DS2450S - 16-Bit 1-Wire Quad ADC | Maxim Integrated | SOIC-8
Référence : DS2450S ✗ Fin de vieDS2450S Présentation
A 1-Wire ADC combines the functions of an analog-to-digital converter with a single-wire serial interface. The 1-Wire protocol is a proprietary Dallas/Maxim bus standard that uses a single bidirectional data line (plus ground return) to carry both power and communication, allowing multiple devices to share one master GPIO pin. The DS2450S is part of the broader ADC family (successive-approximation ADC -> ADC -> data converter -> mixed-signal IC) and is uniquely positioned at the sensing edge of distributed 1-Wire networks where each node needs local analog measurement.
Key features include 1-Wire parasitic power support (with optional external VCC), four independently configurable analog input channels, user-programmable resolution per channel, hardware alarm thresholds with conditional-search participation, and on-chip SRAM that retains the channel configuration while the device is powered. The DS2450S also exposes a power-on-reset flag so the bus master can detect when channel settings must be restored.
The architecture combines a capacitive-charge-distribution SAR core with an input multiplexer and per-channel configuration memory. The 1-Wire engine implements the standard Dallas hierarchical command set (ROM functions, memory functions, conditional search) and provides a 64-bit unique serial number for multi-drop identification. Total conversion time scales with resolution: at 12 bits across four channels, a full sweep takes roughly 4 ms.
Typical applications include remote environmental monitoring (temperature, pressure transducer excitation read-back), industrial 4-20 mA loop digitization, building automation sensor nodes, battery monitoring, and any multi-channel analog sensing point that benefits from the 1-Wire bus's wire-count savings. The conditional-search feature allows a master to poll many DS2450S devices simultaneously to detect which ones have crossed an alarm threshold.
When designing with the DS2450S, plan bus topology carefully: 1-Wire networks require a strong pull-up during the low-impedance slot, and long cables degrade rise times. Use a 4.7 kΩ pull-up with short stubs, and budget conversion latency per channel when the master polls multiple devices. The DS2450S is in NRND/EOL status, so new designs should evaluate the modern DS2450 or successor 1-Wire ADCs.
This page synthesizes distributor pricing, drop-in package equivalents, and practical 1-Wire bus design notes not collated in the manufacturer datasheet, giving procurement and design engineers a faster path from specification to working hardware.
Alternatives de remplacement direct pour DS2450S — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec DS2450S (même facteur de forme et même empreinte) — différant par Input Voltage Range, Resolution, Active Power Consumption, Architecture, Conditional Search.
DS2450S+
✅ Remplacement directContactez-nous pour le prix
Voir la fiche technique →DS2450S+T&R
✅ Remplacement directContactez-nous pour le prix
Voir la fiche technique →DS2450
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
DS2450S Valeurs maximales et caractéristiques électriques
| Résolution | 16 bit |
| Number of Channels | 4 input / 1 ADC (4-to-1 mux) |
| ADC Architecture | Successive Approximation (SAR) |
| Plage de tension d'entrée | 0 V to 2.56 V or 0 V to 5.12 V (user-programmable per channel) |
| Programmable Resolution | 1 to 16 bits per channel |
| Communication Interface | Dallas 1-Wire (single-wire, parasitic-power capable) |
| Tension d'alimentation | 5 V single supply (parasitic or external VCC) |
| Active Power Consumption | 2.5 mW (typical) |
| Idle Power Consumption | 25 µW (typical) |
| Unique Serial Number | 64-bit 1-Wire ROM ID (per device) |
| On-chip Memory | SRAM for per-channel range/resolution/alarm settings |
| Conditional Search | Yes (per-channel alarm flag participation) |
| Power-on Reset Flag | Yes (master detects need to restore settings) |
| Boîtier | 8-pin SOIC (SO-8) |
| Température de fonctionnement | -40C to +85C (industrial) |
Configuration des broches de DS2450S
| Broche 1 | GND — Ground return for 1-Wire bus and analog signals |
| Broche 2 | DQ — 1-Wire data line (bidirectional, open-drain, requires external pull-up) |
| Broche 3 | VCC — Optional external 5V supply (leave open for parasitic power) |
| Broche 4 | AD4 — Analog input channel 4 (0 to 2.56V or 5.12V) |
| Broche 5 | AD3 — Analog input channel 3 (0 to 2.56V or 5.12V) |
| Broche 6 | AD2 — Analog input channel 2 (0 to 2.56V or 5.12V) |
| Broche 7 | AD1 — Analog input channel 1 (0 to 2.56V or 5.12V) |
| Broche 8 | NC — Not connected (per datasheet) |
Applications typiques
DS2450S convient pour 6 applications: Distributed Environmental Monitoring, Industrial 4-20 mA Loop Digitization, Building Automation Sensor Nodes, Remote Battery Monitoring, HVAC and Refrigeration Sensing, Multi-Sensor Weather Stations.
