Renesas EL7536IY-T7

Overview

EL7536IY-T7 from Intersil is a synchronous, integrated-FET 1A step-down DC/DC regulator with internal compensation, operating from 2.5V to 5.5V input and delivering adjustable output from 0.8V to VIN. It features 1.4MHz PWM switching, <1µA shutdown current, 100ms open-drain POR output, and over-temperature/short-circuit protection in a 10-lead MSOP package.

For engineers reviewing the EL7536IY-T7 datasheet, EL7536IY-T7 pinout, EL7536IY-T7 application, or EL7536IY-T7 equivalent, key selection considerations include its internally compensated voltage-mode control, 70mΩ PMOS + 45mΩ NMOS R_DS(ON), 94% peak efficiency at 1A, -40°C to +85°C operation, and single-side PCB layout enabling <0.15in² footprint.

Technical Context

The EL7536IY-T7 implements a fixed-frequency (1.4MHz typical) voltage-mode PWM controller with internal compensation, eliminating external loop components. Its synchronous dual-MOSFET power stage uses a PMOS high-side switch and NMOS low-side switch, enabling 100% duty-cycle operation for near-VIN output regulation.

It integrates thermal shutdown (145°C trip, 130°C hysteresis), current limiting (~1.5A), soft-start (~650µs), and a dedicated RSI-controlled POR output with 100ms delay. The separate SGND and PGND pins enforce clean signal/power ground separation critical for stability and noise immunity.

Key Specifications

Pinout & Package

EL7536IY-T7 is housed in a 10-lead MSOP package (MDP0043), 3.0mm × 4.9mm × 1.1mm max height, RoHS-compliant with matte tin terminations. The fused-lead construction delivers θ_JA = 115°C/W (high-thermal-conductivity board) or 206°C/W (low-conductivity board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with EL7536IY-T7, ISL97536 offers higher temperature rating and marginal efficiency gain with drop-in compatibility, while TPS62231DRYT trades adjustability and integrated POR for ultra-low IQ and smaller size-making it suitable only for fixed-voltage, space-constrained applications where reset sequencing is managed elsewhere.

Availability

EL7536IY-T7 is available at Aetrix Electronics and suitable for portable computing, battery-powered instrumentation, optical module power, and handheld industrial scanners requiring stable component supply and long-lifecycle availability.

Supply support for EL7536IY-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-performance DC/DC converters, precision amplifiers, and interface solutions.

The EL7536 belongs to Intersil's monolithic synchronous buck regulator product line, engineered specifically for space-constrained, battery-operated portable electronics demanding high efficiency, low quiescent current, and robust protection features.

FAQ

What is the recommended inductor value for EL7536IY-T7 in a standard 3.3V-to-1.8V conversion?

The EL7536IY-T7 datasheet specifies a nominal inductor value of 1.8µH for 3.3V input and 1.8V output at 1A. Inductor values between 1.5µH and 2.2µH are acceptable due to the device's internal compensation. Use shielded, high-saturation-current types rated for ≥1.5A DC and ≥2A peak to avoid saturation under current limit conditions. The EL7536IY-T7's 1.4MHz switching frequency allows compact magnetics without compromising transient response.

Does EL7536IY-T7 support 100% duty cycle, and what is the practical minimum input voltage for a 3.3V output?

Yes, EL7536IY-T7 supports 100% duty cycle via its PMOS high-side switch, enabling VO to approach VIN minus IR drops. For a 3.3V output, the theoretical minimum VIN is ~3.3V + (I_OUT × R_{DS(ON)_PMOS}). At 1A and 70mΩ, this yields ~3.37V. In practice, maintain ≥3.5V input to ensure stable regulation and avoid increased ripple near 100% duty cycle. The EL7536IY-T7's 2.5V absolute minimum VIN rating applies only to startup-not sustained 100% operation.

How should the POR and RSI pins be configured if the Power-On Reset function is not needed in my design?

If POR is unused, connect RSI (Pin 6) directly to SGND (Pin 1) and leave POR (Pin 8) unconnected-no pull-up resistor is required. This disables POR assertion entirely. Do not float RSI, as it may cause spurious resets. The EL7536IY-T7 continues full regulation regardless; disabling POR only removes the reset signal. Confirm host MCU has alternate reset provisioning before omitting POR, as the EL7536IY-T7 itself does not require it for operation.

What is the maximum achievable output voltage accuracy for EL7536IY-T7, and which parameters dominate error?

The EL7536IY-T7 achieves ±1.25% total output voltage error over temperature and line/load conditions. Dominant contributors are the ±10mV (±1.25%) tolerance of the internal 800mV feedback reference (V_FB) and resistor divider ratio tolerance. Using 0.5% resistors limits divider error to <0.5%, making V_FB the primary accuracy limiter. Layout-induced errors (e.g., PGND/SQND separation, FB trace routing) can add ±0.1–0.2%. The EL7536IY-T7's internal compensation and fixed V_FB make it inherently more accurate than externally compensated alternatives.

Can EL7536IY-T7 be used with ceramic output capacitors only, and what is the minimum recommended value?

Yes, EL7536IY-T7 is designed exclusively for ceramic output capacitors-no electrolytic or tantalum required. The datasheet mandates 10µF to 22µF X5R/X7R MLCCs for stability due to internal compensation. At 1A load and 3.3V input, 10µF is sufficient unless operating at VIN < 3V, IO > 0.7A, or TJ > 75°C, in which case 22µF is recommended. The EL7536IY-T7's control loop is optimized for the ESR and ESL of these ceramics; using lower values risks instability and excessive output ripple.