The TPSM265R1SILR is a fully integrated step-down power module from Texas Instruments that accepts an input voltage range of 3 V to 65 V and delivers up to 100 mA of output current in a 2.8 mm × 3.7 mm × 1.9 mm MicroSiP package. The module integrates the controller, power MOSFETs, and output inductor into a single device, eliminating the most challenging aspects of high-voltage buck converter design—inductor selection, loop compensation, and layout optimization—while providing the efficiency and thermal performance required for industrial and process control applications.

Wide Input Voltage Range with High Voltage Tolerance

The 3-V to 65-V input range of the TPSM265R1SILR accommodates a broad spectrum of power sources, from single-cell lithium batteries and 5-V logic rails to 12-V, 24-V, and 48-V industrial buses. The 65-V maximum input rating provides substantial margin above standard industrial bus voltages, protecting against the voltage transients and surges that are common in factory automation, process control, and automotive environments. This wide range also simplifies design reuse across platforms operating from different supply architectures.

Fully Integrated Power Stage

The module's MicroSiP construction incorporates a controller, high-side and low-side MOSFETs, and a shielded output inductor within a single package. This integration eliminates the need for external inductor selection, reduces parasitic elements that degrade efficiency and EMI performance, and simplifies PCB layout by removing the sensitive switch-node routing that complicates discrete designs. The shielded inductor construction also minimizes radiated magnetic fields, contributing to the module's CISPR11 (EN55011) EMI compliance.

Ultra-Low Quiescent Current

The TPSM265R1SILR achieves a typical quiescent current of 10.5 µA, making it exceptionally well-suited to always-on and battery-powered applications where standby power consumption directly affects system runtime or energy cost. In shutdown mode, with the enable pin held below approximately 0.6 V, the quiescent current drops further to 4.6 µA at a 12-V input. The module operates in pulse frequency modulation (PFM) mode to maintain high efficiency at light loads, transitioning seamlessly to continuous conduction at heavier loads without external mode selection.

Precision Enable, UVLO, and Hysteresis

The enable pin provides precision ON/OFF control with adjustable undervoltage lockout and hysteresis, allowing designers to define exact power-up and power-down thresholds for the input supply. This feature is valuable in systems where the power module must remain off until the input bus has stabilized, or where sequencing with other rails is required. The hysteresis prevents oscillation at the UVLO threshold under slowly rising or noisy input conditions.

Control Scheme and Transient Response

The TPSM265R1SILR employs a hysteretic control architecture that requires no loop compensation, eliminating one of the most time-consuming and error-prone aspects of switching regulator design. The device behaves as a hysteretic voltage regulator operating within upper and lower feedback regulation thresholds with typically 10 mV of hysteresis. This control method provides excellent line and load transient response while maintaining stable operation across the full input and output voltage range. The module supports monotonic startup into pre-biased outputs, a requirement in systems where multiple rails power up in sequence and the output capacitor may retain charge from a previous cycle.

Protection and Monitoring Features

Comprehensive protection features include cycle-by-cycle current limiting of the peak inductor current, which limits output current during overload or short-circuit conditions. Thermal shutdown disables the device when the junction temperature exceeds 170°C and restarts automatically when the temperature falls to 160°C, providing self-protection without permanent latch-off. An open-drain power-good (PGOOD) output enables sequencing and monitoring of the output voltage, supporting system-level power management architectures.

Soft-Start Configuration

Three soft-start options are available: minimum delay (no soft start), an internal fixed 900-µs ramp, and externally programmable soft start using a capacitor connected to the appropriate pin. The selectable soft-start enables designers to limit inrush current during startup, particularly important when the output capacitance is large or when the input supply has limited current capability.

Industrial Field Transmitters and Process Sensors

The TPSM265R1SILR is particularly well-matched to field transmitters and process sensor interfaces operating from 12-V or 24-V industrial loops. The wide input range tolerates the voltage variations and transients present on industrial power buses, while the ultra-low quiescent current minimizes the current drawn from the loop supply. The small footprint allows the power supply to be placed close to the sensor signal chain, reducing noise coupling and distribution losses.

PLC, DCS, and PAC Systems

Programmable logic controllers (PLCs), distributed control systems (DCS), and programmable automation controllers (PACs) commonly employ distributed power architectures in which point-of-load regulators must be compact and efficient. The TPSM265R1SILR's integrated inductor and minimal external component count make it ideal for these space-constrained, high-reliability environments.

Negative Output and Inverting Buck-Boost Applications

The TPSM265R1SILR can be configured in an inverting buck-boost topology to generate a negative output voltage with respect to the input, enabling bipolar supply generation from a single positive rail. This capability is useful in analog signal chains requiring negative bias voltages, such as operational amplifier supplies and sensor excitation circuits.

High-Voltage Battery and Energy Storage Systems

Battery management systems and energy storage converters often operate from high-voltage battery stacks where a simple, robust auxiliary supply is needed for control and monitoring circuitry. The 65-V input rating and wide operating temperature range make the TPSM265R1SILR suitable for these applications, where reliability and long-term stability are paramount.

The TPSM265R1EVM evaluation module provides a fully assembled and tested platform for characterizing the module's performance. The EVM is configured to evaluate operation at up to 100 mA with an input voltage range of 3 V to 65 V and an output voltage range of 1.223 V to 15 V. Test points provide access to critical signals for efficiency, transient response, and thermal measurements. WEBENCH Power Designer supports the TPSM265R1, allowing engineers to generate complete custom regulator designs with optimized external components.

When comparing the TPSM265R1SILR to alternative solutions, the primary trade-offs are output current capability versus integration and voltage range. For applications requiring more than 100 mA, the broader TPSM series offers higher-current modules with similar integration benefits. For designs where the 65-V input range is not required, lower-voltage modules may offer higher efficiency or smaller size. The TPSM265R1SILR's distinctive value lies in its combination of high voltage tolerance, integrated inductor, and ultra-low quiescent current within a footprint smaller than most discrete solutions.

The TPSM265R1SILR demonstrates that high-voltage power conversion need not compromise on simplicity or efficiency. By integrating the controller, MOSFETs, and inductor into a 2.8 mm × 3.7 mm package, Texas Instruments has created a module that reduces design risk, shortens development cycles, and enables compact power solutions for the most demanding industrial environments. Its 65-V input rating, 10.5-µA quiescent current, and comprehensive protection features address the reliability and efficiency requirements of field transmitters, PLC systems, and high-voltage battery applications. For engineers seeking a proven, well-supported path to a simple, robust auxiliary power supply, the TPSM265R1SILR provides an exceptional balance of integration, performance, and design simplicity.