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SEGGER J-Link Isolators
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J-Link Isolators

Adapters & Accessories

Galvanic isolation adapters for J-Link debug probes, protect host and probe from ground loops and high-voltage target environments. Available in India from GSAS.

Type

Galvanic isolation adapter

Interfaces

JTAG, SWD

Isolation

Basic isolation, 1 kV DC

Compatibility

All J-Link models

Use Case

High-voltage & motor control targets

Authorized SEGGER partner
Local FAE & application engineering
Hands-on training & integration
Manufacturer warranty

About J-Link Isolators

J-Link Isolators

J-Link Isolators provide galvanic isolation between the J-Link debug probe and the target hardware, protecting both the probe and the host PC from ground potential differences, voltage spikes, and electrical noise that are common in motor control, power electronics, industrial automation, and automotive applications. Without isolation, a ground loop between the USB-connected host and a target operating at a different ground potential can damage the debug probe, corrupt debug communication, or, in worst cases, destroy the host PC’s USB controller.

When Isolation Is Essential

Any target that drives inductive loads or sits on a different ground reference than the debug host benefits from an isolation barrier. Motor control boards, inverter designs, and automotive ECUs connected to vehicle ground are common examples. The J-Link Isolator inserts inline between the J-Link probe and the target’s debug connector, providing basic galvanic isolation rated at 1 kV DC while passing JTAG or SWD signals at up to 4 MHz.

The isolators use the standard 20-pin JTAG/SWD connector and come in two separate variants: the JTAG Isolator and the SWD Isolator. The JTAG variant cannot pass SWD (SWD uses a bidirectional data pin), so choose the variant that matches your debug interface. One important safety boundary, stated plainly by SEGGER: these devices provide basic isolation only, which protects your equipment from ground-potential differences and electrical spikes. They are not personnel protection. Wherever hazardous voltages are present, SEGGER requires additional protection measures (double or reinforced isolation) to protect people in case the first insulation barrier fails.

Features

FeatureSpecification
Isolation TypeGalvanic, basic isolation (1 kV DC)
VariantsJTAG Isolator and SWD Isolator (separate devices; the JTAG variant cannot pass SWD)
Connector20-pin standard J-Link connector
Interface SpeedUp to 4 MHz through the isolation barrier
CompatibilityJ-Link BASE, PLUS, PRO, ULTRA, WiFi; Flasher production programmers
Use CasesMotor control, power electronics, automotive, industrial
InstallationInline between J-Link and target; the SWD Isolator is powered from the probe side and may require enabling J-Link target power
SafetyBasic isolation only; additional protection required for hazardous voltages per SEGGER

GSAS Micro Systems, SEGGER’s authorized engineering partner in India, supplies J-Link Isolators with competitive pricing and short lead times. For teams in Bengaluru, Hyderabad, Chennai, Pune, Mumbai, and Delhi NCR working on motor drives, power converters, or any application where the target ground is not shared with the debug host, the isolator is an essential companion to a J-Link BASE, PLUS, or PRO. Our field application engineers advise on isolation requirements for high-voltage benches. Request a quote for single units or lab kits.

Common questions about J-Link Isolators

When do I need a J-Link isolator?
Whenever the target does not share a ground reference with the debug host: motor control boards, inverters, mains-connected power supplies, and automotive ECUs on vehicle ground. Without isolation, a ground loop can damage the probe or the host PC's USB controller.
What isolation voltage do J-Link isolators provide?
Both the JTAG and SWD Isolators provide basic isolation rated at 1 kV DC per SEGGER. Basic isolation protects equipment from ground-potential differences and spikes; SEGGER requires additional protection measures wherever hazardous voltages are present, so it is not a personnel-safety barrier on its own.
Does an isolator affect debug speed?
The isolators pass JTAG or SWD signals at up to 4 MHz per SEGGER, lower than a directly connected probe's maximum interface clock. Debugging works normally; flash downloads on very fast probes simply run at the isolator's interface speed.
Where can I buy J-Link isolators in India?
GSAS Micro Systems, SEGGER's authorized engineering partner in India, stocks J-Link isolators with competitive pricing and short lead times, with INR invoicing and GST documentation.

Interested in J-Link Isolators?

Get pricing, an evaluation unit, or a technical consultation from our application engineers.

Request a Quote Demo