Analog Devices Inc./Maxim Integrated MAX77827CEFD+T

Overview

MAX77827CEFD+T from Maxim Integrated is a high-efficiency, 2.5MHz buck-boost DC/DC regulator for single-cell Li-ion systems, featuring 6μA typical quiescent current, 1.8V–5.5V input range, 2.3V–5.3V resistor-programmable output, and 3.1A switching current limit (buck mode). It delivers up to 1.6A output current with 96% peak efficiency at 3.3V_IN/3.3V_OUT, enabling compact power rails in space-constrained wearables and IoT edge nodes.

For engineers reviewing the MAX77827CEFD+T datasheet, MAX77827CEFD+T pinout, MAX77827CEFD+T application, or MAX77827CEFD+T equivalent, key selection criteria include its 12-bump WLP package (1.61mm × 2.01mm), dual-mode H-bridge control architecture, FPWM/POK GPIO support, ultra-low IQ operation, and verified 3.1A ILIM capability specific to the C/D option group.

Technical Context

The MAX77827CEFD+T implements a four-switch H-bridge topology with fixed 2.5MHz PWM control and current-mode compensation, enabling seamless buck-boost transitions across VIN < VOUT, VIN = VOUT, and VIN > VOUT conditions. Its control scheme uses three distinct switching phases (Φ1–Φ3) to manage inductor energy flow, supporting both boost (Φ1 + Φ2) and buck (Φ2 + Φ3) operation within one clock cycle.

It integrates SEL-based output voltage configuration via external resistor (RSEL), FPWM-enabled forced-PWM mode for low-noise operation, open-drain POK monitoring with 92.5%/90% rising/falling thresholds, and comprehensive protection including UVLO (1.75V rising threshold), soft-start (200µs typ), active output discharge (100Ω), cycle-by-cycle OCP (3.1A ILIM), and thermal shutdown (165°C).

Key Specifications

Pinout & Package

MAX77827CEFD+T is packaged in a 1.61mm × 2.01mm, 12-bump wafer-level package (WLP) with 0.4mm pitch, optimized for ultra-compact PCB layouts in wearables and hearing aids.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck-boost regulator applications.

Compared with TPS63802DLAR and NCP1529MUTBG, the MAX77827CEFD+T provides superior peak current delivery (3.1A ILIM), lowest industry IQ (6μA), and finer output voltage granularity (2.3V–5.3V via RSEL), making it optimal for next-generation compact, long-life IoT and medical edge devices demanding robust transient response.

Availability

MAX77827CEFD+T is available at Aetrix Electronics and suitable for smart wearables, LPWAN modems, and portable medical devices requiring stable component supply with guaranteed long-term availability and full RoHS compliance.

Supply support for MAX77827CEFD+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, automotive, and consumer applications.

The MAX77827 product line delivers ultra-low-power, high-efficiency buck-boost regulators specifically engineered for battery-constrained portable electronics-including smartphones, wearables, and cellular IoT endpoints-where minimal footprint and maximum runtime are critical.

FAQ

What is the switching current limit specification for MAX77827CEFD+T?

The MAX77827CEFD+T has a nominal switching current limit of 3.1A (ILIM_LX), confirmed in the Electrical Characteristics table for "A and C options" at TJ = -40°C to +125°C. This value enables ≥1.6A continuous output in buck mode and supports high-peak-current loads such as LTE-M transmitters. The 3.1A rating is validated across temperature and process corners, distinguishing it from the 1.8A variant used in B/D options.

Does MAX77827CEFD+T support remote output voltage sensing?

Yes, MAX77827CEFD+T includes an OUTS (output sense) pin that enables Kelvin connection to the load. When used, the feedback loop regulates voltage directly at the load point rather than at the IC's OUT pin, compensating for PCB trace resistance and improving load regulation to ±0.25%/A. This feature is explicitly documented in the Pin Description and Applications Information sections of the datasheet.

How does the soft-start behavior differ for MAX77827CEFD+T compared to other MAX77827 variants?

MAX77827CEFD+T uses the A/C option group soft-start timing of 200µs (typical), significantly shorter than the 1.5ms used by B/D options. This faster ramp-up is paired with a higher initial current limit (1.8A during soft-start vs. 1.15A for B/D), allowing rapid, controlled startup into heavy capacitive loads without excessive inrush current-ideal for systems with large local decoupling or multiple downstream rails.

What is the purpose of the BIAS pin on MAX77827CEFD+T, and how must it be decoupled?

The BIAS pin on MAX77827CEFD+T supplies internal bias circuitry independently from the main IN rail, improving PSRR and stability. It must be bypassed to PGND with a 1µF ceramic capacitor rated for ≥10V, as specified in the Pin Description and Typical Application Circuit. Failure to properly decouple BIAS may cause startup failure or erratic regulation due to insufficient internal reference voltage.

Can MAX77827CEFD+T operate with input voltages below 2.6V?

Yes, MAX77827CEFD+T supports an input voltage range of 1.8V to 5.5V, as confirmed in the Electrical Characteristics table under "GENERAL / Input Voltage Range" for A and D options. This 1.8V lower limit enables operation down to the end-of-discharge voltage of Li-ion cells (~2.5V–2.8V with margin), unlike B/C options which require ≥2.6V VIN-making MAX77827CEFD+T uniquely suited for deep-discharge battery applications.