Analog Devices Inc./Maxim Integrated MAX864EEE+

Overview

MAX864EEE+ from Maxim Integrated is a CMOS dual-output charge-pump DC-DC converter that generates +2V_IN and −2V_IN from a single +1.75V to +6.0V input, requires only four external capacitors, delivers up to 20mA output current per rail, features pin-selectable switching frequencies (7–185kHz), and includes 1µA logic-controlled shutdown. It serves as a compact split-supply generator for GaAsFET bias and analog circuitry in space-constrained portable systems.

For engineers reviewing the MAX864EEE+ datasheet, MAX864EEE+ pinout, MAX864EEE+ application, or MAX864EEE+ equivalent, key selection criteria include input voltage range (+1.75V to +6.0V), dual-rail output capability (±2×VIN), 16-pin QSOP package footprint compatibility, shutdown quiescent current (≤1µA), and frequency-programmable operation for capacitor size vs. supply current trade-offs.

Technical Context

The MAX864EEE+ implements a two-stage charge-pump architecture: first a voltage-doubling stage (C1/C2 flying caps), then an inverting stage (C2/C4) deriving V− from the boosted V+. Its internal oscillator supports four discrete frequencies via FC0/FC1 logic inputs, directly determining capacitor sizing and efficiency across load conditions.

Output regulation is unregulated-V+ and V− droop linearly with load due to fixed 55Ω typical source impedance (at +25°C, VIN = 5V). Shutdown disconnects internal switches and routes V+ to IN via 22Ω and V− to GND via 6Ω, enabling rapid wake-up while limiting leakage to ≤1µA over −40°C to +85°C.

Key Specifications

Pinout & Package

MAX864EEE+ is housed in a 16-pin QSOP package (3.99mm × 4.98mm footprint), pin-compatible with industry-standard 16-pin SOIC but with 0.635mm lead pitch and 1.73mm max height. N.C. pins (9, 10, 13, 14) must be connected to ground for thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output charge-pump applications.

Compared with MAX865EUA+, MAX864EEE+ trades smaller footprint for full frequency programmability and QSOP thermal performance; compared with TPS60403DBVR, it offers lower quiescent current and simpler BOM at the expense of peak output current and soft-start functionality.

Availability

MAX864EEE+ is available at Aetrix Electronics and suitable for low-voltage GaAsFET bias, split-supply data-acquisition systems, and LCD panel bias applications requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MAX864EEE+ 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and consumer markets.

The MAX864EEE+ belongs to Maxim's charge-pump DC-DC converter product line, designed specifically to replace inductor-based solutions in space- and cost-sensitive portable electronics requiring compact, low-noise dual-rail generation.

FAQ

What is the minimum input voltage required for MAX864EEE+ startup?

The MAX864EEE+ has a minimum start-up voltage of +1.25V (typical) and +1.75V (guaranteed operational range). Below +1.25V, the internal oscillator may not initiate; stable dual-rail operation is only ensured above +1.75V across the full −40°C to +85°C temperature range. Always verify startup behavior under worst-case battery discharge conditions before final design sign-off.

Can MAX864EEE+ drive loads exceeding 20mA on both V+ and V− simultaneously?

No-MAX864EEE+ specifies 20mA maximum per rail under typical conditions (VIN = 5V, +25°C). Simultaneous loading causes cumulative droop: V+ droop = (I_V+ + I_V−) × R_S+, V− droop = I_V− × R_S−. At 20mA each, V+ drops ~2.2V and V− drops ~1.1V, degrading regulation. For >20mA total, parallel MAX864EEE+ units or higher-current alternatives like TPS60403 are recommended.

How does frequency selection affect output ripple in MAX864EEE+?

Higher pump frequencies (e.g., 185kHz) reduce output ripple for a given capacitor value-e.g., 1µF yields ~40mV_p-p at 185kHz vs. ~350mV_p-p at 7kHz (VIN = 1.9V). However, ripple also depends on capacitor ESR and load current. To halve ripple, double C3/C4 values *and* maintain low-ESR ceramics-frequency alone cannot compensate for poor capacitor selection in MAX864EEE+ designs.

Is MAX864EEE+ pin-compatible with other Maxim charge pumps like MAX865?

No-MAX864EEE+ uses a 16-pin QSOP package with dedicated FC0/FC1, SHDN, and dual flying-capacitor terminals; MAX865EUA+ uses an 8-pin µMAX package with fixed 185kHz operation and no frequency control pins. While functionally similar, their pinouts, footprints, and control interfaces are incompatible-PCB redesign is required for substitution.

What happens to V+ and V− outputs during MAX864EEE+ shutdown?

During MAX864EEE+ shutdown (SHDN = LOW), V+ is internally connected to IN through a 22Ω switch and V− is connected to GND through a 6Ω switch. This discharges both outputs toward their respective reference potentials, preventing floating rails and reducing system-level leakage. Recovery time to full output is typically <1ms after SHDN returns HIGH, as confirmed in Figure 19 of the MAX864EEE+ datasheet.