Texas Instruments UCD7242RSJR

Overview

UCD7242RSJR from Texas Instruments is a digital dual synchronous-buck power driver IC integrating two independent high-side/low-side NMOS gate drivers, on-die current sensing (±5%), thermal monitoring, and fault protection. It delivers up to 10 A per channel at switching frequencies up to 2 MHz, with internal 6.25 V VGG regulation and 170°C thermal shutdown-used in VRM/EVRD voltage regulator modules for server CPUs and telecom processors.

For engineers reviewing the UCD7242RSJR datasheet, UCD7242RSJR pinout, UCD7242RSJR application, or UCD7242RSJR equivalent, key selection criteria include dual-channel current limit accuracy (15 A ±0.5 A), integrated BST charge pump support per channel, synchronous vs. discontinuous conduction mode control via SRE pins, and QFN-32 package thermal performance under 125°C junction operation.

Technical Context

The UCD7242RSJR implements two fully independent synchronous buck driver channels, each with dedicated PWM, SRE, FLT, IMON, BST/BSW, and SW nodes. Its gate drivers deliver high peak current to drive integrated 15.5 mΩ high-side and 6.5 mΩ low-side MOSFETs, with programmable dead time (5–11 ns) and blanking (60 ns) to prevent cross-conduction.

It features dual-mode operation: synchronous rectification enabled when SRE = HIGH (CCM across all loads), or forced diode conduction when SRE = LOW (DCM at light loads). The internal VGG regulator (6.25 V ±0.5 V) supports VIN from 4.75 V to 18 V; external VGG bias enables operation down to 2.2 V input.

Key Specifications

Pinout & Package

UCD7242RSJR uses a thermally enhanced 32-pin QFN package (6 mm × 6 mm, RSJ code), with exposed thermal pad (pin 32) and 0.5 mm pitch. Pin assignment supports dual independent buck stages, with mirrored A/B signal groups and shared PGND/VIN planes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual synchronous-buck driver applications.

Compared with LM5113SDX/NOPB and MP86957DQKT-Z, the UCD7242RSJR uniquely combines dual-channel gate driving, ±5% on-die current sensing, and analog thermal telemetry in a single QFN-32 package-making it the only option for digitally controlled, telemetry-rich VRM designs requiring both precision and reliability.

Availability

UCD7242RSJR is available at Aetrix Electronics and suitable for server VRMs, telecom processor supplies, notebook GPU regulators, and industrial FPGA power systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for UCD7242RSJR 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in high-reliability power conversion solutions.

The UCD7242RSJR belongs to TI's Fusion Digital Power driver family, engineered specifically for tightly coupled, digitally controlled multiphase VRMs in computing and communications infrastructure where precision current sensing and thermal awareness are mandatory.

FAQ

What is the maximum continuous output current per channel for the UCD7242RSJR?

The UCD7242RSJR supports up to 10 A continuous output current per channel under recommended operating conditions (T_J ≤ 125°C, f_s ≤ 1 MHz, proper PCB thermal design). This rating assumes use of the internal 15.5 mΩ high-side and 6.5 mΩ low-side MOSFETs with adequate heatsinking and airflow. Derating applies at higher frequencies or ambient temperatures-see TI SLUS962B Figure 12 for MTTF curves at 10 A load.

How does the SRE pin affect operation of the UCD7242RSJR?

The SRE pin on the UCD7242RSJR determines conduction mode: when SRE = HIGH, the device operates in continuous conduction mode (CCM) with synchronous rectification active; when SRE = LOW, it enters discontinuous conduction mode (DCM) and holds the low-side FET off, forcing freewheeling through the body diode. This allows dynamic efficiency optimization-CCM for full-load performance, DCM for light-load efficiency-without changing external circuitry.

Can the UCD7242RSJR operate with an input voltage below 4.75 V?

Yes, the UCD7242RSJR can operate with VIN as low as 2.2 V by disabling the internal VGG regulator using the VGG_DIS pin and supplying an external 4.75–6.2 V gate drive voltage to the VGG pin. This bypasses the internal LDO and enables compatibility with low-input industrial or battery-backed systems where VIN falls below the internal regulator's minimum dropout requirement.

What is the function of the IMON pin on the UCD7242RSJR?

The IMON pin on the UCD7242RSJR provides a precision current-source output proportional to load current: 20 μA per ampere (±5% accuracy). When connected to a grounded resistor, it generates a voltage (e.g., 1 V at 50 A with 20 Ω) for real-time current monitoring by an external digital controller such as the UCD92xx series-enabling accurate phase current balancing, overcurrent protection, and adaptive loop compensation in VRM applications.

Does the UCD7242RSJR include thermal protection, and how is it implemented?

Yes, the UCD7242RSJR includes integrated thermal protection: an on-die temperature sensor feeds the TMON pin (10 mV/°C, 470 mV offset at 0°C), and triggers thermal shutdown at 170°C junction temperature. Upon trip, all switching halts, FLT flags assert, and operation resumes only after die temperature falls below 150°C (20°C hysteresis). This protects against sustained overload or inadequate cooling in high-power density applications like server VRMs.