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Texas Instruments LM63DIMA
- Part No.:
- LM63DIMA
- Manufacturer:
- Texas Instruments
- Category:
- Thermal Management
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM63DIMA.pdf
- Description:
- IC TEMP SENSOR REMOTE FAN 8-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,410
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Product details
Overview
LM63DIMA from Texas Instruments is a remote diode digital temperature sensor IC with integrated PWM fan speed control, local/remote temperature sensing (±3.0°C remote accuracy at 60–100°C), SMBus 2.0 interface, and multi-function ALERT/TACH pin - deployed for thermal management of Intel Pentium 4/Mobile Pentium 4 processors and GPUs in desktops, servers, and workstations.
For engineers reviewing the LM63DIMA datasheet, LM63DIMA pinout, LM63DIMA application, or LM63DIMA equivalent, key selection considerations include its 8-pin SOIC package, 0.125°C remote temperature resolution, factory-trimmed diode non-ideality compensation, user-programmable 8-step PWM lookup table, and smart-tach RPM measurement capability for brushless fans.
Technical Context
The LM63DIMA implements a ΔVBE-based remote diode sensing architecture with a 10-bit plus sign ΔΣ ADC, supporting both local die temperature and external thermal diode measurements. Its SMBus 2.0 slave interface uses fixed 7-bit address 1001100b and does not support clock stretching.
It integrates a programmable open-drain PWM output (5 mA sink capability) with acoustic noise reduction via an 8-step user-defined lookup table, and supports dual-mode ALERT/TACH pin operation - either as interrupt-capable open-drain alert output or tachometer input with smart-tach pulse correction for PWM-driven fans.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Remote Temp Accuracy | ±3.0°C max over 60–100°C range for Intel Pentium 4 thermal diodes; enables reliable CPU/GPU thermal throttling decisions |
| Local Temp Accuracy | ±3.0°C max over 25–125°C ambient; monitors IC self-heating and board-level thermal conditions |
| Remote Resolution | 0.125°C (11-bit + sign format); supports fine-grained fan speed ramping and precise thermal margining |
| SMBus Compatibility | Fully compliant with SMBus 2.0 timing and protocol; no clock stretching; fixed slave address 0x4C |
| PWM Output Sink | 5 mA max at VDD = 3.3 V; drives gate of external N-channel MOSFET for fan voltage modulation |
| Supply Range | 3.0 V to 3.6 V; matches standard 3.3 V system rails with 1.3 mA typical quiescent current |
| Tach Input Support | Smart-tach mode corrects corrupted pulses from PWM-driven fans; measures RPM using 90 kHz counter clock |
Pinout & Package
LM63DIMA is housed in an 8-pin SOIC (D package), 3.9 mm × 4.9 mm body, 1.27 mm pitch, with exposed pad not electrically connected. 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 supply rail; requires 0.1 µF + 100 pF ceramic bypass and local 10 µF bulk capacitance |
| 2 D+ | Analog Input | Anode connection to remote thermal diode; must be paired with 2.2 nF capacitor to D− |
| 3 D− | Analog Input | Cathode connection to remote thermal diode; forms RC filter with D+ for noise rejection |
| 4 PWM | Open-Drain Digital Output | Drives external fan MOSFET gate; default low at power-on; supports 100% duty cycle disable |
| 5 GND | Ground Reference | Common analog/digital return; must be low-impedance and star-connected near VDD bypass |
| 6 ALERT/TACH | Multi-Function I/O | User-selectable between open-drain alert (active-low) or tachometer input; defaults to ALERT |
| 7 SMBDAT | Bi-directional Data Line | SMBus data line; open-drain; requires external pullup; supports read/write register access |
| 8 SMBCLK | Digital Input | SMBus clock input; master-generated; no clock stretching supported |
Key Features
| Feature | Design Value |
|---|---|
| Factory-Trimmed Diode Calibration | Pre-compensated for 1.0021 non-ideality and series resistance of Intel 0.13 µm Pentium 4 thermal diodes - eliminates calibration effort for compatible CPUs |
| Programmable 8-Step PWM Lookup Table | Enables non-linear fan speed vs. temperature curves to reduce acoustic noise while maintaining thermal safety margins |
| Smart-Tach RPM Measurement | Corrects distorted tach pulses caused by PWM fan drive, enabling accurate RPM feedback without external signal conditioning |
| Offset Register for Alternate Diodes | Allows software adjustment of remote temperature readings to accommodate different thermal diode non-ideality factors (e.g., GPUs, ASICs) |
| Three ALERT Operating Modes | Configurable as hardware temperature comparator, software interrupt flag, or SMBus ARA-compliant alert - supports diverse system architectures |
Applications
| Computer Processor Thermal Management | Graphics Processor Thermal Management |
|---|---|
|
Use Scenario: Real-time monitoring of Intel Pentium 4/Mobile Pentium 4 processor junction temperature via on-die thermal diode. IC Role / Device Role / Timing Role: Remote diode sensor and closed-loop fan controller; provides temperature data to system BIOS or EC for dynamic fan speed adjustment. Use Value: Enables ±3.0°C accurate thermal response within 31.25 ms conversion time, preventing CPU thermal throttling or shutdown under load. |
Use Scenario: Active cooling control for discrete GPU modules in gaming PCs and workstations using onboard thermal diodes. IC Role / Device Role / Timing Role: Dual-sensing node measuring both local board temperature and GPU remote diode; drives PWM fan via lookup table. Use Value: Reduces acoustic noise by up to 10 dB(A) through non-linear fan curve programming while maintaining GPU junction < 105°C. |
| Server Blade Thermal Monitoring | Industrial Embedded Controller Cooling |
|
