Renesas ISL78234EVAL2Z

Overview

ISL78234EVAL2Z from Intersil is an evaluation board designed to demonstrate the ISL78234 4A synchronous buck regulator in automotive point-of-load applications. It supports 2.7V–5.5V input, delivers 1.8V default output (adjustable 0.8V–3.3V), operates at 2MHz default switching frequency, and includes hardware for EN/SYNC control, PFM/PWM mode selection, and test points for phase node and output monitoring.

For engineers reviewing the ISL78234EVAL2Z datasheet, ISL78234EVAL2Z pinout, ISL78234EVAL2Z application, or ISL78234EVAL2Z equivalent, this board enables rapid validation of ISL78234 performance under real automotive load transients, efficiency vs. load, thermal behavior, and loop stability with internal/external compensation - all within a production-grade 4-layer FR-4 PCB layout.

Technical Context

The ISL78234EVAL2Z implements a complete reference design for the ISL78234 4A buck regulator, featuring a 0.68µH Vishay IHLP inductor rated for 13.5A saturation current, four 47µF Taiyo Yuden ceramic output capacitors, and dual 22µF Murata input capacitors. It uses internal compensation by default (COMP tied to VDD) but supports external RC network configuration via C6/R5 for transient-optimized loop response.

Board-level controls include SW1 for IC enable/disable and SW2 for PFM (light-load skip mode) or forced PWM operation. Test points (J1–J2) provide direct access to PHASE and VOUT nodes, while the 2.025" × 2.725" footprint complies with AEC-Q200 passive component requirements and integrates a thermal pad-connected copper pour for thermal management.

Key Specifications

Availability

ISL78234EVAL2Z is available at Aetrix Electronics and suitable for automotive ADAS domain controllers, infotainment power rails, and body electronics requiring stable component supply during pre-production validation and design-in phases.

Supply support for ISL78234EVAL2Z 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 semiconductor company specializing in high-performance analog and power management ICs for automotive, industrial, and aerospace applications.

The ISL78234EVAL2Z belongs to Intersil's ISL7823x evaluation platform family, engineered specifically to accelerate qualification of low-I_Q, AEC-Q100-compliant buck regulators in demanding automotive point-of-load systems.

FAQ

What is the primary function of the ISL78234EVAL2Z?

The ISL78234EVAL2Z is an evaluation board used to characterize and validate the ISL78234 4A synchronous buck regulator. It provides a fully assembled, tested PCB with input/output filtering, thermal management, and user-accessible control signals - enabling engineers to measure efficiency, transient response, thermal performance, and loop stability without designing a custom board. The ISL78234EVAL2Z itself is not a power component but a development tool for the ISL78234 IC.

Does the ISL78234EVAL2Z support adjustable output voltage?

Yes, the ISL78234EVAL2Z supports output voltage adjustment from 0.8V to 3.3V using the feedback resistor divider (R2/R3). By default, R2 = 200kΩ and R3 = 100kΩ set VOUT = 1.8V per the ISL78234's 0.6V reference. Changing R2 per Equation 1 in UG062 allows precise tuning - for example, R2 = 66kΩ yields 1.0V, while R2 = 450kΩ yields 3.3V. The ISL78234EVAL2Z includes pads and documentation to support this reconfiguration.

Can the ISL78234EVAL2Z operate in both PFM and PWM modes?

Yes, the ISL78234EVAL2Z supports both PFM (pulse-frequency modulation) and forced PWM operation via SW2. In PFM mode (SW2 left), the ISL78234 enters skip-cycle mode at light loads to improve light-load efficiency. In forced PWM mode (SW2 right), it maintains constant 2MHz (or programmed) frequency regardless of load - critical for EMI-sensitive automotive systems. This dual-mode capability is implemented directly on the ISL78234EVAL2Z board and verified in UG062 Table 1 and Figures 15–16.

What are the key layout features of the ISL78234EVAL2Z PCB?

The ISL78234EVAL2Z uses a 4-layer FR-4 PCB with 2oz copper, optimized for minimal power loop area between PHASE, PGND, VIN, and CIN/COUT. Key features include a solid thermal pad connection with thermal vias per TB389, wide low-inductance traces for high di/dt paths, separation of noisy PHASE routing from sensitive FB traces, and dedicated test points (J1/J2) for oscilloscope probing. These layout practices ensure accurate measurement of switching waveforms and thermal performance - as confirmed in UG062 Figures 5–10 and Section "PCB Layout Recommendation".

Is the ISL78234EVAL2Z compatible with other ISL7823x evaluation boards?

Yes - the ISL78234EVAL2Z shares identical mechanical dimensions, layer stackup, component placement, and schematic topology with the ISL78233EVAL2Z and ISL78235EVAL2Z, differing only in the installed regulator (U1 = ISL78234AARZ) and minor resistor values for current rating. UG062 explicitly states "ISL78233EVAL2Z and ISL78234EVAL2Z schematics are equivalent" and confirms shared layout, test points, and control functions. This common platform simplifies comparative evaluation across the 3A/4A/5A ISL7823x family.