Texas Instruments LM5185EVM-SIO

Overview

LM5185EVM-SIO from Texas Instruments is a single-isolated-output evaluation module designed to demonstrate the LM5185-Q1 100-VIN primary-side-regulated (PSR) flyback DC/DC controller. It delivers 16.4 V ±1.5% at up to 1.8 A across 20–60 V input, achieves >90% peak efficiency, supports optocoupler-free regulation, and provides 1500-V RMS isolation for traction inverter, OBC, and BMS bias rail development.

For engineers reviewing the LM5185EVM-SIO datasheet, LM5185EVM-SIO test setup, LM5185EVM-SIO hardware design files, or LM5185EVM-SIO safety guidelines, this page consolidates verified EVM specifications, bench test procedures, PCB layout references, thermal performance data, and TI's official compliance documentation - all aligned with SNVU869 (August 2023) user's guide.

Technical Context

The LM5185EVM-SIO implements a PSR flyback topology using the LM5185-Q1 controller to sample primary winding voltage for precise output regulation without optocouplers or auxiliary windings. It operates at 350 kHz switching frequency (VIN = 48 V, IOUT = 0.5 A) and supports programmable UVLO (19 V turn-on / 18 V turn-off), soft-start (25 ms), and loop compensation via external RC networks.

Hardware includes a 12 µH EFD15 flyback transformer (ZD2250-AE), NVMFS021N10MCLT1G 100-V MOSFET, 16.4-V isolated output referenced to ISO-GND, and dual ground domains (PGND and AGND) with galvanic separation validated at 1500-V RMS. Input range is factory-set to 20–60 V but extendable to 6–90 V with component modifications.

Key Specifications

Availability

LM5185EVM-SIO is available at Aetrix Electronics and suitable for traction inverter gate driver biasing, onboard charger auxiliary power supply, and HEV/EV HVAC control system prototyping requiring stable component supply, traceable sourcing, and automotive-grade reference design validation.

Supply support for LM5185EVM-SIO 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

Texas Instruments is a global semiconductor company specializing in analog, embedded processing, and power management ICs, with leadership in automotive-grade power controllers and evaluation platforms.

The LM5185EVM-SIO belongs to TI's automotive-qualified PSR flyback evaluation module family, engineered to accelerate development of isolated bias supplies for high-voltage EV subsystems including inverters, chargers, and battery management systems.

FAQ

What is the primary function of the LM5185EVM-SIO?

The LM5185EVM-SIO is an evaluation module that demonstrates the LM5185-Q1 primary-side-regulated flyback controller in a complete, tested hardware implementation. It enables engineers to validate isolated 16.4-V output generation, measure efficiency and regulation across 20–60 V input, assess thermal performance under load, and verify safety-critical isolation (1500 V RMS) - all without optocouplers or auxiliary windings. The LM5185EVM-SIO serves strictly as a lab development tool, not a production-ready power supply.

Can the LM5185EVM-SIO operate outside its default 20–60 V input range?

Yes - the LM5185EVM-SIO can be modified to operate from 6 V to 90 V input. To achieve 6–20 V operation, the EN/UVLO resistor divider must be adjusted to lower the turn-on threshold, and the transformer may require replacement for proper core saturation margin. For 60–90 V operation, the power MOSFET must be upgraded to ≥150 V rating (e.g., NVMFS021N10MCLT1G is rated 100 V, so substitution is required), and the input bulk capacitor must be replaced with a ≥100 V-rated part. These changes are documented in TI's SNVU869 user's guide.

What safety precautions apply when using the LM5185EVM-SIO?

The LM5185EVM-SIO is classified as a TI HV EVM and poses real electrical hazards: certain nodes exceed 75 V during operation, and hot spots develop on the PCB under full load. Users must de-energize before probing, use isolated test equipment with overvoltage protection, wear insulated gloves and safety glasses, work within an Emergency Power Off (EPO)-protected environment, and never touch the board while powered. TI mandates qualified professional handling only - it is prohibited for consumer, educational, or production use per TI's Standard Terms for Evaluation Modules.

Does the LM5185EVM-SIO include design files for custom implementation?

Yes - the LM5185EVM-SIO package includes fully documented hardware design resources: a complete schematic (Figure 4-1), six-layer PCB layout views (top/mid/bottom layers), and a detailed bill of materials (Table 4-1) listing all 42 components with manufacturer part numbers (e.g., ZD2250-AE transformer, NVMFS021N10MCLT1G MOSFET, GRM32ER71E226KE15L output capacitors). These files are provided in TI's SNVU869 user's guide and support derivative designs compliant with automotive AEC-Q200 component requirements.

How is output voltage regulated on the LM5185EVM-SIO without an optocoupler?

The LM5185EVM-SIO achieves tight output regulation (16.4 V ±1.5%) using primary-side sensing: the LM5185-Q1 controller samples reflected voltage across the primary winding during demagnetization to infer secondary output voltage. This eliminates the need for optocouplers and tertiary bias windings, reducing solution size, cost, and component count. Regulation accuracy depends on transformer turns ratio consistency, snubber network stability, and FB pin resistor tolerance - all validated in the LM5185EVM-SIO's factory configuration per Table 1-2 of SNVU869.