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Texas Instruments LM63DIMAX
- Part No.:
- LM63DIMAX
- Manufacturer:
- Texas Instruments
- Category:
- Thermal Management
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM63DIMAX.pdf
- Description:
- IC TEMP SENSOR DIG W/FAN 8-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,144
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Product details
Overview
LM63DIMAX from Texas Instruments is a remote diode digital temperature sensor IC with integrated PWM fan speed control, ±3°C remote diode accuracy (60–100°C), 0.125°C remote resolution, and SMBus 2.0 interface - designed for thermal management of Intel Pentium 4/Mobile Pentium 4 processors and GPUs in desktops, laptops, and servers.
For engineers reviewing the LM63DIMAX datasheet, LM63DIMAX pinout, LM63DIMAX application, or LM63DIMAX equivalent, key selection considerations include its dual-sensing capability (local + remote diode), user-programmable 8-step PWM lookup table for acoustic noise reduction, multi-function ALERT/TACH pin, and LM86-compatible register set and pinout for drop-in migration.
Technical Context
The LM63DIMAX implements a ΔVBE-based remote diode sensing architecture with 10-bit plus sign ΔΣ ADC, factory-trimmed for 1.0021 non-ideality and series resistance of Intel 0.13 µm Pentium 4 thermal diodes. It supports offset correction via dedicated Remote Temperature Offset registers to accommodate alternate diodes.
Its integrated open-drain PWM output operates at configurable frequency with ±10% accuracy, while the ALERT/TACH pin functions either as interrupt-capable open-drain ALERT output or tachometer input with Smart-Tach mode for corrupted PWM-driven fan pulses - both controlled via Configuration Register bits.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Remote Temp Accuracy | ±3.0°C max (60–100°C, IPWML ≤5 mA) - ensures reliable thermal throttling for CPU/GPU junction monitoring |
| Local Temp Accuracy | ±3.0°C max (25–125°C) - enables accurate ambient or die temperature tracking for system-level thermal margining |
| Remote Resolution | 0.125°C (11-bit + sign) - provides fine-grained temperature feedback for precise fan curve tuning |
| Supply Voltage | 3.0 V to 3.6 V - compatible with standard 3.3 V rail; requires 0.1 µF + 100 pF bypassing at VDD |
| SMBus Compatibility | SMBus 2.0 compliant - supports alert response address (ARA), timeout reset, and full slave protocol without clock stretching |
| PWM Output Sink | 5 mA max (LM63D version) - drives external MOSFET or fan controller with open-drain logic and pull-up required |
| Conversion Time | 31.25 ms per cycle - fixed ADC latency; conversion rate adjustable via register to reduce average supply current |
Pinout & Package
LM63DIMAX is housed in an 8-pin SOIC (D package), with 1.27 mm pitch and JEDEC MS-012AC footprint. Thermal resistance junction-to-ambient is 168°C/W on 2 oz. copper PCB.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VDD | Power Supply Input | +3.3 V ±0.3 V analog/digital supply; requires local 0.1 µF ceramic + 100 pF ceramic bypass to GND |
| 2 - D+ | Analog Input | Anode connection to remote thermal diode; 2.2 nF capacitor required between D+ and D− |
| 3 - D− | Analog Input | Cathode connection to remote thermal diode; 2.2 nF capacitor required between D+ and D− |
| 4 - PWM | Open-Drain Digital Output | Pulse-width modulated fan speed control signal; power-on default = low; requires external pull-up |
| 5 - GND | Ground | Common analog and digital return path; must be low-impedance and star-connected near VDD bypass |
| 6 - ALERT/TACH | Digital I/O (configurable) | User-selectable function: open-drain ALERT output (default) or tachometer input with Smart-Tach pulse recovery |
| 7 - SMBDAT | Bi-directional SMBus Data | Open-drain bidirectional data line; requires external pull-up; supports SMBus 2.0 ARA and timeout protocols |
| 8 - SMBCLK | Digital Input | SMBus clock input; master-generated only; no clock stretching supported |
Key Features
| Feature | Design Value |
|---|---|
| Factory-trimmed diode sensing | Calibrated for Intel Pentium 4/Mobile Pentium 4 thermal diodes (1.0021 non-ideality); eliminates need for external calibration |
| Programmable 8-step PWM lookup table | Enables non-linear fan speed vs. temperature curves to reduce acoustic noise without firmware intervention |
