Texas Instruments LM20123MHE/NOPB

Overview

LM20123MHE/NOPB from Texas Instruments is a 3A, 1.5 MHz synchronous buck regulator in HTSSOP-16 with exposed pad, delivering adjustable output down to 0.8V from 2.95–5.5V input. It features peak current mode control, integrated 32 mΩ/36 mΩ FETs, and supports pre-biased startup-used in FPGA core power rails where tight voltage accuracy and transient response are critical.

For engineers reviewing the LM20123MHE/NOPB datasheet, LM20123MHE/NOPB pinout, LM20123MHE/NOPB application, or LM20123MHE/NOPB equivalent, key selection factors include its 96% efficiency at 1.5 MHz, precision enable with 66 mV hysteresis, soft-start/tracking dual-function pin, ±1.5% output voltage accuracy, and integrated OVP/UVLO/thermal shutdown for robust system-level power sequencing.

Technical Context

The LM20123MHE/NOPB implements peak current mode control with nonlinear (parabolic) slope compensation-dynamically adjusted per output voltage to ensure stability across 0.8–5.5V VOUT range. Its error amplifier delivers 510 µmho transconductance and 2000 V/V gain, enabling stable loop compensation with only two external components (RC1, CC1) regardless of output capacitor type.

It integrates dual N-channel MOSFETs (32 mΩ low-side, 36 mΩ high-side), a 2.7V internal sub-regulator (VCC), analog bias supply (AVIN) with RC filtering requirement, and independent AGND/PVIN/PGND domains to isolate noise-sensitive feedback and power paths-critical for low-noise digital load applications.

Key Specifications

Pinout & Package

LM20123MHE/NOPB uses a 16-pin HTSSOP package (PWP0016A) with exposed thermal pad (EP), optimized for PCB heat dissipation without heatsinks.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS54332DR and MP2315DJ-LF-Z, LM20123MHE/NOPB uniquely combines 1.5 MHz operation, pre-biased startup, and SS/TRK tracking in a 2.95–5.5V input range-making it optimal for compact, multi-rail 3.3V/5V systems where sequencing integrity and thermal efficiency are prioritized over ultra-wide VIN.

Availability

LM20123MHE/NOPB is available at Aetrix Electronics and suitable for FPGA core power, DSP I/O regulation, ASIC memory interfaces, and industrial PLC digital I/O modules requiring stable component supply across automotive and industrial temperature ranges.

Supply support for LM20123MHE/NOPB 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 ICs, with decades of expertise in high-efficiency DC-DC conversion.

The LM20123MHE/NOPB belongs to TI's PowerWise® synchronous buck regulator family-designed specifically for high-current, low-voltage point-of-load applications in FPGA, DSP, and ASIC power systems where efficiency, thermal performance, and sequencing reliability are critical.

FAQ

What is the maximum recommended output current for LM20123MHE/NOPB in continuous operation?

The LM20123MHE/NOPB is rated for 3A continuous output current under standard thermal conditions (θJA = 38°C/W, TA = 25°C). At full load, its integrated 32 mΩ low-side and 36 mΩ high-side FETs generate ~360 mW conduction loss. With proper PCB copper area under the exposed pad, sustained 3A operation remains within 125°C junction limit. Derating is advised above 60°C ambient or with restricted airflow.

Does LM20123MHE/NOPB support startup into a pre-biased output voltage?

Yes, LM20123MHE/NOPB supports pre-biased startup: during initial power-up, the low-side FET remains off until the SS/TRK soft-start ramp exceeds the voltage present at the FB pin. This prevents reverse current flow into an already-powered load-critical for FPGA and ASIC applications where cross-rail parasitic paths exist. No external diode or circuitry is needed.

What is the purpose of the AVIN pin on LM20123MHE/NOPB, and how must it be connected?

The AVIN pin on LM20123MHE/NOPB supplies clean bias voltage to the analog circuitry (error amplifier, reference, comparators). It must be connected to PVIN through an RC filter (typically RF = 10 Ω, CF = 100 nF) to attenuate high-frequency switching noise. Failure to filter AVIN degrades FB accuracy and can cause instability or erratic PGOOD behavior-TI specifies this connection as mandatory in all operating conditions.

Can LM20123MHE/NOPB be used to track another voltage rail, and how is this configured?

Yes, LM20123MHE/NOPB supports voltage tracking via the SS/TRK pin. To track an external rail (e.g., 1.2V master), connect SS/TRK to that rail through a resistive divider that scales it to ≤800 mV. When SS/TRK voltage is below 800 mV, the internal reference is overridden, forcing FB to follow the scaled tracking signal. This enables coordinated power-up of multiple rails without external supervisors.

What are the absolute maximum ratings for PVIN and junction temperature on LM20123MHE/NOPB?

The absolute maximum PVIN rating for LM20123MHE/NOPB is +6V, and the maximum junction temperature is 150°C. Exceeding either risks permanent damage. The device includes thermal shutdown activation at 160°C (with 10°C hysteresis), but this is a fault-protection limit-not an operational rating. For reliable 3A operation, design must maintain TJ ≤125°C using the exposed pad and appropriate PCB copper area per TI's layout guidelines.