Texas Instruments LM2664M6X

Overview

LM2664M6X from Texas Instruments is a CMOS switched-capacitor voltage inverter IC that converts 1.8 V to 5.5 V positive input into corresponding −1.8 V to −5.5 V negative output, delivers up to 40 mA, 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 LM2664M6X datasheet, LM2664M6X pinout, LM2664M6X application, or LM2664M6X equivalent, key selection criteria include input voltage range (1.8–5.5 V), shutdown current (1 µA), conversion efficiency (91% at 40 mA), SOT-23-6 package compatibility, and charge-pump capacitor requirements for low-noise negative rail generation.

Technical Context

The LM2664M6X implements a two-phase switched-capacitor topology using four internal CMOS MOSFET switches driven by a 160-kHz oscillator; energy transfer relies on external flying (CAP+/CAP−) and output (OUT/GND) capacitors. Its functional block includes switch array, oscillator, and shutdown control logic.

Shutdown mode disables switching and reduces supply current to 1 µA by pulling SD pin below 20% of V+; normal operation requires SD tied to V+. Output voltage regulation is unregulated - VOUT ≈ −V+ under no load, with drop determined by RSW (4–8 Ω) and capacitor ESR.

Key Specifications

Pinout & Package

SOT-23-6 (DBV) package: 2.90 mm × 1.60 mm body, 1.45 mm max height, JEDEC MO-178 compliant, tape-and-reel (3000 pcs/reel), RoHS-compliant Sn lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX660CPA+ and ICL7660SIPAZ, the LM2664M6X offers optimal balance of 40 mA capability, 1 µA shutdown, SOT-23-6 size, and 160-kHz EMI profile - making it ideal for mid-current portable instrumentation where efficiency and footprint are jointly constrained.

Availability

LM2664M6X is available at Aetrix Electronics and suitable for portable instrumentation, RS-232 interface power, and operational amplifier dual-supply generation requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for LM2664M6X 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 connectivity technologies, with decades of expertise in power management innovation.

The LM2664M6X belongs to TI's switched-capacitor DC/DC converter product line, engineered specifically for compact, inductorless negative voltage generation in battery-powered portable electronics.

FAQ

What is the maximum continuous output current specification for the LM2664M6X?

The LM2664M6X is rated for up to 40 mA of continuous output current under recommended operating conditions (T_A = −40°C to +85°C, V+ = 5 V). Absolute maximum rating allows 50 mA, but sustained operation above 40 mA may exceed thermal limits or degrade output regulation. The 40 mA value reflects the point where output impedance (12 Ω typical) and efficiency (91%) remain within guaranteed performance bounds per the SNVS005E datasheet.

Can the LM2664M6X generate −10 V output from a 5 V input?

No, the LM2664M6X cannot generate −10 V from a 5 V input in single-stage operation - its output is strictly an inverted replica of V+, yielding −5 V maximum. However, the datasheet confirms cascading multiple LM2664M6X units (e.g., two stages) can achieve −10 V, though with reduced efficiency and increased output resistance. For dedicated −10 V generation, TI recommends alternatives like the ICL7660SIPAZ or charge-pump controllers supporting higher gain ratios.

What external capacitors are required for stable operation of the LM2664M6X?

The LM2664M6X requires two external capacitors: a 3.3 µF low-ESR flying capacitor (C1) between CAP+ and CAP− pins, and a 3.3 µF low-ESR output capacitor (C2) between OUT and GND. TI specifies ≤0.3 Ω ESR for both; recommended types include OS-CON aluminum polymer (Nichicon), TPS tantalum (AVX), or X7R ceramic (Murata, Taiyo Yuden). Higher ESR increases output impedance and ripple, directly degrading regulation and efficiency.

Does the LM2664M6X require an external resistor network to set output voltage?

No, the LM2664M6X is an unregulated inverting charge pump - its output voltage is inherently −V+ (e.g., −3.3 V from 3.3 V input) with no feedback or adjustment pins. To achieve regulated negative output, TI's application note shows adding an external LDO like the LP2980 downstream of the LM2664M6X, using resistive feedback to set V_OUT = 1.23 V × (1 + R1/R2). The LM2664M6X itself has no voltage-setting components.

Is the LM2664M6X pin-compatible with other SOT-23-6 voltage inverters such as the MAX660?

No, the LM2664M6X is not pin-compatible with the MAX660 - their pinouts differ significantly. LM2664M6X assigns GND to Pin 1, OUT to Pin 2, CAP− to Pin 3, SD to Pin 4, V+ to Pin 5, and CAP+ to Pin 6. The MAX660 uses Pin 1 for V+, Pin 2 for GND, Pin 3 for CAP+, Pin 4 for CAP−, Pin 5 for V_OUT, and Pin 6 for OSC. PCB redesign is required for substitution; always verify pin mapping against respective datasheets before replacement.