Analog Devices Inc. ADM803TAKS-REEL7

Overview

ADM803TAKS-REEL7 from Analog Devices is a microprocessor supervisory circuit in 3-lead SC70 package, featuring open-drain active-low RESET output, 3.08 V reset threshold, 240 ms typical power-on reset timeout, and operation down to 1 V VCC. It monitors 3.3 V supply rails in embedded controllers and portable instrumentation.

For engineers reviewing the ADM803TAKS-REEL7 datasheet, ADM803TAKS-REEL7 pinout, ADM803TAKS-REEL7 application, or ADM803TAKS-REEL7 equivalent, key selection criteria include reset threshold accuracy (±2.5% over −40°C to +125°C), ultra-low 17 μA supply current, open-drain output requiring external pull-up, and SC70 package compatibility with space-constrained PCB layouts.

Technical Context

The ADM803TAKS-REEL7 implements a precision voltage comparator with built-in glitch immunity to reject fast transients on VCC, ensuring robust reset assertion during brownout and power-up. Its internal timer guarantees minimum 140 ms and typical 240 ms reset pulse width after VCC exceeds the 3.08 V threshold.

Designed for low-power systems, it operates across −40°C to +125°C with VCC range 1.0 V to 5.5 V and consumes only 17 μA at 3.6 V. The open-drain RESET output requires an external pull-up resistor and sinks up to 1.2 mA at VTH min while maintaining <0.3 V low-level voltage.

Key Specifications

Pinout & Package

ADM803TAKS-REEL7 is housed in a 3-lead SC70 (KS-3) package with gull-wing leads, 0.65 mm pitch, and 0.10 mm coplanarity. Pin 1 is GND, Pin 2 is RESET (open-drain), and Pin 3 is VCC - consistent with Figure 3 and Table 4 of the ADM803/ADM809/ADM810 datasheet Rev. I.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TTR and TPS3808G30DBVR, the ADM803TAKS-REEL7 offers superior thermal stability (±2.5% over −40°C to +125°C vs. ±3.5% for MAX809TTR) and smaller SC70 footprint, though its open-drain output mandates external component placement not required by the alternatives.

Availability

ADM803TAKS-REEL7 is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical instruments, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM803TAKS-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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The ADM803 series belongs to Analog Devices' microprocessor supervisory product line, engineered specifically for reliable power-on reset and brownout protection in resource-constrained embedded systems operating across harsh environmental conditions.

FAQ

What is the exact reset threshold voltage of the ADM803TAKS-REEL7 and how does it vary with temperature?

The ADM803TAKS-REEL7 has a nominal reset threshold of 3.08 V, with a maximum deviation of ±2.5% across the full operating temperature range of −40°C to +125°C. At 25°C, the threshold is specified as 3.04 V to 3.11 V; over −40°C to +85°C it is 3.00 V to 3.15 V; and over −40°C to +125°C it is 2.95 V to 3.21 V. This tight tolerance ensures precise 3.3 V rail supervision without premature or delayed reset assertion in the ADM803TAKS-REEL7.

Does the ADM803TAKS-REEL7 require an external pull-up resistor, and why?

Yes, the ADM803TAKS-REEL7 requires an external pull-up resistor on its open-drain RESET pin because it can only sink current - not source it. Without a pull-up, the RESET line floats when deasserted, risking undefined logic states that could cause microprocessor malfunction. A typical 10 kΩ to 100 kΩ resistor to VCC (or another logic supply) ensures clean high-level signaling. This design allows flexible voltage translation, making the ADM803TAKS-REEL7 compatible with both 3.3 V and 5 V host systems.

What is the minimum VCC voltage at which the ADM803TAKS-REEL7 continues to assert RESET?

The ADM803TAKS-REEL7 continues to assert RESET down to VCC = 1.0 V, as confirmed in the Absolute Maximum Ratings table and General Description section of the datasheet. Below this voltage, internal circuitry ceases operation and RESET may float or become indeterminate. This 1 V brownout hold capability ensures robust reset behavior during deep supply sags - a critical feature for automotive cold-crank scenarios and battery-depleted portable devices using the ADM803TAKS-REEL7.

How does the ADM803TAKS-REEL7 handle fast transients on the VCC line?

The ADM803TAKS-REEL7 incorporates a glitch-immune reset comparator that rejects transients shorter than 100 μs when the overdrive (VTH – VCC) is ≥100 mV, per Figure 11. This architecture prevents false resets caused by switching noise, ESD coupling, or load-step artifacts on the monitored supply. Unlike basic voltage detectors, the ADM803TAKS-REEL7's internal filtering ensures only sustained undervoltage conditions trigger reset - a key reliability factor in electrically noisy industrial and automotive environments.

Is the ADM803TAKS-REEL7 pin-compatible with other members of the ADM803/ADM809/ADM810 family?

No - the ADM803TAKS-REEL7 is not pin-compatible with ADM809 or ADM810 variants. While all share the same 3-lead SC70 footprint, the ADM803 uses Pin 1 = GND, Pin 2 = RESET (open-drain), Pin 3 = VCC; ADM809/ADM810 swap GND and RESET positions (Pin 1 = VCC, Pin 2 = RESET, Pin 3 = GND). Substituting without PCB revision will cause functional failure. Always verify pin mapping from Figure 3 (ADM803/ADM809) and Figure 4 (ADM810) before replacement - the ADM803TAKS-REEL7 must be used only in designs laid out for ADM803 pinout.