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Texas Instruments LM64CILQ-F/NOPB
- Part No.:
- LM64CILQ-F/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Thermal Management
- Package:
- 24-WFQFN Exposed Pad
- Datasheet:
-
LM64CILQ-F/NOPB.pdf
- Description:
- IC TEMP SENSOR REMOTE 24WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,575
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Product details
Overview
LM64CILQ-F/NOPB from Texas Instruments is a remote diode temperature sensor IC with integrated PWM fan speed control, 5 GPIOs, and SMBus 2.0 interface. It delivers ±1.0°C remote diode accuracy (120°C–140°C), 0.125°C resolution, and tachometer input for closed-loop thermal management in high-performance computing systems.
For engineers reviewing the LM64CILQ-F/NOPB datasheet, LM64CILQ-F/NOPB pinout, LM64CILQ-F/NOPB application, or LM64CILQ-F/NOPB equivalent, key selection criteria include remote diode accuracy over 120–140°C, programmable 8-step PWM lookup table for acoustic noise reduction, open-drain ALERT/T_Crit outputs, and 24-pin WQFN package compatibility with space-constrained PCB layouts.
Technical Context
The LM64CILQ-F/NOPB implements a ΔVBE-based remote diode sensing architecture with a 10-bit plus sign ΔΣ ADC, factory-trimmed for MMBT3904 diodes with +16°C junction offset correction. Its digital comparators monitor local and remote temperatures against user-programmable high/low/T_Crit setpoints, triggering open-drain ALERT and T_Crit outputs without latching.
It integrates an SMBus 2.0-compliant two-wire interface with TIMEOUT support, 1.1 mA typical supply current at 3.3 V, and configurable PWM output frequency (±10% accuracy) driven by an 8-step non-linear lookup table-enabling precise fan speed vs. temperature response curves to suppress acoustic noise in graphics and processor thermal subsystems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Remote Diode Accuracy | ±1.0°C max (120°C–140°C range); enables reliable thermal throttling near GPU/CPU junction limits |
| Temperature Resolution | 0.125°C (11-bit remote, 8-bit local); supports fine-grained thermal feedback for dynamic fan control |
| PWM Output | Open-drain, programmable 8-step lookup table; allows non-linear fan speed mapping to reduce acoustic noise |
| SMBus Interface | 2.0-compatible, 10–100 kHz clock, TIMEOUT reset; ensures robust communication in multi-device thermal buses |
| Supply Voltage | 3.0–3.6 V DC; compatible with standard 3.3 V system rails and low-noise bypassing (0.1 µF || 100 pF) |
| Tachometer Input | Digital input with 90 kHz counter clock; measures fan RPM directly from open-collector tach signal |
| GPIO Count | 5 open-drain GPIOs + 5 default-input GPD pins; provides flexible I/O for status signaling, mode selection, or fault handling |
Pinout & Package
LM64CILQ-F/NOPB is housed in a 24-pin WQFN package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad for enhanced heat dissipation in thermally dense applications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GPIO1–GPIO5 | Digital I/O (open-drain) | Configurable as inputs or open-drain outputs with 10 kΩ pull-up; used for system signaling or control coordination |
| GPD1–GPD5 | Digital input (default) | Hardwired logic-level inputs; must be tied high/low to configure boot-time behavior or device addressing |
| PWM | Open-drain fan drive output | Drives external MOSFET/fan driver; power-on default = low; supports duty-cycle modulation via LUT |
| TACH | Digital tachometer input | Counts pulses from fan's open-collector tach output; updates every 1.0 Hz for RPM calculation |
| ALERT / T_Crit | Open-drain interrupt outputs | ALERT asserts on temp violation (high/low/T_Crit); T_Crit asserts only on critical overtemp - no latching |
| D+ / D− | Remote diode analog inputs | Connect to anode/cathode of MMBT3904 or equivalent diode; require 2.2 nF capacitor across pins |
| SMBDAT / SMBCLK | SMBus bidirectional data/clock | Compliant with SMBus 2.0 timing; includes TIMEOUT detection (25–35 ms low pulse resets state machine) |