Distributed Environmental Monitoring
The DS2450S brings 16-bit ADC resolution to 1-Wire sensor networks that already mix DS18B20 temperature sensors and DS2406 switches, allowing engineers to add voltage-mode humidity, soil-moisture, or photodiode channels without adding new wiring. Each of the four inputs is independently programmable for 2.56V or 5.12V range and 1 to 16 bits of resolution, so a single part can digitize a 1.2V reference and a 4.5V battery simultaneously. The on-chip alarm thresholds and conditional-search flag let a master scan hundreds of nodes and identify only those that crossed limits, dramatically reducing bus traffic in large deployments. Active power of 2.5 mW allows parasitic-power operation in most cable lengths. Per-channel resolution is set in on-chip SRAM, which the master restores after the part's power-on-reset flag asserts on each power-up.
Recommandé
Industrial 4-20 mA Loop Digitization
The DS2450S accepts 0 to 5.12V inputs that map cleanly onto the 1-5V drop across a 250-ohm loop-sense resistor, allowing direct digitization of 4-20 mA industrial transmitters without instrumentation amplifiers. Its 16-bit resolution delivers 13 bits of useful span across the 4-20 mA live-zero region, sufficient for most process-control monitoring. The 1-Wire interface means a single CAT5 cable can carry power, ground, and bidirectional data for up to dozens of loop readings, slashing conduit cost in retrofit installations. Per-channel alarm registers let the master flag loops that drift out of range without polling every channel at full resolution. Active power is 2.5 mW and idle is 25 µW, so loop-power budgeting is rarely a concern.
Recommandé
Building Automation Sensor Nodes
The DS2450S is a natural fit for low-cost building-automation nodes that combine light, CO2 reference voltage, occupancy-indicator voltage, and thermistor-divider signals on one 1-Wire bus drop. With four independent inputs and programmable 1-16 bit resolution, designers can allocate 16 bits to lighting-level photodiodes and only 8 bits to simple occupancy flags, optimizing total conversion latency. The 1-Wire parasitic-power capability eliminates the need for a local regulator at each node, while the 64-bit ROM ID provides per-node addressing for commissioning software. Conditional search enables the BMS master to wake only the sensors whose readings crossed setpoints, saving bus bandwidth on quiet nights. Per-channel configuration is stored in on-chip SRAM and reloaded by the master after each power-on-reset.
Recommandé
Remote Battery Monitoring
The DS2450S can digitize up to four battery-cell voltages in a single 1-Wire node, with per-channel 0-5.12V range covering Li-ion and lead-acid chemistries without external dividers for cells up to 5 V nominal. Resolution is user-programmable from 1 to 16 bits, so a 12-bit sweep across four cells completes in about 4 ms - fast enough for periodic log-rate sampling. Active 2.5 mW and idle 25 µW power draw means the part can be parasitically powered from the 1-Wire bus while idle, drawing from the battery only during conversion. Per-channel alarm thresholds can flag over-voltage or under-voltage conditions without master intervention. This makes DS2450S well-suited for backup-battery health monitoring in telecom and UPS installations.
Recommandé
HVAC and Refrigeration Sensing
The DS2450S provides four 16-bit-capable analog inputs that map directly onto common HVAC transducer outputs: temperature-divider voltage, humidity-sensor voltage, refrigerant-pressure transducer 0-5V, and indoor-air-quality sensor output. Its -40C to +85C industrial temperature range covers most rooftop and chiller environments, and the 8-pin SOIC package simplifies conformal-coated board layouts. With 1-Wire parasitic power and the conditional-search alarm flag, the unit controller can poll hundreds of rooftop units and only respond to those whose readings crossed service thresholds. Per-channel resolution can be reduced to 8 bits for non-critical humidity channels, freeing conversion bandwidth for 16-bit pressure readings.
