STMicroelectronics RHF1009AK1

Overview

RHF1009AK1 from STMicroelectronics is a radiation-hardened, adjustable shunt voltage reference delivering 2.5 V to 5.5 V output with ±0.2% initial accuracy at 25 °C, 30 ppm/°C max tempco, 60 µA–12 mA operating current, and ELDRS-free performance up to 300 krad - deployed in space data acquisition systems as a precision ADC reference under extreme thermal and radiation stress.

For engineers reviewing the RHF1009AK1 datasheet, RHF1009AK1 pinout, RHF1009AK1 application, or RHF1009AK1 equivalent, this device is selected for high-reliability analog signal conditioning in radiation-intensive environments where long-term voltage stability, low noise (880 nV/√Hz typ.), and SEL immunity up to 120 MeV·cm²/mg are mandatory design requirements.

Technical Context

The RHF1009AK1 implements a second-order temperature-compensated bandgap architecture optimized for wide-temperature operation (−55 °C to +125 °C) and radiation tolerance. Its internal double-bonding achieves 110 mΩ equivalent output resistance, enabling stable regulation across cathode current variations from 60 µA to 12 mA.

It operates as a two-terminal shunt reference requiring external resistor divider (R1/R2) for voltage programming. Stability is guaranteed with ≥47 nF capacitive load on the cathode; oscillation risk exists below that threshold or at ultra-low Ik (<60 µA) with large Ck (>1 µF), evidenced by 5 kHz noise peaks in spectral density measurements.

Key Specifications

Pinout & Package

Ceramic Flat-10 package: hermetically sealed, gold-plated leads, 6.48 mm × 6.48 mm footprint, 2.44 mm height, non-electrically connected metallic lid.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt voltage reference applications.

Compared with LM3411H and REF7025-SP, the RHF1009AK1 uniquely balances radiation hardness, adjustable output, and ultra-low minimum current - making it the only option for programmable, low-power, flight-certified shunt references in constrained SWaP-C satellite platforms.

Availability

RHF1009AK1 is available at Aetrix Electronics and suitable for spacecraft telemetry systems, satellite ADC reference subsystems, aerospace avionics sensors, and radiation-tolerant power management requiring stable component supply across extended production lifecycles and mission-critical traceability.

Supply support for RHF1009AK1 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, designing and manufacturing silicon solutions for automotive, industrial, and aerospace markets with emphasis on reliability and environmental compliance.

The RHF1009AK1 belongs to ST's Rad-Hard Analog portfolio, engineered specifically for space-grade analog signal integrity - prioritizing radiation tolerance, long-term stability, and wide-temperature operation in mission-critical orbital and deep-space systems.

FAQ

What is the minimum capacitive load required for stable operation of the RHF1009AK1?

The RHF1009AK1 requires a minimum capacitive load of 47 nF on the cathode terminal to prevent oscillation across its full operating current (60 µA–12 mA) and temperature (−55 °C to +125 °C) range. With smaller loads, micro-oscillations up to 2 mV_rms may occur, particularly near 5 kHz when Ck exceeds 1 µF and Ik drops below 100 µA - verified in Figures 17–24 of DS9897 Rev 7.

Can the RHF1009AK1 be used as a fixed 2.5 V reference without external resistors?

No - the RHF1009AK1 is an adjustable shunt reference requiring an external resistor divider (R1/R2) between cathode and anode to set VRef. It has no internal trimming or fixed-output mode. For 2.5 V operation, R1 and R2 must be selected per Equation 1 in Section 4.1 of DS9897 Rev 7 to achieve precise 2.5 V at the VRef node under specified IK conditions.

Is the metallic lid of the Ceramic Flat-10 package electrically connected?

No - the upper metallic lid is explicitly isolated: it is not electrically connected to any pin, nor to the IC die inside the package, as confirmed in Section 5.1 and Figure 26 of DS9897 Rev 7. This isolation prevents unintended coupling paths and simplifies PCB layout in high-impedance reference circuits.

What radiation test standards does the RHF1009AK1 meet for flight qualification?

The RHF1009AK1 is QML-V qualified per MIL-PRF-38535 Class V and tested per MIL-STD-883 TM 1019 for total ionizing dose (TID), including ELDRS characterization at both high-dose (50–300 rad/s) and low-dose (0.01 rad/s) rates up to 300 krad. SEL testing was performed at 125 °C with particle angles of 0° and 60°, confirming immunity up to 120 MeV·cm²/mg.