Analog Devices Inc./Maxim Integrated MAX6419UK23-T

Overview

MAX6419UK23-T from Maxim Integrated is an active-high, push-pull microprocessor reset supervisor IC for dual-voltage systems, featuring a factory-trimmed VCC reset threshold of 2.313V (±2.5%), an adjustable RESET IN input monitoring down to 1.26V, capacitor-adjustable reset timeout (275µs to >10ms), and 1.7µA typical quiescent current. It asserts reset during VCC or RESET IN undervoltage or manual reset assertion and holds reset for the timeout period after recovery - used in automotive engine control units for reliable cold-cranking brownout detection.

For engineers reviewing the MAX6419UK23-T datasheet, MAX6419UK23-T pinout, MAX6419UK23-T application, or MAX6419UK23-T equivalent, key selection criteria include its dual-threshold architecture (fixed + adjustable), SOT23-5 package compatibility, guaranteed reset validity down to VCC = 1V, and immunity to sub-50µs VCC transients when overdriven by 100mV.

Technical Context

The MAX6419UK23-T integrates two independent voltage-monitoring comparators: one laser-trimmed for VCC with 2.313V nominal threshold (±2.5% over −40°C to +125°C), and one adjustable comparator referenced to 1.26V at RESET IN, enabling external resistor-divider–based monitoring of secondary rails like I/O or analog supplies. Its reset logic combines ORed fault conditions (VCC < VTH, RESET IN < VRST, or MR low) with a precision 240nA current source charging an external SRT capacitor to generate the timeout delay.

Unlike fixed-time supervisors, the MAX6419UK23-T's timeout is programmable via CSRT (0F to 10nF), yielding tRP = (2.71 × 10⁶) × CSRT + 275µs, with ±15% tolerance over temperature. The active-high push-pull RESET output drives up to 800µA high (VOH ≥ 0.8×VCC) and sinks 3.2mA low (VOL ≤ 0.4V at VCC ≥ 4.5V), ensuring robust interface to modern µP reset inputs without external pull-ups.

Key Specifications

Pinout & Package

SOT23-5 package: ultra-compact 2.9mm × 1.6mm footprint with 0.95mm pitch, optimized for space-constrained automotive and portable PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6420UK23-T and TLV809E23DBVR, the MAX6419UK23-T uniquely delivers active-high push-pull drive, dual-voltage supervision, and capacitor-programmable timeout in one SOT23-5 device - making it optimal for space-constrained automotive and industrial designs requiring flexible, robust reset control.

Availability

MAX6419UK23-T is available at Aetrix Electronics and suitable for automotive engine control units, medical infusion pumps, industrial PLC I/O modules, and ADAS camera ECUs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6419UK23-T 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

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, communications, and computing markets.

The MAX6412–MAX6420 family was designed specifically for low-power, high-reliability microprocessor supervision in thermally demanding and electrically noisy environments - emphasizing precision threshold accuracy, programmable timing, and dual-rail flexibility.

FAQ

What is the exact factory-trimmed VCC reset threshold voltage for MAX6419UK23-T?

The MAX6419UK23-T has a factory-trimmed VCC reset threshold of 2.313V (nominal), with ±2.5% accuracy over the full −40°C to +125°C operating temperature range. This value corresponds to the "23" suffix in the part number per Maxim's Reset Voltages Suffix Table, and is laser-trimmed during production to ensure tight tolerance without external calibration. The MAX6419UK23-T uses this fixed threshold to supervise the primary supply while simultaneously monitoring a secondary rail via its adjustable RESET IN input.

How do I calculate the external capacitor value needed for a specific reset timeout with MAX6419UK23-T?

To set a desired reset timeout period (tRP) for MAX6419UK23-T, use the formula CSRT = (tRP − 275µs) / 2.71 × 10⁶, where tRP is in seconds and CSRT is in farads. For example, a 5ms timeout requires CSRT = (0.005 − 0.000275) / 2,710,000 ≈ 1.74nF. Use a low-leakage ceramic capacitor (≤10nA) placed close to the SRT pin with minimal trace length to avoid timing errors. The MAX6419UK23-T's internal 240nA ramp current source charges this capacitor to 0.65V to terminate the reset pulse.

Does MAX6419UK23-T support manual reset functionality, and how is it implemented?

Yes, MAX6419UK23-T supports manual reset via its MR pin (Pin 4), which is active-low and features an internal 20kΩ pull-up resistor to VCC. Asserting MR low - for example, by connecting a normally open momentary switch between MR and GND - immediately triggers reset assertion. The reset remains active for the full timeout period after MR is released. No external debounce circuitry is required due to built-in 75ns glitch rejection and 1µs minimum pulse width tolerance. This function operates independently of VCC and RESET IN monitoring, providing field-service or diagnostic reset capability in the MAX6419UK23-T.

Can MAX6419UK23-T monitor a 1.8V supply as the secondary rail using the RESET IN pin?

Yes, MAX6419UK23-T can monitor a 1.8V supply on its RESET IN pin by configuring an external resistor divider. Since the internal reference is 1.26V, use R1 and R2 such that VMON_TH = 1.26V × (R1 + R2)/R2 = 1.8V. Solving gives R1/R2 ≈ 0.429; selecting R2 = 1MΩ yields R1 ≈ 429kΩ. The MAX6419UK23-T's RESET IN input draws only 10nA, so high-value resistors minimize current drain. This allows precise supervision of the 1.8V rail while the VCC pin monitors the primary 2.313V supply - a core capability of the MAX6419UK23-T's dual-threshold architecture.

What is the maximum allowable VCC transient duration that will not cause spurious reset on MAX6419UK23-T?

The MAX6419UK23-T rejects VCC transients up to 50µs in duration when the transient overdrive is 100mV below the reset threshold (i.e., VCC dips to 2.213V for the MAX6419UK23-T's 2.313V threshold). This immunity is specified in the "Maximum Transient Duration vs. Reset Threshold Overdrive" graph in the datasheet. Shorter transients (e.g., 20µs) are tolerated even with larger overdrive (e.g., 200mV). This robustness prevents false resets in electrically noisy environments like automotive power systems, where load dumps or switching noise could otherwise disrupt the MAX6419UK23-T's supervision function.