Texas Instruments LM5114BMF/NOPB

Overview

LM5114BMF/NOPB from Texas Instruments is a single-channel, low-side gate driver IC designed to drive enhancement-mode GaN FETs and low-side MOSFETs in high-frequency DC-DC converters. It delivers 7.6-A peak sink and 1.3-A peak source current, operates from 4-V to 12.6-V VDD, features independent P_OUT/N_OUT outputs for adjustable turn-on/turn-off strength, and includes UVLO with 3.25-V rising threshold and 0.4-V hysteresis - enabling reliable operation in boost, flyback, and isolated synchronous rectifier applications.

For engineers reviewing the LM5114BMF/NOPB datasheet, LM5114BMF/NOPB pinout, LM5114BMF/NOPB application, or LM5114BMF/NOPB equivalent, key selection considerations include its TTL-compatible inputs (2.4-V VIH, 0.8-V VIL), 12-ns typical propagation delay, 0.23-Ω pulldown sink resistance at 10 V, 2-Ω pullup source resistance, and SOT-23-6 package with exposed thermal pad for high-power-density designs.

Technical Context

The LM5114BMF/NOPB implements a dual-output, non-overlapping gate drive architecture with separate open-drain P_OUT (source) and N_OUT (sink) terminals, enabling independent control of MOSFET/GaN FET turn-on and turn-off via external gate resistors. Its input stage accepts TTL logic levels and tolerates up to 14-V input voltage regardless of VDD, supporting direct interfacing with PWM controllers.

Internally, it integrates an under-voltage lockout (UVLO) circuit that disables outputs and activates a clamping PNP transistor when VDD falls below 3.25 V, holding N_OUT ≤ 1.0 V during power-up/down. The device also provides power-off pulldown (≤10 Ω at 0 V VDD) and low input capacitance (2.5 pF typical) to minimize timing jitter and layout sensitivity in high-dV/dt environments.

Key Specifications

Pinout & Package

The LM5114BMF/NOPB is housed in a 6-pin SOT-23 package (2.90 mm × 1.60 mm) with an exposed thermal pad on the bottom surface, requiring soldering to PCB ground plane for optimal thermal performance (R_θJB = 24.9°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-side gate driver applications.

Compared with LM5114MF/NOPB, the LM5114BMF/NOPB offers superior noise immunity in industrial power stages due to its fixed 0.68-V hysteresis and TTL thresholds; versus MAX5048BAUT+T, it adds critical fail-safe clamping during undervoltage conditions - essential for GaN FET reliability.

Availability

LM5114BMF/NOPB is available at Aetrix Electronics and suitable for boost converters, isolated synchronous rectifiers, and GaN-based motor drives requiring stable component supply, long-term lifecycle support, and traceable sourcing for production ramp.

Supply support for LM5114BMF/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 company delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The LM5114BMF/NOPB belongs to TI's high-speed gate driver product line, engineered specifically for efficient, reliable switching of GaN FETs and low-side MOSFETs in high-frequency, high-density power conversion systems.

FAQ

What is the function of the INB pin on the LM5114BMF/NOPB?

The INB pin on the LM5114BMF/NOPB is the inverting logic input, enabling active-low gate control. When driven high, it forces N_OUT low and disables P_OUT - useful for shutdown or fault-handling sequences. In normal operation, INB is held low (to VSS) to allow IN to control the output state. Its TTL-compatible threshold (0.8 V max for logic low) ensures compatibility with standard PWM controllers without level shifting.

Does the LM5114BMF/NOPB support GaN FETs, and what design considerations apply?

Yes, the LM5114BMF/NOPB is explicitly qualified for enhancement-mode GaN FETs like the EPC2001. Key design considerations include placing the LM5114BMF/NOPB within 5 mm of the GaN gate, using short symmetric gate traces, adding 1.5–2.7 Ω external resistors on P_OUT/N_OUT paths to damp oscillations, and ensuring solid thermal connection via the exposed pad - all critical to harness its 7.6-A sink current without gate ringing or false triggering.

How does the UVLO feature behave on the LM5114BMF/NOPB during power-up?

During power-up, the LM5114BMF/NOPB's UVLO circuit holds both outputs inactive until VDD exceeds 3.25 V (rising threshold). Once enabled, it maintains operation down to 2.85 V due to 0.4-V hysteresis. Crucially, if VDD drops below threshold, the internal PNP transistor activates and clamps N_OUT to ≤1.0 V - preventing partial turn-on of the driven FET and ensuring safe power-down behavior unique to the LM5114BMF/NOPB among pin-compatible alternatives.

Can the LM5114BMF/NOPB drive multiple MOSFETs in parallel?

Yes, the LM5114BMF/NOPB is designed to drive multiple parallel MOSFETs thanks to its 7.6-A peak sink current and low 0.23-Ω pulldown resistance. This capability allows a single LM5114BMF/NOPB to replace multiple lower-current drivers in high-current applications such as high-power boost stages or motor phase legs - provided gate loop inductance is minimized and thermal dissipation (via exposed pad) is maintained within R_θJA = 108.1°C/W limits.

What is the purpose of the split P_OUT and N_OUT outputs on the LM5114BMF/NOPB?

The split P_OUT (source) and N_OUT (sink) outputs on the LM5114BMF/NOPB enable independent adjustment of MOSFET/GaN FET turn-on and turn-off speeds using separate external gate resistors. This decoupling allows designers to optimize EMI (via slower turn-on) while preserving efficiency (via fast turn-off), suppress Miller-induced oscillations, and tailor switching behavior to specific FET characteristics - a capability not available in single-output gate drivers.