LM63CIMAX - ±1°C Remote Diode Temp Sensor + Fan Control | TI
MPN: LM63CIMAX ✓ Hoạt độngLM63CIMAX Tóm tắt
A remote-diode temperature sensor is a class of thermal management IC that exploits the temperature-dependent base-emitter voltage of a bipolar or substrate diode to infer junction temperature far away from the sensor itself. Remote-diode sensors sit within the thermal management IC hierarchy (PMIC > thermal management > temperature sensor > remote-diode sensor) and are essential in desktop PCs, servers, and any system where a hot spot must be monitored without placing the sensor physically on the heat source.
Key specifications include ±1°C remote-diode accuracy (0°C to +125°C) and ±3°C accuracy from 0°C to +85°C, 8-/10-bit-plus-sign internal/remote resolution, a 2-wire SMBus (I²C-compatible) digital interface, and a programmable PWM fan-control output with tachometer input for closed-loop RPM feedback. Supply voltage is 3.0V to 3.6V and quiescent current is roughly 1.3 mA during active conversion.
The LM63CIMAX integrates a sigma-delta ADC for noise rejection, on-chip offset trim performed at the factory to minimize diode non-ideality errors, and a tachometer counter that reports fan RPM over the SMBus. The MAX package exposes a single remote-diode differential input pair (D+/D−) and the fan-driver PWM output (Fan Out), plus the digital interface pins (SDA, SCL, ALERT, GND, VDD, FAN_IN/TACH).
Typical applications include CPU/GPU thermal monitoring in desktop and server motherboards, fan-speed control in telecom equipment, and chassis-intake temperature sensing in industrial controllers. The integrated fan tachometer input enables closed-loop RPM regulation rather than open-loop PWM drive, which reduces acoustic noise and extends fan life.
When designing with the LM63CIMAX, keep the D+/D− routing balanced, length-matched, and surrounded by ground to cancel noise pickup that would otherwise appear as temperature noise. Decouple VDD close to the IC with a 0.1 µF ceramic capacitor and avoid routing the remote-diode traces near switching fan-drive signals to preserve accuracy.
Bộ thay thế dễ dàng lắp đặt cho LM63CIMAX — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với LM63CIMAX (cùng hình factor và footprint) — khác nhau ở Package, Function, Remote Diode Accuracy, Fan Control Output, Interface.
LM63CIMAX/NOPB
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| Chức năng | Remote Diode Temperature Sensor with PWM Fan Driver |
| Remote Diode Accuracy | ±1°C (0°C to +125°C) |
| Local Sensor Accuracy | ±3°C (0°C to +85°C) |
| Supply Voltage (VDD) | 3.0 V to 3.6 V |
| Supply Current (active) | 1.3 mA typ |
| Resolution (Remote) | 10-bit + sign |
| Resolution (Local) | 8-bit + sign |
| Giao diện | 2-Wire SMBus (I²C-compatible) |
| Fan Output | PWM, open-drain |
| Tachometer Input | Yes (Fan RPM feedback) |
| Remote Diode Inputs | D+ / D− differential pair |
| Nhiệt độ hoạt động | 0°C to +125°C |
| Hộp | 8-pin SOIC (MAX) |
| Kiểu lắp đặt | Surface Mount |
| Cấp MSL | 1 |
| Trạng thái RoHS | Compliant |
Cấu hình chân LM63CIMAX
| Chân 1 | GND — Ground reference for IC and remote-diode measurement |
| Chân 2 | VDD — Positive supply input, 3.0V to 3.6V (3.3V typical) |
| Chân 3 | D+ — Remote-diode positive input (anode of substrate diode) |
| Chân 4 | D− — Remote-diode negative input (cathode of substrate diode) |
| Chân 5 | ALERT — Open-drain interrupt output (active low when threshold exceeded) |
| Chân 6 | TACH / FAN_IN — Fan tachometer input for closed-loop RPM feedback |
| Chân 7 | Fan Out — PWM fan-driver output (open-drain) |
| Chân 8 | SDA — SMBus/I²C data line (open-drain, requires external pull-up) |
Ứng dụng tiêu biểu
LM63CIMAX phù hợp cho 6 Áp dụngs: CPU/GPU Thermal Monitoring on Desktop & Server Boards, Closed-Loop Fan-Speed Control in Telecom & Networking Equipment, Chassis-Intake Air Temperature Sensing in Industrial Controllers, Laptop & Notebook Thermal Management, Set-Top Box / Game Console Fan Control, FPGA / ASIC Board Thermal Protection.