| Smart-Tach tachometer mode | Recovers valid RPM counts from distorted pulses caused by PWM-driven brushless fans - avoids missed-count errors |
| Offset register for alternate diodes | Two-byte RTOHB/RTOLB registers allow software correction for non-Intel diodes with different ideality factors |
| LM86-compatible pinout & registers | Enables hardware and firmware reuse in existing LM86-based designs - simplifies upgrade paths and BOM consolidation |
Applications
| Computer Processor Thermal Management | Graphics Processor Thermal Management |
|---|---|
|
Use Scenario: Real-time junction temperature monitoring and dynamic fan speed control for Intel Pentium 4 and Mobile Pentium 4 CPUs in desktops, laptops, and workstations. IC Role / Device Role / Timing Role: Dual-sensor temperature monitor (local + remote diode) with integrated PWM output and SMBus alert signaling. Use Value: Enables silent, responsive thermal regulation using factory-trimmed diode accuracy and programmable fan curves - reducing system acoustic noise by up to 10 dB(A) versus linear control. |
Use Scenario: GPU die temperature tracking and active cooling coordination in discrete graphics cards and embedded GPU modules. IC Role / Device Role / Timing Role: Remote diode sensor interfaced to GPU thermal diode; delivers 0.125°C-resolution readings to host BIOS/firmware every 31.25 ms. Use Value: Prevents GPU thermal throttling and shutdown by triggering early-stage fan ramp-up before critical thresholds - sustaining peak compute performance under sustained load. |
| Electronic Test Equipment | Industrial Controls |
|
Use Scenario: Ambient and component-level temperature supervision in benchtop instruments requiring stable thermal reference and fan-cooled power stages. IC Role / Device Role / Timing Role: Local temperature sensor + remote diode interface for power FETs or regulators; ALERT output tied to system fault latch. Use Value: Provides traceable, SMBus-accessible temperature data with ±3°C accuracy across 0–85°C operating range - meeting calibration-grade environmental monitoring requirements. |
Use Scenario: Fan-cooled PLC cabinets and motor drive enclosures where ambient and heatsink temperatures must be monitored for predictive maintenance. IC Role / Device Role / Timing Role: Dual-point thermal supervisor with tachometer input verifying fan operation and PWM output enabling closed-loop airflow control. Use Value: Detects fan failure via TACH loss and triggers ALERT-driven shutdown or alarm - preventing overheating-induced component degradation in unattended systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar remote diode temperature sensing and fan control applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM86IMX | ±1°C remote accuracy (60–100°C), higher precision; identical 8-pin SOIC package and LM63-compatible register map | Better suited for high-end servers and workstations requiring tighter thermal margins and faster response | Select LM86IMX when ±1°C remote accuracy is mandatory and supply voltage allows 3.0–3.6 V operation |
| ADM1032ARMZ | ±2°C remote accuracy, 12-bit remote resolution (0.0625°C), supports 2.7–5.5 V supply; different pinout and register structure | Offers wider voltage range and finer resolution but requires PCB redesign and firmware adaptation | Choose ADM1032ARMZ for multi-rail systems or when sub-0.1°C remote resolution justifies layout change |
Compared with LM86IMX and ADM1032ARMZ, the LM63DIMAX delivers optimal balance of cost, compatibility, and acoustic noise reduction via its 8-step PWM lookup table - making it ideal for mainstream computing platforms where LM86 pin/register compatibility is valued but ±3°C accuracy suffices.
Availability
LM63DIMAX is available at Aetrix Electronics and suitable for computer processor thermal management, graphics processor thermal management, and industrial control applications requiring stable component supply, long-term lifecycle support, and verified thermal performance.
Supply support for LM63DIMAX 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 company specializing in analog, embedded processing, and connectivity technologies, with leadership in precision analog and thermal management ICs.
The LM63 product line was developed specifically for intelligent thermal monitoring and acoustic-aware fan control in x86 computing platforms - targeting CPU, GPU, and chipset thermal management with SMBus integration.
