Renesas EL7554IRE-T7

Overview

EL7554IRE-T7 from Intersil is a synchronous 4A step-down DC/DC regulator with integrated PMOS/NMOS power FETs, operating from 3V to 6V input and delivering adjustable output down to 0.8V. It achieves up to 96% efficiency at 4A load, supports 1MHz switching frequency, and includes junction temperature monitoring and ±5% voltage margining for manufacturing test validation. It is used in FPGA core/I/O power supplies requiring compact, high-efficiency point-of-load regulation.

For engineers reviewing the EL7554IRE-T7 datasheet, EL7554IRE-T7 pinout, EL7554IRE-T7 application, or EL7554IRE-T7 equivalent, key selection considerations include its 28-pin HTSSOP package with exposed thermal pad, constant-frequency PWM operation with external synchronization capability, soft-start and full start-up control (including tracking and adjustable ramp), and integrated over-temperature protection with 135°C shutdown threshold.

Technical Context

The EL7554IRE-T7 implements current-mode PWM control using patented on-chip resistorless current sensing derived from the upper PMOS FET, enabling fast transient response and precise over-current protection. Its 100% duty-cycle capability-enabled by complementary CMOS power switches-allows output voltages approaching VIN minus only RDSON1 and inductor IR drops.

It integrates a precision 1.26V bandgap reference (±1% initial accuracy, 50ppm/°C TC), programmable switching frequency (300–440kHz typical, up to 1MHz), and dual-input tracking comparator (STP/STN) for coordinated multi-rail startup. The VTJ pin provides a linear 1.2V–0.8V analog output corresponding to junction temperature (TJ = (VTJ − 1.2)/−0.00384 + 75°C), eliminating need for external thermal sensors.

Key Specifications

Pinout & Package

The EL7554IRE-T7 is housed in a thermally enhanced 28-lead HTSSOP package (MDP0048) with an exposed thermal pad requiring solder connection to PCB ground plane for effective heat dissipation. Thermal resistance θJA is as low as 26°C/W on a 2-layer board with proper layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck regulator applications.

Compared with TPS544B20RTWR and MP2315GJ-Z, the EL7554IRE-T7 uniquely combines 3–6V input compatibility, ±5% margining, VTJ-based thermal monitoring, and four-mode start-up control-making it optimal for FPGA/DSP core supplies requiring production testability and thermal visibility in space-constrained designs.

Availability

EL7554IRE-T7 is available at Aetrix Electronics and suitable for FPGA core supplies, DSP/CPU core power delivery, and logic bus regulation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for EL7554IRE-T7 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

Intersil Corporation (now part of Renesas Electronics) is a U.S.-based analog and power management IC designer known for high-efficiency DC/DC converters, precision references, and interface solutions.

The EL7554 product line was designed specifically for high-density, high-reliability point-of-load applications in computing and communications infrastructure-emphasizing thermal telemetry, manufacturing test support, and multi-rail sequencing without external components.

FAQ

What is the maximum output voltage achievable with the EL7554IRE-T7?

The EL7554IRE-T7 supports output voltages up to nearly VIN, enabled by its 100% duty-cycle capability and internal CMOS power FETs. With a 6V input, the practical maximum is approximately VIN − (RDSON1 × IO) − (RL × IO), where RDSON1 is 35mΩ (typical) and RL is inductor DCR. For example, at 4A and 20mΩ total drop, VO(max) ≈ 5.8V. The EL7554IRE-T7 datasheet confirms operation up to "nearly VIN" with no minimum dropout voltage limitation.

How does the EL7554IRE-T7 implement voltage margining, and what pins control it?

The EL7554IRE-T7 implements ±5% voltage margining using two dedicated pins: TM (pin 6) and SEL (pin 7). When TM is high and SEL is high, output increases by +5%; when TM is high and SEL is low, output decreases by −5%; both pulled low yields nominal output. Pull-down resistors (1k–100kΩ) are required if unused. This function is fully integrated-no external DAC or op-amps needed-and is documented in Table 2 of the EL7554IRE-T7 datasheet.

What thermal management practices are required for reliable operation of the EL7554IRE-T7?

Reliable thermal operation of the EL7554IRE-T7 requires soldering the exposed thermal pad to a PCB ground plane, maximizing copper area, and placing 6–12 thermal vias (13–25 mil) beneath the pad connecting to inner ground layers-without thermal reliefs. Layout must separate PGND and SGND, connecting them at one point near pin 28. The EL7554IRE-T7's θJA can reach 26°C/W with proper implementation, and junction temperature is continuously monitored via the VTJ pin.

Can the EL7554IRE-T7 synchronize its switching frequency to an external clock?

Yes, the EL7554IRE-T7 supports external synchronization via its oscillator circuit. To synchronize, apply a clean square wave to the COSC pin through a series resistor (typically 100Ω), with amplitude matching the internal ramp (0.2–1.2V). The EL7554IRE-T7 datasheet recommends setting the internal self-oscillation frequency ~20% lower than the sync frequency to accommodate component tolerances and ensure lock stability across temperature and voltage.

What is the purpose of the STP and STN pins on the EL7554IRE-T7, and how are they used?

The STP (pin 25) and STN (pin 26) pins form a differential tracking comparator that enables coordinated startup with other power rails. When STP voltage exceeds STN by ≥100mV, the EL7554IRE-T7 begins regulation-allowing linear tracking (e.g., 1.8V rail tracking 2.5V rail) or offset startup. Both pins feature 2µA internal pull-ups, so leaving them open configures standalone operation. This eliminates need for external sequencing ICs in multi-rail systems.