Analog Devices Inc./Maxim Integrated MAX6349ZPUT

Overview

MAX6349ZPUT from Maxim Integrated is a 150mA, low-dropout linear voltage regulator with integrated microprocessor reset circuit, preset for +1.8V output and -10% reset threshold (Z suffix), housed in a 6-pin SOT23 package. It delivers ultra-low 25µA quiescent current, 180mV dropout at 100mA, and features open-drain active-low RESET output - optimized for battery-powered handheld instruments and USB devices requiring reliable power sequencing and brownout protection.

For engineers reviewing the MAX6349ZPUT datasheet, MAX6349ZPUT pinout, MAX6349ZPUT application, or MAX6349ZPUT equivalent, key selection criteria include its fixed +1.8V output, -10% reset tolerance (2.08V–2.28V threshold), manual reset input (MR), thermal/short-circuit protection, and compatibility with 1µF ceramic output capacitors - all critical for space-constrained, low-power embedded systems.

Technical Context

The MAX6349ZPUT implements a P-channel MOSFET pass transistor architecture enabling low dropout (180mV @ 100mA) and zero reverse leakage current. Its internal 1.23V reference feeds both the regulator error amplifier and reset comparator, ensuring tight tracking between output voltage and reset threshold (0.835×V_ADJ to 0.915×V_ADJ for adjustable mode; 2.08V–2.28V for Z-version).

It integrates a dedicated manual reset input (MR) with 20kΩ internal pullup to OUT, 120ns glitch rejection, and 500ns MR-to-RESET delay - enabling external hardware-initiated resets without affecting regulation stability. The reset timeout is guaranteed ≥100ms, with push-pull or open-drain output options selected by part number suffix (ZPUT = open-drain active-low RESET).

Key Specifications

Pinout & Package

MAX6349ZPUT is packaged in a 6-pin SOT23-6 (JEDEC MO-178AA) with exposed pad thermal enhancement. GND serves as both electrical ground and primary heat path; recommended soldering to large PCB copper area improves thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout regulator with integrated reset applications.

Compared with MAX6349ZPUT, MAX6329ZPUT replaces MR with SHDN - trading manual reset for ultra-low shutdown current (<1µA), while TPS76318QDBVRQ1 demands external supervision and offers tighter output accuracy but no integrated reset logic or MR function.

Availability

MAX6349ZPUT is available at Aetrix Electronics and suitable for hand-held instruments, USB peripheral devices, PCMCIA cards, and cordless telephone base stations requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MAX6349ZPUT 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, communications, and consumer applications.

The MAX6329/MAX6349 family targets battery-powered portable electronics needing highly integrated, micropower voltage regulation and deterministic reset behavior - combining LDO, supervisor, and manual reset in one 6-pin SOT23 device.

FAQ

What is the exact reset threshold voltage range for MAX6349ZPUT?

The MAX6349ZPUT has a −10% reset threshold specified for its +1.8V output, resulting in a guaranteed V_TH range of 2.08V to 2.28V at T_A = 0°C to +85°C. This threshold is factory-trimmed and tracked to the output voltage via the internal 1.23V reference, ensuring consistent brownout detection across operating conditions. The MAX6349ZPUT uses this fixed threshold without external resistor adjustment.

Does MAX6349ZPUT support adjustable output voltage?

No, MAX6349ZPUT does not support adjustable output voltage. The "Z" suffix denotes a fixed +1.8V output with −10% reset threshold. Adjustable operation requires connecting the SET pin to an external resistor divider - but MAX6349ZPUT is configured with internal feedback for +1.8V; using SET for adjustment would require a different variant such as MAX6349WUT (adjustable) or MAX6349VUT (1.8V with −5% threshold).

How does the manual reset (MR) pin behave on MAX6349ZPUT?

On MAX6349ZPUT, the MR pin is an active-low input with 20kΩ internal pullup to OUT. When pulled low (≤0.2×V_OUT), it forces the open-drain RESET output low immediately and holds it asserted for ≥100ms after MR returns high. MR operates independently of V_OUT level - meaning it can trigger reset even when regulation is nominal. This makes MAX6349ZPUT suitable for user-initiated reboots or test-mode entry.

What output capacitor is required for stable operation of MAX6349ZPUT?

MAX6349ZPUT requires a minimum 1µF ceramic (X7R or X5R) or tantalum output capacitor placed close to the OUT and GND pins. This value ensures stability across 0°C to +85°C and up to 150mA load. Larger values (e.g., 10µF) improve PSRR and transient response but are not mandatory. Avoid Z5U/Y5V dielectrics below −10°C unless capacitance is increased to ≥2.2µF.

Is MAX6349ZPUT pin-compatible with other MAX6329/MAX6349 variants?

Yes, MAX6349ZPUT is pin-compatible with all MAX6329/MAX6349 SOT23-6 variants, including MAX6329ZPUT and MAX6349TUT. All share identical pinout (IN, GND, MR/SHDN, RESET, SET, OUT), same footprint, and compatible thermal design. However, functional differences exist: MR (MAX6349) vs. SHDN (MAX6329), and reset output type (open-drain vs. push-pull) - these require corresponding schematic and firmware updates despite mechanical compatibility.