My Inquiry
My Account
Texas Instruments LM90CIMM/NOPB
- Part No.:
- LM90CIMM/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Analog and Digital Output
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LM90CIMM/NOPB.pdf
- Description:
- SENSOR DIGITAL 0C-85C 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:193
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM90CIMM/NOPB from Texas Instruments is a ±3°C accurate dual-sensing digital temperature sensor with local diode and remote thermal diode measurement capability, SMBus 2.0 interface, 0.125°C remote resolution, and T_CRIT_A/ALERT alarm outputs - used for real-time thermal monitoring in CPU/GPU thermal management subsystems.
For engineers reviewing the LM90CIMM/NOPB datasheet, LM90CIMM/NOPB pinout, LM90CIMM/NOPB application, or LM90CIMM/NOPB equivalent, key selection criteria include remote diode accuracy across 30–100°C, 8-pin VSSOP package compatibility, SMBus timeout support, diode fault detection, and T_CRIT hysteresis programmability.
Technical Context
The LM90CIMM/NOPB implements a delta-VBE remote sensing architecture with 11-bit plus sign ADC for remote junctions and 8-bit ADC for on-chip temperature, supporting mobile Pentium III–calibrated non-ideality (1.008) and user-adjustable offset compensation via RTOLB/RTOHB registers.
Its dual-alarm system uses independent digital comparators against programmable HIGH/LOW/T_CRIT limits for both local and remote channels, with ALERT operating as SMBus-compliant open-drain interrupt and T_CRIT_A delivering true comparator output with hysteresis derived from TH register value.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Remote Temp Accuracy | ±3.0°C max over TA=30–50°C, TD=60–100°C - enables reliable CPU die thermal tracking without calibration |
| Local Temp Accuracy | ±4.0°C max over TA=25–125°C - sufficient for ambient or PCB-level thermal supervision |
| Remote Resolution | 0.125°C (11-bit + sign) - supports fine-grained fan speed control and thermal throttling thresholds |
| Supply Voltage | 3.0–3.6 V - compatible with standard 3.3 V rail without LDO overhead |
| Quiescent Current | 0.8 mA typ at 16 Hz conversion - low power for always-on thermal monitoring |
| SMBus Compatibility | Fully compliant with SMBus 2.0 including TIMEOUT and ARA protocol - ensures interoperability in multi-sensor server/laptop systems |
| Diode Fault Detection | Detects open, short-to-VDD, short-to-GND conditions and reports via OPEN bit and forced RTHB/RTLB codes - prevents false thermal shutdown |
Pinout & Package
LM90CIMM/NOPB is housed in an 8-pin VSSOP (DGK) package - 3.0 mm × 3.0 mm body, 0.65 mm pitch, exposed thermal pad optional - optimized for space-constrained laptop motherboard and server DIMM thermal zones.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Positive supply input | Accepts 3.0–3.6 V; internal regulator powers analog/digital blocks; requires local 0.1 µF bypass |
| D+ | Remote diode current source | Drives 110–315 µA into external diode anode; sensitive to parasitic capacitance & ESD |
| D− | Remote diode return sink | Completes remote sensing loop; must connect directly to diode cathode - no series resistance |
| T_CRIT_A | Critical temperature alarm output | Open-drain, active-low; asserts when any temp exceeds T_CRIT; includes hysteresis from TH register |
| GND | Power ground reference | Common return for analog/digital circuits; tie to low-impedance system ground plane |
| ALERT | Configurable alert/interrupt output | Open-drain SMBus-compatible flag; supports comparator, interrupt, or ARA modes per FILTER register |
| SMBData | Bi-directional SMBus data line | Open-drain; requires external pull-up; handles command/data transfer and ARA response |
| SMBCLK | SMBus clock input | Asynchronous master-driven clock; supports 10–100 kHz; no clock stretching supported |
Key Features
| Feature | Design Value |
|---|---|
| Offset register compensation | RTOLB/RTOHB registers enable correction of non-ideality errors across diverse IC thermal diodes (e.g., AMD, Intel, ASICs) |
| Diode fault detection circuitry | Identifies open-circuit, short-to-rail, and floating D+ conditions and flags them in STATUS register without false T_CRIT activation |
| T_CRIT hysteresis control | Programmable TH register sets hysteresis for T_CRIT_A output - prevents chatter during thermal transients near critical threshold |
