Texas Instruments LM2853MHX-1.5

Overview

LM2853MHX-1.5 from Texas Instruments is a 3A, 550 kHz synchronous buck regulator in an exposed-pad HTSSOP-14 package, delivering a factory-programmed 1.5V output from 3.0–5.5V input. It integrates internal 40 mΩ high-side and 32 mΩ low-side MOSFETs, type-three compensation, and soft-start control-enabling compact point-of-load regulation for FPGA core supplies.

For engineers reviewing the LM2853MHX-1.5 datasheet, LM2853MHX-1.5 pinout, LM2853MHX-1.5 application, or LM2853MHX-1.5 equivalent, key selection criteria include its fixed 1.5V output, 12 µA shutdown current, thermal shutdown at 165°C, and compatibility with standard 4.7–6.8 µH inductors and 120–220 µF output capacitors per TI's recommended design ranges.

Technical Context

The LM2853MHX-1.5 employs voltage-mode PWM control with internal type-three compensation, eliminating external compensation components. Its dual-rail architecture separates AVIN (3.0–5.5V control supply) from PVIN (1.5–5.5V power input), supporting flexible system-level power sequencing.

Switching occurs at a nominal 550 kHz (325–725 kHz over temperature), enabling small magnetics while maintaining >85% efficiency at 3A load (V_IN = 5V, V_OUT = 1.5V). Protection includes cycle-by-cycle current limiting (3.6–5 A threshold), thermal shutdown with 10°C hysteresis, and UVLO on AVIN (2.47–3.0 V with hysteresis).

Key Specifications

Pinout & Package

Package: HTSSOP-14 with exposed thermal pad (TI package drawing PWP, JEDEC MO-153 variant MXA14A). The exposed pad is internally connected to GND and must be soldered to a PCB ground plane for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck regulator applications.

Compared with TPS54318RTER and MP2315GJ-Z, the LM2853MHX-1.5 offers guaranteed 1.5V accuracy without external resistors, split-rail flexibility for sequencing-critical systems, and proven stability with minimal external components-making it optimal for cost-sensitive, thermally constrained 5V-input FPGA/DSP applications.

Availability

LM2853MHX-1.5 is available at Aetrix Electronics and suitable for FPGA core power, DSP local regulation, and broadband networking infrastructure requiring stable component supply and long-term industrial lifecycle support.

Supply support for LM2853MHX-1.5 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 leader specializing in analog, embedded processing, and power management technologies, with decades of expertise in high-reliability power conversion ICs.

The LM2853MHX-1.5 belongs to TI's SIMPLE SWITCHER® synchronous buck regulator family, engineered for ease-of-use in space- and cost-constrained point-of-load applications where minimal external components and predictable thermal behavior are critical.

FAQ

What is the output voltage tolerance of the LM2853MHX-1.5 across temperature and line conditions?

The LM2853MHX-1.5 delivers a factory-programmed 1.5V output with guaranteed tolerance of ±1.13% (1.4663 V to 1.5337 V) over the full operating junction temperature range (−40°C to +125°C) and input voltage range (3.0 V to 5.5 V AVIN). This specification is validated per TI's Electrical Characteristics table and applies under closed-loop, non-switching measurement conditions at the SNS pin.

Can the LM2853MHX-1.5 operate with different voltages on AVIN and PVIN, and what are the constraints?

Yes, the LM2853MHX-1.5 supports split-rail operation: AVIN powers the control circuitry (3.0–5.5 V), while PVIN supplies the power switches (1.5–5.5 V). PVIN must always be ≤ AVIN, and for PVIN < 3.3 V, TI recommends using output filter component values specified for the 3.3 V output variant to ensure stability. This architecture enables independent sequencing and improves transient immunity in multi-rail systems.

What is the recommended soft-start capacitor value for the LM2853MHX-1.5, and why is it limited to 1–50 nF?

TI recommends a 2.2 nF ceramic capacitor for ~3 ms startup time, calculated using the internal 450 kΩ SS pullup resistor and RC time constant. The 1–50 nF range is strictly enforced because outside this window, fault recovery behavior degrades: during short-circuit events, the soft-start voltage must track the output to enable graceful restart, and out-of-range capacitance disrupts this synchronization and may cause latch-up or uncontrolled re-start.

Does the LM2853MHX-1.5 require external compensation components, and how does its type-three compensation simplify design?

No, the LM2853MHX-1.5 integrates a complete type-three compensation network, eliminating all external compensation components. This on-chip solution ensures stable loop response when used with TI-recommended inductor (4.7–6.8 µH) and output capacitor (120–220 µF, 50–150 mΩ ESR) ranges. Designers only need to select passive components per Table 1 in the datasheet-no loop analysis or compensation tuning is required.

How should the exposed thermal pad of the LM2853MHX-1.5 be connected on the PCB for optimal thermal and electrical performance?

The exposed pad (EP) of the LM2853MHX-1.5 is internally connected to GND but must not serve as the primary ground return path. It must be fully soldered to a dedicated PCB ground plane using ≥6 thermal vias (0.3 mm diameter, spaced ≤1 mm apart) to achieve the rated θ_JA = 38°C/W. Lab data confirms that incomplete pad soldering degrades both thermal resistance and load regulation accuracy due to increased ground impedance.