Analog Devices Inc./Maxim Integrated MAX6354LTUK

Overview

MAX6354LTUK from Maxim Integrated is a dual-voltage microprocessor supervisory IC with active-low push-pull reset output referenced to VCC2, precision factory-set thresholds of 4.63V (VCC1) and 3.08V (VCC2), 20µA supply current, and guaranteed RESET validity down to VCC2 = 1.0V. It monitors two independent power rails in multivoltage embedded systems such as industrial controllers and portable instrumentation.

For engineers reviewing the MAX6354LTUK datasheet, MAX6354LTUK pinout, MAX6354LTUK application, or MAX6354LTUK equivalent, key selection criteria include dual-supply threshold accuracy, reset output referencing scheme (VCC2), watchdog absence, SOT23-5 package compatibility, and operation across –40°C to +85°C.

Technical Context

The MAX6354LTUK implements independent voltage comparators for VCC1 and VCC2, asserting reset whenever either supply drops below its respective factory-trimmed threshold. Its reset output is a push-pull driver referenced to VCC2 - not open-drain - enabling direct interface with VCC2-domain logic without external pull-ups.

No watchdog timer or third-voltage monitor is present; this variant belongs to the MAX6354 subgroup (SOT23-5, VCC2-referenced RST, no WDI, no RSTIN). It guarantees functional reset assertion with VCC2 ≥ 1.0V or VCC1 ≥ 1.0V, and exhibits 20ppm/°C threshold tempco and 100ms minimum reset pulse width.

Key Specifications

Pinout & Package

MAX6354LTUK is housed in a 5-pin SOT23-5 package (JEDEC MO-178AA), with 1.6mm × 2.9mm footprint and 1.1mm max height. Pin 1 is RST (active-low push-pull, VCC2-referenced), Pin 2 is GND, Pin 3 is MR (debounced manual reset input), Pin 4 is VCC2 (monitored +3.3V supply), and Pin 5 is VCC1 (monitored +5V supply).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-voltage supervisory applications.

Compared with MAX6354MTUK, the MAX6354LTUK provides tighter alignment with +5V rail specifications; compared with TPS3808G33DBVR, it delivers true dual-supply supervision without external components or compromise on reset drive strength.

Availability

MAX6354LTUK is available at Aetrix Electronics and suitable for industrial controllers, portable medical devices, automotive body electronics, and networked sensor nodes requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6354LTUK 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) designs high-performance analog and mixed-signal ICs for power, sensing, and timing applications, with emphasis on reliability and integration.

The MAX6351–MAX6360 family delivers precision dual/triple-voltage supervision for multirail embedded systems, targeting applications where independent rail monitoring and deterministic reset behavior are critical to system integrity.

FAQ

What is the function of the RST pin on the MAX6354LTUK?

The RST pin on the MAX6354LTUK is an active-low, push-pull reset output referenced to VCC2. It asserts low when either VCC1 falls below 4.63V or VCC2 falls below 3.08V, and remains valid as long as VCC2 ≥ 1.0V or VCC1 ≥ 1.0V. This eliminates the need for an external pull-up resistor and ensures rail-aligned reset signaling in VCC2-domain circuits - a key design feature of the MAX6354LTUK.

Does the MAX6354LTUK include a watchdog timer?

No, the MAX6354LTUK does not include a watchdog timer. It belongs to the MAX6354 subgroup (along with MAX6353 and MAX6357), which lacks WDI functionality. Watchdog capability is only present in MAX6358/MAX6359/MAX6360 variants. The MAX6354LTUK provides pure dual-voltage supervision with manual reset only - a deliberate simplification reflected in its SOT23-5 package and absence of WDI pin.

What are the exact voltage thresholds programmed into the MAX6354LTUK?

The MAX6354LTUK has factory-trimmed voltage thresholds of 4.63V for VCC1 (±0.13V over –40°C to +85°C) and 3.08V for VCC2 (±0.08V over –40°C to +85°C). These values are confirmed in the Voltage Threshold Levels table of the datasheet, where suffix "LT" maps directly to this 4.63V/3.08V combination. Both thresholds exhibit 20ppm/°C tempco, ensuring stability across the full operating temperature range of the MAX6354LTUK.

Can the MAX6354LTUK operate with VCC1 = 3.3V and VCC2 = 1.8V?

No - the MAX6354LTUK is not specified to operate with VCC1 = 3.3V or VCC2 = 1.8V. Its thresholds are fixed at 4.63V and 3.08V, and the Absolute Maximum Ratings require VCC1/VCC2 ≥ 1.2V (min operating voltage). Supplying 3.3V to VCC1 would result in permanent undervoltage on that rail, causing continuous reset assertion. The MAX6354LTUK is designed exclusively for +5V/+3.3V dual-rail systems, as defined by its LT suffix and electrical specifications.

Is the MR input on the MAX6354LTUK internally pulled up, and to which supply?

Yes, the MR input on the MAX6354LTUK features an internal pull-up resistor of 32kΩ to 100kΩ (typical 63.5kΩ) connected to VCC1. This is explicitly stated in the Electrical Characteristics table under "MR Pullup Resistance". Therefore, MR must not exceed VCC1 voltage, and if unused, should be left unconnected or tied to VCC1 - never to VCC2 or another rail. This VCC1-referenced pullup is a consistent design element across the MAX6354LTUK and related variants.