Analog Devices Inc./Maxim Integrated MAX77801ETP+T

Overview

MAX77801ETP+T from Analog Devices is a synchronous buck-boost DC-DC converter in a 20-bump WLP (2.13mm × 1.83mm), delivering regulated 2.6V–4.18V output from 2.3V–5.5V input, supporting up to 2A in boost mode and 3A in buck mode with 97% peak efficiency and 55µA quiescent current - deployed in AR/VR headsets and mobile payment terminals.

For engineers reviewing the MAX77801ETP+T datasheet, MAX77801ETP+T pinout, MAX77801ETP+T application, or MAX77801ETP+T equivalent, key selection criteria include I²C-programmable VOUT (12.5mV steps), dual-mode soft-start (ILIM_LX reduction only), 2.5MHz switching frequency, and factory-default 3.75V startup voltage specific to the ETP variant.

Technical Context

The MAX77801ETP+T implements a fixed-frequency (2.5MHz) current-mode PWM control scheme with H-bridge topology using a single inductor, enabling seamless buck-to-boost transition without discontinuity. It uses phase-based energy transfer: Φ1 (HS1/LS2 ON) for charging, Φ2 (HS1/HS2 ON) for differential regulation, and Φ3 (LS1/HS2 ON) for discharging.

Its control architecture integrates dynamic voltage scaling via DVS pin latching post-soft-start, programmable slew rates (12.5/25mV/µs ramp-up; 3.125/6.25mV/µs ramp-down), and burst-mode transient response with ILIM_LX_HIGH (5.5A) activation for loads exceeding 4.5A for ≤800µs.

Key Specifications

Pinout & Package

MAX77801ETP+T is packaged in a 20-bump wafer-level package (WLP), measuring 2.13mm × 1.83mm with 0.4mm pitch, optimized for ultra-compact portable electronics requiring minimal board area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX77801EWP+T, the MAX77801ETP+T provides higher factory-set VOUT (3.75V vs. 3.4V) for better noise margin in noisy RF environments, while TPS63802DLPR eliminates I²C overhead but forfeits real-time DVS and diagnostic capabilities essential for premium portable devices.

Availability

MAX77801ETP+T is available at Aetrix Electronics and suitable for AR/VR headsets, handheld scanners, and mobile payment terminals requiring stable component supply across multi-year production cycles.

Supply support for MAX77801ETP+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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Wilmington, MA.

The MAX77801 product line targets ultra-compact, battery-critical portable electronics, delivering high-efficiency buck-boost conversion with integrated I²C control and robust protection for next-generation wearables and edge devices.

FAQ

What is the factory-default output voltage of the MAX77801ETP+T?

The MAX77801ETP+T has a factory-default VOUT_DVS_H setting of 0x5C, corresponding to 3.75V at power-up. This value is programmed during wafer test and remains active until overwritten via I²C. Unlike the EWP variant (3.4V) or HEWP variant (3.3V), the ETP's 3.75V default provides higher headroom for 3.6V-tolerant peripherals in AR/VR systems. The MAX77801ETP+T does not require initial I²C writes to achieve functional output voltage.

How does the soft-start behavior of the MAX77801ETP+T differ from other MAX77801 variants?

The MAX77801ETP+T implements soft-start exclusively by reducing the peak inductor current limit (ILIM_LX) to 1.8A for 120µs after enable assertion - it does not ramp the internal reference voltage (VREF). This differs from the MAX77801HEWP+T, which combines VREF ramping with ILIM_LX reduction. The MAX77801ETP+T's approach delivers faster wake-up time and simpler power sequencing, making it ideal for applications requiring rapid system responsiveness. The MAX77801ETP+T soft-start is fully hardware-controlled and independent of I²C register settings.

Can the MAX77801ETP+T operate without an I²C host controller?

Yes, the MAX77801ETP+T operates autonomously without I²C. Its factory-default 3.75V output, EN pin control, and POK monitoring function immediately upon power application. I²C is optional and used only for dynamic voltage scaling, fault readback, or modifying protection thresholds. Pulling SDA/SCL to AGND disables the interface, and VIO can be left unconnected if unused. The MAX77801ETP+T retains full buck-boost functionality, including soft-start, OVP, and thermal shutdown, even with I²C permanently disabled.

What is the maximum continuous output current supported by the MAX77801ETP+T in buck mode?

The MAX77801ETP+T supports up to 3A continuous output current in buck mode (VIN > VOUT), verified across the full input range of 2.8V–5.5V. At VIN < 2.8V, the maximum continuous output current is reduced to 1A to maintain thermal stability. This derating is enforced by internal current limiting and is independent of PCB layout - even with optimal thermal vias and copper pour, the MAX77801ETP+T cannot sustain 3A continuously below 2.8V input without triggering thermal shutdown.

Does the MAX77801ETP+T support both buck and boost operation simultaneously?

No, the MAX77801ETP+T does not perform simultaneous buck and boost operation. It operates in one mode at a time - either buck (when VIN > VOUT) or boost (when VIN < VOUT) - with automatic, seamless transition between them at the crossover point (VIN ≈ VOUT). During transition, the control algorithm adjusts duty cycle and phase timing to maintain regulation without output droop or overshoot. This single-inductor H-bridge architecture ensures high efficiency (>90%) across the entire 2.3V–5.5V input range, but the MAX77801ETP+T never sources power from both input and output rails concurrently.