CPU/GPU Thermal Monitoring on Desktop & Server Boards
The LM63CIMAX fits CPU/GPU thermal monitoring because its remote-diode input accurately reads the substrate diode of a processor or graphics chip from a distance, while its local channel monitors board-level air temperature. With ±1% accuracy over 0°C to +125°C on the remote channel and a 2-wire SMBus interface, it delivers CPU die temperature readings directly to the EC/super-IO at typical sample rates of 1 Hz. Place the LM63CIMAX within 10 cm of the remote diode, route D+/D− as a length-matched differential pair surrounded by ground, and use the integrated PWM output to drive the heatsink fan's 4-wire PWM input.
Được đề xuất
Closed-Loop Fan-Speed Control in Telecom & Networking Equipment
The LM63CIMAX is well-suited to closed-loop fan-speed control in telecom and networking equipment because it combines a remote-diode temperature sensor, a PWM fan-driver output, and a tachometer input on the same die. The firmware can program a target RPM and the LM63CIMAX's tachometer counter reports the actual fan speed over SMBus, enabling acoustic-aware variable-speed cooling. The 8-SOIC package and 3.3V single-rail supply fit typical line-card / base-station board constraints, and the open-drain PWM output can sink up to the fan driver's gate capacitance directly.
Được đề xuất
Chassis-Intake Air Temperature Sensing in Industrial Controllers
For chassis-intake air temperature sensing in industrial controllers, the LM63CIMAX uses its local on-die sensor to monitor ambient inlet air with ±3°C accuracy from 0°C to +85°C. This reading can be combined with the remote-diode reading to model thermal gradients across the chassis and trigger fan-boost profiles before ASIC hotspots cross the alarm threshold. The 8-SOIC (MAX) package and SMBus interface integrate cleanly into any 3.3V-managed industrial backplane.
Được đề xuất
Laptop & Notebook Thermal Management
The LM63CIMAX supports laptop and notebook thermal management by reading the CPU's remote substrate diode and driving the system fan's PWM input with a speed command derived from that temperature. The 1.3 mA active current is low enough to leave the IC in always-on mode for instant system wake on thermal alarm, and the SMBus interface lets the embedded controller share the temperature with the OS for graceful throttling. Pair it with a 4-wire PWM fan to enable silent idle / active-load acoustic profiles.
Được đề xuất
Set-Top Box / Game Console Fan Control
In set-top boxes and game consoles, the LM63CIMAX provides single-IC remote-diode temperature sensing plus PWM fan control in an 8-SOIC package that fits a small main board. The integrated ALERT pin can wake the SoC when SoC temperature exceeds a programmable threshold, and the tachometer input lets firmware verify the fan is actually spinning at the commanded RPM. The 3.0V-to-3.6V supply aligns with 3.3V system rails common in consumer electronics.
