My Inquiry
My Account
Texas Instruments LM64CILQX-F
- Part No.:
- LM64CILQX-F
- Manufacturer:
- Texas Instruments
- Category:
- Thermal Management
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LM64CILQX-F.pdf
- Description:
- IC TEMP SENSOR REMOTE 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,394
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM64CILQX-F from Texas Instruments is a ±1°C remote diode temperature sensor IC with integrated PWM fan speed control, 5 GPIOs, tachometer input, and SMBus 2.0 interface - designed for real-time thermal monitoring and acoustic fan noise reduction in high-performance computing systems.
For engineers reviewing the LM64CILQX-F datasheet, LM64CILQX-F pinout, LM64CILQX-F application, or LM64CILQX-F equivalent, key selection considerations include remote diode accuracy (±1.0°C max over 120–140°C), 10-bit+sign resolution (0.125°C), 24-pin WQFN package, SMBus TIMEOUT support, and programmable 8-step PWM lookup table for non-linear fan response.
Technical Context
The LM64CILQX-F implements a ΔVBE-based remote diode sensing architecture with a 10-bit+sign delta-sigma ADC, factory-trimmed for MMBT3904 diodes with +16°C junction offset correction (TACTUAL = TLM64 + 16°C). It supports dual temperature domains: local (±3.0°C max, 25–125°C) and remote (±1.0°C max, 120–140°C).
Its digital subsystem includes SMBus 2.0-compliant timing (10–100 kHz clock, 25–35 ms TIMEOUT), open-drain ALERT/T_Crit outputs with configurable masking, tachometer input with ±10% fan RPM accuracy, and a dedicated 8-step LUT for PWM duty-cycle mapping - enabling quiet, temperature-proportional fan control without host CPU intervention.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Remote Temp Accuracy | ±1.0°C max (120–140°C range); enables precise GPU/CPU junction thermal throttling without calibration overhead |
| Remote Resolution | 0.125°C (11-bit+sign format); supports fine-grained thermal ramp detection and closed-loop fan tuning |
| PWM Output | Open-drain, SMBus-programmable 8-step LUT; eliminates need for external microcontroller to implement quiet fan curves |
| Tachometer Input | ±10% fan RPM accuracy at 90 kHz counter clock; validates actual cooling performance against commanded PWM duty |
| SMBus Interface | 2.0-compliant with TIMEOUT reset (25–35 ms); ensures bus recovery from lockup without system reset |
| Supply Range | 3.0 V to 3.6 V DC; compatible with standard 3.3 V logic rails and low-noise LDOs |
| Package | 24-pin WQFN (4 mm × 4 mm, 0.5 mm pitch); supports high-density thermal management layouts with minimal PCB footprint |
Pinout & Package
LM64CILQX-F is housed in a 24-pin WQFN package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are validated per TI SNAS207B Rev. January 2024.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GPIO1–GPIO5 | Digital I/O (open-drain) | Configurable as inputs or outputs with 10 kΩ typical pull-up; enable status signaling, fault handshaking, or auxiliary control |
| GPD1–GPD5 | Digital input (default) | Hard-wired configuration pins; set SMBus address (A0), startup mode, or LUT behavior at power-on |
| PWM | Open-drain fan drive output | Drives external MOSFET/fan driver; defaults low at power-on; supports 8-step non-linear duty mapping |
| TACH | Digital tachometer input | Counts open-collector fan pulses; enables closed-loop RPM verification and stall detection |
| ALERT / T_Crit | Open-drain interrupt outputs | ALERT signals configurable thermal violations; T_Crit asserts only on critical overtemperature (non-latching comparator) |
| D+ / D− | Remote diode analog inputs | Differential pair for MMBT3904-connected transistor; requires 2.2 nF capacitor between pins for noise rejection |
| SMBDAT / SMBCLK | SMBus bidirectional interface | Two-wire serial bus compliant with SMBus 2.0; supports TIMEOUT, ALERT response address (ARA), and multi-drop topology |
Key Features
| Feature | Design Value |
|---|---|
| ±1°C remote diode accuracy (120–140°C) | Enables reliable thermal margining for modern CPUs/GPUs without per-unit calibration or software compensation |
| Programmable 8-step PWM lookup table | Allows non-linear fan speed vs. temperature curves to reduce acoustic noise during mid-range thermal loads |
| Integrated tachometer input with ±10% RPM accuracy | Verifies actual fan operation and detects stalled fans before thermal runaway occurs |
