Analog Devices Inc./Maxim Integrated DS1819CR-5/T&R

Overview

DS1819CR-5/T&R from Maxim Integrated is a 3.3V microprocessor supervisory circuit in SOT-23-5 package, featuring 5% VCC trip point (3.00–3.15 V), 140–280 ms reset pulse width, watchdog timeout of 1.12 s, pushbutton reset input, and industrial temperature range (−40°C to +85°C). It halts and restarts out-of-control microprocessors during power transients or software lockup in embedded control systems.

For engineers reviewing the DS1819CR-5/T&R datasheet, DS1819CR-5/T&R pinout, DS1819CR-5/T&R application, or DS1819CR-5/T&R equivalent, key selection criteria include VCC trip accuracy, reset timing consistency, watchdog strobe interface compatibility, pushbutton debounce behavior, and SOT-23-5 footprint constraints in space-constrained MCU power management designs.

Technical Context

The DS1819CR-5/T&R implements a precision bandgap-based voltage monitor with 5 mV hysteresis for stable 3.0 V supply detection, combined with a 1.12 s watchdog timer that resets on ST input transitions and supports disable-by-float. Its dual-reset architecture includes active-low RST and active-high RST outputs, both held active for ≥140 ms after power-up or fault recovery.

It integrates pushbutton reset debouncing with 500 ns delay from PBRST low-to-release to RST assertion, and maintains valid RST output down to 1.0 V VCC via push-pull driver - extendable to 0 V using external 100 kΩ pull-down resistor. Input thresholds follow VIH ≥ 0.8×VCC and VIL ≤ 0.3×VCC across operating range.

Key Specifications

Pinout & Package

SOT-23-5 surface-mount package (2.9 mm × 1.6 mm × 1.1 mm), lead-free and RoHS-compliant, optimized for automated PCB assembly and thermal performance in dense layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823TEUK+T and TPS3808G01DBVR, the DS1819CR-5/T&R delivers integrated 3.0 V ±5% monitoring, native pushbutton reset, and identical SOT-23-5 footprint - enabling drop-in replacement in 3.3 V systems without layout change or added passives.

Availability

DS1819CR-5/T&R is available at Aetrix Electronics and suitable for industrial PLC controllers, smart metering modules, automotive body control units, and IoT edge sensor nodes requiring stable component supply and long-term lifecycle assurance.

Supply support for DS1819CR-5/T&R 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, automotive, and communications applications.

The DS1819CR-5/T&R belongs to the MicroMonitor™ family - engineered specifically for reliable microprocessor supervision in 3.3 V embedded systems where power integrity, software watchdog coverage, and manual reset capability must coexist in minimal footprint.

FAQ

What is the exact VCC trip point range for DS1819CR-5/T&R?

The DS1819CR-5/T&R has a guaranteed VCC trip point of 3.00 V to 3.15 V at 25°C, corresponding to ±5% tolerance around 3.0 V nominal. This range is specified across the full industrial temperature range (−40°C to +85°C) and ensures consistent brownout detection in 3.3 V systems with typical LDO output variation. The DS1819CR-5/T&R uses an internal temperature-compensated reference to maintain accuracy without external calibration.

Does DS1819CR-5/T&R support both active-low and active-high reset outputs simultaneously?

Yes, the DS1819CR-5/T&R provides two independent reset outputs: Pin 1 (RST) is active-low and Pin 3 (RST) is active-high. Both assert synchronously during power failure, watchdog timeout, or pushbutton reset events, and remain active for a minimum of 140 ms. This dual-output capability allows direct interfacing with MCUs requiring either polarity without external logic inversion - a feature confirmed in the device's block diagram and pin assignment table.

Can the watchdog function of DS1819CR-5/T&R be disabled, and how?

Yes, the watchdog function in DS1819CR-5/T&R can be disabled by leaving the ST (strobe) input pin floating or tri-stated. The datasheet explicitly states that "the watchdog can be disabled by floating (or tri-stating) the ST input" and provides Figure 6 as a sample disable circuit. No pull-up or pull-down resistor is required - high-impedance termination is sufficient. This behavior is verified in the Operation section and applies identically to all DS1819 'A' and 'B' variants, including DS1819CR-5/T&R.

What is the minimum VCC level at which DS1819CR-5/T&R guarantees valid RST output?

The DS1819CR-5/T&R guarantees valid RST output down to 1.0 V VCC using its internal push-pull driver. For operation down to 0 V, an external 100 kΩ resistor from RST to GND is recommended - this configuration maintains asserted reset state throughout full power collapse, as validated in Figure 9 and the Output Valid Conditions section. This capability is unique to the DS1819CR-5/T&R among comparable supervisors and supports fail-safe behavior in critical systems.

Is DS1819CR-5/T&R pin-compatible with MAX823/24/25 devices?

Yes, the DS1819CR-5/T&R is pin- and function-compatible with the MAX823/24/25 family per the Features section, which states "Pin- and function-compatible with the MAX823/24/25 products." However, functional equivalence is limited to the 'A' variant configuration: DS1819CR-5/T&R implements PBRST on Pin 4 and RST on Pin 3 (like DS1819A), whereas MAX823 uses Pin 4 for ST and lacks PBRST. Direct replacement requires verifying matching variant type and signal routing.