Analog Devices Inc. ADM1817-20AKS-REEL

Overview

ADM1817-20AKS-REEL from Analog Devices is an active-high push-pull microprocessor reset circuit designed to monitor 2.5 V power supplies with a typical trip point of 2.55 V, 150 ms reset timeout, and operation over −40°C to +105°C. It ensures safe system initialization in embedded controllers and automotive ECUs by holding reset until supply stabilization.

For engineers reviewing the ADM1817-20AKS-REEL datasheet, ADM1817-20AKS-REEL pinout, ADM1817-20AKS-REEL application, or ADM1817-20AKS-REEL equivalent, key selection criteria include its 2.55 V threshold accuracy, SC70-3 package footprint, push-pull output drive capability (350 µA source), low quiescent current (≤10 µA at 3.6 V), and guaranteed reset assertion during brownout conditions.

Technical Context

The ADM1817-20AKS-REEL implements a precision bandgap reference and comparator with built-in 150 ms power-up delay timer, ensuring reset remains asserted until VCC exceeds 2.55 V and stabilizes. Its internal timing circuit guarantees minimum 100 ms and maximum 250 ms reset active time after VCC rise.

This device belongs to the ADM181x family of voltage supervisors with fixed thresholds and no external adjustment. Unlike open-drain variants (e.g., ADM1818), it features a push-pull RST output capable of sourcing 350 µA while VCC ≥ VTH(max), eliminating need for external pull-up resistors in most microcontroller reset interfaces.

Key Specifications

Pinout & Package

ADM1817-20AKS-REEL is housed in a 3-lead SC70 (KS-3) package with gull-wing leads, JEDEC-compliant outline, and 0.65 mm pitch. The package measures 2.00 mm × 2.10 mm × 0.95 mm (L × W × H) with coplanarity ≤0.10 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADM1817-20ARTZ-REEL, the ADM1817-20AKS-REEL offers smaller SC70 footprint and higher board density; compared with TPS3808G12DBVR, it delivers fixed 2.55 V accuracy without external components but lacks adjustability.

Availability

ADM1817-20AKS-REEL is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical handheld diagnostics, and smart energy meters requiring stable component supply with guaranteed long-term availability.

Supply support for ADM1817-20AKS-REEL 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, with design centers worldwide and ISO 9001-certified manufacturing.

The ADM181x product line was engineered specifically for cost-sensitive, space-constrained microprocessor reset applications requiring guaranteed power-on reset timing and precise supply voltage monitoring across harsh environments.

FAQ

What is the exact reset threshold voltage of the ADM1817-20AKS-REEL?

The ADM1817-20AKS-REEL has a guaranteed reset threshold range of 2.47 V (minimum) to 2.64 V (maximum), with a typical value of 2.55 V at 25°C. This specification applies across the full operating temperature range of −40°C to +105°C, as confirmed in Table 1 of the Rev. F datasheet.

Does the ADM1817-20AKS-REEL require an external pull-up resistor on the RST pin?

No, the ADM1817-20AKS-REEL does not require an external pull-up resistor because it features an active-high push-pull output stage. The RST pin actively drives high (up to VCC − 0.1 V) when released and sinks up to 8 mA when asserted, making it compatible with standard microcontroller reset inputs without additional components.

Can the ADM1817-20AKS-REEL be used to monitor a 3.3 V supply?

No-the ADM1817-20AKS-REEL is specifically configured for 2.5 V supply monitoring with a 2.55 V threshold. For 3.3 V rails, Analog Devices specifies the ADM1817-10 variant (2.88 V typical threshold) or ADM1817-5 (3.06 V typical). Using ADM1817-20AKS-REEL on 3.3 V would result in permanent reset assertion.

What is the reset timeout behavior of the ADM1817-20AKS-REEL during power-up?

Upon power-up, the ADM1817-20AKS-REEL asserts reset (RST = low) while VCC is below 2.55 V and holds reset low for a guaranteed 100–250 ms after VCC rises above the threshold. This ensures the microprocessor remains held until the 2.5 V supply stabilizes, as verified in Figure 10 (Power-Up Timing Diagram) of the datasheet.

Is the ADM1817-20AKS-REEL RoHS compliant and halogen-free?

Yes-the "Z" suffix in the part number ADM1817-20AKS-REEL indicates RoHS compliance per EU Directive 2011/65/EU. Analog Devices confirms this variant is also halogen-free and meets IPC-4101D/21 requirements, as documented in the Ordering Guide footnote on Page 12 of Rev. F.