Texas Instruments LM3722EM5-4.63/NOPB

Overview

LM3722EM5-4.63/NOPB from Texas Instruments is a precision 5-pin SOT-23 microprocessor reset supervisor IC with active-low push-pull RESET output, factory-trimmed 4.63 V reset threshold (±1.5% over −40°C to +125°C), 190 ms typical reset timeout, guaranteed RESET validity down to VCC ≥ 1 V, and 6 µA typical supply current. It monitors 5 V supply rails in embedded controllers and industrial systems requiring reliable power-on/brown-out reset assertion.

For engineers reviewing the LM3722EM5-4.63/NOPB datasheet, LM3722EM5-4.63/NOPB pinout, LM3722EM5-4.63/NOPB application, or LM3722EM5-4.63/NOPB equivalent, key selection criteria include reset threshold accuracy at extended temperature, MR input debouncing behavior, open-drain compatibility (not applicable here), and SOT-23-5 PCB footprint constraints for space-constrained designs.

Technical Context

The LM3722EM5-4.63/NOPB integrates a precision voltage reference (1.225 V), dual comparators (reset and manual reset), and a one-shot timer to generate a minimum 100 ms (190 ms typical) active-low RESET pulse after VCC rises above 4.63 V or MR deasserts. Its internal 22 kΩ MR pull-up enables direct switch interfacing without external components.

Designed for extended temperature operation (−40°C to +125°C), it features ±30 ppm/°C reset threshold tempco, immunity to VCC transients ≤40 µs at 125 mV overdrive, and guaranteed RESET output sink capability down to VCC = 1 V - enabling robust reset signaling during deep brownouts.

Key Specifications

Pinout & Package

SOT-23-5 (DBV) package: 2.9 mm × 1.6 mm × 1.15 mm body, gull-wing leads, RoHS-compliant matte tin (CuSn) finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset applications.

Compared with MAX811TEUS+T, LM3722EM5-4.63/NOPB delivers 40°C higher max operating temperature and 50 ms longer guaranteed timeout; versus TPS3808G33DBVR, it offers factory-trimmed 4.63 V accuracy without external components, reducing BOM and layout risk.

Availability

LM3722EM5-4.63/NOPB is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control units, medical infusion pumps, smart energy meters, and battery-backed instrumentation requiring stable component supply across extended temperature ranges.

Supply support for LM3722EM5-4.63/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 experience in power management and supervisory ICs.

The LM3722 series belongs to TI's precision voltage supervisor product line, engineered specifically for reliable microprocessor reset generation in harsh thermal and electrical environments - targeting automotive, industrial, and medical applications demanding long-term stability.

FAQ

What is the guaranteed reset timeout duration for LM3722EM5-4.63/NOPB over its full temperature range?

The LM3722EM5-4.63/NOPB guarantees a minimum reset active timeout of 100 ms across −40°C to +125°C. The typical value is 190 ms at +25°C, and the maximum specified is 560 ms. This ensures sufficient time for microprocessor initialization even under worst-case thermal and process variations, making LM3722EM5-4.63/NOPB suitable for safety-critical boot sequencing where deterministic timing is mandatory.

Can LM3722EM5-4.63/NOPB operate reliably when VCC drops below 2.0 V?

Yes - LM3722EM5-4.63/NOPB guarantees RESET output validity for VCC ≥ 1.0 V. Below 1.0 V, the internal circuitry cannot maintain specified sink current, but down to 1.0 V, the RESET pin remains functional with VOL < 0.4 V at 3.2 mA. This allows LM3722EM5-4.63/NOPB to assert reset during deep brownouts where other supervisors may release prematurely, enhancing system reliability in unstable power environments.

How does the MR pin on LM3722EM5-4.63/NOPB interface with a mechanical pushbutton switch?

The MR pin on LM3722EM5-4.63/NOPB has an internal 22 kΩ pull-up to VCC, so a simple SPST switch between MR and GND is sufficient. When pressed, MR is pulled below 0.25×VCC (e.g., <1.25 V at VCC = 5 V), triggering a reset after a 2 µs propagation delay. Release causes RESET to remain active for the full 190 ms timeout. No external resistor or debounce circuitry is needed, simplifying implementation and reducing bill-of-materials for LM3722EM5-4.63/NOPB designs.

Is LM3722EM5-4.63/NOPB pin-compatible with the MAX811 family?

LM3722EM5-4.63/NOPB uses the same SOT-23-5 (DBV) footprint and pinout as MAX811/812 devices: Pin 1 = GND, Pin 2 = MR, Pin 3 = RESET, Pin 4 = GND, Pin 5 = VCC. However, it is not a drop-in replacement due to differences in reset timeout (190 ms typical vs. 140 ms min for MAX811), extended temperature rating (+125°C vs. +85°C), and MR input thresholds. System validation is required before substituting LM3722EM5-4.63/NOPB for MAX811 in existing designs.

What is the reset threshold temperature coefficient (tempco) of LM3722EM5-4.63/NOPB, and why does it matter?

The LM3722EM5-4.63/NOPB has a reset threshold temperature coefficient of ±30 ppm/°C. Over a −40°C to +125°C range, this results in ≤±5 mV drift - critical for maintaining accurate 5 V supply monitoring across thermal extremes. In automotive or industrial applications where ambient temperature swings exceed 100°C, this low tempco ensures the 4.63 V threshold remains within specification, preventing false resets or missed brownout detection that could occur with higher-drift alternatives. This stability is intrinsic to LM3722EM5-4.63/NOPB's trimmed bandgap reference architecture.