Renesas ISL85415DEMO1Z

Overview

The ISL85415DEMO1Z from Renesas Electronics is an evaluation kit designed to demonstrate the ISL85415 wide-input synchronous buck regulator, delivering a preset 3.3V output at up to 500mA from 3V–36V input. It features integrated NMOS FETs, selectable PFM/PWM operation, and supports adjustable switching frequency (300kHz–2MHz) via external resistor on the FS pin. The board enables rapid validation of point-of-load power delivery in industrial and embedded systems.

For engineers reviewing the ISL85415DEMO1Z datasheet, ISL85415DEMO1Z pinout, ISL85415DEMO1Z application, or ISL85415DEMO1Z equivalent, this kit provides hands-on verification of voltage regulation stability, light-load efficiency modes, load transient response, and synchronization capability - all critical for designing robust DC/DC converters in space-constrained, wide-VIN applications.

Technical Context

The ISL85415DEMO1Z implements the ISL85415 IC in a fixed 3.3V configuration using a 90.9kΩ feedback resistor (R1) and 20kΩ programming resistor (R2), per Equation 1. Its default 500kHz switching frequency is set by tying the FS pin to VCC via R10 (0Ω), but can be reconfigured to 300kHz–2MHz using R12 values from 340kΩ to 32.4kΩ.

EN is hardwired to VCC via R7 for continuous operation; disabling requires removing R7 and populating R8. SYNC is biased to VCC via R6 (200kΩ) for forced PWM mode; grounding SYNC selects PFM. Soft-start and compensation are internally configured by default (R15 = 0, R11 = 0), with external options available via jumper pads.

Key Specifications

Availability

ISL85415DEMO1Z is available at Aetrix Electronics and suitable for point-of-load power design, wide-VIN industrial converter validation, and embedded system DC/DC prototyping requiring stable component supply and fast time-to-test.

Supply support for ISL85415DEMO1Z 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

Renesas Electronics is a global semiconductor leader delivering microcontrollers, analog, power, and SoC solutions for automotive, industrial, infrastructure, and IoT applications.

The ISL85415DEMO1Z belongs to Renesas' broad portfolio of evaluation kits for its ISL854xx family of wide-VIN synchronous buck regulators - engineered specifically to simplify design-in of high-efficiency, low-quiescent-current DC/DC conversion in harsh or variable-input environments.

FAQ

What is the primary function of the ISL85415DEMO1Z?

The ISL85415DEMO1Z is an evaluation kit that demonstrates the performance of the ISL85415 synchronous buck regulator. It delivers a preset 3.3V output at up to 500mA from a 3V–36V input, enabling engineers to validate efficiency, transient response, PFM/PWM mode behavior, and synchronization capability before integrating the ISL85415 into their final design. The ISL85415DEMO1Z includes all necessary passive components and test points for immediate bench testing.

Can the output voltage of the ISL85415DEMO1Z be changed from 3.3V?

Yes, the ISL85415DEMO1Z output voltage is adjustable from 0.6V to 15V by modifying the feedback resistor divider (R1 and R2), as defined in Equation 1 in the AN1860 user's manual. For example, Table 1 lists R1 = 90.9kΩ and R2 = 28.7kΩ for 2.5V output. When setting VOUT below 1.8V, the switching frequency and compensation must be adjusted to 300kHz due to minimum on-time limitations - a requirement explicitly documented for the ISL85415DEMO1Z.

How is the switching frequency configured on the ISL85415DEMO1Z?

The ISL85415DEMO1Z defaults to 500kHz by tying the FS pin to VCC via R10 (0Ω). To change frequency, R10 is removed and R12 is populated: 340kΩ sets 300kHz, 120kΩ yields ~800kHz, and 32.4kΩ achieves 2MHz. The FS pin must never be left floating, and resistor values must be selected per the ISL85415 datasheet calculations - a constraint directly specified for the ISL85415DEMO1Z in AN1860 Rev 2.00.

Does the ISL85415DEMO1Z support external synchronization?

Yes, the ISL85415DEMO1Z includes a SYNC pin accessible via test point P7. By default, R6 (200kΩ) pulls SYNC to VCC for forced PWM operation at the selected switching frequency. To enable external clock synchronization, R6 is removed and the external signal is applied to P7. This capability is confirmed in the "SYNC Control" section of AN1860 and verified in Figures 25–30 showing synchronized waveforms.

What test equipment is recommended for evaluating the ISL85415DEMO1Z?

AN1860 specifies a 0–50V/2A power supply, electronic loads capable of sinking up to 1.5A, 100MHz quad-trace oscilloscope, digital multimeters, and a signal generator. These requirements are based on the ISL85415DEMO1Z's 36V max input, 500mA output, and need to capture switching waveforms (e.g., LX, PG, EN) and load transients - all validated in the efficiency curves (Figures 5–10) and transient response plots (Figures 25–26) of the official user's manual.