Key Features
| Feature | Design Value |
|---|---|
| Factory-trimmed remote diode sensing | ±1.0°C accuracy over 120–140°C using MMBT3904 diode; eliminates need for system-level calibration |
| Programmable 8-step PWM lookup table | Enables non-linear fan speed vs. temperature curve to minimize acoustic noise during mid-range operation |
| Dual open-drain alert outputs | ALERT signals general thermal violations; T_Crit provides dedicated critical overtemperature indication without hysteresis |
| Integrated tachometer counter | Measures fan RPM directly with 65535-count full-scale range and 1 Hz update rate - no external counter required |
| SMBus 2.0 TIMEOUT support | Resets interface state if SMBDAT/SMBCLK held low >25 ms; prevents bus lockup in noisy or faulted environments |
Applications
| Computer Processor Thermal Management | Graphics Processor Thermal Management |
|---|---|
Use Scenario: Real-time monitoring of CPU die temperature and active PWM-driven cooling in desktop/server platforms. IC Role / Device Role / Timing Role: Remote diode sensor measuring CPU thermal diode; generates PWM signal to modulate 4-wire fan speed based on junction temperature. Use Value: Enables precise thermal throttling within ±1.0°C of actual CPU junction temp, reducing risk of thermal runaway while minimizing fan noise via 8-step LUT. |
Use Scenario: Closed-loop thermal control of discrete GPU modules where diode placement is constrained near VRM or memory stacks. IC Role / Device Role / Timing Role: Measures remote diode on GPU package; drives PWM fan and reports RPM via TACH; triggers T_Crit on critical overtemp. Use Value: Delivers 0.125°C resolution and ±1.0°C accuracy at 120–140°C - matching GPU thermal trip thresholds - with no software calibration needed. |
| Voltage Regulator Module Monitoring | Electronic Instrumentation Cooling Control |
Use Scenario: Thermal supervision of high-current VRMs powering CPUs/GPUs, where localized heating requires independent diode sensing. IC Role / Device Role / Timing Role: Local temperature sensor monitors LM64's own die; remote channel reads VRM MOSFET diode; ALERT flags overtemp events. Use Value: Simultaneous local (±3.0°C) and remote (±1.0°C) measurement enables differential thermal analysis between controller and power stage. |
Use Scenario: Fan-cooled test equipment (e.g., oscilloscopes, spectrum analyzers) requiring silent operation and stable internal temperature. IC Role / Device Role / Timing Role: Controls PWM fan speed using 8-step LUT to maintain instrument ambient at <40°C; GPIOs signal thermal fault states. Use Value: Acoustic noise reduction achieved through non-linear fan ramping - critical for lab-grade instrumentation where fan hum interferes with measurements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar remote diode temperature sensing and PWM 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 tachometer input; uses I²C instead of SMBus | Lacks TACH pin - requires external counter or MCU polling for RPM; better suited for precision-only thermal monitoring | Select when absolute remote accuracy >0.75°C is required and tachometer feedback is handled externally |
| ADM1032ARMZ-REEL | ±2.0°C remote accuracy (0°C–125°C), no PWM output; relies on host MCU for fan control logic | No integrated PWM or LUT - fan drive must be implemented externally; simpler register map but less autonomous | Select when system already implements fan control in firmware and only needs dual-zone temperature reporting |
Compared with LM64CILQ-F/NOPB, LM96163CIMTX/NOPB offers higher resolution and tighter accuracy but sacrifices tachometer integration and SMBus TIMEOUT support, while ADM1032ARMZ-REEL reduces feature count to prioritize cost and simplicity over autonomous thermal actuation.
Availability
LM64CILQ-F/NOPB is available at Aetrix Electronics and suitable for computer processor thermal management, graphics processor thermal management, and voltage regulator module monitoring requiring stable component supply and long-term industrial lifecycle support.
