STMicroelectronics STEVAL-ISB037V1

Overview

STEVAL-ISB037V1 from STMicroelectronics is an evaluation board for the LD39020 200 mA, 1.8 V ±0.5% low-dropout linear regulator with 80 dB PSRR at 1 kHz, 20 μA quiescent current at no load, and DFN4 (1 mm × 1 mm) package. It supports input voltage range 2.4 V–5.5 V and requires only two 1 µF ceramic capacitors for operation in battery-powered portable electronics.

For engineers reviewing the STEVAL-ISB037V1 datasheet, STEVAL-ISB037V1 schematic, STEVAL-ISB037V1 application circuit, or STEVAL-ISB037V1 compatible LDO regulators, this board enables rapid validation of the LD39020's low-noise, high-PSRR 1.8 V supply performance in space-constrained, ultra-low-power designs such as wearables and mobile SoC core rails.

Technical Context

The board implements the LD39020ADTPU18R configured for fixed 1.8 V output, with input filtering via C1 (1 µF), output regulation and stability via C2 (1 µF), and logic-controlled shutdown via the EN pin. The layout follows ST's recommended footprint and thermal pad grounding for the DFN4-1x1 package.

All signal paths - including Vin_f/Vin_s, Vout_f/Vout_s, and enable routing - are routed to test points and a GSPG1407161120SG header (CN1) for external monitoring and control. No on-board voltage adjustment or feedback resistor network is present; output is factory-trimmed and non-adjustable.

Key Specifications

Availability

STEVAL-ISB037V1 is available at Aetrix Electronics and suitable for wearable device prototyping, smartphone power rail validation, and IoT sensor node LDO qualification requiring stable component supply and documented reference design implementation.

Supply support for STEVAL-ISB037V1 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

STMicroelectronics is a global semiconductor leader delivering intelligent power, analog, MEMS, and microcontroller solutions for automotive, industrial, and consumer applications.

This evaluation board belongs to ST's STEVAL series of application-ready reference designs, developed specifically to accelerate adoption of their high-PSRR, ultra-low-I_Q LDOs in battery-sensitive portable electronics.

FAQ

What input voltage range does the STEVAL-ISB037V1 support?

The board accepts 2.4 V to 5.5 V DC input, matching the operating range of the LD39020 regulator. This covers common single-cell lithium-based batteries (2.7–4.2 V), regulated 3.3 V system rails, and USB-powered 5 V inputs - all while maintaining stable 1.8 V output without dropout.

Can the output voltage be adjusted on this board?

No. STEVAL-ISB037V1 implements the LD39020ADTPU18R variant, which has a factory-trimmed fixed 1.8 V output. There is no feedback resistor network or solder jumper for adjustment; output voltage accuracy is ±0.5% over temperature and line/load conditions per the device datasheet.

Does the board include enable/shutdown functionality?

Yes. The EN pin of the LD39020 is routed to header CN1 (pin 7), allowing external logic-level control (0 V = shutdown, >1.2 V = active). In shutdown mode, quiescent current drops to 0.03 μA typical, enabling zero-power standby in battery-critical applications.

What capacitor types and values are used on the board?

The board uses two 1 µF X5R or X7R ceramic capacitors: C1 at the input (Vin_f to GND) and C2 at the output (Vout_f to GND). These meet the LD39020's stability requirements and are placed per ST's layout guidelines for minimal ESR and ESL in the DFN4 footprint.