L6611 is a digitally programmable secondary housekeeping controller from BCD TECHNOLOGY. It has OV/UV detection, AC mains UV (brownout) detection, online digital trimming, digitally selectable options, error amplifiers, main supply on/off control and power good signal, 50mA crowbar drive for auxiliary output OVP, open ground protection, 8ms digital soft start and 64 ms UV/OC blanking at start-up.
The L6611 is a control and housekeeping IC developed in BCD technology, intended for acting at the secondary side of desktop PC's or server's switching power supplies. It monitors standard voltage rails (+3.3V, +5V, +12V) and an auxiliary supply line, sending feedback signals to primary controllers and reporting faults like undervoltage (UV) or overvoltage (OV).
A key feature of this IC is its digital programming capability that enables accurate trimming of output voltage rails during production test via software, without external discrete trimming components. It also allows selection of how UV and OC conditions are handled in the main converter, either in latched-mode or bouncing-mode.
| Technology | BCD technology |
|---|---|
| Monitored Rails | +3.3V, +5V, +12V |
| UV/OC Blanking Time | 64 ms |
| Soft Start Time | 8 ms |
| Crowbar Drive Current | 50mA |
| Power Good Delay | 250ms |
| PS-ON Delay | 2.5ms |
| Vdd Supply Source | Auxiliary power supply output voltage |
The Housekeeping's main function is to control and monitor the voltages generated by both the main and the auxiliary converter.
It is programmed via software by forcing the PROG pin high (+5V), which disconnects normal functionality and enables DATA and CLOCK inputs.
The modes are latched-mode, where information is latched and released only by forcing a restart, and bouncing-mode, which attempts to automatically restart the converter after a 1-second wait.