Exact device and ordering identity
UCC256402DDBR is an LLC resonant-controller ordering code in TI’s UCC25640x family, available in a 14-terminal DDB package. It is a control IC with an integrated high-voltage gate-drive function, not an all-in-one isolated supply module with transformer and switching FETs included. A successful replacement must match the specific UCC256402 variant’s feature configuration and start-up requirements, not just the UCC25640x family number.
Operating and control considerations
The manufacturer describes hybrid hysteretic control and optimized burst mode with configurable soft-on/soft-off behavior to reduce standby losses and audible noise. Adaptive dead-time control and the specified gate-driver source/sink capability must be paired with suitable MOSFET gate charge, resonant tank and transformer. An integrated high-voltage startup function and active X-cap discharge are control and safety-support functions whose external circuit context matters. These statements do not establish certified end-product standby performance without system measurements.
Package, sourcing and engineering trade-offs
Engineering approval should compare DDB pinout, PFC interface, resonant-frequency limits, startup behavior, optocoupler feedback and burst-mode control against the existing power board. Switching to a different LLC controller can change transformer magnetizing requirements and overcurrent protection timing. Procurement should provide the exact DDBR suffix together with target power, input bus and standby or acoustic constraints.
Manufacturer-verified selection specifications
| Selection parameter | TI-verified value | Engineering condition |
|---|---|---|
| Burst | Burst mode with Soft-ON and Soft-OFF periods | Refer to exact manufacturer operating conditions |
| Disable burst | User option to disable burst mode | Refer to exact manufacturer operating conditions |
| Control | Hybrid hysteretic control (HHC) | Refer to exact manufacturer operating conditions |
| Dead time | Robust adaptive dead-time control | Refer to exact manufacturer operating conditions |
| Gate driver | Integrated high-voltage gate driver with 0.6A source and 1.2A sink capability | Refer to exact manufacturer operating conditions |
| Startup | Integrated high voltage startup function | Refer to exact manufacturer operating conditions |
| Xcap | Active X-capacitor discharge function | Refer to exact manufacturer operating conditions |
| Catalog package | SOIC-14 | Match exact TI mechanical drawing before footprint or replacement approval |
Procurement and datasheet
Request a quotation for UCC256402DDBR using the complete orderable number, target quantity and package requirement. Stock, pricing and delivery timing require a direct RFQ confirmation; no on-page availability or price is promised. Source-listed alternative candidates, where present, are for engineering evaluation and do not establish drop-in compatibility.
