Texas Instruments LM2682MM/NOPB

Overview

LM2682MM/NOPB from Texas Instruments is a CMOS switched-capacitor voltage inverter that converts +2.0V to +5.5V input into −4.0V to −11.0V negative output, delivering up to 10 mA with 90 Ω typical output impedance and 94% power efficiency at 10 mA. It operates at 6 kHz switching frequency and targets low-noise, inductorless biasing in portable electronics.

For engineers reviewing the LM2682MM/NOPB datasheet, LM2682MM/NOPB pinout, LM2682MM/NOPB application, or LM2682MM/NOPB equivalent, key selection criteria include input voltage range (2.0–5.5 V), output impedance (90 Ω typ), efficiency (≥90% at 10 mA), operating temperature (−40°C to +85°C), and VSSOP-8 package compatibility with space-constrained PCB layouts.

Technical Context

The LM2682MM/NOPB implements a two-stage charge-pump topology: first inverting VIN to −VIN, then doubling to −2VIN using three external capacitors. Its internal oscillator runs at 12–30 kHz, driving four MOSFET switches with matched on-resistance to minimize output impedance.

Output regulation relies on external capacitor ESR and value selection-C1 ≥6 V, C2/C3 ≥12 V-and ripple is governed by VRIPPLE = IOUT × (2×ESRC3 + 1/[2×fOSC×C3]). No internal feedback loop exists; regulated operation requires external op-amp and reference (e.g., LM358 + LM4040-5.0).

Key Specifications

Pinout & Package

VSSOP-8 (DGK) package: 3.0 mm × 3.0 mm body, 0.65 mm pitch, 1.1 mm max height, exposed pad not electrically connected. RoHS-compliant, Sn lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar switched-capacitor inverter applications.

Compared with MAX680ESA+ and ICL7660SIPAZ, the LM2682MM/NOPB offers the lowest output impedance (90 Ω) and highest efficiency (94%) in the VSSOP-8 form factor, making it optimal for space- and battery-limited applications where low ripple and minimal thermal rise are critical.

Availability

LM2682MM/NOPB is available at Aetrix Electronics and suitable for LCD contrast biasing, GaAs amplifier biasing, and interface power supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LM2682MM/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 high-reliability ICs for industrial, automotive, and consumer markets.

The LM2682MM/NOPB belongs to TI's switched-capacitor power management product line, designed specifically for compact, inductor-free DC/DC voltage inversion in portable and space-constrained electronics.

FAQ

What is the primary function of the LM2682MM/NOPB?

The LM2682MM/NOPB is a fixed-ratio switched-capacitor voltage inverter that converts a positive input voltage (2.0–5.5 V) into a corresponding negative output voltage (−4.0 V to −11.0 V) with no inductors required. Its core function is to generate clean, efficient negative bias rails for analog and interface circuits, and the LM2682MM/NOPB achieves this using only three external capacitors and an internal 6 kHz oscillator-driven charge-pump architecture.

Can the LM2682MM/NOPB operate from a 3.3 V supply?

Yes, the LM2682MM/NOPB fully supports 3.3 V input operation within its specified 2.0–5.5 V range. At VIN = 3.3 V, it delivers approximately −6.6 V at the VOUT pin with 10 mA load, maintaining 90 Ω typical output impedance and ≥90% power efficiency. The LM2682MM/NOPB's performance remains stable across this range, making it ideal for mixed-voltage systems where 3.3 V logic coexists with analog bias requirements.

What are the mandatory external components for basic LM2682MM/NOPB operation?

The LM2682MM/NOPB requires exactly three external capacitors: C1 (flying capacitor, ≥3.3 μF, ≥6 V rating), C2 (phase capacitor, ≥3.3 μF, ≥12 V rating), and C3 (output filter, ≥3.3 μF, ≥12 V rating). All must be low-ESR ceramic types. No resistors, inductors, or feedback networks are needed. The LM2682MM/NOPB's fixed −2× topology eliminates configuration overhead, and proper capacitor selection directly determines output impedance and ripple performance.

Is the LM2682MM/NOPB pin-compatible with the SOIC-8 version of the same device?

No, the LM2682MM/NOPB uses the VSSOP-8 (DGK) package with 0.65 mm pitch and 3.0 × 3.0 mm body, while the SOIC-8 version (e.g., LM2682MX/NOPB) has 1.27 mm pitch and 4.9 × 6.0 mm body. Although both share identical pin numbering and functions per Table 1, their footprints, thermal characteristics (VSSOP: 220°C/W θJ-A; SOIC: 140°C/W), and reflow profiles differ. The LM2682MM/NOPB is not mechanically interchangeable without PCB redesign.

How does temperature affect LM2682MM/NOPB output voltage accuracy?

The LM2682MM/NOPB has no internal voltage reference or feedback; its output voltage is purely a function of input voltage and charge-transfer efficiency. Over −40°C to +85°C, VIN tolerance and capacitor ESR drift cause ≤±3% deviation in VOUT magnitude. For example, at VIN = 5.0 V and 85°C, VOUT typically measures −9.7 V instead of −10.0 V due to increased switch resistance and capacitor losses. The LM2682MM/NOPB is not specified for precision regulation-external op-amp compensation (Figure 7) is required for tight tolerance.