Analog Devices Inc./Maxim Integrated MAX764EPA+

Overview

MAX764EPA+ from Maxim Integrated is a high-efficiency, low-quiescent-current inverting DC-DC switching regulator with internal P-channel MOSFET, preset for -5V output, 3V–16V input range, and 250mA output current capability. It delivers up to 1.5W in compact designs for battery-powered portable instruments and LCD bias generation.

For engineers reviewing the MAX764EPA+ datasheet, MAX764EPA+ pinout, MAX764EPA+ application, or MAX764EPA+ equivalent, key selection considerations include its current-limited PFM control scheme (120µA max supply current), -5V fixed output or adjustable mode (-1V to -16V), 300kHz switching frequency enabling <5mm surface-mount magnetics, and operation across -40°C to +85°C industrial temperature range.

Technical Context

The MAX764EPA+ employs a BiCMOS current-limited pulse-frequency-modulated (PFM) control architecture that combines ultra-low light-load quiescent current (<120µA) with high heavy-load efficiency (>80% at 100mA). Its internal P-channel MOSFET features 0.75A peak current limit and 1.4Ω typical on-resistance, enabling continuous-conduction mode operation under medium loads.

It operates from a single positive input (V+) referenced to GND, generating negative output by inverting topology where LX swings between V+ (switch ON) and |VOUT| + diode drop (switch OFF), constrained by 21V absolute V+–VOUT differential. The 1.5V precision reference (±1% over temp) feeds an error comparator driving a dual one-shot timing circuit (16µs max on-time, 2.3µs min off-time) for regulation.

Key Specifications

Pinout & Package

MAX764EPA+ is housed in an 8-pin plastic DIP package (0.300" wide), lead-free and RoHS-compliant per Maxim's standard packaging for this grade.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX774CPA+, MAX764EPA+ offers simpler implementation and lower IQ for ≤1.5W loads; compared with TPS60403DBVR, it delivers 4× higher output current and supports adjustable negative voltages, at the cost of requiring an inductor and slightly higher quiescent draw.

Availability

MAX764EPA+ is available at Aetrix Electronics and suitable for portable instrument power, LCD bias generation, battery-powered remote sensors, LAN adapter auxiliary supply, and industrial embedded systems requiring stable component supply across extended temperature ranges.

Supply support for MAX764EPA+ 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, automotive, and communications markets.

The MAX764EPA+ belongs to Maxim's legacy high-efficiency inverting DC-DC regulator family, designed specifically for low-power, battery-operated systems requiring compact, reliable negative voltage generation without external switches.

FAQ

What is the maximum output current capability of the MAX764EPA+?

The MAX764EPA+ delivers up to 250mA output current when V+ = 16V and VOUT = -5V, as confirmed in the Electrical Characteristics table under "IOUT" parameter. At lower input voltages (e.g., V+ = 5V), maximum output current drops to ~140mA due to power dissipation limits and LX peak current constraint of 0.75A. This is verified in the "Maximum Output Current vs. Supply Voltage" graph (Figure MAX764-04) on page 4 of the datasheet.

Can the MAX764EPA+ generate output voltages other than -5V?

Yes, the MAX764EPA+ supports adjustable output from -1V to -16V using two external resistors (R1 and R2) connected as a voltage divider from OUT to GND, with FB tied to the divider junction. The internal 1.5V reference (REF) sets the regulation point, and R1 is typically fixed at 150kΩ while R2 is calculated per the formula R2 = R1 × |VOUT| / 1.5V. This dual-mode capability is explicitly documented in the General Description and Design Procedure sections.

What is the recommended inductor value for the MAX764EPA+?

A 47µH surface-mount inductor is recommended for most MAX764EPA+ applications, as stated in both the General Description and Design Procedure sections. Inductors in the 22µH–68µH range are acceptable; values below 22µH risk excessive peak current and reduced efficiency, while higher values are permissible but offer diminishing returns. The inductor must support ≥0.75A peak current and exhibit low DC resistance (<100mΩ preferred) to maintain high efficiency.

Does the MAX764EPA+ require an external Schottky diode?

Yes, the MAX764EPA+ requires an external Schottky diode (e.g., 1N5817 or 1N5818) connected between LX and the negative output rail. This is mandated by the inverting topology and high 300kHz switching frequency, which demands fast recovery and low forward voltage. The datasheet explicitly specifies a 0.75A average current rating and recommends Schottky types for best efficiency, noting silicon alternatives (e.g., MUR105) only for high-temperature/light-load edge cases.

How does the shutdown function operate on the MAX764EPA+?

The MAX764EPA+ enters shutdown mode when the SHDN pin is driven high (≥1.6V), reducing supply current to ≤5µA and discharging the OUT node to GND. SHDN is TTL/CMOS-compatible and must be tied to GND for normal operation. During shutdown, internal biasing-including the 1.5V reference-is disabled. This behavior is specified in the Electrical Characteristics table (ISHDN parameter) and detailed in the Shutdown Mode section of the Detailed Description.