Texas Instruments LM2664M6

Overview

LM2664M6 from Texas Instruments is a CMOS switched-capacitor voltage inverter IC that converts 1.8 V to 5.5 V positive input into −1.8 V to −5.5 V negative output, delivers up to 40 mA load current, operates at 160 kHz oscillator frequency, and features 12 Ω typical output impedance - used in portable instrumentation and op-amp dual-supply generation.

For engineers reviewing the LM2664M6 datasheet, LM2664M6 pinout, LM2664M6 application, or LM2664M6 equivalent, key selection criteria include its SOT-23-6 package footprint, shutdown control via SD pin, 1 µA shutdown current, 91% conversion efficiency at full load, and compatibility with low-ESR ceramic or tantalum flying/output capacitors.

Technical Context

The LM2664M6 implements a four-switch charge-pump topology with internal CMOS MOSFETs, operating at a fixed 160 kHz oscillator frequency (80 kHz switching frequency), enabling low-output-impedance inversion without inductors. Its functional block includes oscillator, switch drivers, and a synchronous switching array controlled by internal timing logic.

Shutdown mode is activated by pulling the SD pin below 20% of V+, reducing quiescent supply current to 1 µA while disabling internal oscillator and switch control. The device's output voltage accuracy and ripple depend directly on external capacitor ESR and capacitance values, not internal regulation.

Key Specifications

Pinout & Package

LM2664M6 is housed in a 6-pin SOT-23 (DBV) package measuring 2.90 mm × 1.60 mm × 1.45 mm max height, with gull-wing leads and RoHS-compliant matte tin (SN) lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX660CPA+ and TPS60403DBVR, the LM2664M6 offers the lowest shutdown current (1 µA), smallest SOT-23 footprint, and optimal balance of efficiency (91% at 40 mA) and capacitor cost-making it preferred for space-constrained, battery-sensitive designs where 40 mA suffices.

Availability

LM2664M6 is available at Aetrix Electronics and suitable for handheld instruments, RS-232 interface power, and operational amplifier dual-supply generation requiring stable component supply across production lifecycles.

Supply support for LM2664M6 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 precision power conversion and low-power design.

The LM2664M6 belongs to TI's switched-capacitor voltage converter product line, engineered specifically for compact, inductorless negative rail generation in portable and battery-powered systems.

FAQ

What is the minimum input voltage required for stable operation of the LM2664M6?

The LM2664M6 operates reliably from 1.8 V to 5.5 V input. At 1.8 V, it delivers −1.8 V output with ≥90% efficiency at light loads. Below 1.8 V, regulation degrades and startup may fail. Designers should verify dropout behavior using Equation (1) from the datasheet when selecting external capacitors for low-VIN applications. The LM2664M6 maintains functionality across its full specified range without external biasing.

Can the LM2664M6 be used to generate voltages beyond −5.5 V?

No - the LM2664M6 is strictly limited to inverting its input: output equals −V_IN, so maximum negative output is −5.5 V at 5.5 V input. Cascading multiple LM2664M6 units (e.g., two in series) can produce −2×V_IN, but efficiency drops significantly and output resistance increases per Equation (4) in the datasheet. For >−5.5 V, a dedicated inverting flyback or transformer-based solution is recommended instead of cascading LM2664M6 devices.

Does the LM2664M6 require external diodes or inductors?

No - the LM2664M6 is a fully integrated switched-capacitor inverter with four internal CMOS switches; it requires only two external capacitors (C1 flying cap, C2 output cap) and no diodes, inductors, or transformers. This eliminates magnetic components, reduces EMI, and simplifies layout. The device's 12 Ω typical output impedance includes internal switch R_DS(on) and is independent of external passive count.

How does shutdown mode affect the output voltage of the LM2664M6?

When the SD pin is pulled low (<0.8 V), the LM2664M6 disables its oscillator and internal switches, halting charge transfer. The OUT pin enters high-impedance state - output voltage decays passively through load leakage and capacitor self-discharge. No reverse current flows from OUT to GND or V+. To maintain hold-up, an external Schottky diode from OUT to GND is unnecessary and not recommended, as the LM2664M6 has no body-diode path to ground.

What capacitor types are recommended for optimal performance with the LM2664M6?

Texas Instruments recommends low-ESR ceramic (X7R, X5R), tantalum (AVX TPS, Sprague 593D), or OS-CON aluminum polymer capacitors for both C1 (flying) and C2 (output). Ceramic capacitors (e.g., 3.3 µF, 10 V, ≤100 mΩ ESR) yield lowest ripple and highest efficiency. Avoid standard electrolytics with >500 mΩ ESR - they increase output impedance and reduce efficiency below 85%. The LM2664M6's performance metrics assume 3.3 µF, ≤0.3 Ω ESR capacitors per Figure 9 test circuit.