STMicroelectronics RHR801K1

Overview

RHR801K1 from STMicroelectronics is a rad-hard, very high-speed single comparator designed for precision timing and signal conditioning in radiation-intensive environments. It delivers 7 ns propagation time (typ.), 1.1 ns rise/fall time into 10 pF, and operates from 3 V to 5 V single supply. Its ceramic Flat-8 hermetic package supports applications in satellite telemetry clock recovery and high-energy physics front-end sampling.

For engineers reviewing the RHR801K1 datasheet, RHR801K1 pinout, RHR801K1 application, or RHR801K1 equivalent, key selection criteria include radiation tolerance (100 krad high-dose rate, no SEL at 120 MeV·cm²/mg), rail-to-rail MOS output drive capability (±35 mA at 5 V), and input hysteresis (1.5–4.0 mV typ.) for noise-immune threshold detection.

Technical Context

The RHR801K1 employs a high-speed complementary BiCMOS process to achieve its 7 ns propagation delay and 1.1 ns edge transitions while maintaining low power (1.4 mA typical at 3.3 V). Its input stage features differential thresholds with ±2 V absolute max differential voltage and common-mode range from (VCC−) + 0.5 V to (VCC+) − 1.2 V.

It integrates rail-to-rail MOS output drivers capable of sourcing/sinking up to 55 mA (at −55 °C, 5 V), with guaranteed VOH ≥ 4.70 V and VOL ≤ 300 mV under 5 mA load. Radiation hardening includes full QML-V qualification per MIL-STD-883 TM 1019 for both high-dose (180 krad/h) and low-dose (36 rad/h) TID exposure.

Key Specifications

Pinout & Package

The RHR801K1 is housed in a hermetic ceramic Flat-8 package (SMD pin code 5962R10215), mass 0.45 g. The upper metallic lid is electrically isolated from pins and die.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed rad-hard comparator applications.

Compared with EL7104CSZ-T7 and HA-5147-5, the RHR801K1 uniquely combines sub-10 ns speed, full QML-V radiation certification, and ceramic Flat-8 hermeticity-making it the sole option for flight-critical timing in LEO/MEO missions requiring simultaneous speed, hardness, and reliability.

Availability

RHR801K1 is available at Aetrix Electronics and suitable for spacecraft telemetry clock recovery, satellite payload sampling trigger, high-energy physics beam timing, and deep-space transponder phase detection requiring stable component supply across extended temperature and radiation environments.

Supply support for RHR801K1 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 specializing in automotive, industrial, and aerospace-grade ICs, with over 30 years of rad-hard product development.

The RHR801K1 belongs to ST's Rad-Hard Analog portfolio, engineered specifically for timing-critical functions in spaceborne electronics where radiation-induced failure is unacceptable.

FAQ

What is the maximum operating temperature for RHR801K1?

The RHR801K1 is rated for continuous operation from −55 °C to +125 °C ambient temperature. Junction temperature must not exceed 150 °C; thermal resistance junction-to-case is 40 °C/W, so proper heatsinking or PCB copper pour is required at high power dissipation points.

Can RHR801K1 operate from dual supplies?

Yes - the device supports dual-supply operation (e.g., VCC+ = +2.5 V, VCC− = −2.5 V) with common-mode input range extending from (VCC−) + 0.5 V to (VCC+) − 1.2 V. Input differential voltage must remain within ±2 V, and ESD diodes require external current limiting if inputs exceed rails.

How is output impedance matched for 50 Ω systems?

A 1 kΩ series resistor is required between OUT and the 50 Ω transmission line (per Fig. 39), as the RHR801K1 cannot drive 50 Ω directly. This limits peak output current while preserving signal integrity; input traces must also be 50 Ω matched with minimal stub length to avoid reflections.

Is external hysteresis necessary for noise immunity?

No - the RHR801K1 features built-in 1.5–4.0 mV hysteresis, sufficient for most high-speed applications. External positive feedback (e.g., R1/R2/R3 network) is optional and used only when wider thresholds (e.g., >10 mV) are needed for extreme EMI environments like particle accelerator vaults.