STMicroelectronics RHFXH163245K1

Overview

RHFXH163245K1 from STMicroelectronics is a radiation-hardened 16-bit bidirectional level-shifting transceiver with dual supply (VCCA = 1.8–3.6 V, VCCB = 1.4–3.6 V), cold-spare capability, and hermetic Ceramic Flat-48 packaging. It interfaces 3.3 V and 1.8 V buses in mixed-voltage aerospace systems, supports asynchronous two-way data transfer via DIR-controlled direction, and guarantees functionality down to 1.4 V on VCCB.

For engineers reviewing the RHFXH163245K1 datasheet, RHFXH163245K1 pinout, RHFXH163245K1 application, or RHFXH163245K1 equivalent, key selection criteria include TID tolerance (300 krad(Si)), SEL immunity (110 MeV·cm²/mg), cold-spare I/O behavior at 0 V supply, propagation delays under rad-hard operating conditions (e.g., tPHL1 ≤ 6 ns @ 3.3 V/1.8 V), and strict power sequencing requirements (VCCA ≥ VCCB).

Technical Context

This device implements dual-domain CMOS logic with independent A-side (VCCA) and B-side (VCCB) supply domains, enabling voltage translation between non-matching bus voltages while maintaining signal integrity across radiation environments. Direction control is managed by dedicated nDIR inputs per 8-bit port, and output enable is handled by separate /G pins - both referenced to VCCB.

Cold-spare operation requires simultaneous grounding of VCCA and VCCB to achieve high-impedance I/Os without leakage or bus contention; internal I_OFF ≤ ±10 µA at 0 V ensures fail-safe redundancy. Bus hold circuitry provides input stabilization (I_HOLD up to ±75 µA), and each A-side output includes a built-in 26 Ω series resistor for drive strength control and ESD robustness.

Key Specifications

Pinout & Package

Ceramic Flat-48 package (SMD 5962F11207), 1.5 g mass, hermetic seal, gold-plated terminations, compliant with QML-V flight qualification.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional level-shifting applications.

Compared with RHFXH163245K1 (Engineering Model), the K01V offers full flight qualification documentation and process traceability, while K07V adds grounded-lid mechanical enhancement and Device Type 02 VCCB optimization - both retain identical electrical and radiation performance but differ in certification scope and thermal management.

Availability

RHFXH163245K1 is available at Aetrix Electronics and suitable for spacecraft onboard data handling, satellite payload interface, and mission-critical avionics requiring stable component supply under extended lead times and rigorous traceability.

Supply support for RHFXH163245K1 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, with design and manufacturing facilities across Europe, Asia, and the Americas, serving automotive, industrial, and aerospace markets.

RHFXH163245K1 belongs to ST's rad-hard ASIC and interface IC product line, engineered specifically for high-reliability space and nuclear applications demanding extreme radiation tolerance, hermetic packaging, and long-term obsolescence mitigation.

FAQ

What is the minimum operating voltage for RHFXH163245K1 on the B-side supply (VCCB)?

The RHFXH163245K1 guarantees functional operation at VCCB = 1.4 V when VCCA = 1.4 V and input thresholds are set to 0.35×VCCA/0.65×VCCA. Performance parameters (e.g., propagation delay, drive strength) are specified starting at VCCB = 1.65 V. Below 1.4 V, operation is not characterized or guaranteed.

Can RHFXH163245K1 operate with VCCB higher than VCCA?

No. The datasheet explicitly forbids VCCB > VCCA under all conditions. Violation may cause erroneous outputs during power-up/down transitions due to internal biasing conflicts, though it does not damage the device or degrade long-term reliability. VCCA must always be ≥ VCCB.

Is cold-spare mode supported when only one supply rail is grounded?

No. Cold-spare operation requires both VCCA and VCCB to be simultaneously tied to ground. Activating cold-spare with only VCCA = 0 V or only VCCB = 0 V is prohibited and may result in undefined I/O states or excessive leakage current - the architecture mandates dual-rail shutdown for safe high-impedance isolation.

Does RHFXH163245K1 require external pull-up or pull-down resistors on control inputs?

No. All control inputs (DIRx, /Gx) feature integrated bus hold circuitry that maintains valid logic states without external resistors. However, unused inputs must still be tied to GND per datasheet guidance to prevent noise coupling and ensure predictable cold-spare behavior.