Analog Devices Inc./Maxim Integrated DS1814AR-5-U

Overview

DS1814AR-5-U from Maxim Integrated is a 5V microprocessor supervisory circuit with precision power monitoring (±5% VCC trip at 4.75V), watchdog timer (1.12s timeout), and pushbutton reset control. It delivers active-low reset output, 140ms minimum reset pulse width, and operates across -40°C to +85°C in SOT-23-5 for embedded microcontroller systems requiring reliable power-up/power-down sequencing and fault recovery.

For engineers reviewing the DS1814AR-5-U datasheet, DS1814AR-5-U pinout, DS1814AR-5-U application, or DS1814AR-5-U equivalent, key selection criteria include its 4.75V VCC threshold, 1.12s watchdog timeout, push-pull RST output valid down to 1.0V VCC, SOT-23-5 package compatibility, and functional alignment with MAX823/824/825 series in 5V systems.

Technical Context

The DS1814AR-5-U integrates three core supervision functions: precision voltage monitoring using a temperature-compensated bandgap reference and comparator (trip point 4.75V ±5%), a 1.12-second watchdog timer triggered by ST input transitions, and debounced pushbutton reset logic on PBRST with ≥140ms active-low output pulse. All functions drive a single active-low RST output.

Its reset output uses a push-pull driver capable of maintaining valid logic levels down to VCC = 1.0V; below that, an external 100kΩ pull-down resistor extends validity to 0V. The ST input requires periodic transitions ≤1.12s to prevent timeout, while PBRST accepts active-low signals with internal 50kΩ pull-up and noise immunity against <100ns glitches.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package with 1.6mm × 2.9mm footprint, 0.95mm height, and gull-wing leads. RoHS-compliant, lead-free finish.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX823SESA+ and TPS3808G15DBVR, the DS1814AR-5-U uniquely combines fixed 4.75V ±5% monitoring, integrated watchdog timer, and pushbutton reset in one SOT-23-5 package-reducing BOM count and enabling faster, more robust system-level fault recovery without design compromises.

Availability

DS1814AR-5-U is available at Aetrix Electronics and suitable for industrial automation, medical devices, automotive body electronics, and point-of-sale terminals requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for DS1814AR-5-U 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 industrial, medical, and communications applications.

The DS1814AR-5-U belongs to Maxim's MicroMonitor™ family-engineered specifically for 5V microprocessor supervision with integrated voltage monitoring, watchdog timing, and pushbutton reset in minimal footprint.

FAQ

What is the exact VCC trip point and tolerance for DS1814AR-5-U?

The DS1814AR-5-U has a nominal VCC trip point of 4.75V with ±5% tolerance, meaning it asserts reset when VCC falls below 4.50V and releases reset only after VCC rises above 4.75V plus hysteresis (10mV). This specification is validated across -40°C to +85°C and ensures reliable brownout detection in 5V systems without external calibration. The DS1814AR-5-U datasheet confirms this value under DC Electrical Characteristics.

Does DS1814AR-5-U support both watchdog and pushbutton reset simultaneously?

Yes, the DS1814AR-5-U supports concurrent watchdog and pushbutton reset functions. Its 'A' variant (indicated by 'A' in part marking) includes both ST (strobe input for watchdog) and PBRST (pushbutton reset input) pins. A pushbutton press generates a ≥140ms RST pulse independent of watchdog status, while ST transitions reset the 1.12s watchdog timer. Both events assert the same active-low RST output, making DS1814AR-5-U ideal for dual-fault-tolerance designs.

Can DS1814AR-5-U operate below 1.0V VCC?

No-the DS1814AR-5-U's RST output remains valid down to 1.0V VCC using its internal push-pull driver. Below 1.0V, the output becomes indeterminate unless an external 100kΩ pull-down resistor is added from RST to GND, which extends valid reset assertion to 0V VCC. This configuration draws leakage current when RST is high but ensures fail-safe behavior during deep undervoltage. The DS1814AR-5-U datasheet explicitly defines this design option in the "Output Valid Conditions" section.

Is DS1814AR-5-U pin-compatible with MAX823 series devices?

Yes, the DS1814AR-5-U is pin- and function-compatible with the MAX823/824/825 family in 5V configurations. Pin 1 (RST), Pin 2 (GND), Pin 4 (ST), and Pin 5 (VCC) map identically; Pin 3 is PBRST on DS1814AR-5-U versus RST on MAX823 variants-but both serve as active-low reset outputs. This allows direct substitution in most layouts, though firmware may require minor adjustment if relying on dual-reset outputs. The DS1814AR-5-U product brief confirms this compatibility.

What is the maximum recommended slew rate for VCC during power-up?

The DS1814AR-5-U specifies a minimum VCC slew rate of 12.5 V/s during rising edge to ensure accurate power-on reset timing and avoid metastability in the internal comparator. Slower slew rates may cause delayed or inconsistent RST deassertion, risking incomplete microprocessor initialization. This requirement is documented in the AC Electrical Characteristics table of the DS1814AR-5-U datasheet and applies across the full operating temperature range.