Analog Devices Inc./Maxim Integrated MAX1719EUT

Overview

The MAX1719EUT from Maxim Integrated is a monolithic CMOS switched-capacitor voltage inverter with logic-controlled shutdown, designed to generate a regulated negative output (up to –VIN) from a +1.5V to +5.5V input supply. It operates at 125kHz, delivers up to 25mA continuous output current, achieves 99.9% voltage conversion efficiency, and uses only two 1µF external ceramic capacitors. It is commonly used to power analog circuitry requiring local –5V from a +5V logic rail.

For engineers reviewing the MAX1719EUT datasheet, MAX1719EUT pinout, MAX1719EUT application, or MAX1719EUT equivalent, key selection considerations include its 125kHz oscillator frequency, inverted shutdown polarity (SHDN high = shutdown), 6-pin SOT23-6 package, 23Ω typical output resistance at +5V input, and compatibility with low-ESR ceramic flying/output capacitors.

Technical Context

The MAX1719EUT implements a two-phase charge-pump topology using four on-chip power MOSFET switches to invert the input voltage without inductors. Its oscillator frequency is fixed at 125kHz, enabling compact external capacitor sizing while maintaining low output impedance.

Shutdown is active-high for the MAX1719EUT (unlike MAX1720/MAX1721), pulling OUT to GND via a 4Ω internal switch and reducing supply current to 1nA. Output voltage follows VOUT ≈ –(VIN – IOUT × RO), where RO is dominated by switch resistance and capacitor ESR - not regulation.

Key Specifications

Pinout & Package

MAX1719EUT is housed in a 6-pin SOT23-6 package with exposed pad (not thermally enhanced). Pin functions are validated per Maxim's official datasheet (19-1439 Rev 2) and confirmed across multiple distributor schematics (Digi-Key, Mouser).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1721EUT, the MAX1719EUT offers identical efficiency, output capability, and footprint but differs in shutdown polarity - critical for GPIO compatibility. Against MAX860ESA+, the MAX1719EUT trades regulation and output current for smaller size, lower quiescent current, and integrated shutdown.

Availability

MAX1719EUT is available at Aetrix Electronics and suitable for battery-powered equipment, small LCD panels, GaAs PA bias supply, and handheld terminals requiring stable component supply with consistent lead times and full traceability.

Supply support for MAX1719EUT 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 MAX1719EUT belongs to Maxim's switched-capacitor voltage inverter product line, engineered for ultra-small, inductorless negative rail generation in space- and power-constrained portable electronics.

FAQ

What is the shutdown behavior of the MAX1719EUT?

The MAX1719EUT features an inverting shutdown input: driving SHDN high places the device in shutdown mode, reducing supply current to 1nA and actively pulling the OUT pin to GND through a 4Ω internal switch. This behavior is distinct from the MAX1720/MAX1721, which use non-inverting shutdown. The MAX1719EUT remains fully functional under this condition and resumes normal operation within 80µs after SHDN is driven low.

Can the MAX1719EUT generate regulated output voltages?

No, the MAX1719EUT is an unregulated charge-pump inverter. Its output voltage follows VOUT ≈ –(VIN – IOUT × RO), where RO is ~23Ω at +5V input. Output droop increases linearly with load current - for example, at 20mA load, VOUT drops ~460mV below –VIN. For regulated –2×VIN output, Maxim recommends the MAX868; for regulated –VIN, a post-regulator stage is required.

What capacitor values are recommended for the MAX1719EUT?

The MAX1719EUT is optimized for two 1µF X7R ceramic capacitors: C1 (flying capacitor) and C2 (output reservoir capacitor), both with low ESR (<100mΩ). A third 1µF ceramic capacitor (C3) is required as input bypass. Using 10µF capacitors (as in MAX1720) degrades efficiency and increases startup time. Tantalum or electrolytic capacitors are not recommended due to higher ESR and reliability concerns.

How does temperature affect the MAX1719EUT's output resistance?

The MAX1719EUT's output resistance (RO) increases with temperature: from ~20Ω at –40°C to ~35Ω at +85°C (measured at VIN = +5V). This results in greater output voltage droop at elevated temperatures and high load currents. For designs operating across –40°C to +85°C, worst-case droop must be calculated using RO(max) = 35Ω and IOUT(max) = 25mA, yielding up to 875mV droop - critical for analog circuits with tight headroom.

Is the MAX1719EUT pin-compatible with other devices in its family?

Yes, the MAX1719EUT shares identical 6-pin SOT23-6 pinout and package dimensions with MAX1720EUT and MAX1721EUT. All three devices have identical IN, GND, C1+, C1−, OUT, and SHDN pin assignments. However, shutdown polarity differs: MAX1719EUT uses active-high SHDN, while MAX1720EUT/MAX1721EUT use active-low. Swapping them requires logic-level inversion in the control path.