Analog Devices Inc./Maxim Integrated MAX6409BS44-T

Overview

MAX6409BS44-T from Maxim Integrated is an ultra-low-power, active-low push-pull voltage detector IC designed for battery and power-supply monitoring in portable electronics. It features a factory-trimmed 4.38V threshold (±2.5% over −40°C to +85°C), 500nA supply current, and guaranteed valid output down to VCC = 1.0V. It is used in Li+-based devices requiring precise brownout detection with manual reset capability.

For engineers reviewing the MAX6409BS44-T datasheet, MAX6409BS44-T pinout, MAX6409BS44-T application, or MAX6409BS44-T equivalent, key selection criteria include reset threshold accuracy, ultra-low ICC, UCSP-4 package footprint, MR input timing, and immunity to sub-µs VCC transients.

Technical Context

The MAX6409BS44-T implements a precision bandgap reference comparator with hysteresis of 9.5mV, enabling robust rejection of fast negative-going VCC transients. Its internal 50kΩ MR pullup ensures TTL/CMOS-compatible manual reset functionality without external components.

It operates across VCC = 1.2V to 5.5V and guarantees correct logic state at VCC as low as 1.0V. Propagation delay is 42µs (typ) for VCC falling edge with 100mV overdrive, and startup time is 88µs from VCC = 0 to threshold.

Key Specifications

Pinout & Package

MAX6409BS44-T is housed in a 4-bump UCSP (2 × 2 mm, 0.5mm pitch) chip-scale package - 70% smaller than SC70 - optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6409BS43-T and TLV803EB33DBZR, the MAX6409BS44-T provides the optimal balance of precise 4.38V detection, ultra-low power, MR flexibility, and minimal 2×2mm UCSP footprint for next-gen wearables and compact IoT nodes.

Availability

MAX6409BS44-T is available at Aetrix Electronics and suitable for portable medical devices, USB-C accessories, and battery-backed memory modules requiring stable component supply and long-term lifecycle support.

Supply support for MAX6409BS44-T 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 consumer applications.

The MAX6406–MAX6411 family was designed specifically for ultra-low-power voltage supervision in space- and energy-constrained portable electronics, emphasizing minimal ICC, tiny UCSP packaging, and factory-trimmed thresholds.

FAQ

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

The MAX6409BS44-T has a nominal reset threshold of 4.38V, with a tolerance of ±2.5% over the full operating temperature range (−40°C to +85°C). This value is laser-trimmed at wafer test and confirmed in Table 1 of the datasheet under suffix "44*". The MAX6409BS44-T is part of the 3.30V–4.63V threshold group within the MAX6409/MAX6410/MAX6411 series.

Does the MAX6409BS44-T require an external pullup resistor on its OUT pin?

No, the MAX6409BS44-T does not require an external pullup resistor on its OUT pin because it features an active-low push-pull output stage. Unlike open-drain variants (e.g., MAX6411), the MAX6409BS44-T can actively drive both logic low (≤0.4V at 1.6mA sink) and high (≥0.8×VCC at 800µA source), eliminating external components for standard µP reset interfacing.

How does the manual reset (MR) input behave on the MAX6409BS44-T?

The MR input on the MAX6409BS44-T is active-low with an internal 50kΩ pullup to VCC. When pulled low (e.g., via momentary switch to GND), it immediately asserts the active-low OUT signal regardless of VCC level. OUT remains asserted as long as MR is held low. If unused, MR may be left floating or tied to VCC - no external components are needed.

Can the MAX6409BS44-T operate reliably at VCC = 1.0V?

Yes, the MAX6409BS44-T guarantees correct output logic state down to VCC = 1.0V, as explicitly stated in the datasheet. This ensures deterministic reset behavior during deep brownout events - critical for preserving state in low-power microcontrollers and retaining SRAM contents during battery depletion.

What is the package type and footprint of the MAX6409BS44-T?

The MAX6409BS44-T uses a 4-bump UCSP (Ultra Compact Silicon Package) with 2×2 mm body size and 0.5 mm bump pitch. It is identical in footprint to other MAX6406–MAX6411 variants and requires no leadframe - direct solder bumps interface to the PCB. Package drawing code is 21-0117G, and it is supplied in tape-and-reel only.