Agilent/Keysight N4851A

The Agilent/Keysight N4851A is a MIPI D-PHY digital acquisition probe engineered for real-time debugging and testing of MIPI D-PHY interfaces in mobile and embedded systems. It captures CSI-2 and DSI protocol traffic transparently between devices or operates in active test mode with simultaneous stimulus injection and response analysis. The probe integrates with 16800 and 16900 Series logic analyzers to deliver hierarchical trace visibility, protocol decoding, packet inspection, and intelligent triggering on protocol violations and user-defined packet content.

Technical Specifications

• Maximum Acquisition Speed: 800 Mbps


• Lane Configuration: 1 or 2 lanes


• Voltage Support: Low power and high speed voltage levels


• User-Defined Payload: Up to 2048 bits


• Logic Analyzer Requirement: 16800 or 16900 Series with 68 channels minimum


• Probe Interface: 90-pin cable compatible with Agilent 1695x-series logic analyzer cards


• External Connectors: SMA (m-m) connectors for stimulus integration with N4861A probe

Key Features

• Real-time acquisition of MIPI D-PHY traffic with hierarchical trace display


• CSI-2 and DSI protocol decoder with integrated packet viewer


• Bi-directional communication and bus mode change monitoring


• Protocol-specific triggering on packets, individual bits, and violations


• Analysis-only mode for transparent device-to-device traffic capture


• Active test mode enabling customizable stimulus generation and simultaneous device response analysis


• High impedance probing options including flying leads and soft-touch connectors

Typical Applications

• Camera interface validation (CSI-2 testing)


• Display interface characterization (DSI testing)


• Mobile SoC peripheral debugging


• Controller and device behavior analysis


• System integration verification

Compatibility & Integration The N4851A operates as a modular component within Keysight's 16800/16900 Series logic analyzer platform. It pairs with the N4861A MIPI D-PHY Stimulus Probe for integrated stimulus-response testing. Probing solutions support various mechanical interfaces optimized for signal integrity.