STMicroelectronics RH-PM4424LK1

Overview

RH-PM4424LK1 from STMicroelectronics is a radiation-hardened, dual low-side MOSFET/IGBT gate driver designed for high-reliability aerospace power systems. It delivers 4.5 A peak sink/source per channel (9 A in parallel), features 110 ns typical propagation delay with ≤5 ns inter-channel matching, supports 4.65–18 V supply, and operates across –55 °C to +125 °C in hermetic FLAT-16 packaging - enabling use in synchronous buck converters and radiation-intensive motor controllers.

For engineers reviewing the RH-PM4424LK1 datasheet, RH-PM4424LK1 pinout, RH-PM4424LK1 application, or RH-PM4424LK1 equivalent, key selection criteria include radiation tolerance (100 krad TID), dual-channel timing symmetry, CMOS/TTL-compatible 5 V logic inputs, ±5 V SGND-to-PGND common-mode range, and parallel-output capability for high-current gate driving in space-grade SMPS and DC-DC modules.

Technical Context

The RH-PM4424LK1 implements two independent low-side drivers using ST's lateral DMOS process, each with matched source (Rhi ≈ 1.1 Ω typ.) and sink (Rlo ≈ 1.4 Ω typ.) output stages. Its input stage accepts TTL/CMOS logic with VIH ≥ 2.0 V and VIL ≤ 0.8 V, and includes undervoltage lockout (VUVLO = 4.65 V) with 300 mV hysteresis to prevent erratic operation during brownout.

Operation relies on segregated ground domains: SGND references PWM inputs and tolerates ±5 V bounce versus PGND (power ground), while OUTH_x/OUTL_x outputs are open-drain configured for flexible external gate resistor placement. Parallel operation is enabled by tightly matched propagation delays and identical drive strength, allowing synchronized 9 A peak current delivery when PWM_1/PWM_2 and output pairs are tied.

Key Specifications

Pinout & Package

Package: Hermetic FLAT-16 (QML-V qualified), metal lid electrically floating, optimized for thermal dissipation (550 mW/channel) and radiation hardness.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual low-side gate driver applications.

Compared with IXDN614PI and MAX5078AASA+, RH-PM4424LK1 uniquely combines QML-V qualification, 100 krad TID tolerance, dual-channel timing symmetry, and hermetic FLAT-16 packaging - making it the sole option for production flight hardware requiring guaranteed performance under cumulative radiation exposure.

Availability

RH-PM4424LK1 is available at Aetrix Electronics and suitable for spacecraft power distribution units, satellite DC-DC converter modules, and aerospace motor control actuators requiring stable component supply across extended mission lifetimes and extreme environmental conditions.

Supply support for RH-PM4424LK1 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 decades of heritage in radiation-hardened technology and QML-V manufacturing.

RH-PM4424LK1 belongs to ST's RHRPM (Radiation-Hardened Power Management) product line, engineered specifically for high-reliability power conversion in space environments where TID, SEL, and thermal robustness are non-negotiable design constraints.

FAQ

What is the maximum allowable gate capacitance this driver can switch at 300 kHz?

RH-PM4424LK1 supports up to 50 nF total gate capacitance per channel at 300 kHz with V_CC = 10 V and 2.2 Ω external gate resistors, based on thermal limits (1.10 W max at 70 °C ambient) and measured 30 ns rise/fall times. Exceeding 50 nF risks exceeding junction temperature limits unless PCB copper area and airflow are enhanced per layout guidelines in DS11485 Section 9.

Can SGND and PGND be shorted together on the PCB?

Yes - SGND and PGND may be shorted at a single point near the device or decoupled with a 0 Ω resistor or ferrite bead, provided the resulting common-mode voltage remains within ±5 V. Shorting simplifies layout but sacrifices noise isolation; decoupling preserves input-stage immunity against high-di/dt PGND transients in high-power sections.

Is parallel operation supported for only the outputs, or must inputs also be tied?

Both inputs (PWM_1 and PWM_2) and outputs (OUTH_1/OUTL_1 and OUTH_2/OUTL_2) must be tied together for parallel operation. The ≤5 ns inter-channel delay matching ensures simultaneous switching; tying only outputs without synchronized inputs causes undefined behavior and potential shoot-through due to timing skew.

Does the device require external bootstrap capacitors for high-side drive?

No - RH-PM4424LK1 is a low-side-only driver. It does not integrate high-side level-shifting or bootstrap circuitry. For high-side FET drive, an external isolated gate driver or transformer-coupled solution is required; this device serves exclusively as a dual low-side gate controller with OUTH_x/OUTL_x open-drain outputs.