| Three-mode ALERT operation | Configurable as hardware comparator, software-managed interrupt, or SMBus ARA responder - adapts to host controller architecture |
| Factory-trimmed remote accuracy | ±3°C guaranteed over 30–100°C remote range using 1.008 non-ideality factor - eliminates need for system-level calibration |
Applications
| Laptop CPU Thermal Management | Server Blade Temperature Monitoring |
|---|---|
Use Scenario: Real-time die temperature tracking of dual-core mobile processors during turbo boost and sustained load. IC Role / Device Role / Timing Role: Remote diode sensor interfacing to CPU-integrated thermal diode; local sensor monitors chipset VRM temperature. Use Value: Enables dynamic fan control and OS-initiated throttling with ±3°C accuracy - avoids thermal throttling latency and false shutdowns. | Use Scenario: Distributed thermal supervision across multiple server blades in a 1U chassis with shared SMBus bus. IC Role / Device Role / Timing Role: Slave node on SMBus providing local + remote temperature readings; T_CRIT_A triggers immediate power-down if CPU exceeds 95°C. Use Value: Supports ARA protocol for unambiguous fault identification among 12+ sensors - reduces firmware polling overhead by >70%. |
| Workstation GPU Thermal Protection | Industrial Embedded Controller Cooling |
Use Scenario: Monitoring discrete GPU die temperature and VRAM junction temperature in high-end rendering workstations. IC Role / Device Role / Timing Role: Dual remote sensing via two external diodes (GPU core + memory controller); ALERT signals thermal violation to BMC. Use Value: 0.125°C resolution allows precise ramp-rate control of liquid cooling pumps - maintains GPU junction < 85°C under 300W load. | Use Scenario: Fanless industrial PC operating in -20°C to +70°C ambient with passive heatsink and thermal margin monitoring. IC Role / Device Role / Timing Role: Local temperature sensor only; LOW/HIGH limits trigger warning LEDs; T_CRIT_A drives mechanical relay cutoff. Use Value: Shutdown occurs at exactly 85°C (programmed T_CRIT) with 5°C hysteresis - prevents capacitor derating and ensures 10-year MTBF. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-sensing temperature monitoring applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM86CIMM/NOPB | Pin- and register-compatible; identical SMBus interface and accuracy; lacks diode fault detection logic | No OPEN-bit reporting or forced −128°C/127°C fault codes - requires external validation of diode integrity | Select when diode reliability is assured and cost reduction is prioritized over fault diagnostics |
| MAX6657ESA+ | Same 8-pin SOIC package; ±4°C remote accuracy; no T_CRIT_A output; ALERT only supports SMBus mode | Single-alert output; no dedicated critical alarm path - requires software polling to detect T_CRIT breach | Select for legacy SMBus systems where T_CRIT_A hardware assertion is not required |
Compared with LM86CIMM/NOPB and MAX6657ESA+, the LM90CIMM/NOPB uniquely delivers integrated diode fault detection with diagnostic register visibility and a dedicated hardware T_CRIT_A output - essential for fail-safe thermal shutdown in mission-critical computing platforms.
Availability
LM90CIMM/NOPB is available at Aetrix Electronics and suitable for laptop thermal management, server blade monitoring, and industrial embedded controller cooling requiring stable component supply and long-term lifecycle assurance.
Supply support for LM90CIMM/NOPB 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
Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, precision, and industrial-grade performance.
The LM90CIMM/NOPB belongs to TI's precision analog temperature sensor product line, engineered specifically for high-accuracy remote diode thermal monitoring in compute-intensive platforms where junction-level thermal integrity is safety-critical.
FAQ
What is the remote diode accuracy specification for LM90CIMM/NOPB across its full operating range?
The LM90CIMM/NOPB guarantees ±3.0°C maximum remote diode temperature error over TA = 30°C to 50°C and TD = 60°C to 100°C, and ±4.0°C maximum over TA = 0°C to 85°C and TD = 25°C to 125°C. This accuracy is factory-trimmed for the 1.008 non-ideality factor typical of mobile Pentium III thermal diodes. The LM90CIMM/NOPB achieves this without system-level calibration due to its internal offset compensation registers (RTOLB/RTOHB).
Does LM90CIMM/NOPB support SMBus TIMEOUT and ARA protocols as stated in the official TI datasheet?
