LM75AIMX/NOPB - ±2°C Digital Temp Sensor & Thermal Watchdog, I2C, SOIC-8 | Texas Instruments
Référence : LM75AIMX/NOPB ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $1.92 | $1,92 |
| 10 | $1.72 | $17,20 |
| 100 | $1.28 | $128,00 |
| 500 | $0.96 | $480,00 |
| 1 000 | $0.78 | $780,00 |
LM75AIMX/NOPB Présentation
A digital temperature sensor such as the LM75A is a mixed-signal IC that combines an on-die thermal diode, sigma-delta ADC, calibration registers, and a digital serial interface to report die temperature in a standard two's-complement format. Within the broader component taxonomy, the LM75A belongs to the local temperature sensor family, which sits under analog/mixed-signal sensors, under sensors, and ultimately under semiconductors. Compared with thermistors, the LM75A eliminates linearization math, PCB real estate, and ADC channel overhead; compared with remote-diode sensors, the LM75A sacrifices baseboard hot-spot accuracy for BOM simplicity.
Key features include 9-bit (0.5°C LSB) signed two's complement output, user-programmable 9-bit O.S. (overtemperature shutdown) and Hysteresis registers, a fault-queue counter to suppress false triggers, and three selectable I2C address pins (A0/A1/A2) that allow up to eight LM75A devices on a single bus. Standby current is just 1 µA typical, and the O.S. output is an open-drain interrupt that can wire-OR multiple devices.
Technically, the LM75A uses a thin-film on-die thermal element whose forward voltage is sampled by a chopper-stabilized delta-sigma ADC against an internal bandgap reference; the digital value is then stored in the 16-bit temperature register (high byte + sign/low byte). The SMBus-compatible interface supports standard (100 kHz), fast (400 kHz), and high-speed (3.4 MHz) modes, and the part includes power-on reset and a configurable hardware shutdown mode for battery-powered designs.
Typical applications include base-station equipment thermal monitoring, server and desktop PC system protection, office electronics (printers, copiers), portable battery packs, HVAC controllers, and any thermistor-replacement design. The combination of 2.7V operation, SMBus compatibility, and eight selectable addresses makes it especially attractive for multi-zone chassis monitoring in networking and industrial control.
When designing with the LM75A, place the part at the actual thermal hot spot of the board and provide a low-impedance ground pour, since the die temperature is what is reported rather than ambient air. A 0.1 µF decoupling capacitor within 5 mm of VDD is recommended, and pull-up resistors on SDA, SCL, and O.S. must be sized to the bus capacitance and the chosen I2C speed.
This page synthesizes current distributor pricing, drop-in replacement options, and practical PCB layout guidance not assembled in the manufacturer datasheet alone.
Alternatives de remplacement direct pour LM75AIMX/NOPB — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
LM75AIM/NOPB
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
LM75BIM-5+
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
LM75BD
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
LM75BIMA
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
LM75BDP
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
LM75AIMX/NOPB Valeurs maximales et caractéristiques électriques
| Type de capteur | Digital Temperature Sensor (Local) |
| Sensing Temperature Range | -55°C to +125°C |
| Accuracy (max) | ±2°C (-25°C to +100°C) |
| Résolution | 9 bits (0.5°C LSB) |
| Supply Voltage (VDD) | 2.7 V to 5.5 V |
| Supply Current (standby) | 1 µA (typical) |
| Interface | I2C / SMBus-compatible, 2-wire serial |
| Selectable I2C Addresses | 8 (via A0, A1, A2 pins) |
| Overtemperature Output (O.S.) | Open-drain, active-low interrupt |
| Type de sortie | 2-Wire Serial, I2C™ |
| Boîtier | SOIC-8 (D) 3.90 mm |
| Type de montage | Surface Mount |
| Température de fonctionnement | -55°C to +125°C |
| Statut RoHS | Compliant |
| Lead-Free | Yes |
| Pin/Package Count | 8 |
Configuration des broches de LM75AIMX/NOPB
| Broche 1 | SDA — Serial Data (I2C bidirectional, open-drain, requires pull-up) |
| Broche 2 | SCL — Serial Clock (I2C input) |
| Broche 3 | O.S. — Overtemperature Shutdown output (open-drain, active low) |
| Broche 4 | GND — Ground |
| Broche 5 | A2 — User-configurable I2C address bit 2 (tri-state) |
| Broche 6 | A1 — User-configurable I2C address bit 1 (tri-state) |
| Broche 7 | A0 — User-configurable I2C address bit 0 (tri-state) |
| Broche 8 | VDD — Supply voltage (2.7V to 5.5V) |
Applications typiques
LM75AIMX/NOPB convient pour 7 applications: Base Station Thermal Monitoring, Server and Desktop PC Thermal Protection, Battery Pack Temperature Monitoring, Office Electronics and Printer Thermal Management, Industrial HVAC and Chassis Monitoring, Test and Measurement Equipment, Portable and Wearable Devices.
