Analog Devices Inc./Maxim Integrated MAX6738XKVD3+

Overview

The MAX6738XKVD3+ from Maxim Integrated is a dual-voltage microprocessor supervisor IC with one factory-trimmed reset threshold (VTH1 = 2.925V) and one adjustable reset input (RSTIN, 488mV internal reference), open-drain active-low RESET output, manual reset input (MR), and 150ms minimum reset timeout. It monitors primary supply VCC1 (1.8V–5.0V) and secondary supply VCC2 (0.9V–3.3V), and is used in portable battery-powered systems requiring reliable power-on reset and brownout detection.

For engineers reviewing the MAX6738XKVD3+ datasheet, MAX6738XKVD3+ pinout, MAX6738XKVD3+ application, or MAX6738XKVD3+ equivalent, key selection considerations include its SC70-5 package footprint, 6µA quiescent current, dual-supply monitoring capability with adjustable RSTIN, MR timing behavior (150ms timeout), and compatibility with low-voltage core/I/O rail sequencing in space-constrained embedded designs.

Technical Context

The MAX6738XKVD3+ implements independent voltage comparators for VCC1 and VCC2 against factory-set thresholds (VTH1 = 2.925V, VTH2 = 2.188V per suffix "V" in Table 2), plus a dedicated 488mV reference comparator for the RSTIN input. Reset assertion occurs when any monitored voltage falls below its threshold, and reset remains asserted for ≥150ms after all voltages recover.

It features an open-drain RESET output requiring external pullup, a CMOS-compatible MR input with 1.5kΩ internal pullup to VCC1, and operates across -40°C to +85°C with supply current as low as 5µA at VCC1 = 1.8V and VCC2 = 1.2V. The device uses BiCMOS process technology and contains 249 transistors.

Key Specifications

Pinout & Package

MAX6738XKVD3+ is housed in a 5-pin SC70-5 package (1.6mm × 1.6mm × 0.9mm height), optimized for high-density portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply supervisor applications.

Compared with MAX6738XKTD3+, MAX6738XKVD3+ offers lower VTH1/VTH2 thresholds better aligned with 3.0V/2.2V systems, while TPS3808G15DBVR lacks integrated dual-supply capability entirely-making MAX6738XKVD3+ the only drop-in solution for compact, low-quiescent dual-rail reset control.

Availability

MAX6738XKVD3+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial handheld terminals, notebook power sequencing, GPS tracking modules, and battery-backed embedded controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6738XKVD3+ 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 demanding industrial, automotive, and communications applications.

The MAX6736–MAX6745 family was engineered specifically for ultra-low-power dual- and triple-voltage microprocessor supervision in space- and energy-constrained portable electronics, emphasizing sub-10µA operation and SC70 packaging.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6738XKVD3+?

The MAX6738XKVD3+ has a factory-trimmed VCC1 reset threshold (VTH1) of 2.925V, with ±75mV tolerance over -40°C to +85°C. This value is defined by the "V" suffix per Table 2 in the MAX6736–MAX6745 datasheet and applies specifically to the MAX6738XKVD3+ variant-not to other members of the MAX6738 family with different suffixes.

Does the MAX6738XKVD3+ support monitoring a 1.2V core supply?

Yes, the MAX6738XKVD3+ supports monitoring a 1.2V core supply via its VCC2 input, which accepts voltages from 0.9V to 3.3V. Its factory-set VCC2 threshold (VTH2) is 2.188V, so for 1.2V supervision, use the RSTIN input with a resistor divider referenced to the 488mV internal comparator-enabling accurate trip points down to 0.5V without external references.

What is the function of the RSTIN pin on the MAX6738XKVD3+?

The RSTIN pin on the MAX6738XKVD3+ is an adjustable reset input with a fixed 488mV internal reference comparator. When the voltage at RSTIN falls below 488mV, RESET is asserted. It enables monitoring of third supplies (e.g., battery, auxiliary rail) using an external resistor divider, and draws only ±10nA input current-minimizing system power loss.

Is the RESET output of the MAX6738XKVD3+ push-pull or open-drain?

The RESET output of the MAX6738XKVD3+ is open-drain active-low, as confirmed by the Selector Guide and Pin Description table. It requires an external pullup resistor to VCC1 (typically 10kΩ–100kΩ) and is compatible with bidirectional µP reset pins. This differs from push-pull variants like MAX6739XKVD3+.

What does the "D3" suffix indicate in MAX6738XKVD3+?

The "D3" suffix in MAX6738XKVD3+ specifies a 150ms minimum reset timeout period (tRP), per Table 3 of the datasheet. This timing begins after all monitored supplies exceed their thresholds and ensures sufficient reset assertion duration for reliable microprocessor initialization-distinct from the "D7" option (1200ms min) used in systems with slower power ramps.