Silicon Labs SI7005EVB-UDP

Overview

SI7005EVB-UDP from Silicon Laboratories is an evaluation board for the Si7005 digital I²C humidity and temperature sensor IC. It provides a ready-to-use platform to validate sensor performance, interface timing, calibration accuracy (±4.5% RH, ±1°C), and integrated heater functionality across –40 to +85°C. Designed for rapid prototyping in HVAC/R, thermostats, and asset tracking systems, it supports direct connection to microcontrollers via standard I²C pull-up resistors and includes CEXT capacitor footprint for stability tuning.

For engineers reviewing the SI7005EVB-UDP datasheet, SI7005EVB-UDP pinout, SI7005EVB-UDP application, or SI7005EVB-UDP equivalent, this board enables immediate validation of Si7005 sensor integration-including factory-calibrated RH/temperature output, wake-up time (10–15 ms), conversion timing (18–40 ms), and low-power operation (1 µA avg. per minute) - without custom PCB design or firmware development.

Technical Context

The SI7005EVB-UDP implements the full signal chain of the Si7005 IC: 24-pin QFN package with exposed thermal pad, dedicated SDA/SCL lines routed to 0603 pull-up resistors (10 kΩ), CS-controlled power-down mode, and CEXT terminal for external capacitance (4.7 µF) to stabilize internal oscillator timing. It replicates the reference circuit from Silicon Labs' datasheet Figure 4, including decoupling (0.1 µF + 4.7 µF) and GND plane layout optimized for minimal noise coupling into the capacitive humidity sensing element.

Board-level design enforces best practices for sensor reliability: Kapton® tape-compatible footprint for reflow protection, hydrophobic cover option support (IP67-rated PTFE), and thermal isolation of the sensor die from PCB copper mass-ensuring accurate dew-point calculation and long-term drift <0.25%RH/yr under controlled conditions.

Key Specifications

Availability

SI7005EVB-UDP is available at Aetrix Electronics and suitable for HVAC/R system validation, thermostat/humidistat development, and industrial environmental monitoring requiring stable component supply and rapid sensor characterization.

Supply support for SI7005EVB-UDP 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

Silicon Laboratories is a fabless semiconductor company specializing in mixed-signal ICs for sensing, timing, and connectivity applications, with core expertise in low-power sensor interfaces and precision analog front-ends.

The SI7005EVB-UDP belongs to Silicon Labs' environmental sensor evaluation platform family, engineered to accelerate time-to-test for digital humidity/temperature sensing in demanding industrial and consumer environments where calibration integrity and long-term stability are critical.

FAQ

What is the primary function of the SI7005EVB-UDP evaluation board?

The SI7005EVB-UDP is a dedicated evaluation platform for the Si7005 digital I²C humidity and temperature sensor IC. It provides a fully assembled, tested PCB that implements the manufacturer-recommended reference circuit-including I²C pull-up resistors, decoupling capacitors (0.1 µF and 4.7 µF), CEXT terminal, and proper thermal pad grounding-to enable immediate functional validation, accuracy testing, and firmware integration of the Si7005 without custom hardware design. The board directly supports all documented Si7005 operating modes and register access sequences.

Does the SI7005EVB-UDP include the Si7005 IC pre-mounted?

Yes, the SI7005EVB-UDP comes with the Si7005 IC pre-soldered in its 24-pin QFN package (4×4 mm) and includes the optional factory-installed hydrophobic/oleophobic PTFE protective cover (IP67 rated). The board is shipped fully assembled and ready for connection to a host microcontroller via standard 0.1" headers for VDD, GND, SDA, SCL, and CS signals-no additional component placement or soldering is required to begin evaluation of the SI7005EVB-UDP.

Can the SI7005EVB-UDP be used to verify the Si7005's integrated heater functionality?

Yes, the SI7005EVB-UDP supports full verification of the Si7005's on-chip heater through dedicated trace routing and test points. When the heater is enabled via the Si7005's control register (HEAT = 1), the SI7005EVB-UDP delivers 24–31 mA current draw at 3.3 V, enabling validation of self-diagnostics, condensation prevention, and recovery from high-humidity exposure per Silicon Labs' Bake/Hydrate Procedure. The board's layout isolates heater thermal effects from the sensor die to preserve measurement fidelity during active heating cycles.

What I²C addressing and timing parameters does the SI7005EVB-UDP support?

The SI7005EVB-UDP supports the Si7005's fixed 7-bit I²C slave address of 0x40 and validates timing compliance up to 400 kHz clock frequency, including tSKH (0.6 µs min), tSKL (1.3 µs min), and tVD;ACK (0.9 µs max). Onboard 10 kΩ pull-up resistors on SDA and SCL ensure robust bus signaling across standard microcontroller I/O drivers, and the board reproduces the exact timing margins specified in Table 3 of the Si7005 datasheet Rev. 1.5 for reliable communication during RH and temperature conversions.

How does the SI7005EVB-UDP assist with long-term stability and calibration validation?

The SI7005EVB-UDP enables direct validation of the Si7005's factory calibration and long-term stability claims (≤0.25%RH/yr, <0.05°C/yr) by providing a thermally stable, contamination-controlled platform with documented PCB layout, decoupling, and grounding. Its JEDEC 4-layer reference design minimizes thermal gradients and EMI, allowing users to measure baseline accuracy, hysteresis (±1%RH), repeatability (0.05%RH RMS), and response time (18 s @ 1 m/s airflow) under controlled lab conditions-critical for certifying the SI7005EVB-UDP in applications like medical respiratory therapy or data center micro-environment monitoring.