Analog Devices Inc./Maxim Integrated MAX1044EPA+

Overview

MAX1044EPA+ from Maxim Integrated is a monolithic CMOS switched-capacitor voltage converter IC designed for inverting, doubling, dividing, or multiplying input voltages in low-power analog and mixed-signal systems. It operates from 1.5V to 10V supply, delivers up to 10mA output current with ≤0.5V drop at full load, and features a BOOST pin that raises oscillator frequency by ~6× to reduce capacitor size and shift noise out of audio band. It is commonly used to generate -5V from +5V logic supplies for op-amp biasing in portable instrumentation.

For engineers reviewing the MAX1044EPA+ datasheet, MAX1044EPA+ pinout, MAX1044EPA+ application, or MAX1044EPA+ equivalent, key selection criteria include its -40°C to +85°C industrial temperature rating, BOOST-enabled high-frequency operation (up to ~60kHz), no-external-diode architecture, 98% typical power-conversion efficiency, and compatibility with legacy ICL7660/LTC1044 designs requiring minimal layout changes.

Technical Context

The MAX1044EPA+ implements a charge-pump topology using four on-chip power MOSFET switches, an internal oscillator, and control circuitry to synthesize negative, doubled, halved, or multiplied output voltages without inductors. Its BOOST pin directly modulates oscillator frequency-connecting BOOST to V+ increases f_OSC from ~10kHz (open) to ~60kHz-reducing output impedance and ripple while enabling smaller external capacitors (e.g., 1μF instead of 10μF).

Unlike the ICL7660, the MAX1044EPA+ supports active LV pin control across full supply range (1.5V–10V), allowing optimized low-voltage startup and performance down to 1.5V. Its output voltage is unregulated and load-dependent, with typical output resistance of 65Ω (25°C, 5kHz f_OSC), resulting in ~-4.5V output under 10mA load from 5V input.

Key Specifications

Pinout & Package

MAX1044EPA+ uses an 8-pin plastic DIP package (0.300" wide) with through-hole mounting and RoHS-compliant lead finish. Pin spacing is 0.100", and body dimensions are 0.300" × 0.400".

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar switched-capacitor voltage converter applications.

Compared with ICL7660EPA and MAX660ESA+, the MAX1044EPA+ uniquely balances ultra-low quiescent current (200μA), BOOST-enabled ripple reduction, and full industrial temperature support in a legacy-compatible DIP package - making it optimal for cost-sensitive, noise-aware, and battery-operated instrumentation.

Availability

MAX1044EPA+ is available at Aetrix Electronics and suitable for portable telephones, EIA/TIA-232E interfaces, and handheld instruments requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX1044EPA+ 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 MAX1044 product line delivers compact, inductorless voltage conversion for space- and power-constrained systems - designed specifically to replace legacy ICL7660 solutions with enhanced frequency control and wider operating margins.

FAQ

What is the maximum output current of the MAX1044EPA+ and how does load affect output voltage?

The MAX1044EPA+ delivers up to 10mA output current with a maximum 0.5V output drop under full load. Due to its unregulated charge-pump architecture, output voltage decreases linearly with load: for example, from -5.0V at no load to approximately -4.5V at 10mA when powered from 5V, based on a typical 65Ω output resistance. This behavior is confirmed in the Electrical Characteristics table and Figure 1 of the datasheet.

Can the MAX1044EPA+ operate from a 1.5V supply, and what configuration is required?

Yes, the MAX1044EPA+ is fully specified to operate from 1.5V to 10V. To ensure reliable startup and stable oscillation at 1.5V–3.5V, the LV pin (pin 6) must be connected to GND. This bypasses the internal regulator and enables low-voltage operation - a requirement explicitly stated in the Design Information section and validated across the -40°C to +85°C temperature range.

How does the BOOST pin on the MAX1044EPA+ affect oscillator frequency and system performance?

Connecting the BOOST pin (pin 1) to V+ raises the internal oscillator frequency by approximately six times - e.g., from ~10kHz to ~60kHz. This reduces output impedance, cuts output ripple by over 50%, allows use of smaller external capacitors (e.g., 1μF instead of 10μF), and shifts switching noise above the audio band. These effects are quantified in Figures 1–3 and the Oscillator Frequency Considerations section.

Is the MAX1044EPA+ pin-compatible with the ICL7660EPA, and are there any functional differences?

Yes, the MAX1044EPA+ is pin-compatible with the ICL7660EPA in the 8-pin DIP package, sharing identical pin assignments for V+, GND, CAP+, CAP-, VOUT, LV, OSC, and package outline. The only functional difference is the presence of the BOOST pin (pin 1) on the MAX1044EPA+, which is N.C. on the ICL7660EPA - allowing direct replacement where BOOST functionality is unused.

What external components are required for basic inverting operation of the MAX1044EPA+?

For basic -V+ inverting operation, the MAX1044EPA+ requires two external electrolytic or ceramic capacitors: C1 (charge-pump capacitor, typically 10μF) connected between CAP+ (pin 2) and CAP- (pin 4), and C2 (reservoir capacitor, also 10μF) connected between VOUT (pin 5) and GND (pin 3). A 0.1μF ceramic bypass capacitor between V+ (pin 8) and GND is also recommended to suppress supply noise.