Use Scenario: Multi-point thermal supervision across dense server blades where space-constrained 8-pin SOIC placement is critical. IC Role / Device Role / Timing Role: SMBus-addressable thermal agent reporting local/remote temps to baseboard management controller (BMC). Use Value: Supports hot-swap awareness and predictive fan failure via tachometer input and ALERT status register polling over shared SMBus. |
Use Scenario: Fan-cooled industrial PLC or motion controller operating in 0–85°C ambient with extended lifetime requirements. IC Role / Device Role / Timing Role: Standby-mode-capable thermal supervisor; maintains ALERT functionality while reducing supply current to 300 µA. Use Value: Ensures continuous thermal protection during low-power states without sacrificing fan control responsiveness upon wake-up. |
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 |
|---|---|---|---|
| LM64CIMX/NOPB | Higher remote accuracy (±1.0°C), same 8-pin SOIC, identical register map and pinout; requires tighter diode bias current control | Better suited for high-precision CPU thermal management where ±1°C tolerance is mandated | Select LM64CIMX/NOPB when remote diode accuracy must meet ±1°C over 60–100°C and system layout allows optimized D+/D− routing |
| ADT7461ARTZ-REEL7 | 2.7–5.5 V supply range, ±2°C remote accuracy, integrated tachometer comparator, but no smart-tach pulse correction | Supports wider input voltage systems (e.g., 5 V legacy boards) but lacks robustness against PWM-induced tach corruption | Choose ADT7461ARTZ-REEL7 for 5 V designs needing basic fan control and tach monitoring without PWM fan compatibility demands |
Compared with LM63DIMA, LM64CIMX/NOPB delivers tighter remote sensing accuracy at identical footprint and interface, while ADT7461ARTZ-REEL7 offers broader supply flexibility but sacrifices smart-tach reliability in PWM-driven fan environments.
Availability
LM63DIMA is available at Aetrix Electronics and suitable for computer processor thermal management, graphics processor thermal management, and server blade cooling requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LM63DIMA 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and computing markets.
The LM63 product line was designed specifically for intelligent thermal management in x86-based computing platforms, integrating precision remote diode sensing with programmable fan control to replace discrete thermal monitoring circuits.
FAQ
What is the remote temperature accuracy specification for LM63DIMA?
The LM63DIMA guarantees ±3.0°C maximum remote diode temperature error over the 60°C to 100°C range when used with Intel Pentium 4 or Mobile Pentium 4 thermal diodes. This accuracy includes quantization error and is factory-trimmed for 1.0021 diode non-ideality. The LM63DIMA datasheet specifies this performance under IPWML ≤5 mA and TA = +30°C to +50°C ambient conditions.
Does LM63DIMA support tachometer input for brushless fans?
Yes, LM63DIMA supports tachometer input via its multi-function ALERT/TACH pin, which can be configured as a tachometer input. It includes smart-tach mode to correct corrupted pulses caused by PWM-driven fan power stages. The internal 90 kHz counter clock enables RPM measurement with ±10% accuracy and full-scale count of 65535.
What is the SMBus address of LM63DIMA and is it configurable?
The LM63DIMA has a fixed 7-bit SMBus slave address of 0x4C (1001100b), which cannot be changed via hardware pins or software configuration. It fully complies with SMBus 2.0 timing specifications including tTIMEOUT reset behavior, but does not support clock stretching. All register reads/writes occur over this hardwired address.
Can LM63DIMA operate with a 5 V supply?
No, LM63DIMA is specified only for 3.0 V to 3.6 V supply operation. Absolute maximum VDD rating is 6.0 V, but functional operation outside the 3.0–3.6 V range is not guaranteed. Attempting 5 V operation risks violating input voltage limits on SMBDAT, SMBCLK, and ALERT/TACH pins (max 6.0 V), and may cause incorrect ADC reference or diode bias current errors.
How does the LM63DIMA PWM output interface with a fan driver circuit?
The LM63DIMA PWM pin is an open-drain output rated for 5 mA sink current at 3.3 V. It requires an external pull-up resistor (typically 4.7 kΩ to 3.3 V) and drives the gate of an external N-channel MOSFET that switches fan voltage (e.g., +12 V or +5 V). The PWM duty cycle is determined by remote temperature, 8-step lookup table, and register settings - not by external clock signals.
LM63DIMA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- 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
LM63DIMA FAQ
1.How can I place an order for LM63DIMA through Aetrix?
Please submit a Request for Quotation (RFQ) for LM63DIMA 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 LM63DIMA reliable?
The price and inventory of LM63DIMA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM63DIMA is usually 5 days.
3.What payment methods are accepted for LM63DIMA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM63DIMA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM63DIMA?
LM63DIMA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM63DIMA 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 LM63DIMA?
For technical support, including LM63DIMA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM63DIMA requirements.
6.How does Aetrix verify that LM63DIMA is sourced from the original manufacturer or authorized distributors?
All LM63DIMA 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 LM63DIMA meets industry standards.
7.What is the process for return or replacement of LM63DIMA?
All LM63DIMA units undergo pre-shipment inspection (PSI). If there is an issue with LM63DIMA, 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 LM63DIMA part is unused and in its original packaging.
Return procedure for LM63DIMA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM63DIMA Tags
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EMC2101-R-ACZL-TR
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