Yes, LM90CIMM/NOPB fully complies with SMBus 2.0 specifications including TIMEOUT (tTIMEOUT = 25–35 ms) and Alert Response Address (ARA) protocol. When an ARA command is issued, the LM90CIMM/NOPB transmits its fixed 7-bit slave address (1001100b), then disables its ALERT output by setting the ALERT mask bit (D7 of Configuration register). This behavior satisfies SMBus 2.0 "disengaging of SMBALERT" requirements and prevents bus lockup.
How does the diode fault detection mechanism work in LM90CIMM/NOPB, and what register flags indicate failure?
The LM90CIMM/NOPB detects D+ pin faults including open-circuit, short-to-VDD, and short-to-GND. An open or short-to-VDD condition sets the OPEN bit (D2) in the Status Register (02h), loads RTHB = +127°C and RTLB = 0x00. A short-to-GND condition loads RTHB = −128°C (0x80) but does not set OPEN. These values trigger ALERT if corresponding limit registers are configured below the fault code - enabling unambiguous hardware-level fault isolation without software interpretation.
Can LM90CIMM/NOPB measure both local and remote temperatures simultaneously, and what are their respective resolutions?
The LM90CIMM/NOPB performs sequential conversions: local temperature (8-bit, 1°C LSB) and remote temperature (11-bit plus sign, 0.125°C LSB), completing both in ~31.25 ms. It does not sample simultaneously, but updates registers in round-robin fashion with status bit D7 indicating busy state. The remote reading is stored across two 8-bit registers (RTHB/RTLB) as a left-justified 16-bit word, while local temperature occupies a single byte (LTEMP). Both values are available for read at any time, reflecting the most recent completed conversion.
What is the function of the T_CRIT_A output versus the ALERT output in LM90CIMM/NOPB, and how do they differ in behavior?
T_CRIT_A is a dedicated, hysteresis-controlled comparator output that asserts active-low whenever any measured temperature exceeds its programmed T_CRIT limit - it resets only when temperature falls below (T_CRIT − TH). ALERT is a configurable open-drain flag that responds to violations of HIGH, LOW, or T_CRIT limits and supports three modes (comparator, interrupt, ARA). Unlike ALERT, T_CRIT_A operates independently of SMBus activity and mask bits, making it suitable for hardwired system shutdown circuits requiring deterministic timing and no software dependency.
LM90CIMM/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Sensor Type:
- Digital, Local/Remote
- Sensing Temperature - Local:
- 0°C ~ 85°C
- Sensing Temperature - Remote:
- 0°C ~ 85°C
- Output Type:
- SMBus
- Voltage - Supply:
- 3V ~ 3.6V
- Resolution:
- 7 b (Local), 10 b (Remote)
- Features:
- One-Shot, Output Switch, Programmable Limit, Shutdown Mode, Standby Mode
- Accuracy - Highest (Lowest):
- ±4°C
- Test Condition:
- 25°C ~ 125°C
- Operating Temperature:
- 0°C ~ 125°C
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 8-VSSOP
LM90CIMM/NOPB FAQ
1.How can I place an order for LM90CIMM/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM90CIMM/NOPB on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LM90CIMM/NOPB reliable?
The price and inventory of LM90CIMM/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM90CIMM/NOPB is usually 5 days.
3.What payment methods are accepted for LM90CIMM/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM90CIMM/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM90CIMM/NOPB?
LM90CIMM/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM90CIMM/NOPB order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LM90CIMM/NOPB?
For technical support, including LM90CIMM/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM90CIMM/NOPB requirements.
6.How does Aetrix verify that LM90CIMM/NOPB is sourced from the original manufacturer or authorized distributors?
All LM90CIMM/NOPB products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM90CIMM/NOPB meets industry standards.
7.What is the process for return or replacement of LM90CIMM/NOPB?
All LM90CIMM/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM90CIMM/NOPB, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LM90CIMM/NOPB part is unused and in its original packaging.
Return procedure for LM90CIMM/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM90CIMM/NOPB Tags
-
MCP9700T-E/TT
Microchip Technology
-
MCP9700T-E/LT
Microchip Technology
-
MCP9701T-E/TT
Microchip Technology
-
MCP9701T-E/LT
Microchip Technology
-
TMP235A4DBZR
Texas Instruments
-
MCP9700AT-E/TT
Microchip Technology
-
MCP9700AT-E/LT
Microchip Technology
-
MCP9701AT-E/LT
Microchip Technology
-
MCP9701AT-E/TT
Microchip Technology
,TO-226_straightlead.jpg)
-
LM335Z
STMicroelectronics
-
TMP1075NDRLR
Texas Instruments
-
TMP1075DGKR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
