Texas Instruments LM92CIM/NOPB

Overview

LM92CIM/NOPB from Texas Instruments is a ±0.33°C accurate, 12-bit + sign digital temperature sensor with integrated thermal window comparator and I²C interface. It delivers 0.0625°C resolution, operates from −55°C to +150°C, and features dual open-drain outputs (INT and T_CRIT_A) for independent alarm signaling-used in system thermal management for PC motherboard monitoring and hardware shutdown control.

For engineers reviewing the LM92CIM/NOPB datasheet, LM92CIM/NOPB pinout, LM92CIM/NOPB application, or LM92CIM/NOPB equivalent, key selection criteria include its programmable hysteresis, fault queue for noise immunity, shutdown mode (5 µA), and support for up to four devices on a single I²C bus with A0/A1 address configuration.

Technical Context

The LM92CIM/NOPB integrates a band-gap temperature sensor, 13-bit ADC, and digital comparator logic with user-programmable TLOW/THIGH/T_CRIT thresholds. Its two-wire I²C slave interface uses a fixed 5-bit base address (10010) plus A0/A1 pins for device addressing.

It supports two interrupt modes: Comparator Mode (output resets after each read and reasserts if condition persists) and Event Mode (output latches until next threshold crossing). The T_CRIT_A output operates exclusively in comparator mode and remains asserted independently of reads-enabling hardware-level critical shutdown without host intervention.

Key Specifications

Pinout & Package

LM92CIM/NOPB is housed in an 8-pin SOIC package (Package Number D, R-PDSO-G8), with gull-wing leads and standard JEDEC MS-012AC footprint. Thermal resistance θ_JA = 200°C/W on 2 oz. copper PCB.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital temperature sensor applications.

Compared with LM75BIMM/NOPB and MAX31820MUA+, the LM92CIM/NOPB uniquely combines high-accuracy window comparison, dedicated hardware shutdown output, and configurable fault rejection-making it the only option among the three qualified for ACPI-compliant thermal management and safety-critical overtemperature protection.

Availability

LM92CIM/NOPB is available at Aetrix Electronics and suitable for server thermal management, automotive HVAC control, medical device safety monitoring, and industrial motor drive protection requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LM92CIM/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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets since 1930.

The LM92CIM/NOPB belongs to TI's precision analog temperature sensor product line, engineered specifically for system-level thermal protection and ACPI-compliant thermal monitoring in computing and embedded platforms.

FAQ

What is the maximum operating temperature of the LM92CIM/NOPB?

The LM92CIM/NOPB has a specified operating temperature range of −55°C to +150°C. Its absolute maximum junction temperature is not explicitly stated, but prolonged operation above +125°C is not recommended per TI's datasheet guidance. At +150°C, accuracy degrades to ±1.5°C max, and self-heating effects must be managed via PCB layout and airflow. The LM92CIM/NOPB maintains functional integrity across this full range, making it suitable for under-hood automotive and industrial motor applications.

How does the fault queue function in the LM92CIM/NOPB?

The LM92CIM/NOPB implements a 4-fault queue that requires four consecutive out-of-window temperature readings before asserting the INT or T_CRIT_A outputs. This feature is enabled by setting bit 4 in the Configuration register. It prevents false triggering due to transient noise or short thermal spikes-critical in electrically noisy environments like switch-mode power supplies or motor drives. The queue operates independently of interrupt mode selection and applies uniformly to all comparator conditions.

Can the LM92CIM/NOPB operate from a 3.3V supply?

Yes, the LM92CIM/NOPB operates from 2.7V to 5.5V, fully supporting 3.3V nominal supply rails. Electrical characteristics-including ±0.33°C accuracy at +30°C and 350 µA quiescent current-are guaranteed across this range. Input logic thresholds scale with V_S (e.g., SDA/SCL "1" = 0.7 × V_S), ensuring reliable I²C communication without level shifters. Pull-up resistors should be sized accordingly (e.g., 10 kΩ) to maintain signal integrity and minimize self-heating.

What is the default behavior of the LM92CIM/NOPB at power-up?

At power-up, the LM92CIM/NOPB initializes to known default values: Comparator Interrupt Mode, TLOW = 10°C, THIGH = 64°C, T_CRIT = 80°C, THYST = 2°C, INT and T_CRIT_A active-low, and Pointer register set to Temperature Register (000). These defaults are loaded when V_S crosses the reset threshold shown in Figure 6 of the datasheet. All registers retain these values until explicitly rewritten via I²C, ensuring predictable startup behavior without host initialization overhead.

Does the LM92CIM/NOPB support multiple devices on the same I²C bus?

Yes, the LM92CIM/NOPB supports up to four devices on a single I²C bus using its A0 and A1 address-select pins. These pins configure the two least-significant bits of the 7-bit slave address (base 10010xx), yielding addresses 0x48–0x4B. No external address jumpers or configuration resistors are needed-addressing is purely hardware-defined. Bus capacitance and pull-up sizing must remain within I²C specifications (≤400 pF load, 10 kΩ typical pull-ups) to ensure timing compliance across all devices.