Analog Devices Inc./Maxim Integrated DS2488X+T

Overview

DS2488X+T from Analog Devices is a dual-port 1-Wire bridge IC enabling bidirectional communication, battery charging power delivery, and state reporting between two microcontroller subsystems-e.g., Bluetooth audio SoC in TWS earbuds and case MCU-via single-contact IOA and IOB interfaces. It supports 512kbps pass-through mode, features a factory-programmed 64-bit ROM ID, three open-drain GPIOs (PIOA/PIOB/CD-PIOC), and operates from 1.71V to 3.63V with 5V-tolerant IOA for charger enable.

For engineers reviewing the DS2488X+T datasheet, DS2488X+T pinout, DS2488X+T application, or DS2488X+T equivalent, key selection considerations include its dual 1-Wire arbitration scheme, VL-supplied IOB operation, IOA-based parasitic power and high-voltage detection (4–5V), token-controlled access between ports, and support for UART-to-UART bridging in wearables requiring minimal interconnect.

Technical Context

The DS2488X+T implements a token-based arbitration state machine where TOKEN pin logic level determines active port (IOA = low, IOB = high), and internal 30kHz oscillator drives timer-based transitions. High-voltage detection on IOA (VCMP = 4.0V typ) triggers CD/PIOC activation for external transistor control in power-delivery mode.

Pass-through mode (PTM bit enabled) activates an nMOS bridge with level-shifting capability, requiring VL supply and VPUPA ≥ VL; it enables bidirectional UART data transfer up to 512kbps with automatic timer reset on each falling edge at IOA or IOB.

Key Specifications

Pinout & Package

DS2488X+T uses an 8-ball Wafer-Level Package (WLP) with 0.4mm ball pitch, outline number 21-100497, RoHS-compliant (Z80D1+1 package code).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-interface bridging applications.

Compared with DS2488X+T, DS2482-100+ lacks dual-port arbitration and power-delivery capability, making it unsuitable for earbud-case bridging; MAX14783EASA+ offers higher noise immunity but requires four wires and external protocol handling-neither provides the integrated 1-Wire dual-link, ROM ID, or 4–5V-triggered charger control of DS2488X+T.

Availability

DS2488X+T is available at Aetrix Electronics and suitable for true wireless stereo earbuds, wearable health sensors, and electronic lock systems requiring stable component supply across high-mix, low-volume production cycles.

Supply support for DS2488X+T 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

Analog Devices is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and connectivity applications.

The DS2488X+T belongs to Analog Devices' 1-Wire interface product line, engineered specifically for ultra-low-pin-count, low-power bridging between microcontrollers in space- and cost-constrained consumer electronics like TWS earbuds and smart accessories.

FAQ

What is the primary function of the DS2488X+T in a true wireless stereo system?

The DS2488X+T serves as a dual-port 1-Wire bridge between the Bluetooth audio SoC in each earbud and the charging case MCU. It enables battery status reporting, earbud detection, firmware updates, and charger enable control using only a single contact per earbud-eliminating separate UART or power lines. Its 64-bit ROM ID allows the case to uniquely address left and right earbuds on a shared 1-Wire bus, and its CD/PIOC pin directly controls external charging transistors when IOA detects 4–5V.

Does the DS2488X+T require an external power supply, and if so, which pins depend on it?

Yes-the DS2488X+T requires VL (1.71V to 3.63V) for IOB, PIOA, PIOB, and TOKEN operation. IOA can operate parasitically from its 1-Wire line, but VL is mandatory for pass-through mode and all IOB-side functionality. Without VL, only basic IOA-side communication (e.g., ROM ID read, buffer exchange) is possible; IOB remains inactive. The datasheet specifies VL must be present before enabling 512kbps pass-through mode.

How does the DS2488X+T handle arbitration between its two 1-Wire ports (IOA and IOB)?

The DS2488X+T uses a hardware token arbitration scheme controlled by the TOKEN pin: logic low grants IOA access, logic high grants IOB access. Token assignment is determined by internal state machine logic-including IOA voltage level, timer expiration, and configuration bits (QM, PTM). When IOA detects 4–5V, it automatically yields token to IOB and asserts CD/PIOC; during normal 1-Wire operation, falling edges on either port reset the internal timer to maintain active token ownership-preventing bus lockup in asymmetric traffic scenarios.

Can the DS2488X+T be used without the VL supply in any operational mode?

Yes-but only in limited IOA-only mode. With VL unpowered, DS2488X+T draws parasitic power from IOA and supports ROM ID reads, buffer writes/reads, and GPIO control (PIOA, CD/PIOC) at standard 1-Wire speeds (≤16kbps). However, IOB, PIOB, TOKEN, and pass-through mode are disabled. The device will not respond to IOB commands or generate presence pulses on IOB. For full functionality-including 512kbps bridging, charger control, and dual-port messaging-VL must be supplied.

What is the role of the CD/PIOC pin on the DS2488X+T, and how is it configured?

The CD/PIOC pin on the DS2488X+T is a multifunction terminal controlled by the SEL bit in the configuration register. By default (SEL = 0), it operates as Charger Disable: it floats below 4V IOA and actively pulls low above 4V to enable an external P-channel MOSFET for battery charging. When SEL = 1, it becomes a general-purpose open-drain GPIO (PIOC) referenced to VPUPA. Configuration is performed via the Write Configuration command (0x11); the pin's behavior is hardware-enforced and requires no host polling or software intervention once set.