Texas Instruments LMR36503RFEVM

Overview

LMR36503RFEVM from Texas Instruments is an evaluation module designed to validate the LMR36503 65-V input, 0.3-A synchronous buck converter in real-world power supply designs. It supports selectable output voltages of 3.3 V or 5 V, operates at a fixed 1 MHz switching frequency, and features configurable EN, PGOOD, SYNC/RT, and MODE jumpers for functional testing under varied load and control conditions.

For engineers reviewing the LMR36503RFEVM datasheet, LMR36503RFEVM board layout, LMR36503RFEVM schematic, or LMR36503RFEVM BOM, this EVM enables rapid validation of input voltage range (5.5–65 V), light-load efficiency modes (PFM/FPWM), output regulation stability, and EMI filter performance using its dedicated VIN_EMI, VOUT, SW, and PGOOD test points.

Technical Context

The LMR36503RFEVM implements the LMR36503RFRPET (VQFN-9) IC in a fully assembled, tested PCB layout with optimized power stage components including a 47 µH shielded inductor (MSS6132-473MLB), bulk and ceramic input/output capacitors, and integrated EMI filtering on the VIN_EMI path. It supports both fixed-frequency FPWM and variable-frequency PFM operation via jumper-selectable configuration.

Board-level features include accessible test points for all critical nodes (VIN, VOUT, SW, EN, PGOOD, SYNC/RT, VCC), dual-output voltage selection (3.3 V/5 V) via JVOUT jumper, and configurable startup behavior through JEN and JPGOOD jumpers - enabling direct measurement of transient response, efficiency curves, and fault signaling without external circuitry.

Key Specifications

Availability

LMR36503RFEVM is available at Aetrix Electronics and suitable for power supply validation, DC/DC converter reference design verification, and buck regulator qualification requiring stable component supply and TI-validated hardware.

Supply support for LMR36503RFEVM 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 technologies, with decades of leadership in high-reliability power conversion solutions.

The LMR36503RFEVM belongs to TI's LMR36503 evaluation platform family, engineered specifically to accelerate development of ultra-small, wide-input buck converters for space-constrained industrial, automotive, and IoT applications demanding low quiescent current and robust input voltage tolerance.

FAQ

What is the primary purpose of the LMR36503RFEVM?

The LMR36503RFEVM is an evaluation module built to characterize and validate the LMR36503 65-V, 0.3-A synchronous buck converter. It provides immediate access to key signals-including VIN_EMI, VOUT, SW, EN, and PGOOD-enabling engineers to measure efficiency, transient response, EMI performance, and startup behavior without custom PCB design. The LMR36503RFEVM simplifies prototyping for applications requiring regulated 3.3 V or 5 V outputs from harsh input sources.

How do I configure the LMR36503RFEVM for 5 V output?

To configure the LMR36503RFEVM for 5 V output, install a jumper on JVOUT (pins 1–2). This changes the feedback resistor divider network (R7/R10) to set the output voltage to 5 V instead of the default 3.3 V (open JVOUT). Confirm the setting using the VOUT test point (TP1/TP5) with a multimeter or oscilloscope while powering VIN_EMI between 5.5 V and 65 V. The LMR36503RFEVM schematic confirms this configuration is implemented via discrete resistors R7 (43.2 kΩ) and R10 (59.0 kΩ).

Can the LMR36503RFEVM operate in forced PWM (FPWM) mode?

Yes, the LMR36503RFEVM supports FPWM mode via the JMODE/RT jumper. Install the jumper between pins 2 and 3 of J2 (JMODE/RT) to force constant-frequency operation at 1 MHz (RT-trim configuration). This disables pulse-frequency modulation and ensures consistent switching regardless of load, improving EMI predictability and reducing output voltage ripple during light-load conditions. The LMR36503RFEVM User's Guide explicitly defines this configuration for stable timing-critical applications.

What input voltage range is validated on the LMR36503RFEVM?

The LMR36503RFEVM is validated for input voltages from 5.5 V to 65 V DC, matching the absolute maximum rating of the LMR36503RFRPET IC. The board includes an integrated EMI filter at VIN_EMI and uses 100-V-rated input capacitors (C1, C2, C6, C11, C12) and a 100-V-rated bulk capacitor (C8), ensuring safe operation across the full specified range. Input voltage must be applied between VIN_EMI and GND test points, with current limiting set appropriately for the 0.3-A load limit.

Does the LMR36503RFEVM include EMI filtering?

Yes, the LMR36503RFEVM incorporates a dedicated EMI filter at the VIN_EMI input node, consisting of ferrite bead L2 (FBMH3225HM601NT) and ceramic capacitors C1, C2, C9, and C11/C12. This filter is designed to suppress conducted emissions per CISPR 25 Class 5 requirements and allows direct connection to noisy automotive or industrial supplies. Measurements should be taken at VIN_EMI for conducted EMI compliance testing, as specified in the LMR36503RFEVM User's Guide.