Analog Devices Inc. ADM803ZAKS-REEL7

Overview

ADM803ZAKS-REEL7 from Analog Devices is a 3-lead SC70 microprocessor supervisory circuit with open-drain active-low RESET output, 2.32 V reset threshold (±0.07 V over −40°C to +125°C), 17 μA supply current, and 240 ms typical reset timeout. It monitors VCC down to 1.0 V and asserts reset during power-up, brownout, or power-down in embedded controllers and low-voltage microprocessor systems.

For engineers reviewing the ADM803ZAKS-REEL7 datasheet, ADM803ZAKS-REEL7 pinout, ADM803ZAKS-REEL7 application, or ADM803ZAKS-REEL7 equivalent, key selection criteria include its 2.32 V threshold accuracy, SC70 package footprint, open-drain output requiring external pull-up, operation down to 1 V VCC, and guaranteed 140–460 ms reset assertion window across temperature.

Technical Context

The ADM803ZAKS-REEL7 implements a precision voltage comparator with built-in glitch immunity and an internal 240 ms power-on reset timer. Its reference circuit maintains ±0.07 V threshold tolerance over −40°C to +125°C, enabling reliable reset assertion even under fast VCC transients or degraded supply conditions.

As the Z-suffix variant in the ADM803 family, it delivers 2.32 V nominal reset threshold optimized for 2.5 V system rails. Its open-drain RESET output requires an external pull-up resistor and remains functional down to VCC = 1.0 V, supporting low-power portable and industrial applications where supply collapse behavior must be tightly controlled.

Key Specifications

Pinout & Package

ADM803ZAKS-REEL7 is housed in a 3-lead SC70 (KS-3) package with 0.65 mm lead pitch, 0.10 mm max coplanarity, and JEDEC-compliant dimensions (2.20 mm × 1.35 mm body). The package supports standard reflow profiles and offers thermal impedance of 146°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADM803RAKSZ-REEL7 and TPS3808G125DBVR, the ADM803ZAKS-REEL7 uniquely combines 2.32 V threshold accuracy, 1 V VCC operability, and SC70 footprint - making it the only option for robust 2.5 V rail supervision in space-constrained, wide-temperature, or deep-brownout-critical designs.

Availability

ADM803ZAKS-REEL7 is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical sensor nodes, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM803ZAKS-REEL7 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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The ADM803 family was designed specifically for reliable, low-power microprocessor supervision in space- and power-constrained embedded systems - emphasizing precision threshold accuracy, wide VCC range, and minimal external component count.

FAQ

What is the exact reset threshold voltage of the ADM803ZAKS-REEL7 and how does it vary with temperature?

The ADM803ZAKS-REEL7 has a nominal reset threshold of 2.32 V at 25°C, with a guaranteed range of 2.25 V to 2.38 V over −40°C to +85°C and 2.22 V to 2.42 V over −40°C to +125°C. This 2.32 V specification targets 2.5 V supply rails, providing 10% headroom below nominal voltage to ensure reset assertion before logic corruption occurs. The device uses a trimmed bandgap reference to achieve this stability without external components.

Does the ADM803ZAKS-REEL7 require an external pull-up resistor on the RESET pin?

Yes, the ADM803ZAKS-REEL7 features an open-drain RESET output and requires an external pull-up resistor to a valid logic rail (e.g., 1.8 V, 2.5 V, or 3.3 V). Typical values range from 10 kΩ to 100 kΩ depending on rise time and bus loading requirements. Without this resistor, the RESET signal cannot transition high and will remain indeterminate, preventing proper microprocessor initialization. The ADM803ZAKS-REEL7 itself does not source current on RESET.

Can the ADM803ZAKS-REEL7 operate and assert reset when VCC falls below 1.5 V?

Yes, the ADM803ZAKS-REEL7 is specified to operate and assert RESET down to VCC = 1.0 V - a key differentiator versus many supervisory ICs that cease functioning below 1.5 V. This capability ensures deterministic reset behavior during severe brownout or battery-depletion events. However, below 0.8 V, the output may enter high-impedance; for guaranteed low-state integrity down to 0 V, a 100 kΩ pull-down resistor is recommended per Analog Devices Application Note.

What is the reset timeout duration of the ADM803ZAKS-REEL7 and is it adjustable?

The ADM803ZAKS-REEL7 provides a fixed internal reset timeout of 240 ms (typical) after VCC rises above the threshold, with a guaranteed minimum of 140 ms and maximum of 460 ms over −40°C to +85°C. This timing is generated by an on-chip RC oscillator and is not user-adjustable. No external capacitors or resistors are needed - the 240 ms value was selected to exceed typical microprocessor power-on stabilization times for reliable boot sequencing.

How does the ADM803ZAKS-REEL7 differ from the ADM809ZAKSZ-REEL7?

The ADM803ZAKS-REEL7 and ADM809ZAKSZ-REEL7 share identical reset threshold (2.32 V), temperature range (−40°C to +125°C), package (SC70), and supply current (17 μA), but differ in output architecture: ADM803ZAKS-REEL7 uses open-drain RESET (requiring external pull-up), while ADM809ZAKSZ-REEL7 uses push-pull RESET (internally driven high/low). This makes ADM809ZAKSZ-REEL7 suitable for direct connection to CMOS inputs without external components, whereas ADM803ZAKS-REEL7 supports wired-OR configurations and multi-rail level translation.