Renesas EL7554IREZ-T13

Overview

EL7554IREZ-T13 from Intersil is a monolithic 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 (VTJ), ±5% voltage margining (TM/SEL), and power-good (PG) indication - deployed in FPGA core/I/O power supplies requiring compact, thermally robust point-of-load regulation.

For engineers reviewing the EL7554IREZ-T13 datasheet, EL7554IREZ-T13 pinout, EL7554IREZ-T13 application, or EL7554IREZ-T13 equivalent, key selection criteria include its 28-lead HTSSOP package with exposed thermal pad, constant-frequency PWM operation with external synchronization capability, 100% duty-cycle support for near-V_IN outputs, soft-start timing control via EN capacitor, and full start-up tracking (STP/STN) for multi-rail sequencing.

Technical Context

The EL7554IREZ-T13 implements current-mode PWM control using on-chip resistorless current sensing from the high-side PMOS switch, enabling fast transient response and over-current protection without external sense resistors. Its oscillator uses a relaxation comparator with COSC pin adjustment (200kHz–1MHz), and features internal soft-start (~2ms), under-voltage lockout (2.5V shutdown / 2.8V restart), and thermal shutdown at 135°C with 20°C hysteresis.

It integrates dual synchronous power switches (35mΩ PMOS, 30mΩ NMOS at +25°C), a 1.26V ±1% bandgap reference with 50ppm/°C tempco, and dedicated pins for voltage margining (TM/SEL), junction temperature monitoring (VTJ), and supply tracking (STP/STN). The error amplifier (G_MEA = 125µS) supports Type-1 compensation with typical crossover at 50kHz for stable loop design.

Key Specifications

Pinout & Package

The EL7554IREZ-T13 is housed in a 28-lead HTSSOP package (MDP0048) with exposed thermal pad, optimized for PCB heat spreading via soldered pad and thermal vias. Pin count and function mapping are validated per FN7360 Rev 5.00 datasheet.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Compared with TPS544B20RTWR and MP2315DJ-LF-Z, the EL7554IREZ-T13 uniquely integrates voltage margining, junction temperature monitoring, and supply tracking in a 3V–6V input 4A buck - making it optimal for FPGA/DSP power validation and thermal-aware embedded designs where those functions would otherwise require added components and board area.

Availability

EL7554IREZ-T13 is available at Aetrix Electronics and suitable for FPGA core supplies, DSP I/O regulation, and portable equipment power management requiring stable component supply, RoHS compliance, and long-term industrial temperature support (–40°C to +85°C).

Supply support for EL7554IREZ-T13 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 thermal-aware power solutions.

The EL7554 product line was designed specifically for high-density point-of-load applications in FPGA, DSP, and ASIC systems - emphasizing integration of margining, thermal monitoring, and multi-rail sequencing to reduce system-level validation effort.

FAQ

What is the maximum achievable output voltage of the EL7554IREZ-T13?

The EL7554IREZ-T13 supports up to nearly the input voltage (V_IN) due to its 100% duty-cycle capability enabled by the integrated PMOS high-side switch. The practical maximum is V_IN minus voltage drops across the PMOS R_DS(ON) and inductor DCR - for example, with 5V input, 35mΩ PMOS, and 10mΩ inductor, V_OUT(MAX) ≈ 4.82V. This makes EL7554IREZ-T13 suitable for applications needing V_OUT close to V_IN, such as LDO replacement in low-dropout scenarios.

How does the EL7554IREZ-T13 implement voltage margining, and what pins control it?

The EL7554IREZ-T13 implements ±5% voltage margining using two dedicated pins: TM (pin 6) and SEL (pin 7). When TM is pulled high and SEL is high, output increases by +5%; when TM is high and SEL is low, output decreases by –5%; both grounded yields nominal output. Pull-down resistors (1kΩ–100kΩ) are required if unused. This feature is fully integrated - no external DAC or digital interface is needed - and is directly usable during manufacturing burn-in and functional test of EL7554IREZ-T13-based power rails.

Can the EL7554IREZ-T13 be synchronized to an external clock, and how is this configured?

Yes, the EL7554IREZ-T13 supports external synchronization via its COSC pin (pin 27). To synchronize, apply a clean square wave (CMOS level) through a 100pF capacitor to COSC while setting the internal oscillator frequency ~20% lower than the sync source to accommodate component tolerances. This ensures deterministic phase alignment across multiple EL7554IREZ-T13 regulators - critical for reducing beat frequencies and EMI in multi-phase or tightly spaced power systems.

What is the purpose of the VTJ pin on the EL7554IREZ-T13, and how is it used?

The VTJ pin (pin 5) on the EL7554IREZ-T13 provides a linear analog voltage proportional to junction temperature: V_TJ = 1.2 − 0.00384×(T_J − 75). It outputs ~1.2V at 75°C and decreases ~3.84mV/°C, enabling direct measurement of silicon die temperature without calibration. Designers connect a 0.01µF–0.047µF capacitor from VTJ to SGND for noise filtering, then read the voltage with a microcontroller ADC to log thermal behavior or trigger fan control - eliminating need for external thermal sensors in EL7554IREZ-T13 designs.

Does the EL7554IREZ-T13 require external compensation components, and what type is recommended?

Yes, the EL7554IREZ-T13 requires external compensation on the COMP pin (pin 1) using a Type-1 network (resistor + capacitor). For a 1.8V/4A design at 600kHz switching frequency, typical values are R_C = 2.32kΩ and C_C = 0.018µF - values validated in the datasheet's Table 3. This network sets loop crossover near 50kHz (1/10 of f_SW) for stability. The EL7554IREZ-T13's current-mode architecture simplifies compensation versus voltage-mode controllers, and the integrated error amplifier (G_MEA = 125µS) ensures predictable loop behavior with these standard values.