LMT84LPM - 1.5V 10uA Analog Temp Sensor TO-92 | TI
부품 번호: LMT84LPM ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $0.62 | $0.62 |
| 10 | $0.5 | $5.00 |
| 100 | $0.38 | $38.00 |
| 500 | $0.31 | $155.00 |
| 1,000 | $0.26 | $260.00 |
LMT84LPM 개요
An analog temperature sensor converts local temperature into a proportional voltage that a microcontroller ADC or comparator can read directly, without digital bus configuration. Within the signal chain hierarchy, it sits alongside thermistors and RTDs as a sensing element, but the LMT84 family replaces passive thermistors with a calibrated, linear, push-pull (Class-AB) output that drives heavy loads without an external buffer.
Key features include +/-0.4C typical accuracy (+/-2.7C maximum), 1.5V minimum supply for single-cell battery operation, 0.7 ms power-on time enabling aggressive power-cycling, and Class-AB source/sink output capability. The inverse transfer function also provides inherent failsafe behavior: a shorted output reads as maximum temperature, which systems can detect.
Architecturally, the LMT84 uses a CMOS bandgap-derived sensing core with a Class-AB output stage, giving strong output drive in both directions and low sensitivity to supply noise compared with thermistor divider circuits.
Typical applications include battery-powered sensing nodes, automotive climate and battery-pack monitoring (via the AEC-Q100 Grade 0 qualified LMT84-Q1 variant), appliance and HVAC thermal protection, and portable medical devices.
Design tip: because output swing is negative-sloped, remember ADC code decreases with rising temperature; at 30C the output is approximately 537 mV per the datasheet lookup table.
드롭인 대체품: LMT84LPM — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
LMT84-Q1
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
LMT85
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
LMT86
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
LMT87
✅ 드롭인 ⚠️ 사양 미검증📋 참조 대체품 (카탈로그에 없음)
TMP235
⚡ 동일 패키지📋 참조 대체품 (카탈로그에 없음)
LM94022
⚡ 동일 패키지📋 참조 대체품 (카탈로그에 없음)
LMT84LPM 최대 정격 & 전기적 특성
| 센서 유형 | Analog output local temperature sensor |
| Temperature Range | -50C to +150C |
| Accuracy | +/-0.4C typical, +/-2.7C maximum |
| Sensor Gain | -5.5 mV/C |
| Supply Voltage (Min) | 1.5 V |
| Supply Voltage (Max) | 5.5 V |
| 대기 전류 | 5.4 uA (approx. 10 uA class) |
| Power-On Time | 0.7 ms |
| 출력 유형 | Class-AB push-pull analog |
| Output Polarity | Inverse (voltage decreases with temperature) |
| Output Capability | Strong source and sink current drive |
| 패키지 | TO-92-3 |
| 실장 유형 | Through Hole |
| Automotive Qualification | LMT84-Q1 variant AEC-Q100 Grade 0 |
| RoHS 상태 | Compliant |
LMT84LPM 핀 구성
| 핀 1 | VDD — Power supply, 1.5V to 5.5V |
| 핀 2 | VOUT — Analog temperature output, -5.5 mV/C inverse slope |
| 핀 3 | GND — Ground |
일반적인 애플리케이션
LMT84LPM 적합 용도: 6 애플리케이션s: Battery-Powered Sensing Nodes, Automotive Thermal Monitoring, Appliance and HVAC Temperature Sensing, Portable Medical Devices, RF and Radio Module Temperature Compensation, Industrial Thermal Protection and Cutoff.
Battery-Powered Sensing Nodes
The LMT84's 5.4 uA quiescent current and 1.5V minimum supply make it ideal for coin-cell and single-cell battery nodes. Its 0.7 ms power-on time enables aggressive duty-cycling: the MCU can power the sensor only during a reading, cutting average current far below continuous-operation sensors. Placed on the battery or PCB hotspot with the output feeding an MCU ADC input, the -5.5 mV/C linear transfer avoids lookup tables, and no divider current flows since the Class-AB output sources current directly.
추천
Automotive Thermal Monitoring
The AEC-Q100 Grade 0 qualified LMT84-Q1 variant, manufactured on an automotive grade flow, covers -50C to +150C with +/-0.4C typical accuracy - suited to cabin climate control, battery pack, and powertrain thermal sensing. The inverse analog output resists wired-OR contention and a shorted output reads as an implausible maximum temperature, aiding fault detection. Signal conditioning is minimal because the Class-AB push-pull output can drive RC filters and cable capacitance toward an MCU ADC without a buffer amplifier.
