Analog Devices Inc./Maxim Integrated MAX8511ETA18+T

Overview

MAX8511ETA18+T from Maxim Integrated is a 1.8V fixed-output, ultra-low-noise, low-dropout linear regulator delivering up to 120mA with 120mV dropout at full load and 40μA ground current. It uses a P-channel MOSFET pass element, operates from 2V–6V input, and requires only input/output ceramic capacitors-no bypass capacitor needed. It targets noise-sensitive RF and portable power rails in Bluetooth radios and digital cameras.

For engineers reviewing the MAX8511ETA18+T datasheet, MAX8511ETA18+T pinout, MAX8511ETA18+T application, or MAX8511ETA18+T equivalent, key selection criteria include its 1.8V preset output, TDFN-8 (2mm × 2mm) package, 230μV_RMS output noise, 72dB PSRR at 1kHz, and shutdown current <1μA-critical for battery life and signal integrity in space-constrained designs.

Technical Context

The MAX8511ETA18+T implements a P-channel MOSFET series pass transistor with 1Ω typical R_DS(ON), enabling low dropout and eliminating base-drive current loss. Its error amplifier compares a 1.225V bandgap reference against internal feedback to regulate output without external resistors.

No BP pin is present-unlike the MAX8510-so it omits the noise-bypass path and achieves 230μV_RMS output noise (100Hz–100kHz) instead of 11μV_RMS. Shutdown logic disables the reference, error amp, and gate driver, reducing supply current to <1μA while placing OUT in high-impedance state.

Key Specifications

Pinout & Package

MAX8511ETA18+T is housed in an 8-pin TDFN-EP (2mm × 2mm × 0.8mm) package with exposed pad connected to GND for thermal performance. Pin 1 is IN; Pin 2 is GND; Pin 3 is SHDN; Pin 4 is N.C.; Pin 5 is OUT; Pins 6/7/8 are N.C.; EP is internally tied to GND and must be soldered to a large ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with the MAX8511ETA18+T, the XC6219B182MR-G offers lower quiescent current but sacrifices thermal safety and noise rejection, while the ADP125ARHZ-1.8-R7 provides headroom for future current scaling at the expense of size and complexity-making MAX8511ETA18+T optimal for compact, noise-sensitive 120mA applications.

Availability

MAX8511ETA18+T is available at Aetrix Electronics and suitable for Bluetooth portable radios, digital cameras, personal stereos, and portable medical sensors requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MAX8511ETA18+T 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power-management ICs for demanding industrial, communications, and consumer applications.

The MAX8510/MAX8511/MAX8512 family was engineered specifically for ultra-low-noise, low-quiescent power delivery in space-constrained portable electronics-emphasizing minimal external components, ceramic-capacitor compatibility, and robust protection features.

FAQ

What is the maximum input voltage rating for the MAX8511ETA18+T?

The MAX8511ETA18+T has an absolute maximum input voltage of +7V referenced to GND. However, its operational input range is specified from 2V to 6V. Exceeding 6V may cause excessive power dissipation or violate safe operating area limits, especially at elevated temperatures. Always maintain VIN ≤ 6V in normal use to ensure reliability and stay within datasheet-specified electrical characteristics for the MAX8511ETA18+T.

Does the MAX8511ETA18+T require an external bypass capacitor on the BP pin?

No, the MAX8511ETA18+T does not have a BP (bypass) pin and therefore requires no external bypass capacitor. Unlike the MAX8510, which uses a BP pin and 10nF capacitor to achieve 11μV_RMS noise, the MAX8511ETA18+T is optimized for minimal external components-relying on internal architecture to deliver 230μV_RMS noise with only input and output ceramic capacitors. This simplifies layout and reduces BOM count for the MAX8511ETA18+T.

What is the thermal resistance (θ_JA) of the MAX8511ETA18+T in its TDFN package?

The MAX8511ETA18+T in the 8-pin TDFN-EP (2mm × 2mm) package has a junction-to-ambient thermal resistance (θ_JA) of 83.9°C/W, measured per JEDEC JESD51-7 on a four-layer board. This value assumes proper soldering of the exposed pad to a large ground plane. With 120mA load and 120mV dropout, power dissipation is ~14.4mW-resulting in <1.3°C junction rise above ambient, confirming suitability for sealed or thermally constrained enclosures using the MAX8511ETA18+T.

Can the MAX8511ETA18+T be used with X5R or Y5V ceramic output capacitors?

Yes, the MAX8511ETA18+T is stable with 1μF X5R or X7R ceramic capacitors across its full operating temperature range. However, Y5V and Z5U dielectrics exhibit significant capacitance and ESR variation with temperature and bias voltage; using them may compromise stability below -10°C. For guaranteed performance, select X5R/X7R types rated ≥1μF at 1.8V DC bias-this ensures consistent regulation and transient response in all conditions where the MAX8511ETA18+T is deployed.

What happens to the output of the MAX8511ETA18+T when the SHDN pin is pulled low?

When the SHDN pin of the MAX8511ETA18+T is pulled to ≤0.4V, the device enters shutdown mode: the internal voltage reference, error amplifier, and gate driver are disabled, the P-channel pass transistor turns off, and the OUT pin transitions to a high-impedance state. Output voltage collapses, and total supply current drops to <1μA. The device remains in this state until SHDN rises above 1.5V, at which point it resumes regulation with typical startup delay of 300μs-ensuring predictable power sequencing for the MAX8511ETA18+T.