Base Station Thermal Monitoring
The LM75AIMX/NOPB's 2.7V-5.5V supply and 8 selectable I2C addresses make it ideal for multi-zone thermal monitoring in cellular and Wi-Fi base-station equipment. Each radio card, PA module, and fan controller can host a dedicated LM75AIMX/NOPB, and the O.S. open-drain outputs wire-OR into the system controller's interrupt for fan-speed or shutdown control. The part's ±2°C accuracy is sufficient for board-level hotspot protection between -25°C and +100°C. The SOIC-8 footprint simplifies hand-rework and probe access during field service.
Recommandé
Server and Desktop PC Thermal Protection
Inside a server or desktop PC, the LM75AIMX/NOPB replaces legacy thermistor-and-ADC solutions, freeing an analog channel and removing the linearization firmware. Placed near the CPU VRM, DIMM slots, or the chassis intake, it provides 9-bit (0.5°C) resolution and asserts O.S. when the trip register is exceeded. The SMBus-compatible interface interoperates with the standard PECI/SMBus management stack, and the 1 µA standby current is negligible. Designers can put eight sensors on a single bus with unique A0/A1/A2 strap addresses, supporting multi-zone protection.
Recommandé
Battery Pack Temperature Monitoring
The LM75AIMX/NOPB's low 1 µA standby current, 2.7V minimum supply, and 8-pin SOIC footprint are well suited to multi-cell Li-ion battery packs where cells need both temperature and ID. Mounted to the cell-tab thermal plane, it reports die temperature over I2C to the battery gauge; its O.S. output can directly drive a MOSFET that interrupts the discharge path on overtemperature. The SOIC-8 package is robust against mechanical stress and can be hand-soldered for prototype packs. The wide 2.7V-5.5V supply range is also compatible with 3S-4S pack voltages regulated down by the gauge IC.
Recommandé
Office Electronics and Printer Thermal Management
In laser printers, copiers, and multifunction devices, the LM75AIMX/NOPB monitors the fuser temperature, paper path, and motor driver heat sinks, providing a digital readout over I2C and a hardware O.S. shutdown signal. The ±2°C accuracy is sufficient for fuser stabilization feedback, and the open-drain O.S. output can hold the MCU in reset until temperatures are within spec. The wide 2.7V-5.5V supply means the same SKU can be used in both 3.3V and 5V printer designs, simplifying BOM logistics across product families.
Recommandé
Industrial HVAC and Chassis Monitoring
In industrial HVAC controllers, the LM75AIMX/NOPB delivers a 2-wire digital temperature measurement and an open-drain alert, replacing discrete thermistor solutions that require ADC channels and linearization. Each LM75AIMX/NOPB in a fan array can share the bus and assert O.S. individually; the MCU scans for fault and ramps the affected fan. The SOIC-8 (D) package withstands industrial soldering processes, and the part's -55°C to +125°C operating range covers outdoor cabinet environments. The 3 selectable address pins enable 8 sensors per bus for multi-zone control.
Recommandé
Test and Measurement Equipment
Bench-top instruments and ATE chassis often need multiple temperature channels to monitor internal power supplies, FPGA heat sinks, and load-bank thermals. The LM75AIMX/NOPB's 9-bit resolution (0.5°C LSB) and 8 selectable addresses let a single I2C bus cover 8 zones, while the O.S. open-drain output can mute the test output on over-temperature. The 1 µA standby current has negligible impact on overall system power. Designers can reuse the same SKU across product lines, and the SOIC-8 hand-solder-friendly footprint supports rapid prototyping of new bench configurations.
