Analog Devices Inc./Maxim Integrated DS2490S+

Overview

DS2490S+ from Maxim Integrated is a USB-to-1-Wire bridge IC that enables full-speed 12Mbps USB host communication with 1-Wire buses, supports regular/overdrive/flexible 1-Wire speeds, provides active 5V strong pullup and slew-rate-controlled timing for long-line networks up to 300m, and operates from 0°C to +70°C in a 24-pin SOIC package.

For engineers reviewing the DS2490S+ datasheet, DS2490S+ pinout, DS2490S+ application, or DS2490S+ equivalent, key selection criteria include USB remote wake-up capability, programmable 1-Wire timing (tLOW1, tDSO, slew rate), crystal-based oscillator accuracy, integrated USB transceiver compliance, and support for stiff 5V pullup on EEPROMs, sensors, and iButton devices.

Technical Context

The DS2490S+ integrates a USB 1.1 device controller with vendor-specific command handling, a dedicated 1-Wire interface controller featuring active edge shaping and non-TTL threshold sensing, and a 12MHz crystal oscillator for precise waveform timing. It implements four USB endpoints (EP0–EP3) across four alternate interface settings to support configurable interrupt polling (1ms or 10ms) and bulk packet sizes (16B or 64B).

Its 1-Wire interface delivers programmable pulldown slew rate (target 4±0.5µs fall time), flexible Write-1 low time (4–11µs), data sample offset (10–24µs), and strong pullup duration control-including semi-infinite and infinite modes-with hardware-based active pullup current switching (IWEAKPU → IACTPU) timed by internal thresholds (VIAPO, VIAPTO).

Key Specifications

Pinout & Package

DS2490S+ is housed in a 24-pin SOIC (300-mil) package with exposed pad not connected internally. Pin functions are validated per Maxim's official DS2490 datasheet Rev. 19-4993.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar USB-to-1-Wire bridge applications.

Compared with DS9490R and TUSB3410, the DS2490S+ delivers integrated 1-Wire timing control, active 5V pullup, and overdrive support in a minimal-footprint 24-pin SOIC - making it optimal for space-constrained embedded USB peripherals where deterministic 1-Wire performance is critical.

Availability

DS2490S+ is available at Aetrix Electronics and suitable for industrial asset tagging, secure access control, environmental sensor hubs, legacy system modernization, and USB peripheral development requiring stable component supply and long-term lifecycle assurance.

Supply support for DS2490S+ 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) designs precision analog, mixed-signal, and digital ICs for industrial, medical, communications, and computing applications.

The DS2490S+ belongs to Maxim's 1-Wire interface product line, engineered specifically to simplify USB host connectivity to 1-Wire sensor, memory, and security devices while maintaining full protocol compliance and timing fidelity.

FAQ

What is the primary function of the DS2490S+?

The DS2490S+ is a dedicated USB-to-1-Wire bridge IC that converts USB host commands into precisely timed 1-Wire communication sequences. It handles all physical-layer requirements - including reset/presence detection, read/write time slots, strong pullup generation, and slew-rate-controlled edges - freeing the host from low-level timing management. Its crystal-based oscillator ensures consistent performance across temperature and voltage variations, making DS2490S+ ideal for industrial-grade 1-Wire peripherals.

Does the DS2490S+ support overdrive 1-Wire speed?

Yes, the DS2490S+ fully supports overdrive 1-Wire speed with nominal timing values of tRSTL = 64µs and tSLOT = 10.4µs. It achieves this using its internal 12MHz crystal oscillator for accurate waveform generation and includes dedicated overdrive-mode timing registers. The DS2490S+ also allows dynamic switching between regular, overdrive, and flexible speeds via MODE_CMD commands - a capability confirmed in Maxim's DS2490 datasheet Rev. 19-4993 section "1-Wire Speed Codes".

What is the purpose of the SUSO pin on the DS2490S+?

The SUSO (Suspend Output) pin on the DS2490S+ is an open-drain output that reflects the USB suspend state: HIGH indicates active USB communication, LOW indicates suspended state. This signal enables external circuitry - such as power switches or status LEDs - to respond to USB power management events without host polling. As specified in the DS2490 datasheet section "SUSPEND OUTPUT", SUSO is driven directly by the USB device controller and requires an external pullup resistor to function correctly in DS2490S+ designs.

Can the DS2490S+ drive long 1-Wire networks?

Yes, the DS2490S+ is explicitly designed for long 1-Wire networks up to 300m. It achieves this through slew-rate-controlled falling edges (target fall time 4±0.5µs), active 5V strong pullup with threshold-triggered current switching, and non-TTL input threshold sensing for improved noise margin. These features are documented in the DS2490 datasheet sections "SLEW RATE CONTROL" and "1-Wire Interface Controller", confirming DS2490S+ suitability for large-scale sensor deployments where cable capacitance and EMI would disrupt standard 1-Wire interfaces.

Is the DS2490S+ RoHS-compliant?

Yes, the DS2490S+ is RoHS-compliant and lead(Pb)-free, as indicated by the "+" suffix in its ordering part number per Maxim's official documentation. The DS2490S+T&R tape-and-reel variant meets EU RoHS Directive 2011/65/EU requirements, with all homogeneous materials verified to contain ≤0.1% lead by weight. This compliance is stated in the "ORDERING INFORMATION" table of the DS2490 datasheet Rev. 19-4993 and applies to both DS2490S+ and DS2490S+T&R variants.