| SMBus 2.0 TIMEOUT and ARA support | Guarantees bus-level fault recovery and unambiguous multi-device interrupt source identification in dense server environments |
| Local + remote dual-sensing with independent setpoints | Supports hierarchical thermal management: local die temp triggers immediate throttling; remote diode temp governs fan response |
Applications
| Computer Processor Thermal Management | Graphics Processor Thermal Management |
|---|---|
|
Use Scenario: Real-time junction temperature monitoring of x86 or ARM CPUs during burst workloads. IC Role / Device Role / Timing Role: Remote diode sensor measuring CPU package diode; PWM output directly modulates 4-wire fan speed based on thermal headroom. Use Value: Maintains CPU within safe operating limits while minimizing acoustic noise via 8-step LUT-driven fan curve. |
Use Scenario: Thermal supervision of discrete GPUs in gaming PCs or AI inference servers. IC Role / Device Role / Timing Role: Measures GPU die temperature using integrated diode; triggers T_Crit output for emergency shutdown if >125°C. Use Value: Prevents silicon damage by enforcing hard thermal limits with sub-1°C accuracy and <34.4 ms conversion latency. |
| Voltage Regulator Module (VRM) Monitoring | Industrial Power Supply Thermal Control |
|
Use Scenario: Monitoring VRM MOSFET temperature in high-current CPU/GPU power delivery circuits. IC Role / Device Role / Timing Role: Remote diode attached to VRM high-side FET; GPIOs signal overtemperature to PMIC or host controller. Use Value: Enables dynamic current derating before VRM thermal shutdown, improving system uptime and reliability. |
Use Scenario: Fan-cooled AC/DC or DC/DC power supplies in telecom or industrial enclosures. IC Role / Device Role / Timing Role: Local temperature sensor monitors ambient air near heatsink; PWM output adjusts fan to maintain stable output regulation. Use Value: Compensates for ambient drift and load-dependent heating without requiring external MCU firmware. |
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 |
|---|---|---|---|
| LM96163CIMTX/NOPB | Higher remote accuracy (±0.75°C), 12-bit resolution, but no integrated PWM output - requires external fan controller | Used where precision exceeds LM64CILQX-F capability and fan control is handled separately | Select when absolute thermal measurement fidelity is prioritized over integration and board space |
| ADM1032ARMZ-REEL | ±2°C remote accuracy, SMBus 1.1 only, no tachometer input or LUT-based PWM - simpler feature set | Deployed in cost-sensitive embedded systems where basic thermal alerting suffices | Select when fan speed control is managed externally and SMBus 2.0 features like TIMEOUT are not required |
Compared with LM96163CIMTX/NOPB and ADM1032ARMZ-REEL, the LM64CILQX-F uniquely integrates ±1°C remote sensing, 8-step PWM LUT, tachometer feedback, and SMBus 2.0 TIMEOUT in a single 24-pin WQFN - reducing BOM count and eliminating coordination latency between sensing and actuation.
Availability
LM64CILQX-F is available at Aetrix Electronics and suitable for computer processor thermal management, graphics processor thermal management, and voltage regulator module applications requiring stable component supply across extended product lifecycles.
Supply support for LM64CILQX-F 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 and embedded processing solutions, with core expertise in precision sensing, power management, and industrial interface technologies.
The LM64CILQX-F belongs to TI's thermal management IC portfolio, engineered specifically for intelligent, self-contained fan control in high-performance computing and graphics platforms where acoustic noise, thermal safety, and SMBus interoperability are critical.
FAQ
What is the remote diode temperature accuracy specification for LM64CILQX-F?
The LM64CILQX-F achieves ±1.0°C maximum remote diode temperature accuracy over the 120°C to 140°C range when used with an MMBT3904 diode-connected transistor. This accuracy includes quantization error and is factory-trimmed. At broader ranges (25°C to 140°C), the max error is ±3.0°C. The LM64CILQX-F applies a fixed +16°C offset to reported remote values to reflect actual diode junction temperature (TACTUAL = TLM64CILQX-F + 16°C).
