 80?

The T1–T5 pins on the ATA5428-PLSW 80 are dedicated wake-up inputs that remain active in power-down mode, enabling immediate system wake upon button press without microcontroller intervention. Each pin supports active-low logic and can optionally serve as a secondary PWR_ON trigger. This feature is essential for sub-100 ms response in passive entry systems and reduces average current consumption in battery-powered remotes.

Does the ATA5428-PLSW 80 require external crystal load capacitors?

No, the ATA5428-PLSW 80 integrates load capacitors for the XTAL1/XTAL2 interface - a 9 pF capacitor is built-in, eliminating the need for external load caps in most designs. This integration simplifies BOM, improves start-up reliability (>–1.5 kΩ worst-case real start-up impedance), and reduces sensitivity to PCB parasitics. Crystal frequency accuracy is further enhanced via software calibration of control registers 2 and 3 to compensate initial XTAL tolerance.