Texas Instruments LM2776DBVR

Overview

LM2776DBVR from Texas Instruments is a CMOS switched-capacitor voltage inverter IC that converts 2.7 V to 5.5 V positive input into a corresponding negative output (e.g., −3.3 V or −5.0 V) with up to 200 mA output current, 2 MHz switching frequency, and >90% efficiency-used in op-amp dual-rail supplies for portable instrumentation.

For engineers reviewing the LM2776DBVR datasheet, LM2776DBVR pinout, LM2776DBVR application, or LM2776DBVR equivalent, key selection criteria include input voltage range (2.7–5.5 V), output current capability (200 mA), PFM/constant-frequency mode behavior, thermal shutdown threshold (150°C), and SOT-23-6 package compatibility with space-constrained PCB layouts.

Technical Context

The LM2776DBVR implements a four-switch charge-pump topology with internal MOSFETs operating at 2 MHz nominal frequency, enabling low output impedance (<2.5 Ω) and minimal external component count (only three ceramic capacitors required). Its PFM mode reduces quiescent current to 100 µA at light loads while maintaining regulation.

It integrates undervoltage lockout (2.4 V fall / 2.6 V rise), current limiting (400 mA typical), thermal shutdown (150°C trip), and active output discharge during shutdown (1.85 mA pull-down), making it suitable for battery-powered systems requiring robust fault protection without inductors.

Key Specifications

Pinout & Package

The LM2776DBVR is housed in a 6-pin SOT-23 package (2.90 mm × 1.60 mm body size) with exposed pad not electrically connected. Pin assignment follows TI's DBV footprint standard and supports reflow soldering on standard PCB assemblies.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage inverter applications.

Compared with MAX680ESA+ and TPS60403DBVR, the LM2776DBVR offers superior efficiency (>90% vs. ~82%), integrated thermal/current protection, and 2 MHz operation enabling lower ripple and smaller capacitors-making it optimal for new portable designs demanding reliability and power density.

Availability

LM2776DBVR is available at Aetrix Electronics and suitable for operational amplifier power supplies, audio amplifier power supplies, and data converter supplies requiring stable component supply across automotive infotainment, industrial handheld meters, and medical diagnostic devices.

Supply support for LM2776DBVR 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.

The LM2776DBVR belongs to TI's switched-capacitor DC/DC converter product line, engineered specifically for compact, inductorless negative voltage generation in battery-powered portable systems where size, efficiency, and reliability are critical.

FAQ

What is the maximum continuous output current of the LM2776DBVR?

The LM2776DBVR delivers up to 200 mA of continuous output current under recommended operating conditions (TA = −40°C to +85°C, VIN = 2.7–5.5 V). This rating assumes proper thermal management-such as adequate copper pour on GND and thermal vias-and use of low-ESR ceramic capacitors. At 200 mA, output voltage drops by ≤500 mV from ideal −VIN due to ROUT ≈ 2.5 Ω.

Does the LM2776DBVR require an external inductor?

No, the LM2776DBVR does not require an external inductor. It uses a switched-capacitor (charge-pump) architecture with three external ceramic capacitors (CIN, COUT, C1) to invert the input voltage. This eliminates magnetic components, reduces EMI, and simplifies PCB layout-making LM2776DBVR ideal for space-constrained portable applications where inductors would increase height and cost.

How does the enable (EN) pin function on the LM2776DBVR?

The EN pin on the LM2776DBVR controls device operation: applying >1.2 V enables normal switching, while <0.4 V forces shutdown mode. In shutdown, LM2776DBVR draws only 0.1–1 µA and actively discharges VOUT to GND via a 1.85 mA internal sink. This prevents floating negative rails that could damage downstream circuitry or cause op-amp latch-up during power sequencing.

What is the switching frequency range of the LM2776DBVR?

The LM2776DBVR operates at a nominal switching frequency of 2 MHz, with a guaranteed range of 1.7–2.3 MHz across temperature and input voltage. This high frequency enables use of small 0603/0805 ceramic capacitors and minimizes output voltage ripple-critical for noise-sensitive analog circuits. Frequency remains stable under load and does not vary with output current in constant-frequency mode.

Can the LM2776DBVR generate outputs other than −VIN?

No, the LM2776DBVR is a fixed-ratio inverter and generates only −VIN ± dropout (typically −2.7 V to −5.5 V). It does not support adjustable or regulated outputs like buck-boost regulators. Output voltage accuracy depends on input regulation, ROUT, and load current-e.g., at VIN = 3.6 V and IOUT = 100 mA, VOUT ≈ −3.35 V. For regulated negative outputs, consider TI's TPS6040x family with feedback resistors.