Does LM64CILQX-F support SMBus TIMEOUT functionality?
Yes, the LM64CILQX-F fully supports SMBus 2.0 TIMEOUT functionality. If SMBDAT or SMBCLK lines remain low for 25–35 ms, the device resets its SMBus state machine and places both pins in high-impedance mode. This prevents bus lockup in noisy or fault-prone environments and is verified in TI SNAS207B Rev. January 2024, Section 5.8.
How many GPIOs does LM64CILQX-F provide, and what are their electrical characteristics?
The LM64CILQX-F provides five general-purpose I/O pins (GPIO1–GPIO5), each configurable as open-drain digital input or output with a typical 10 kΩ pull-up to VDD. Additionally, it offers five general-purpose default input pins (GPD1–GPD5) that must be tied high or low at power-on to configure SMBus address (A0) and startup behavior. All GPIOs operate within the 3.0–3.6 V supply range.
What is the function of the TACH input on LM64CILQX-F?
The TACH input on LM64CILQX-F accepts open-collector tachometer pulses from a 2- or 4-wire fan, enabling real-time RPM measurement with ±10% accuracy. It uses a 90 kHz internal counter clock and updates fan count every 1.0 Hz. This allows the LM64CILQX-F to verify fan operation, detect stalls, and close the thermal control loop independently of host software.
Can LM64CILQX-F drive a fan directly, or does it require external circuitry?
The LM64CILQX-F cannot drive a fan directly. Its PWM pin is an open-drain digital output rated for 6 mA sink current (0.55 V max saturation at 6 mA). It must interface with external fan driver circuitry - typically an N-channel MOSFET or dedicated fan controller IC - to supply the required current and voltage to the fan motor. The LM64CILQX-F handles only the logic-level PWM signal generation and thermal decision-making.
LM64CILQX-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Fan Control, Temp Monitor
- Sensor Type:
- Internal and External
- Sensing Temperature:
- 0°C ~ 85°C, 25°C ~ 140°C
- Accuracy:
- ±1°C Local(Max), ±3°C Remote(Max)
- 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:
- 24-WQFN (4x5)
LM64CILQX-F FAQ
1.How can I place an order for LM64CILQX-F through Aetrix?
Please submit a Request for Quotation (RFQ) for LM64CILQX-F 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 LM64CILQX-F reliable?
The price and inventory of LM64CILQX-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM64CILQX-F is usually 5 days.
3.What payment methods are accepted for LM64CILQX-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM64CILQX-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM64CILQX-F?
LM64CILQX-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM64CILQX-F 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 LM64CILQX-F?
For technical support, including LM64CILQX-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM64CILQX-F requirements.
6.How does Aetrix verify that LM64CILQX-F is sourced from the original manufacturer or authorized distributors?
All LM64CILQX-F 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 LM64CILQX-F meets industry standards.
7.What is the process for return or replacement of LM64CILQX-F?
All LM64CILQX-F units undergo pre-shipment inspection (PSI). If there is an issue with LM64CILQX-F, 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 LM64CILQX-F part is unused and in its original packaging.
Return procedure for LM64CILQX-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM64CILQX-F Tags
-
EMC2101-ACZL-TR
Microchip Technology
-
MCP9844T-BE/MNY
Microchip Technology
-
EMC2101-R-ACZL-TR
Microchip Technology
-
MCP98244T-BE/MNY
Microchip Technology
-
TC670ECHTR
Microchip Technology
-
SE98ATP,547
NXP Semiconductors
-
AMC6821SDBQR
Texas Instruments
-
MAX6604AATA+T
Analog Devices Inc./Maxim Integrated
-
ADT7475ARQZ-REEL
onsemi
-
MAX6643LBBAEE+
Analog Devices Inc./Maxim Integrated
-
MAX6684ESA+T
Analog Devices Inc./Maxim Integrated
-
MAX6639AEE+
Analog Devices Inc./Maxim Integrated
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…