Recommandé
Portable and Wearable Devices
The LM75AIMX/NOPB's 1 µA typical standby current and 2.7V minimum supply enable continuous thermal monitoring of portable devices such as smart wearables, handheld scanners, and battery-powered IoT nodes. Placed near the battery and the SoC, the part provides 9-bit (0.5°C LSB) resolution and an O.S. interrupt that wakes the SoC only when temperature limits are crossed, minimizing average power. The SOIC-8 (D) package is small enough for wearables yet easy to rework for prototype builds. The I2C interface is supported by virtually all modern low-power MCUs, simplifying firmware integration.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour LM75AIMX/NOPB — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | LM75AIM/NOPB | LM75BIM-5+ | LM75BD | LM75BIMA | LM75BDP |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | SOIC-8 (D) | VSSOP-8 (DGK) - different footprint | SOIC-8 - same | SOIC-8 - same | SOIC-8 - same | TSSOP-8 - different footprint |
| Temperature Range | -55°C to +125°C | -55°C to +125°C | -55°C to +125°C | -55°C to +125°C | -55°C to +125°C | -55°C to +125°C |
| Accuracy (max) | ±2°C | ±2°C | ±2°C | ±2°C | ±2°C | ±2°C |
| Resolution | 9 bits (0.5°C LSB) | 9 bits | 9 bits | 9 bits | 9 bits | 9 bits |
| Supply Voltage | 2.7V to 5.5V | 2.7V to 5.5V | 2.7V to 5.5V | 2.7V to 5.5V | 2.7V to 5.5V | 2.7V to 5.5V |
| Interface | I2C/SMBus | I2C/SMBus | I2C/SMBus | I2C/SMBus | I2C/SMBus | I2C/SMBus |
| Register Compatibility | LM75A native | LM75A native | LM75B (NXP-compatible) | LM75B (NXP-compatible) | LM75B (NXP-compatible) | LM75B (NXP-compatible) |
| RoHS Compliant | Yes | Yes | Yes | Yes | Yes | Yes |
Principaux différenciateurs
- 8 selectable I2C addresses on a single bus (vs Generic thermistor + ADC solution)
- Hardware overtemperature interrupt (O.S. pin) (vs TMP102)
- Wide -55°C to +125°C sensing range (vs TMP36 analog sensor)
- 1 µA typical standby current (vs TMP102 (10 µA active))
Notes de conception
Place the LM75AIMX/NOPB at the actual thermal hot spot of the PCB, with the SOIC-8 (D) thermal pad sitting on a low-impedance ground pour. The die temperature is what is reported, not ambient air, so proximity to heat sources (VRMs, FETs, magnetics) is essential. Add a 0.1 µF X7R decoupling capacitor within 5 mm of the VDD pin, and route the SDA/SCL lines as short as possible to the MCU, avoiding parallel runs with switching-power traces.
Pull-up resistors on SDA, SCL, and O.S. are required. Sizing depends on bus capacitance: at 100 kHz standard mode, 4.7 kΩ is typical; at 400 kHz fast mode, 2.2 kΩ is often needed. For 8 sensors on the same bus, sum the pin capacitances and verify against the I2C fall-time spec. The O.S. line may be wire-ORed across multiple LM75A devices to a single interrupt, but a single pull-up is required at the MCU end.
Do not assume the LM75A and LM75B register maps are identical: the LM75A uses TI's native register layout, while the LM75B (LM75BIM-5+, LM75BD, LM75BDP) matches NXP's register layout. Software written for the LM75A will need a small revision if substituting to LM75B. Also, the tri-state A0/A1/A2 pins must be tied to GND, VDD, or left floating (no-connect) to select the desired I2C address; do not strap them to intermediate voltages. The fault-queue register should be set to a non-zero value to suppress false O.S. triggers from switching noise.
Informations de conformité
RoHS and lead-free status per Texas Instruments LM75A product page and the NOPB suffix. AEC-Q100 is not qualified for the LM75AIMX/NOPB; see LM75A-Q1 (separate SKU) for automotive applications. Halogen-free status not explicitly stated in the verified web data.