Supply support for LM64CILQ-F/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 specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in precision sensing and power management ICs.
The LM64CILQ-F/NOPB belongs to TI's thermal management product line, designed specifically for autonomous, closed-loop fan control in high-performance computing and graphics systems where acoustic noise, thermal accuracy, and SMBus interoperability are critical.
FAQ
What is the remote diode temperature accuracy specification for LM64CILQ-F/NOPB?
The LM64CILQ-F/NOPB achieves ±1.0°C maximum remote diode temperature accuracy over the 120°C to 140°C range when used with a factory-trimmed MMBT3904 diode-connected transistor. This accuracy includes quantization error and is validated across the full operating ambient range of 0°C to +85°C. The LM64CILQ-F/NOPB also supports ±3.0°C accuracy from 25°C to 140°C for broader thermal monitoring use cases.
Does LM64CILQ-F/NOPB support tachometer input for fan RPM measurement?
Yes, LM64CILQ-F/NOPB includes a dedicated TACH digital input pin that accepts open-collector tachometer pulses. It features a 65535-count full-scale counter clocked at 90 kHz and updates fan RPM readings once per second. This eliminates the need for external counting circuitry and enables direct RPM feedback for closed-loop fan control within the LM64CILQ-F/NOPB itself.
How does the 8-step PWM lookup table in LM64CILQ-F/NOPB improve acoustic performance?
The 8-step PWM lookup table in LM64CILQ-F/NOPB allows non-linear mapping of temperature to fan duty cycle - for example, holding low fan speed until a threshold is crossed, then ramping quickly. This avoids mid-speed operation where fans generate peak acoustic noise. The LM64CILQ-F/NOPB implements this autonomously without MCU intervention, directly reducing audible fan whine in graphics and server applications.
What SMBus features does LM64CILQ-F/NOPB support beyond basic read/write operations?
LM64CILQ-F/NOPB fully supports SMBus 2.0, including TIMEOUT detection (resetting the interface state if SMBDAT/SMBCLK remain low >25 ms), ALERT response address (ARA) protocol for multi-device interrupt arbitration, and SMBus-specific electrical characteristics like VIH/VIL hysteresis (400 mV). These features ensure robust bus operation in complex thermal management subsystems with multiple sensors and controllers.
Can LM64CILQ-F/NOPB operate with both local and remote temperature sensing simultaneously?
Yes, LM64CILQ-F/NOPB continuously measures both its own die temperature (local) and a remote diode temperature in each 31.25 ms conversion cycle. Local accuracy is ±3.0°C from 25°C to 125°C; remote accuracy is ±1.0°C from 120°C to 140°C. Both readings update registers simultaneously and feed independent digital comparators for ALERT and T_Crit generation - enabling dual-zone thermal protection in a single IC.
LM64CILQ-F/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 24-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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)
LM64CILQ-F/NOPB FAQ
1.How can I place an order for LM64CILQ-F/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM64CILQ-F/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 LM64CILQ-F/NOPB reliable?
The price and inventory of LM64CILQ-F/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM64CILQ-F/NOPB is usually 5 days.
3.What payment methods are accepted for LM64CILQ-F/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM64CILQ-F/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM64CILQ-F/NOPB?
LM64CILQ-F/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM64CILQ-F/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 LM64CILQ-F/NOPB?
For technical support, including LM64CILQ-F/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM64CILQ-F/NOPB requirements.
6.How does Aetrix verify that LM64CILQ-F/NOPB is sourced from the original manufacturer or authorized distributors?
All LM64CILQ-F/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 LM64CILQ-F/NOPB meets industry standards.
7.What is the process for return or replacement of LM64CILQ-F/NOPB?
All LM64CILQ-F/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM64CILQ-F/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 LM64CILQ-F/NOPB part is unused and in its original packaging.
Return procedure for LM64CILQ-F/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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