Analog Devices Inc./Maxim Integrated MAX1795EUA+T

Overview

MAX1795EUA+T from Maxim Integrated is a high-efficiency, step-up DC-DC converter optimized for low-voltage portable devices. It delivers up to 180mA output current at 3.3V or 120mA at 5.0V from inputs as low as 0.7V, features True Shutdown™ with 2μA shutdown current, and integrates synchronous rectification to eliminate external Schottky diodes-enabling compact power solutions in digital audio players and wireless handsets.

For engineers reviewing the MAX1795EUA+T datasheet, MAX1795EUA+T pinout, MAX1795EUA+T application, or MAX1795EUA+T equivalent, this page provides verified technical context, validated pin functions, confirmed efficiency curves (≥95% at light load), real-world LBI/LBO comparator behavior in shutdown, and precise current-limiting specs (0.25A NFET switch limit) critical for battery-powered system design.

Technical Context

The MAX1795EUA+T uses a minimum-off-time, current-limited control architecture combining PWM-like efficiency with pulse-skipping quiescent current benefits-achieving 25μA operating current and up to 500kHz variable-frequency switching. Its internal N-channel MOSFET (R_DS(ON) = 0.17Ω typ) and P-channel synchronous rectifier enable high efficiency without external diodes.

True Shutdown™ fully disconnects OUT from BATT during shutdown, placing OUT in high-impedance state while maintaining active LBI/LBO comparator operation. The integrated LX-damping switch (R_DAMP = 100–400Ω) suppresses inductor ringing to reduce EMI without affecting output ripple.

Key Specifications

Pinout & Package

MAX1795EUA+T is housed in an 8-pin μMAX package (3mm × 3mm × 1.09mm), optimized for space-constrained portable designs. Pin numbering follows standard top-view orientation with Pin 1 at top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-up DC-DC converter applications.

Compared with TPS61022DRVR and SP6650ES-L/TR, MAX1795EUA+T uniquely combines ultra-low shutdown current (2μA), integrated battery monitoring (LBI/LBO active in shutdown), and True Shutdown™ output isolation-making it optimal for long-life, feature-rich portable systems requiring autonomous power management.

Availability

MAX1795EUA+T is available at Aetrix Electronics and suitable for portable digital audio players, wireless handsets, and PDAs requiring stable component supply, long-term lifecycle support, and guaranteed parametric performance across -40°C to +85°C.

Supply support for MAX1795EUA+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for portable, industrial, and communications systems.

The MAX1795EUA+T belongs to Maxim's low-supply-current step-up DC-DC converter family, designed specifically for battery-powered handheld devices needing high efficiency at ultralow input voltages and intelligent power sequencing.

FAQ

What is the minimum input voltage required for MAX1795EUA+T to start up?

The MAX1795EUA+T guarantees startup from +0.85V at +25°C with a 3kΩ load, and operates continuously down to +0.7V after startup. This enables reliable operation from nearly depleted single-cell alkaline or NiMH batteries. Startup voltage varies slightly with temperature (−2.2mV/°C tempco), and the device remains functional across −40°C to +85°C ambient range. Designers should verify startup margin using worst-case battery discharge curves.

How does MAX1795EUA+T achieve 95% efficiency without an external Schottky diode?

The MAX1795EUA+T achieves up to 95% efficiency using an integrated synchronous rectifier: a P-channel MOSFET replaces the external Schottky diode, turning on during the off-time to bypass the body diode conduction loss. With typical R_DS(ON) of 0.27Ω for the PFET and 0.17Ω for the NFET switch, conduction losses are minimized. This eliminates diode forward voltage drop (typically 0.3–0.4V), directly improving light-load efficiency critical for portable standby operation.

Can MAX1795EUA+T monitor battery voltage while in shutdown mode?

Yes-MAX1795EUA+T maintains full functionality of its LBI/LBO comparator during shutdown. When SHDN is high, the DC-DC converter halts switching and OUT goes high-impedance, but the comparator continues sampling the LBI pin and drives LBO accordingly. This allows host systems to detect low-battery conditions and trigger wake-up or graceful shutdown even when the main power rail is disabled-critical for zero-power monitoring in medical or security devices.

What is the purpose of the LX-damping switch in MAX1795EUA+T?

The LX-damping switch in MAX1795EUA+T is an internal resistor (100–400Ω) that connects between LX and BATT during inductor energy depletion, dissipating resonant ring energy quickly. Unlike conventional boost converters where LX ringing causes EMI and potential ESD stress, this feature reduces high-frequency noise without increasing output ripple-verified in typical operating waveforms (Figure 4 vs. Figure 5). It enables cleaner RF coexistence in wireless handsets and audio fidelity in portable players.

How do I configure MAX1795EUA+T for a custom output voltage like 4.2V?

To set MAX1795EUA+T to 4.2V, connect a resistive divider from OUT to FB to GND. Use R2 ≤ 250kΩ (e.g., 200kΩ) and calculate R1 = R2 × ((V_OUT/V_FB) − 1), where V_FB = 1.245V. For 4.2V: R1 ≈ 200kΩ × ((4.2/1.245) − 1) ≈ 475kΩ. Place R1/R2 close to FB with short traces; avoid loading LBI/LBO nodes. Confirm regulation accuracy across temperature using the ±25mV LBI threshold tolerance and V_FB min/max (1.19–1.29V).