Renesas EL7535IY

Overview

EL7535IY from Intersil is a synchronous, integrated-FET 350mA step-down DC/DC regulator in a 10-lead MSOP package. It operates from 2.5V to 6V input, delivers adjustable output from 0.8V to VIN via resistor divider, and features 1.4MHz PWM switching, internal compensation, and <1µA shutdown current. It powers Li-ion–based portable devices requiring compact, high-efficiency regulation.

For engineers reviewing the EL7535IY datasheet, EL7535IY pinout, EL7535IY application, or EL7535IY equivalent, key selection criteria include its fixed 1.4MHz switching frequency, dual MOSFET integration (70mΩ PMOS / 45mΩ NMOS), POR open-drain output with 100ms delay, thermal shutdown at 145°C, and compatibility with minimal external components (2×10µF ceramic caps + 1.8µH inductor).

Technical Context

The EL7535IY implements voltage-mode PWM control with an internally compensated error amplifier and fixed 1.4MHz oscillator. Its synchronous topology uses integrated P-channel and N-channel MOSFETs, eliminating the need for an external catch diode and enabling up to 94% efficiency at 350mA load.

It integrates Power-On Reset (POR) with 100ms delay referenced to output voltage threshold (97% of VFB rising, 86% falling), plus RSI-triggered reset override. Protection includes cycle-by-cycle current limiting at 1.5A, overtemperature shutdown (145°C trip, 130°C hysteresis), and undervoltage lockout (2.19V startup, 100mV hysteresis).

Key Specifications

Pinout & Package

EL7535IY is housed in a Pb-free, RoHS-compliant 10-lead MSOP package (MDP0043), measuring 3.0mm × 4.9mm × 1.1mm max height, with fused-lead construction for improved thermal resistance (θJA = 100°C/W on 4-layer board).

Key Features

Applications

Equivalent & Alternatives

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

Compared with EL7535IY, both ISL80019 and ISL80019A offer lower current rating (300mA vs. 350mA), omit the POR/RSI interface entirely, require external compensation components, and lack the same level of integration-making them unsuitable drop-in replacements but viable alternatives only when those features are omitted from the system architecture.

Availability

EL7535IY is available at Aetrix Electronics and suitable for portable medical monitors, handheld industrial scanners, and Li-ion–powered test instrumentation requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for EL7535IY 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 is a pioneer in high-performance analog and power management ICs, now part of Renesas Electronics, delivering solutions for industrial, infrastructure, and mobile computing markets.

The EL7535IY belongs to Intersil's monolithic DC/DC regulator product line, engineered specifically for space-constrained, battery-operated systems demanding high efficiency, integrated protection, and simplified design with minimal external components.

FAQ

What is the maximum output current capability of the EL7535IY?

The EL7535IY delivers 350mA continuously under specified thermal conditions (TA ≤ +85°C, 4-layer PCB). It supports 500mA peak current for short durations, and its internal current limit is set at 1.5A to handle fault conditions. Derating is required above 85°C ambient, per the package power dissipation curves in the datasheet. The EL7535IY maintains regulation across this range without external current-sense components.

Does the EL7535IY require external compensation components?

No, the EL7535IY features an internally compensated voltage-mode controller, eliminating the need for external compensation networks. This allows stable operation using only two 10µF ceramic capacitors and one 1.8µH inductor. The fixed compensation is optimized for standard component values-deviating significantly from recommended L/C values may compromise loop stability. The EL7535IY's design removes a common source of layout sensitivity and tuning effort.

How does the POR function work on the EL7535IY, and can it be disabled?

The EL7535IY's POR output is an open-drain signal that stays low for ~100ms after the output voltage reaches 97% of its target (e.g., 97% of 1.8V = 1.746V). It can be triggered early via the RSI pin. To disable POR, leave the POR pin unconnected and tie RSI to ground-this prevents unintended resets. The EL7535IY does not provide an internal disable option; external pull-up and grounding define its behavior. No configuration register or pin strapping is involved.

What are the thermal performance characteristics of the EL7535IY package?

The EL7535IY uses a fused-lead 10-lead MSOP package (MDP0043) with θJA = 100°C/W on a 4-layer board and 125°C/W on a 2-layer board. Its max junction temperature is +125°C, with thermal shutdown activating at +145°C and restarting at +130°C. Layout best practices-such as maximizing PGND copper area, placing vias under the package, and separating SGND/PGND-directly impact achievable output current. The EL7535IY's thermal design enables full 350mA operation at +85°C ambient with proper PCB implementation.

Is the EL7535IY pin-compatible with newer Intersil or Renesas buck regulators?

No, the EL7535IY is not pin-compatible with newer offerings like the ISL80019 or ISL80019A-the latter have different pin assignments (e.g., missing POR/RSI pins) and require external compensation. The datasheet explicitly states they are "NOT PIN-FOR-PIN" substitutes. Migration would require PCB redesign, firmware updates for reset handling, and recalculation of feedback and LC components. The EL7535IY remains a standalone solution for legacy designs relying on its integrated POR and compact footprint.