FAQ
What is the remote temperature accuracy specification for LM63DIMAX?
The LM63DIMAX guarantees ±3.0°C maximum remote diode temperature error over 60–100°C (with IPWML ≤5 mA) and ±3.0°C over 25–125°C for all versions. This accuracy is factory-trimmed for Intel Pentium 4/Mobile Pentium 4 thermal diodes and includes quantization error. Local temperature accuracy is ±3.0°C from 25°C to 125°C. The LM63DIMAX achieves this using ΔVBE sensing with 10-bit plus sign ΔΣ ADC and supports offset correction for alternate diodes via RTOHB/RTOLB registers.
How does the ALERT/TACH pin function on LM63DIMAX?
The ALERT/TACH pin on LM63DIMAX is a user-configurable multifunction terminal. By default at power-on, it operates as an open-drain ALERT output that pulls low when local or remote temperature exceeds programmed limits. When reconfigured via the Configuration Register, it becomes a tachometer input supporting Smart-Tach mode to accurately measure RPM from PWM-driven brushless fans with distorted pulse trains. The pin's behavior is fully software-controlled and does not require hardware modification.
Is LM63DIMAX pin-compatible with LM86?
Yes, LM63DIMAX features an LM86-compatible pinout and register set, enabling direct hardware replacement in many LM86-based designs. Both devices use identical 8-pin SOIC packaging and share register addresses for temperature readings, limits, configuration, and status. However, LM63DIMAX offers ±3°C remote accuracy (vs. ±1°C for LM86), and its PWM output is optimized for acoustic noise reduction via the 8-step lookup table - differences that may require minor firmware tuning for full feature parity.
What supply voltage range does LM63DIMAX support?
LM63DIMAX operates from 3.0 V to 3.6 V DC on the VDD pin, with typical supply current of 1.3 mA during active conversion and 300 µA in STANDBY mode. The device requires low-noise bypassing: a 0.1 µF ceramic capacitor in parallel with a 100 pF ceramic capacitor placed close to the VDD pin, plus bulk capacitance (~10 µF) nearby. Operation outside this range risks functional failure or permanent damage, as absolute maximum VDD is 6.0 V.
Does LM63DIMAX support SMBus Alert Response Address (ARA)?
Yes, LM63DIMAX fully supports SMBus 2.0 Alert Response Address (ARA) protocol. When the ALERT/TACH pin is configured as ALERT output and the ALERT Configuration bit is low, the device responds to ARA (0x0C) by transmitting its 7-bit slave address (0x4C) and releasing the ALERT line - satisfying SMBus disengagement requirements. This allows multi-device SMBus systems to identify the LM63DIMAX as the alert source without bus contention or lockup, ensuring robust system-level thermal fault handling.
LM63DIMAX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Fan Control, Temp Monitor
- Sensor Type:
- Internal and External
- Sensing Temperature:
- 0°C ~ 125°C
- Accuracy:
- ±3°C
- Topology:
- ADC (Sigma Delta), Comparator, Fan Speed Control, Register Bank
- Output Type:
- 2-Wire SMBus
- Output Alarm:
- Yes
- Output Fan:
- Yes
- Voltage - Supply:
- 3V ~ 3.6V
- Operating Temperature:
- 0°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
LM63DIMAX FAQ
1.How can I place an order for LM63DIMAX through Aetrix?
Please submit a Request for Quotation (RFQ) for LM63DIMAX 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 LM63DIMAX reliable?
The price and inventory of LM63DIMAX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM63DIMAX is usually 5 days.
3.What payment methods are accepted for LM63DIMAX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM63DIMAX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM63DIMAX?
LM63DIMAX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM63DIMAX 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 LM63DIMAX?
For technical support, including LM63DIMAX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM63DIMAX requirements.
6.How does Aetrix verify that LM63DIMAX is sourced from the original manufacturer or authorized distributors?
All LM63DIMAX 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 LM63DIMAX meets industry standards.
7.What is the process for return or replacement of LM63DIMAX?
All LM63DIMAX units undergo pre-shipment inspection (PSI). If there is an issue with LM63DIMAX, 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 LM63DIMAX part is unused and in its original packaging.
Return procedure for LM63DIMAX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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