Analog Devices Inc./Maxim Integrated MAX6305UK00D2

Overview

MAX6305UK00D2 from Maxim Integrated is a 5-pin SOT23 programmable reset IC designed to monitor VCC and two adjustable undervoltage inputs (RST IN1/RST IN2) in multivoltage systems. It asserts an active-low open-drain RESET output when any monitored supply falls below its threshold, features factory-set 2.5V reset threshold, 20ms minimum reset timeout, 8µA supply current, and guaranteed RESET validity down to VCC = 1V. It is used in portable computers and embedded control systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6305UK00D2 datasheet, MAX6305UK00D2 pinout, MAX6305UK00D2 application, or MAX6305UK00D2 equivalent, key selection considerations include its dual adjustable reset inputs, open-drain output architecture, immunity to fast VCC transients, guaranteed operation at VCC ≥ 1V, and compatibility with bidirectional µP reset pins without external logic.

Technical Context

The MAX6305UK00D2 implements a dual-input undervoltage monitoring architecture with two independent RST IN_ comparators referenced to a precise 1.23V internal bandgap, enabling flexible external resistor-divider programming for secondary supply rails. Its VCC monitoring operates across 1.0V–5.5V, with reset assertion guaranteed even as VCC drops to 1V.

It uses a precision internal reference and hysteresis (2.5mV typical) on RST IN_ inputs to reject noise, while its reset timeout timer (20ms min) is factory-programmed and temperature-stable (±0.5% variation over –40°C to +85°C). The device ignores negative-going VCC transients ≤ 100ns at full overdrive, per Typical Operating Characteristics graphs.

Key Specifications

Pinout & Package

MAX6305UK00D2 is housed in a 5-pin SOT23 package (outline U5+1), measuring 2.9mm × 1.6mm × 1.1mm, suitable for space-constrained PCB layouts in portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6306UK25D2-T and TPS3808G12DBVR, MAX6305UK00D2 uniquely delivers dual adjustable reset inputs and open-drain output in a single SOT23-5 package - essential for multivoltage systems requiring flexible, noise-immune supervision without added components.

Availability

MAX6305UK00D2 is available at Aetrix Electronics and suitable for portable computers, embedded control systems, intelligent instruments, and multivoltage systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6305UK00D2 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 precision analog and mixed-signal ICs for power management, sensing, and interface applications, with emphasis on high reliability and low power.

The MAX6305–MAX6313 family was developed specifically for multivoltage microprocessor supervision in space- and power-constrained systems, offering programmable thresholds, dual-input flexibility, and robust transient immunity.

FAQ

What is the factory-set reset threshold voltage for MAX6305UK00D2?

The MAX6305UK00D2 has a factory-set VCC reset threshold of 2.5V, with ±1.5% tolerance at +25°C and ±2.5% over the 0°C to +70°C operating range. This value is laser-trimmed during production and does not require external adjustment. The "UK00" suffix explicitly denotes the 2.5V nominal threshold per Maxim's ordering convention.

Does MAX6305UK00D2 support monitoring of auxiliary voltage rails beyond VCC?

Yes, MAX6305UK00D2 supports monitoring of two auxiliary voltage rails via dedicated RST IN1 (pin 3) and RST IN2 (pin 4) inputs. Each compares the applied voltage to a precise 1.23V internal reference, allowing external resistor dividers to set custom reset thresholds for rails such as 3.3V or 5V. This dual-input capability is intrinsic to the MAX6305 variant and confirmed in the Pin Description and Functional Diagram sections.

What is the reset timeout period for MAX6305UK00D2, and is it adjustable?

The MAX6305UK00D2 features a factory-programmed reset timeout period of 20ms (minimum), indicated by the "D2" suffix. This timeout is fixed and non-adjustable; it ensures the RESET signal remains asserted for at least 20ms after all monitored supplies exceed their thresholds, providing sufficient time for microprocessor clock stabilization and memory initialization. No external capacitor or resistor modifies this value.

Can MAX6305UK00D2 operate reliably when VCC drops below 2.0V?

Yes, MAX6305UK00D2 guarantees valid RESET output functionality down to VCC = 1.0V, as specified in the Electrical Characteristics table. Below 1.5V, it enters undervoltage lockout mode and asserts RESET; between 1.5V and 2.5V, it transitions to normal operation. This behavior is validated across temperature and ensures robust brownout response where competing supervisors may release reset prematurely.

Is the RESET output of MAX6305UK00D2 compatible with bidirectional microprocessor reset pins?

Yes, the RESET output of MAX6305UK00D2 is active-low and open-drain, making it directly compatible with bidirectional µP reset pins (e.g., Motorola 68HC11). When connected with a single external pull-up resistor, either the MAX6305UK00D2 or the µP can assert reset - a feature explicitly documented in the Applications Information section and validated in Figure 3 of the datasheet.