Analog Devices Inc./Maxim Integrated MAX660ESA

Overview

MAX660ESA from Maxim Integrated is a CMOS monolithic charge-pump voltage converter that inverts +1.5V to +5.5V input to -1.5V to -5.5V output or doubles input to +3.0V to +11.0V, delivers 100mA output current, features selectable 10kHz/80kHz oscillator frequency via FC pin, and operates with only two external capacitors-replacing inductor-based switching regulators in space-constrained battery-powered systems like handheld medical instruments.

For engineers reviewing the MAX660ESA datasheet, MAX660ESA pinout, MAX660ESA application, or MAX660ESA equivalent, this page provides verified electrical parameters, temperature-rated SO-8 package details, inverter/doubler mode configuration guidance, and validated alternatives for low-noise dual-rail power generation in portable instrumentation and op-amp biasing circuits.

Technical Context

The MAX660ESA implements a two-phase switched-capacitor topology with internal MOSFET switches, supporting both inverting and voltage-doubling modes via LV pin configuration (LV = GND for inverter, LV = OUT for doubler). Its oscillator frequency is programmable through FC pin state or external capacitor/clock injection, directly affecting ripple frequency (f_RIPPLE = f_OSC/2) and effective output impedance.

Output regulation is unregulated but highly load-stable due to low 6.5Ω typical output resistance and <0.65V voltage drop at 100mA; performance depends critically on external capacitor ESR and value-C1 handles >4× load current, making low-ESR selection essential for C1 over C2.

Key Specifications

Pinout & Package

MAX660ESA uses an 8-pin SO package (JEDEC MS-012, 150-mil width), with exposed pad not present and no thermal slug. Pin numbering follows standard SO convention: Pin 1 (FC) at top-left corner, counterclockwise to Pin 8 (V+).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage-conversion applications.

Compared with MAX860ESA and ICL7660SIA, the MAX660ESA delivers 2× higher output current and 8.5× lower output resistance, enabling robust dual-rail generation for op-amps and interface ICs without external pass transistors or parallel configurations.

Availability

MAX660ESA is available at Aetrix Electronics and suitable for hand-held medical instruments, operational-amplifier power supplies, laptop peripheral interfaces, and industrial interface power supplies requiring stable component supply across extended temperature ranges.

Supply support for MAX660ESA 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) designs precision analog and mixed-signal ICs for power management, data conversion, and interface applications, with emphasis on high-reliability industrial and medical markets.

The MAX660ESA belongs to Maxim's switched-capacitor voltage converter product line, engineered specifically for inductor-free dual-rail generation in battery-powered portable equipment where size, EMI, and efficiency are critical constraints.

FAQ

What is the maximum input voltage the MAX660ESA can handle?

The MAX660ESA has an absolute maximum supply voltage rating of +6V between V+ and GND. Operation above +5.5V risks permanent damage. For reliable long-term use, the recommended operating input voltage range is +1.5V to +5.5V, as specified in the Electrical Characteristics table under "Operating Supply Voltage." This range ensures full functionality in both inverter and doubler modes without exceeding internal device stress limits.

Can the MAX660ESA generate both positive and negative outputs simultaneously?

No, the MAX660ESA produces only one output voltage per configuration: either inverted (−VIN) or doubled (+2VIN), selected by the LV pin. To generate simultaneous ±VOUT, two MAX660ESA devices must be used-one in inverter mode (LV = GND) and one in doubler mode (LV = OUT)-with shared V+ and GND. Cascading or paralleling requires separate external capacitors per device, as shown in Figures 3 and 4 of the datasheet.

How does the FC pin affect efficiency and thermal performance of the MAX660ESA?

When FC = V+, oscillator frequency increases from 10kHz to 80kHz, raising quiescent current from 120µA to ~1mA but reducing required capacitor values (e.g., 10µF vs. 150µF) and output ripple frequency. Higher frequency lowers effective output impedance at high frequencies but increases switching losses. Thermal performance remains within SO-8 limits up to 100mA at +85°C ambient, as confirmed by the 471mW derated power dissipation rating.

Is the MAX660ESA pin-compatible with the ICL7660, and what are the key functional improvements?

Yes, the MAX660ESA is pin-compatible with the ICL7660 in SO-8 packages. Key improvements include 5× higher output current (100mA vs. 20mA), 8.5× lower output resistance (6.5Ω vs. 55Ω), wider input range (+1.5V–+5.5V vs. +1.5V–+10V), selectable oscillator frequency, and LV pin for low-voltage optimization. These enhancements enable direct replacement in most ICL7660 designs without PCB changes.

What capacitor types and values are recommended for optimal MAX660ESA performance at 100mA load?

For 100mA output, use 150µF aluminum electrolytic capacitors (C1 and C2) with ≤0.2Ω ESR, such as Sanyo MV-GX or Nichicon PL series. Low-ESR tantalum (e.g., AVX TPS) is acceptable for C2 but not recommended for C1 due to higher surge current stress. Ceramic capacitors alone are insufficient-hybrid use (ceramic + electrolytic) may reduce ripple but requires careful ESR balancing per Figure 2 and Capacitor Selection section.