Analog Devices Inc./Maxim Integrated MAX6304ESA

Overview

MAX6304ESA from Maxim Integrated is an active-high, push-pull microprocessor supervisory circuit with adjustable reset threshold (≥1.22V), adjustable reset timeout (2.8–5.2 ms with 1500pF), and dual-mode watchdog timer (normal mode: 2.8–5.2 ms; extended mode: up to 2.6 s with same capacitor). It operates from 1.31V to 5.5V, draws only 4µA supply current, and is used in battery-powered embedded controllers requiring reliable brownout and hang detection.

For engineers reviewing the MAX6304ESA datasheet, MAX6304ESA pinout, MAX6304ESA application, or MAX6304ESA equivalent, this page delivers verified electrical parameters, SO-8 package mapping, functional distinctions among MAX6301–MAX6304 variants, and real-world timing behavior under temperature and voltage variation - all critical for low-power µP reset architecture validation.

Technical Context

The MAX6304ESA implements a precision bandgap-based reset comparator with 20mV hysteresis and a 1.22V internal reference, enabling externally adjustable reset thresholds via resistor dividers. Its watchdog timer uses a 500nA precision current source at SWT to generate timeout periods scalable by external capacitance and WDS logic state.

Unlike fixed-threshold supervisors, the MAX6304ESA supports both normal (WDS = GND) and extended (WDS = VCC) watchdog modes - the latter multiplies timeout by 500× without changing capacitor value. Reset assertion is guaranteed down to VCC = 1.31V, and output drive strength scales with supply voltage (VOH = VCC − 0.3V at VCC ≥ 4.5V, ISOURCE = 0.8mA).

Key Specifications

Pinout & Package

MAX6304ESA is housed in an 8-pin SO (Small Outline) package per JEDEC MS-012, with 1.27mm pitch and RoHS-compliant lead finish. Pin 1 is marked with a beveled corner or dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6302ESA, MAX6304ESA reduces BOM count and improves noise margin via push-pull drive; compared with TPS3808G12DBVR, it provides design flexibility for brownout voltage tuning and adaptive watchdog intervals - essential for portable and industrial systems with variable supply conditions.

Availability

MAX6304ESA is available at Aetrix Electronics and suitable for battery-powered medical monitors, industrial embedded controllers, intelligent set-top boxes, portable test instrumentation, and critical µP monitoring systems requiring stable component supply across extended temperature ranges.

Supply support for MAX6304ESA 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, and communications markets.

The MAX6301–MAX6304 family was designed specifically for low-power microprocessor supervision in space-constrained, battery-operated, and mission-critical systems - emphasizing adjustability, transient immunity, and extended temperature reliability.

FAQ

What is the minimum supply voltage required for MAX6304ESA to assert RESET?

The MAX6304ESA guarantees RESET assertion for VCC ≥ 1.31V. Below this voltage, reset functionality is not specified. This threshold ensures reliable operation across 1.8V, 2.5V, and 3.3V logic domains while maintaining compatibility with brownout detection down to 1.31V - a key differentiator versus competitors requiring ≥1.6V.

How does the WDS pin affect the watchdog timeout period in MAX6304ESA?

In MAX6304ESA, the WDS pin selects between two watchdog modes: when pulled low (GND), it enables normal mode with timeout tWD = 2.67 × CSWT (pF → µs); when pulled high (VCC), it activates extended mode, multiplying tWD by 500× - e.g., 1500pF yields ~2.6s instead of ~4ms. This dual-mode capability is unique to the MAX6301–MAX6304 family and eliminates need for discrete timing components.

Can MAX6304ESA monitor voltages other than VCC?

Yes, MAX6304ESA can monitor any DC voltage via the RESET IN pin. By connecting an external resistor divider between the target voltage (VIN) and ground, the reset threshold VRST is calculated as 1.22 × (R1 + R2)/R2. This allows precise brownout detection on auxiliary rails (e.g., 1.8V core, 3.3V I/O) independent of VCC - a feature confirmed in the Typical Operating Circuit and Applications Information sections.

What is the maximum recommended capacitor value for SRT and SWT pins in MAX6304ESA?

The MAX6304ESA datasheet specifies no absolute maximum capacitor value, but practical limits arise from leakage and parasitic effects. For SRT, CSRT = tRP/2.67 (pF) yields 5.2ms timeout at 1500pF; scaling linearly, 10nF gives ~26.7ms. However, capacitor leakage must remain <10nA - so X7R ceramics are preferred over electrolytics. At >100nF, board leakage and trace capacitance begin degrading timing accuracy, making 10nF the effective upper limit for stable operation.

Does MAX6304ESA provide immunity to power-supply transients, and how is it quantified?

Yes, MAX6304ESA features documented power-supply transient immunity. The "Maximum Transient Duration vs. Reset Threshold Overdrive" graph shows that for a 100mV overdrive (i.e., VCC dip 100mV below VRST), the device ignores transients ≤50µs. This immunity stems from internal filtering and comparator hysteresis, and is validated across -40°C to +85°C - making MAX6304ESA suitable for electrically noisy industrial and automotive environments where short spikes are common.