Analog Devices Inc. AD9901KPZ-REEL

Overview

AD9901KPZ-REEL from Analog Devices is an ultrahigh-speed digital phase/frequency discriminator IC designed for direct comparison of TTL/CMOS or ECL inputs up to 200 MHz in PLL systems. It delivers linear phase detection (±360° at 40 kHz, ±270° at 70 MHz), zero dead zone operation, and open-collector outputs configurable for +5 V TTL or –5.2 V ECL supply. It serves as the core error generator in low-phase-noise reference loops and agile IF synthesizers.

For engineers reviewing the AD9901KPZ-REEL datasheet, AD9901KPZ-REEL pinout, AD9901KPZ-REEL application, or AD9901KPZ-REEL equivalent, this page provides verified functional identity, validated 20-lead PLCC package mapping, confirmed dual-mode (TTL/ECL) interface behavior, real-world linear detection range vs. frequency trade-offs, and two field-validated alternative discriminators for secure hopping comms and coherent radar timing chains.

Technical Context

The AD9901KPZ-REEL implements a dual-path architecture: a phase detection path using two divide-by-two D flip-flops and an XOR gate, plus independent frequency discriminator flip-flops (Frequency High/Frequency Low) that override phase output when input frequencies differ by >2×. Its trench-oxide isolation enables stable operation at 200 MHz without prescalers.

It features a constant-gain linear transfer function near lock (0.286 V/rad typical), with gain shifted away from the lock point to eliminate dead zones-unlike conventional digital phase comparators. The internal 0.47 V reference sets ISET via external RSET, enabling programmable output current (0.9–11 mA) and power scaling for lower-frequency operation.

Key Specifications

Pinout & Package

AD9901KPZ-REEL is housed in a 20-lead plastic leaded chip carrier (PLCC, package code P-20A), with 1.27 mm pitch, gull-wing leads, and body size 9.09 mm × 9.09 mm × 3.56 mm. Pin 1 is marked by a corner notch; all grounds must be tied to a low-impedance ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar phase/frequency discriminator applications.

Compared with AD9901KPZ-REEL, AD9902KPZ-REEL extends linear range at higher frequencies but sacrifices ECL compatibility, while MC12080P reduces complexity and cost at the expense of acquisition speed and wide-range linearity-making AD9901KPZ-REEL the optimal choice for secure hopping and radar systems demanding both speed and precision.

Availability

AD9901KPZ-REEL is available at Aetrix Electronics and suitable for low-phase-noise reference loops, fast-tuning agile IF synthesizers, and secure frequency-hopping communications requiring stable component supply across extended production cycles.

Supply support for AD9901KPZ-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, serving precision instrumentation, communications, and defense markets since 1965.

The AD9901KPZ-REEL belongs to Analog Devices' ultrahigh-speed timing IC product line, engineered specifically for phase-critical RF control loops where traditional PLL components introduce unacceptable jitter or acquisition delay.

FAQ

What is the maximum input frequency supported by the AD9901KPZ-REEL?

The AD9901KPZ-REEL supports phase/frequency comparison up to 200 MHz without prescalers. At this frequency, its linear detection range narrows to ±50° due to slew-rate limiting, but it remains fully functional as a frequency discriminator. Verified operation at 200 MHz is documented in the Rev. B datasheet under AC Characteristics and Theory of Operation sections.

Does the AD9901KPZ-REEL support both TTL and ECL logic interfaces simultaneously?

No-the AD9901KPZ-REEL operates in either TTL/CMOS mode (+5 V supply, BIAS tied to +5 V) or ECL mode (–5.2 V supply, BIAS tied to –5.2 V), not both concurrently. Pin configuration and internal biasing are mutually exclusive; mixing supplies risks latch-up or permanent damage. This dual-mode capability enables reuse across legacy ECL and modern TTL systems-but requires board-level supply selection.

How is the output current of the AD9901KPZ-REEL set and why does it matter?

The AD9901KPZ-REEL output current is set by an external RSET resistor connected to the RSET pin: ISET = 0.47 V / RSET. This controls peak output current from 0.9 mA to 11 mA. Lower current reduces power dissipation (nominal 218 mW at +25°C) and eases thermal design in compact RF modules-especially valuable in battery-powered hopping radios operating below 70 MHz.

What does "no dead zone" mean for the AD9901KPZ-REEL, and how is it achieved?

"No dead zone" means the AD9901KPZ-REEL maintains nonzero phase gain precisely at the lock point (0° phase difference), eliminating the zero-gain region found in standard digital XOR phase detectors. It achieves this by shifting the nonlinear region to the endpoints of the transfer curve using divide-by-two flip-flops-ensuring continuous error signal generation and suppressing jitter spikes critical in low-phase-noise applications.

Is the AD9901KPZ-REEL pin-compatible with other devices in the AD990x family?

The AD9901KPZ-REEL is not pin-compatible with AD9902KPZ-REEL or AD9901KQ despite sharing the same functional block diagram-its 20-lead PLCC footprint differs from the 14-lead Cerdip (AD9901KQ) and has distinct ECL/TTL pin assignments (e.g., +VS vs. –VS placement). Board redesign is required when substituting across package variants, even within the same family.