Được đề xuất
FPGA / ASIC Board Thermal Protection
The LM63CIMAX is a strong choice for FPGA/ASIC board thermal protection because its remote-diode input can directly monitor the substrate diode of large FPGAs and ASICs whose package exposes a thermal diode. With ±1% accuracy over 0°C to +125°C and an ALERT interrupt output, the LM63CIMAX can notify the host MCU immediately when an FPGA junction approaches its 100°C limit. The integrated PWM fan driver then throttles the heatsink fan to hold junction temperature below the limit without external fan-driver ICs.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho LM63CIMAX — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | LM63CIMAX/NOPB | LM63CIMA/NOPB | LM63CIMA |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-SOIC (MAX) | 8-SOIC (MAX) - same | 8-SOIC (MA) - smaller | 8-SOIC (MA) - smaller |
| Remote-Diode Accuracy | ±1°C (0°C to +125°C) | ±1°C (0°C to +125°C) | ±1°C (0°C to +125°C) | ±1°C (0°C to +125°C) |
| Local-Sensor Accuracy | ±3°C (0°C to +85°C) | ±3°C (0°C to +85°C) | ±3°C (0°C to +85°C) | ±3°C (0°C to +85°C) |
| Interface | 2-Wire SMBus | 2-Wire SMBus | 2-Wire SMBus | 2-Wire SMBus |
| Supply Voltage | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V | 3.0 V to 3.6 V |
| Resolution (bits) | 10-bit + sign (remote), 8-bit + sign (local) | 10-bit + sign (remote), 8-bit + sign (local) | 10-bit + sign (remote), 8-bit + sign (local) | 10-bit + sign (remote), 8-bit + sign (local) |
| RoHS / Lead-Free | Compliant / Yes | Compliant / Yes (explicit) | Compliant / Yes (explicit) | Check datasheet |
| Tachometer Input | Yes | Yes | Yes | Yes |
| PWM Fan Output | Yes (open-drain) | Yes (open-drain) | Yes (open-drain) | Yes (open-drain) |
Bảo phân biệt quan trọng
- True 8-SOIC MAX package with full 8-pin layout (vsLM63CIMA (MA package))
- Drop-in compatibility with /NOPB lead-free variant (vsDiscrete LM35 analog + firmware fan-control routine)
- Integrated tachometer feedback for closed-loop RPM control (vsMAX31760 (multi-fan, non-pin-compatible))
Ghi chú thiết kế
Estimated: route the D+ and D− traces as a length-matched differential pair (≤10 cm) over a continuous ground pour, and avoid running them parallel to or under the fan-driver PWM output. The remote-diode measurement is a low-level current/voltage conversion (typically 100 µA bias) that is highly susceptible to leakage from switching fan drive signals. Place the LM63 within 3 cm of the remote diode to preserve ±1°C performance.
Place a 0.1 µF ceramic decoupling capacitor as physically close as possible to the VDD pin (Pin 2), with a 10 µF bulk capacitor on the same 3.3 V rail. The SMBus lines (SDA on Pin 8, SCL on Pin 4, ALERT on Pin 5) are open-drain and require external pull-up resistors (typically 2.2 kΩ to 10 kΩ depending on bus capacitance) to 3.3 V. The PWM Fan Out (Pin 7) and TACH/FAN_IN (Pin 6) pins should be guarded against ESD with TVS diodes if the fan is on a connector.
Do not float the ADD pin (Pin 4 / SCL pad or dedicated ADD) on the LM63 — the ADD pin sets the SMBus slave address (0x4C or 0x4D) and floating it can latch an indeterminate address. Also do not assume the /NOPB suffix is optional: if your assembly line is Pb-free, the standard LM63CIMAX part number (non-/NOPB) may have SnPb terminal finish that fails the RoHS compliance step. Use LM63CIMAX/NOPB explicitly for RoHS-compliant assemblies.
Estimated: at typical fan-duty operation (50% PWM at 25 kHz, 3.3 V), the LM63CIMAX self-heating from the open-drain fan-output switching edge is well under 0.2°C. However, mounting the IC adjacent to the fan-connector step-down regulator or PWM power-stage heatsink can introduce local self-heating bias on the local on-die sensor. Mount the LM63 on the cooler side of the board, away from the fan-driver power components, to avoid adding to the ±3°C local-sensor accuracy budget.
Thông tin tuân thủ
LM63CIMAX is RoHS compliant per TI product page; the /NOPB variant explicitly carries lead-free terminal finish. The LM63CIMAX is not AEC-Q100 qualified — for automotive thermal management, choose an AEC-Q100 qualified temperature sensor instead.
