H54G66BYYJX104 Drop-in Replacement — HGCHIPS HGD4H08X42

Sourcing an alternative to H54G66BYYJX104 (SK Hynix)? HGCHIPS HGD4H08X42 is a pin-to-pin compatible part: package, pin-out and function cross-checked against the original datasheet, so it drops into your existing PCB and firmware with no circuit change.

H54G66BYYJX104 Specifications

Cross-reference: H54G66BYYJX104 → HGD4H08X42

Replacement Notes

• No circuit change — identical package and pin-out, replace directly in the BOM for pilot run.
• Lot test reports — 100% tested before shipment, test data available per lot for IQC records.
• Speed and voltage grades — a higher speed grade is downward compatible; commercial grade does not replace industrial grade, pick -40~85C parts for industrial and outdoor designs.
• Qualification advice — send the full part number (with suffix) and platform details so our FAE team can confirm die revision and timing before volume production.

Ordering and Samples

• In stock, ships within 48 hours; price lock available for long-term projects.
• Samples from 10 pcs, cost credited against your first order.
• Small pilot runs and volume production supported with lot traceability.

Related Replacements

Same family: H54G56BYYQX046 / H54G56BYYVX046 / H9HCNNN8KUMLHR-NLE / H9HCNNN8KUMLHR-NME / H9HCNNNBPUMLHR-NLE / H9HCNNNBPUMLHR-NME / H9HCNNNFAMALTR-NME

HGCHIPS HGD4H08X42 part page · Model Finder · Contact: info@hgtech.cc · +86 760 8992 4799

Frequently asked questions

H54G66BYYJX104 — can it drop in without board changes?

No board changes. H54G66BYYJX104 is mapped to H54G66BYYJX104 and designed as a pin-to-pin drop-in: package and pin-out are checked field by field against the original datasheet, so it fits the existing PCB and firmware. Typical use is second-sourcing, EOL cover and allocation shortages.

How do I use the selection table?

Find your original part number, then check density, organization, speed grade, voltage, package and temperature range against your BOM. Any field that differs is stated on the page — we do not claim the parts are identical.

H54G66BYYJX104 — samples and lead time?

Samples from 10 pcs, credited against the first order. In-stock items ship from Shenzhen within 48 hours; long-lead projects can be price-locked. Parts are 100% inspected before shipment and batch test data is available for IQC.

How do I request a quote for H54G66BYYJX104?

Send your target part number, monthly usage and target price to info@hgtech.cc or call +86 760 8992 4799 — we reply within 24 business hours (same day for stock parts).