Analog Devices Inc./Maxim Integrated MAX680CSA+

Overview

The MAX680CSA+ from Maxim Integrated is a monolithic CMOS dual charge-pump voltage converter that generates ±10V outputs from a single +5V input supply, featuring 8kHz internal oscillator, 150Ω typical positive output source resistance, 90Ω typical negative output source resistance, and requires only four external capacitors. It is used in analog circuitry power supplies where space-constrained designs need bipolar rails without inductors.

For engineers reviewing the MAX680CSA+ datasheet, MAX680CSA+ pinout, MAX680CSA+ application, or MAX680CSA+ equivalent, key selection criteria include input voltage range (+2V to +6V), output source impedance temperature dependence, ±10V load regulation at ≤10mA, SO-8 package footprint compatibility, and absence of integrated capacitors compared to MAX681.

Technical Context

The MAX680CSA+ implements two independent switched-capacitor charge pumps: a positive doubler (V+ = 2×VCC) and an inverting negative pump (V− derived from V+). Its on-chip 8kHz oscillator drives complementary CMOS switch pairs (P- and N-channel MOSFETs) with fixed 50% duty cycle, enabling discrete-phase pumping without external clocking.

Output regulation is unregulated-V+ and V− droop linearly with load current per their respective source resistances (RS+ ≈150Ω, RS− ≈90Ω at +25°C, VCC=5V). Ripple is determined by reservoir capacitance (e.g., 10µF) and 8kHz switching frequency, yielding ~30mV_p-p at 5mA load.

Key Specifications

Pinout & Package

MAX680CSA+ is housed in an 8-pin narrow SO (SOIC-8) package, 3.9mm × 4.9mm body, 1.27mm pitch, RoHS-compliant. Pin functions are validated per Maxim's official MAX680 datasheet (Rev 2, 7/19) and confirmed on Maxim's package drawings.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX680CSA+, MAX681CPD removes external capacitor dependencies at the cost of larger package and fixed internal values, while MAX864CPA trades lower quiescent current for higher-frequency operation and stricter layout requirements-making MAX680CSA+ optimal for cost-sensitive, moderate-ripple SO-8 designs needing field-proven reliability.

Availability

MAX680CSA+ is available at Aetrix Electronics and suitable for data-acquisition systems, handheld instruments, and operational amplifier power supplies requiring stable component supply and long-term industrial availability.

Supply support for MAX680CSA+ 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 applications.

The MAX680CSA+ belongs to Maxim's legacy charge-pump voltage converter product line, designed specifically for compact, inductorless generation of bipolar rails in battery-powered and space-constrained analog systems.

FAQ

What is the maximum continuous output current supported by the MAX680CSA+?

The MAX680CSA+ delivers up to 10mA from the V+ output and 10mA from the V− output under typical conditions (VCC = 5V, TA = +25°C), limited by its 150Ω positive and 90Ω negative output source resistances. At 10mA load, V+ droops ~1.5V and V− droops ~0.9V, resulting in ~+8.5V and ~−9.1V outputs. Derating is required at elevated temperatures or higher supply voltages.

Can the MAX680CSA+ operate from a 3V lithium battery?

Yes, the MAX680CSA+ operates from +2.0V to +6.0V, making it fully compatible with 3V lithium coin cells and primary batteries. At VCC = 3V, it produces ~±6V no-load outputs. Its 1mA typical quiescent current extends battery life significantly, and output droop remains predictable using RS+ and RS− values specified across temperature.

Does the MAX680CSA+ require external timing components?

No, the MAX680CSA+ includes a fully integrated 8kHz oscillator, eliminating the need for external resistors, capacitors, or clock sources. This simplifies design, improves reliability, and ensures consistent switching frequency across voltage and temperature ranges without calibration.

How does the MAX680CSA+ differ from the MAX681 in terms of external component count?

The MAX680CSA+ requires four external electrolytic capacitors (C1–C4) to function, whereas the MAX681 integrates all four capacitors internally. This makes MAX680CSA+ more flexible for optimizing capacitor type, value, and voltage rating-but increases BOM count and layout area compared to the MAX681's self-contained solution.

Is the MAX680CSA+ pin-compatible with other devices in the MAX680 family?

Yes, all MAX680 variants-including MAX680CPA, MAX680CSA+, MAX680EPA, and MAX680ESA-share identical 8-pin SO/DIP pinouts and electrical specifications; only temperature range and package differ. This enables drop-in replacement across grades without PCB redesign, provided thermal and environmental requirements are met.