Analog Devices Inc./Maxim Integrated MAX765EPA

Overview

The MAX765EPA from Maxim Integrated is a -12V fixed-output, high-efficiency inverting DC-DC switching regulator with internal P-channel power MOSFET, 250mA output current capability, 120µA max supply current, and 300kHz switching frequency - used in portable instruments and remote data-acquisition systems requiring compact negative voltage generation.

For engineers reviewing the MAX765EPA datasheet, MAX765EPA pinout, MAX765EPA application, or MAX765EPA equivalent, this page delivers verified electrical parameters, validated package mapping (8-pin plastic DIP), confirmed pin functions, thermal performance across -40°C to +85°C, and real-world design constraints including VIN–VOUT differential limit (20V) and LX peak current (0.75A).

Technical Context

The MAX765EPA employs a proprietary current-limited pulse-frequency-modulated (PFM) control scheme that enforces a 16µs maximum on-time and 2.3µs minimum off-time, enabling >80% efficiency across 0.1mA–250mA loads while maintaining ultra-low quiescent current. Its BiCMOS architecture integrates a 1.5V reference, error comparator, and current-sense circuitry to regulate output via feedback at the FB pin.

It operates in either fixed-output mode (FB tied to REF) or adjustable mode (external resistor divider), with output voltage settable from -1V to -16V. The internal P-channel MOSFET features 1.4Ω typical on-resistance and supports peak currents up to 0.75A, enabling continuous conduction at full load without external switch components.

Key Specifications

Pinout & Package

MAX765EPA is housed in an 8-pin plastic DIP (dual in-line package) with 0.3-inch body width and through-hole mounting. Pin 1 is marked by a notch or dot; pins are numbered counter-clockwise from top-left.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar inverting DC-DC regulator applications.

Compared with MAX775EPA and LM2662MX/NOPB, the MAX765EPA offers optimal balance of integration, efficiency, and load capability for medium-power inverting applications - delivering 250mA at -12V with no external switch or timing components, while maintaining sub-120µA quiescent current.

Availability

MAX765EPA is available at Aetrix Electronics and suitable for LCD-bias generators, portable instruments, and remote data-acquisition systems requiring stable component supply with extended temperature support (-40°C to +85°C) and long-term industrial availability.

Supply support for MAX765EPA 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 industrial, communications, and consumer applications.

The MAX764/MAX765/MAX766 family was designed specifically for compact, high-efficiency negative voltage generation in battery-powered and space-constrained systems - emphasizing ultra-low IQ, integrated power switches, and wide input/output flexibility.

FAQ

What is the maximum allowable VIN–VOUT differential for MAX765EPA?

The MAX765EPA has an absolute maximum VIN–VOUT differential of 20V. This constraint arises from the LX pin's voltage swing range (from V+ to |VOUT| + diode drop). Exceeding 20V risks permanent damage to the internal P-channel MOSFET. For example, with VOUT = -12V, VIN must not exceed +8V; with VIN = 16V, VOUT must not be more negative than -4V. Always verify differential compliance in worst-case operating conditions.

Can MAX765EPA operate with an input voltage lower than 3V?

No - the MAX765EPA requires a minimum input voltage of 3.0V to start and maintain regulation. Below 3.0V, the device fails to initiate switching, and output voltage collapses. Startup behavior is confirmed in the "Start-Up Supply Voltage vs. Output Current" graph (Figure MAX764-11), which shows functional operation begins at exactly 3.0V under all load conditions. No brown-out recovery or hysteresis is implemented.

How does the MAX765EPA achieve high efficiency at light loads?

The MAX765EPA achieves high light-load efficiency via its current-limited PFM scheme: it initially limits peak inductor current to half the 0.75A maximum (i.e., 0.375A) for the first two switching pulses. If regulation is restored, it holds that reduced current limit; otherwise, it escalates to full 0.75A. This minimizes switching losses and magnetic core losses at low output currents, sustaining >75% efficiency even at 1mA load.

What is the recommended inductor for MAX765EPA in fixed -12V operation?

A 47µH surface-mount inductor with ≤100mΩ DC resistance and ≥0.75A saturation current is recommended for MAX765EPA in fixed -12V operation. Examples include Coilcraft DO3316P-473ML or Sumida CDRH8D28-470NC. Ferrite-core construction is required to handle 300kHz switching; toroidal or shielded types minimize radiated noise. Inductor selection directly impacts ripple, efficiency, and thermal rise - undersized inductors cause excessive peak current and reduced efficiency.

Is MAX765EPA pin-compatible with MAX764EPA or MAX766EPA?

Yes - MAX765EPA is pin-compatible with MAX764EPA (-5V) and MAX766EPA (-15V) in the same 8-pin DIP package. All three share identical pinout, electrical interface, and control logic. The only functional difference is the factory-trimmed output voltage: MAX764EPA regulates to -5V, MAX765EPA to -12V, and MAX766EPA to -15V. No PCB changes are required when substituting between these variants for system-level voltage scaling.