Renesas EL7556DCMZ-T13

Overview

EL7556DCMZ-T13 from Intersil is an adjustable synchronous DC/DC switching regulator optimized for 5V input and 1.0V–3.8V output, integrating dual NMOS power FETs with 25 mΩ composite R_DS(on), delivering up to 6A continuous output current without external heat sinks. It features VCC2DET interface for Intel P54/P55 microprocessor compatibility, internal 1% precision reference (1.260 V), and ±10% power-good window on PWRGD.

For engineers reviewing the EL7556DCMZ-T13 datasheet, EL7556DCMZ-T13 pinout, EL7556DCMZ-T13 application, or EL7556DCMZ-T13 equivalent, key selection considerations include its fused-lead 28-pin SO package thermal performance (31°C/W with PCB copper), current-mode control with adjustable slope compensation, and dual feedback mode (internal 3.5V or resistor-programmable).

Technical Context

The EL7556DCMZ-T13 implements fixed-frequency current-mode PWM control using a triple-input summing comparator that combines voltage feedback (FB1/FB2), inductor current sensing, and user-adjustable slope compensation via CSLOPE capacitor. Its architecture includes leading-edge blanking (140 ns) to suppress switching noise and break-before-make timing (10 ns) to prevent shoot-through between high-side and low-side FETs.

It integrates a charge-pump-based gate drive system: CP pin drives a 0.1 µF bootstrap capacitor to generate ~11.2 V gate voltage on VHI for the high-side NMOS, while C2V supplies ~7.5 V to the low-side driver. Thermal protection uses die-integrated sensor with 135°C trip point and 40°C hysteresis, directly connectable to OUTEN for automatic shutdown.

Key Specifications

Pinout & Package

EL7556DCMZ-T13 is housed in a RoHS-compliant, Pb-free 28-pin SOIC package with fused-lead thermal construction (MDP0027). Seven pins (7, 9–12, 18–19) are internally connected to the die substrate to enable low-thermal-resistance PCB heat sinking (31°C/W achievable with adequate copper area).

Key Features

Applications

Equivalent & Alternatives

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

Compared with EL7556DCMZ-T13, EL7566 offers higher current capability but lacks Intel interface and thermal packaging; ISL6208 provides broader voltage range and external FET control but increases component count and PCB area-making EL7556DCMZ-T13 optimal for compact, thermally constrained Intel P54/P55 core supplies.

Availability

EL7556DCMZ-T13 is available at Aetrix Electronics and suitable for PC motherboards, local high-power CPU supplies, and GTL+ bus power generation requiring stable component supply, RoHS compliance, and long-lifecycle availability.

Supply support for EL7556DCMZ-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-performance DC/DC regulators, precision references, and thermal-aware power solutions.

The EL7556D product line was engineered specifically for cost-sensitive, high-current CPU core voltage regulation in desktop and server platforms, emphasizing integration, thermal efficiency, and Intel microprocessor interface compliance.

FAQ

What is the maximum continuous output current supported by the EL7556DCMZ-T13?

The EL7556DCMZ-T13 supports up to 6 A continuous output current under specified thermal conditions (ambient ≤67°C with 100 LFPM airflow or ≤77°C with forced cooling). This rating assumes proper PCB copper layout per the fused-lead thermal guidelines in the datasheet, including connection of all seven VSSP pins to a minimum 2 in² copper pour. Peak current capability is 9 A, limited by internal current-limit circuitry.

How does the VCC2DET pin affect output voltage configuration on the EL7556DCMZ-T13?

When VCC2DET is driven high (≥4 V), the EL7556DCMZ-T13 selects FB2 and delivers a factory-trimmed 3.500 V output for Intel P54/P55 compatibility. When VCC2DET is pulled low (≤0.8 V), FB1 becomes active and the output voltage is set by an external resistor divider (VOUT = 1.0 V × (1 + R3/R4)), enabling programmability from 1.0 V to 3.8 V. A 2 µA internal pull-up on FB1 ensures safe shutdown if the divider is disconnected.

Can the EL7556DCMZ-T13 operate without external slope compensation components?

No-the EL7556DCMZ-T13 requires an external CSLOPE capacitor (typically 470 pF) to provide slope compensation for current-mode stability, especially above 50% duty cycle. Omitting CSLOPE risks subharmonic oscillation and poor transient response. The datasheet specifies a recommended COSC:CSLOPE ratio of 1.5:1 (e.g., 1 nF COSC with 680 pF CSLOPE) to maintain consistent loop gain across frequency adjustments.

What thermal resistance can be achieved with the EL7556DCMZ-T13's fused-lead package?

With appropriate PCB layout-connecting all seven VSSP pins (7, 9–12, 18–19) to ≥2 in² of 2-oz copper-the EL7556DCMZ-T13 achieves a junction-to-ambient thermal resistance (θ_JA) of approximately 31°C/W in still air. This is significantly lower than the ~78°C/W typical of standard SO28 packages. Adding 100 LFPM airflow further reduces θ_JA by ~15%, enabling higher ambient operating temperatures without thermal shutdown.

Is the EL7556DCMZ-T13 RoHS compliant and lead-free?

Yes-the "Z" suffix in EL7556DCMZ-T13 denotes Intersil's Pb-free plus anneal construction: 100% matte tin plating, RoHS-compliant molding compound and die attach, qualified for both SnPb and Pb-free reflow profiles per IPC/JEDEC J-STD-020. The device meets MSL Level 3 moisture sensitivity and is rated for peak reflow temperatures up to 260°C.