Analog Devices Inc./Maxim Integrated DS1834DU+

Overview

DS1834DU+ from Maxim Integrated (now Analog Devices) is a dual-voltage supervisor IC that independently monitors 5V and 3.3V power supplies with pushbutton reset override. It features precision temperature-compensated voltage references, 350 ms reset pulse width, CMOS push-pull outputs, and operates from -40°C to +85°C. Used in embedded systems requiring reliable dual-rail power sequencing and manual reset capability.

For engineers reviewing the DS1834DU+ datasheet, DS1834DU+ pinout, DS1834DU+ application, or DS1834DU+ equivalent, key selection criteria include independent 5V/3.3V trip point tolerance configuration (5%/10% or 10%/20%), internal 40 kΩ pull-up on PBRST, push-pull RST output structure enabling valid logic down to 0 V, and supply current draw from the higher of two input rails.

Technical Context

The DS1834DU+ implements dual independent voltage monitoring using precision bandgap references and comparators, each with configurable tolerance via dedicated TOL pins tied to GND or supply rails. Its internal power management draws operating current exclusively from the higher of 5VIN or 3.3VIN, eliminating need for auxiliary biasing.

Reset assertion is synchronized across both rails during pushbutton events, with internally debounced PBRST input and guaranteed 350 ms active-low reset pulse after release. The push-pull RST outputs maintain valid logic states even when supply inputs drop below 1.2 V - a capability not available in open-drain variants like DS1834A.

Key Specifications

Pinout & Package

DS1834DU+ is supplied in an 8-pin SOIC package (150-mil width), pin-compatible with industry-standard 8-pin SOIC footprints. Package dimensions comply with JEDEC MS-012AA.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326US33D3+ and TPS3808G33DBVR, DS1834DU+ uniquely delivers true independent dual-rail monitoring with per-rail tolerance selection, internal PBRST debouncing, and push-pull outputs - eliminating discrete components required by alternatives to achieve equivalent functionality.

Availability

DS1834DU+ is available at Aetrix Electronics and suitable for industrial control systems, medical diagnostics equipment, telecom line cards, and automotive infotainment gateways requiring stable component supply and long-term lifecycle assurance.

Supply support for DS1834DU+ 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

Analog Devices (formerly Maxim Integrated) is a global leader in high-performance analog, mixed-signal, and digital signal processing technologies, serving industrial, automotive, communications, and healthcare markets.

The DS1834DU+ belongs to Maxim's EconoReset™ family of supervisory circuits, designed specifically for cost-sensitive, space-constrained embedded systems needing reliable dual-voltage monitoring and manual reset without external passive components.

FAQ

What is the function of the 5V TOL and 3.3V TOL pins on the DS1834DU+?

The 5V TOL and 3.3V TOL pins configure the voltage trip thresholds for their respective rails. When tied to GND, DS1834DU+ uses 5% tolerance for 5VIN (4.50–4.75 V) and 10% for 3.3VIN (2.80–2.97 V). When tied to their supply rails, it selects 10% (4.25–4.49 V) and 20% (2.47–2.64 V) tolerances. This allows DS1834DU+ to adapt to varying system margin requirements without external resistors.

Does DS1834DU+ require external pull-up resistors on its RST outputs?

No, DS1834DU+ does not require external pull-up resistors. Its RST outputs use a CMOS push-pull structure capable of actively driving both high and low logic states. This design eliminates external components, reduces board area, and ensures valid output levels even when supply voltages drop to 0 V - a key differentiator from open-drain alternatives like DS1834A.

How does DS1834DU+ handle power supply sequencing during startup?

During power-up, DS1834DU+ holds both 5V RST and 3.3V RST active for approximately 350 ms after the monitored supplies reach their selected tolerance windows. This guarantees stable power conditions before releasing reset to the microcontroller or FPGA. The device draws internal current from the higher of the two input rails, simplifying biasing in dual-supply systems.

What is the reset behavior when the PBRST pin is asserted on DS1834DU+?

When PBRST is pulled low for ≥2 ms, DS1834DU+ asserts both 5V RST and 3.3V RST simultaneously. After PBRST is released, the reset signals remain active for 200–500 ms (typical 350 ms), regardless of supply status. The internal 40 kΩ pull-up and hardware debouncing ensure noise immunity and eliminate firmware-level debounce logic.

Can DS1834DU+ operate with only one supply voltage present?

Yes, DS1834DU+ remains functional with only 5VIN or only 3.3VIN applied, provided the active supply is ≥1.2 V. Its internal circuitry draws power from the higher available rail, and both RST outputs retain validity. If both supplies fall below 1.2 V, the push-pull outputs can still maintain valid logic down to 0 V when a 100 kΩ pull-down resistor is added - a capability confirmed in DS1834DU+'s datasheet Figure 5.