Analog Devices Inc./Maxim Integrated MAX881REVKIT

Overview

The MAX881REVKIT from Maxim Integrated is a fully assembled and tested surface-mount evaluation kit designed to demonstrate the operation of the MAX881R inverting charge-pump DC-DC converter, delivering a regulated -2V output (adjustable) with 1mV_p-p ripple, 4mA output current, and Power OK (POK) monitoring-used for GaAsFET biasing in cellular transmitter stages.

For engineers reviewing the MAX881REVKIT datasheet, MAX881REVKIT pinout, MAX881REVKIT application, or MAX881REVKIT equivalent, this board supports rapid validation of input range (2.5V–5.5V), output voltage adjustment via external resistor divider, POK signal integration, low-noise measurement via integrated scope-probe socket (J1), and shutdown control via JU1 jumper.

Technical Context

The MAX881REVKIT implements the MAX881R IC in its standard 10-pin µMAX package, configured with fixed -2V output by default (R1 uninstalled, R2 = 100kΩ 1%), and includes provisions for adjustable output via R1/R2 voltage divider per the equation R1 = −100kΩ(2 × V_OUT + 1). The board uses four ceramic capacitors: one 4.7µF (C4) and three 1µF (C1–C3) low-ESR units.

It features a dedicated 2-pin shunt header (JU1) to control the SHDN pin (Pin 5) of U1, enabling or disabling the IC; an open JU1 enables operation, while closed disables it. The POK signal is routed to a test pad for system-level monitoring of output regulation status (active-low at ≥92.5% of set voltage).

Key Specifications

Availability

MAX881REVKIT is available at Aetrix Electronics and suitable for RF power amplifier biasing, portable transceiver development, and low-noise negative rail generation requiring stable component supply and fast design validation cycles.

Supply support for MAX881REVKIT 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 MAX881R product line targets compact, low-noise negative voltage generation for RF front-end biasing-specifically optimized for GaAsFETs in cellular handsets and portable wireless transmitters.

FAQ

What is the primary function of the MAX881REVKIT?

The MAX881REVKIT is an evaluation platform for the MAX881R inverting charge-pump DC-DC converter. It provides a ready-to-use hardware implementation to verify the IC's -2V regulated output, low-noise performance (1mV_p-p ripple), POK signaling, and shutdown control-enabling rapid validation of GaAsFET biasing circuits without custom PCB design. The MAX881REVKIT includes all necessary passive components and test points.

How do I adjust the output voltage of the MAX881REVKIT beyond -2V?

To adjust the MAX881REVKIT output voltage, install resistor R1 across its footprint to form a voltage divider with R2 (100kΩ, 1%). Use the formula R1 = −100kΩ(2 × V_OUT + 1) and select a 1% tolerance resistor. For example, for −3V output, R1 = 500kΩ. Ensure C4 remains a low-ESR ceramic capacitor (e.g., 4.7µF or 10µF) to maintain stability and low ripple on the MAX881REVKIT.

What does the JU1 jumper do on the MAX881REVKIT?

The JU1 2-pin header on the MAX881REVKIT directly controls the SHDN (shutdown) pin (Pin 5) of the MAX881R IC. With no shunt installed (open), the IC operates normally; installing a shunt (closed) pulls SHDN low, disabling the converter. This allows hardware-level enable/disable testing and integration into system power sequencing without external logic-critical for validating shutdown behavior on the MAX881REVKIT.

Can I measure output noise directly on the MAX881REVKIT?

Yes-the MAX881REVKIT includes a dedicated Berg Electronics 33JR135-1 scope-probe socket (J1) soldered to the VOUT net. Connect an oscilloscope probe directly to J1 and ensure the probe ground contacts the outer shell of the connector to avoid ground loops. This setup enables accurate measurement of the MAX881REVKIT's 1mV_p-p typical output ripple under load, confirming low-noise performance for RF bias applications.

What is the purpose of the POK pad on the MAX881REVKIT?

The POK (Power OK) pad on the MAX881REVKIT provides access to the MAX881R's open-drain active-low output that signals when the regulated output has reached ≥92.5% of its target value. This allows system designers to monitor power-good status, sequence downstream circuitry, or trigger fault alerts. The POK signal is electrically isolated and routed to a test point-making it easy to integrate into host controller monitoring on the MAX881REVKIT.