Analog Devices Inc./Maxim Integrated MAX6333UR23D2+

Overview

MAX6333UR23D2+ from Maxim Integrated is a push/pull active-low microprocessor supervisory circuit in SOT23-3 package, monitoring 1.8V–3.3V supplies with factory-trimmed 2.30V reset threshold and 20ms minimum reset timeout. It asserts RESET when VCC falls below 2.30V and holds it for ≥20ms after VCC recovers, operating down to 0.7V supply and drawing only 3.3µA at 2.5V - used in portable equipment, controllers, and critical µP power monitoring.

For engineers reviewing the MAX6333UR23D2+ datasheet, MAX6333UR23D2+ pinout, MAX6333UR23D2+ application, or MAX6333UR23D2+ equivalent, key selection criteria include guaranteed RESET validity to VCC = 0.7V, ultra-low quiescent current, precise 2.30V threshold tolerance (±1.8% @ +25°C, ±3% over -40°C to +125°C), and compatibility with space-constrained embedded systems requiring reliable brownout detection.

Technical Context

The MAX6333UR23D2+ implements a precision voltage comparator with hysteresis-free threshold detection and internal timing circuitry to generate a fixed-duration reset pulse. Its reset comparator ignores transients ≤24µs at 10V/ms slew rate, ensuring immunity to fast supply glitches.

This device uses a push/pull output stage delivering VOH ≥0.8VCC (at ISOURCE = 200µA, VCC ≥1.8V) and VOL ≤0.4V (at ISINK = 500µA), with full specification across -40°C to +125°C and guaranteed correct state down to VCC = 0.7V - distinguishing it from open-drain variants like MAX6334.

Key Specifications

Pinout & Package

MAX6333UR23D2+ is housed in a RoHS-compliant 3-pin SOT23-3 package (outline 21-0051, land pattern 90-0179), with 1.3mm × 0.8mm footprint and 0.95mm height - optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6333UR23D2+, MAX6327UT23D2+ offers identical threshold and timing but demands external biasing, increasing BOM and layout complexity; TPS3123E18DBVR provides higher threshold and longer timeout but cannot replace the precise 2.30V/20ms combination required for 2.5V rail supervision.

Availability

MAX6333UR23D2+ is available at Aetrix Electronics and suitable for portable/battery-powered equipment, critical µP/µC power monitoring, controllers, intelligent instruments, and automotive subsystems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6333UR23D2+ 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, mixed-signal, and power management ICs for industrial, automotive, communications, and computing applications.

The MAX6333 series belongs to Maxim's ultra-low-voltage µP supervisory product line, engineered specifically for reliable reset generation in space-constrained, battery-sensitive systems operating from 0.7V to 5.5V rails.

FAQ

What is the exact reset threshold voltage of MAX6333UR23D2+ and how tightly is it specified?

The MAX6333UR23D2+ has a factory-trimmed nominal reset threshold of 2.30V, with ±1.8% tolerance at +25°C and ±3% over the full -40°C to +125°C temperature range. This precision eliminates calibration components and ensures consistent brownout detection across environmental conditions - critical for 2.5V system reliability. The threshold is verified per Table 1 in the official datasheet and applies exclusively to the UR23D suffix.

Does MAX6333UR23D2+ support operation down to 0.7V supply, and what happens to RESET output at that level?

Yes, MAX6333UR23D2+ is guaranteed to maintain correct RESET state down to VCC = 0.7V. At this voltage, the push/pull output retains defined logic levels: RESET remains asserted low with VOL ≤0.4V (under 500µA sink), and deassertion VOH ≥0.8VCC is maintained. This behavior is validated per Absolute Maximum Ratings and Electrical Characteristics tables - enabling fail-safe operation during deep brownout events.

What is the reset timeout period of MAX6333UR23D2+, and is it affected by temperature?

The MAX6333UR23D2+ provides a minimum reset timeout period of 20ms, with typical values of 30ms and maximum of 40ms across -40°C to +125°C. The datasheet's "Normalized Reset Timeout Period vs. Temperature" graph confirms <±5% variation over temperature - ensuring predictable hold time regardless of ambient conditions. This stability avoids timing margin issues in µP boot sequences.

How does MAX6333UR23D2+ handle fast transients on the VCC line?

MAX6333UR23D2+ rejects negative-going VCC transients up to 24µs duration when the slew rate is 10V/ms, as confirmed by the "Maximum Transient Duration vs. Reset Comparator Overdrive" curve. This immunity prevents false resets caused by switching noise or EMI - a key differentiator from basic RC-based supervisors. The internal comparator architecture inherently filters such glitches without external components.

Is MAX6333UR23D2+ pin-compatible with legacy Maxim reset ICs like MAX809?

Yes, MAX6333UR23D2+ is explicitly stated as pin-compatible with MAX809/MAX810 and MAX6326/MAX6327/MAX6328 in the Features section. All share identical SOT23-3 pinout (GND, RESET, VCC), enabling drop-in replacement in existing designs - provided the 2.30V threshold and 20ms timeout meet system requirements. No PCB changes are needed for migration.