Recommandé
Multi-Sensor Weather Stations
The DS2450S digitizes four analog weather-sensor channels - wind-direction potentiometer, solar-radiation pyranometer, soil-moisture voltage, and rain-gauge reference - over a single 1-Wire drop that can share cable runs with DS18B20 temperature sensors. The 16-bit resolution captures the full dynamic range of the pyranometer, while the 0-5.12V range accommodates the wind-direction pot's full sweep without external scaling. Conditional-search alarm flags can notify the master when wind speed (read via frequency elsewhere) correlates with dangerous direction changes. Parasitic 1-Wire power keeps the weather-station cabling to two conductors (data + ground), a major advantage at remote mounting points. Active 2.5 mW and idle 25 µW consumption fit within parasitic-power budgets on most days.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour DS2450S — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | DS2450S+ | DS2450S+T&R | DS2450 |
|---|---|---|---|---|
| Package | 8-pin SOIC | 8-pin SOIC - same | 8-pin SOIC - same | 8-pin SOIC - same |
| Brand | Analog Devices (formerly Maxim/Dallas) | Analog Devices - same | Analog Devices - same | Analog Devices - same |
| Resolution | 16 bit (1-16 bit programmable) | 16 bit - same | 16 bit - same | 16 bit - same |
| Analog Input Channels | 4 (multiplexed to 1 SAR ADC) | 4 - same | 4 - same | 4 - same |
| Input Voltage Range | 0-2.56V or 0-5.12V (per channel) | 0-2.56V or 0-5.12V - same | 0-2.56V or 0-5.12V - same | 0-2.56V or 0-5.12V - same |
| Communication Interface | Dallas 1-Wire | Dallas 1-Wire - same | Dallas 1-Wire - same | Dallas 1-Wire - same |
| Active Power | 2.5 mW | 2.5 mW - same | 2.5 mW - same | 2.5 mW - same |
| Idle Power | 25 µW | 25 µW - same | 25 µW - same | 25 µW - same |
Principaux différenciateurs
- Integrated 1-Wire protocol and parasitic power capability (vs ADS1110A6IDBVR (I2C 16-bit ADC))
- Four independent input channels in one SOIC-8 package (vs DS2438 (1-Wire battery monitor with single 10-bit ADC))
- User-programmable per-channel resolution and alarm thresholds (vs Generic 1-Wire temperature-only devices like DS18B20)
Notes de conception
The 1-Wire DQ pin requires an external pull-up resistor, typically 4.7 kΩ to VCC (or to the same rail powering the master). For long cable runs (>30 m), lower the pull-up to 2.2 kΩ to compensate for cable capacitance, and use a small series resistor (22-100 Ω) at the master DQ pin to dampen ringing. Place decoupling capacitors close to the optional VCC pin if external power is used; with parasitic power only, omit VCC altogether.
After each power-on event, the DS2450S asserts a power-on-reset flag that the bus master must service by restoring all per-channel range, resolution, and alarm settings from SRAM defaults - the device does not retain these across power cycles. Forgetting to restore settings results in default 5V range / 8-bit resolution behavior that surprises engineers expecting 16-bit output. In firmware, always check the POR flag after Convert commands and reissue configuration writes before reading data.
1-Wire communication relies on precise timing of master-driven low pulses and slave-driven presence pulses. Long stub lengths or branch connections cause reflections that cause CRC errors and missed presence detect. Use a star or daisy-chain topology with stubs kept under 3 m, and avoid T-junctions in the cable run. For environments with EMI (motors, relays), add a TVS diode and an RC low-pass on the DQ line near the connector.
Informations de conformité
DS2450S is the SnPb (leaded) variant; the '+' suffix variant DS2450S+ is lead-free RoHS. No automotive AEC-Q100 grade; intended for industrial/commercial 1-Wire networks. REACH, halogen-free, and conflict-mineral status not specified in available data.