추천
Appliance and HVAC Temperature Sensing
In refrigerators, thermostats, and HVAC controllers, the LMT84 replaces NTC thermistor dividers, eliminating divider bias current and Steinhart-Hart linearization. The -5.5 mV/C output gives roughly 22 LSB/C on a 10-bit, 3.3V ADC - adequate for 0.5C-class control. Its 1.5V-capable operation allows sensing directly from low-voltage rails, and the TO-92 package can be glued or clipped to metal surfaces for air or evaporator temperature measurement with simple 100 nF output filtering.
추천
Portable Medical Devices
Wearable and handheld medical instruments benefit from the LMT84's 5.4 uA consumption and small SC70 footprint, extending battery life in thermometers and patient monitors. The +/-0.4C typical accuracy supports body-temperature trending, while the analog output integrates easily with low-power MCU ADCs without digital bus timing complexity. For skin-temperature probes, the inverse transfer function and push-pull output maintain signal integrity across long probe leads when paired with a modest RC anti-alias filter.
추천
RF and Radio Module Temperature Compensation
Power amplifiers, VCOs, and crystal oscillators drift with temperature; the LMT84 provides a fast (0.7 ms power-on), low-noise analog voltage that a baseband MCU or FPGA ADC reads for lookup-based power or frequency compensation. Its 5.4 uA draw suits always-on radio nodes, and the SC70 package mounts near the PA die for accurate hotspot sensing. The push-pull output rejects supply ripple better than a thermistor divider, reducing compensation error on noisy RF boards.
추천
Industrial Thermal Protection and Cutoff
The LMT84 feeds a comparator or MCU ADC for over-temperature shutdown in motor drives, power supplies, and LED drivers spanning -50C to +150C. The Class-AB output can directly drive comparator inputs and long wiring with hysteresis networks, and the inverse slope means a broken or shorted sensor produces an out-of-range code that firmware can flag as a fault. The 1.5V-capable supply also allows biasing from an existing low-voltage reference rail without a dedicated regulator.
추천
추천 제품 요약
엔지니어링 참조 데이터: LMT84LPM — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | LMT84-Q1 | LMT85 | LMT87 | TMP235 |
|---|---|---|---|---|---|
| Package | TO-92-3 | SC70-5 | SC70-5 / TO-92-3 | SC70-5 / TO-92-3 | SC70-5 / SOT23-3 |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Sensor Gain | -5.5 mV/C | -5.5 mV/C | -8.2 mV/C | -13.6 mV/C | -5.5 / -8.2 / -10.9 / -13.6 mV/C (pin-selectable) |
| Supply Voltage Range | 1.5 V to 5.5 V | 1.5 V to 5.5 V | 1.5 V to 5.5 V | 1.5 V to 5.5 V | 2.3 V to 5.5 V |
| Temperature Range | -50C to +150C | -50C to +150C | -50C to +150C | -50C to +150C | -40C to +150C |
| Automotive Qualification | No (LMT84-Q1 variant only) | AEC-Q100 Grade 0 | No | No | TMP235-Q1 available |
주요 차별점
- Lowest gain sensitivity to ADC noise in family (vs LMT87)
- 1.5V minimum supply (vs TMP235)
- Automotive upgrade path on same die (vs LMT84-Q1)
설계 노트
Place a 0.1 uF bypass capacitor within 2 mm of the VDD pin; the LMT84 is stable with or without an output capacitor, but adding 100 nF to 1 uF on VOUT forms an RC noise filter. Because the output is push-pull (Class-AB), no pull-up or pull-down resistor is required, unlike thermistor divider circuits.
The LMT84 output slope is negative: temperature rises cause the ADC code to fall. Firmware implementing simple threshold comparisons frequently inverts trip logic and causes shutdown failures. Use the datasheet VOUT lookup table rather than a single linear equation for best accuracy across -50C to +150C, since the transfer curve is slightly nonlinear at range extremes.
Exploit the 0.7 ms power-on time for battery designs: gate the sensor supply with an MCU GPIO or load switch and power it only during conversions. At a 1 Hz sample rate with 1 ms on-time, average sensor current drops to roughly 5 nA plus switch leakage - orders of magnitude below continuous operation of 5.4 uA.
For remote sensing with long leads, add an RC filter (e.g., 1 kOhm + 1 uF) at the ADC input to reject cable pickup; the Class-AB output sinks this loading without drift. Self-heating is minimal at 5.4 uA but avoid routing high-current traces under the TO-92 package for accurate ambient measurement.
규정 준수 정보
LMT84-Q1 variant is AEC-Q100 Grade 0 qualified on automotive grade flow per TI datasheet. Standard LMT84LPM is not automotive qualified.
