Analog Devices Inc. AD8611ARZ

Overview

AD8611ARZ from Analog Devices is a single-channel, ultrafast 4 ns propagation delay comparator with latch function and complementary outputs, operating from 3 V to 5 V single supply. It features 100 MHz input bandwidth, matched rising/falling propagation delays (Δt_P ≤ 2.0 ns), and rail-to-rail input common-mode range down to GND - ideal for clock recovery in high-speed digital receivers.

For engineers reviewing the AD8611ARZ datasheet, AD8611ARZ pinout, AD8611ARZ application, or AD8611ARZ equivalent, key selection criteria include latch enable timing (t_PW(E) = 3 ns), input overdrive sensitivity (5–250 mV), output drive capability (3.2 mA sink/source), and SOIC-8 package compatibility with LT1016/LT1394 footprints.

Technical Context

The AD8611ARZ uses a bipolar PNP input stage enabling −200 mV to +3.0 V input common-mode range on 5 V supply and 0 V to +1.0 V on 3 V supply. Its latch function is active only above 4.3 V supply and requires 0.5 ns setup/hold time.

Propagation delay remains stable across temperature (4.0–5.0 ns at −40°C to +85°C) and tightly matches between rising/falling edges (≤2.0 ns mismatch), supporting duty-cycle–preserving clock regeneration. Input capacitance is 3.0 pF, and differential input voltage rating is ±5 V.

Key Specifications

Pinout & Package

AD8611ARZ is packaged in an 8-lead narrow-body SOIC (R-8) with exposed pad not present; thermal resistance θ_JA = 158°C/W. Pin functions are validated per Analog Devices Rev. B datasheet Figures 1 and 4.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed comparator applications.

Compared with LT1394CS8#PBF and TLV3501CDR, AD8611ARZ uniquely combines 4 ns delay, latch enable, ground-swinging input range, and SOIC-8 pinout - making it the only option for upgrading LT1016/LT1394 designs requiring both speed and output retention.

Availability

AD8611ARZ is available at Aetrix Electronics and suitable for high-speed clock recovery, line receiver, phase detector, and zero-crossing detector applications requiring stable component supply across industrial temperature range (−40°C to +85°C).

Supply support for AD8611ARZ 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 AD8611ARZ belongs to Analog Devices' high-speed comparator product line, engineered specifically for timing-critical applications including clock distribution, data acquisition, and communication infrastructure where sub-5 ns latency and duty-cycle fidelity are mandatory.

FAQ

Does AD8611ARZ support latch functionality at 3 V supply?

No. The latch function of AD8611ARZ is not operational below 4.3 V supply voltage, as specified in the datasheet. At 3 V operation, the LATCH pin is unresponsive and must be held low. This limitation is inherent to the internal logic threshold design and cannot be overridden by external circuitry. For full latch functionality, AD8611ARZ requires V+ ≥ 4.3 V - confirming that AD8611ARZ operates as a standard high-speed comparator without latching under 3 V conditions.

What is the maximum input frequency AD8611ARZ can reliably process?

AD8611ARZ supports accurate comparison of input signals up to 100 MHz with ≥10 mV overdrive at 25°C. At +85°C, ≥50 mV overdrive is recommended for 100 MHz operation. Inputs exceeding 100 MHz fundamental frequency may cause supply current to rise above 20 mA and prevent output settling to a valid logic state. Therefore, AD8611ARZ is rated for 100 MHz maximum input frequency - a hard limit confirmed by characterization in the Rev. B datasheet Figure 14 and Applications section.

Can AD8611ARZ drive standard TTL or CMOS logic directly?

Yes. AD8611ARZ delivers 3.2 mA sink/source capability with VOL ≤ 0.4 V and VOH ≥ 2.4 V at 5 V supply, meeting 74LVC and 74ALVC logic family thresholds. Its complementary QA/QA outputs provide both true and inverted logic states without external inverters. However, pull-up resistors may be needed for full rail-swing at 3 V operation. Thus, AD8611ARZ interfaces directly with most modern CMOS and TTL families - a verified capability documented in Table 1 and Applications Information.

Is AD8611ARZ pin-compatible with LT1016CN8#PBF?

Yes. AD8611ARZ shares identical 8-lead SOIC pinout and terminal assignments with LT1016 and LT1394, as explicitly stated in the General Description and Upgrading sections of the datasheet. Both devices place V+, IN+, IN−, V−, LATCH, GND, QA, and QA on pins 1–8 respectively. This pin-for-pin compatibility enables drop-in replacement - confirmed by Analog Devices' official upgrade guidance and Figure 1/4 pin diagrams for AD8611ARZ.

What thermal considerations apply to AD8611ARZ in SOIC-8 package?

AD8611ARZ in SOIC-8 (R-8) has θ_JA = 158°C/W and θ_JC = 43°C/W per Table 4. With 10 mA total supply current at 5 V (50 mW dissipation), junction temperature rise is ~7.9°C above ambient under still-air conditions. A continuous ground plane and local 1 μF + 10 nF bypassing are mandatory to manage high-frequency switching noise and thermal stability. These values are measured per JEDEC JESD51-2 and validated in the Thermal Resistance section - confirming AD8611ARZ's thermal behavior is fully characterized and design-ready.