Analog Devices Inc./Maxim Integrated MAX6409BS44

Overview

MAX6409BS44 from Maxim Integrated is an ultra-low-power, factory-trimmed voltage detector IC designed for battery and power-supply monitoring in portable electronics. It features a 4.38V nominal reset threshold (±2.5% over –40°C to +85°C), active-low push-pull output, manual reset input (MR), and operates down to VCC = 1.0V - enabling reliable brownout detection in Li+-based systems like MP3 players and pagers.

For engineers reviewing the MAX6409BS44 datasheet, MAX6409BS44 pinout, MAX6409BS44 application, or MAX6409BS44 equivalent, this device delivers precise supply monitoring with 500nA quiescent current, immunity to sub-100ns VCC transients, and guaranteed logic-state validity at ultralow supply voltages - critical for energy-constrained embedded designs.

Technical Context

The MAX6409BS44 uses a precision bandgap reference comparator architecture with factory-laser-trimmed threshold voltage (4.38V typical), achieving ±2.5% accuracy across –40°C to +85°C. Its push-pull output drives low actively (VOL ≤ 0.4V @ ISINK = 100µA, VCC ≥ 1.2V) and high passively (VOH ≥ 0.8×VCC @ ISOURCE = 800µA).

It integrates a 50kΩ internal MR pullup resistor and rejects fast VCC transients via built-in hysteresis (9.5mV typical). Startup time is 88µs from VCC = 0 to threshold, and propagation delay is 20–42µs depending on overdrive voltage - optimized for deterministic reset assertion during supply ramp-down.

Key Specifications

Pinout & Package

MAX6409BS44 is housed in a 4-bump UCSP (Ultra Compact Silicon Package), 2mm × 2mm, bottom-terminal chip-scale package - footprint-compatible with SC70 but occupying only 30% of the area.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage detector applications.

Compared with MAX6409BS43-T, the MAX6409BS44 offers higher trip point for improved noise margin on 4.5V rails; versus TLV803EB33DBZR, it delivers 3.2× lower supply current, integrated MR, and precise 4.38V threshold - making it irreplaceable in long-life, high-accuracy portable supervision.

Availability

MAX6409BS44 is available at Aetrix Electronics and suitable for portable medical devices, handheld scanners, Li+-powered audio players, and pager systems requiring stable component supply with guaranteed long-term availability and RoHS-compliant packaging.

Supply support for MAX6409BS44 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, communications, and consumer applications.

The MAX6406–MAX6411 family was engineered specifically for ultra-low-power voltage supervision in space-constrained, battery-operated equipment - prioritizing nanoscale current draw, chip-scale packaging, and factory-trimmed accuracy over general-purpose flexibility.

FAQ

What is the exact factory-trimmed threshold voltage of the MAX6409BS44?

The MAX6409BS44 has a nominal threshold voltage of 4.38V, with a guaranteed range of 4.270V to 4.489V at –40°C to +85°C (±2.5% tolerance). This value is laser-trimmed at wafer test and confirmed in Table 1 of the official datasheet under suffix "44*".

Does the MAX6409BS44 require external components to operate?

No, the MAX6409BS44 requires no external components: its 4.38V threshold is factory-trimmed, the MR input includes a 50kΩ internal pullup, and the push-pull output needs no external pullup resistor. Only VCC, GND, and optional MR switch connections are necessary for full functionality.

Can the MAX6409BS44 operate reliably below 1.2V?

Yes - the MAX6409BS44 guarantees correct output logic state down to VCC = 1.0V, per Electrical Characteristics table. While the recommended operating range starts at 1.2V, the device remains functional and asserts OUT correctly during deep brownout conditions common in depleted Li+ cells.

What is the maximum transient duration the MAX6409BS44 can ignore on VCC?

Per the "Maximum Transient Duration vs. Threshold Overdrive" graph (Figure 4), the MAX6409BS44 ignores negative-going VCC transients up to ~120µs when overdrive is 10mV (i.e., VCC = 4.37V), and down to ~20µs at 100mV overdrive (VCC = 4.28V). This immunity prevents false resets from switching noise.

Is the UCSP package of the MAX6409BS44 lead-free and RoHS-compliant?

Yes - the MAX6409BS44-T variant (tape-and-reel) is RoHS/lead-free compliant, as confirmed in Maxim's ordering information and materials analysis reports. The top mark "AFL" and package code "B4+3*" denote the lead-free UCSP-4 variant qualified per JEDEC J-STD-020 moisture sensitivity level 1.