The transformer bias winding is used to sense output voltage for regulation, and for low-loss input voltage sensing. Advanced sampling techniques allow CCM operation, and deliver excellent output voltage regulation performance for opto-coupler-less designs at power levels of 100 W and above.
A high-voltage current source enables fast and efficient start-up. Advanced light-load modes are deployed to reduce both controller and system power consumption at no load and light load. These modes enable potential system designs to meet 30-mW no-load power for power designs up to 30 W nominal, 60 W peak.
The device has been designed for ease-of-use and incorporates many features to enable a wide range of designs. Extensive protection features are included to simplify system design.
See the Device Comparison Table for details.
PART NUMBER | PACKAGE | BODY SIZE |
---|---|---|
UCC28630 | SOIC (7) | 4.90 mm x 3.90 mm |
UCC28631 | ||
UCC28632 | ||
UCC28633 | ||
UCC28634 |
Changes from C Revision (March 2015) to D Revision
Changes from B Revision (March 2014) to C Revision
Changes from A Revision (January 2014) to B Revision
Changes from * Revision (January 2014) to A Revision
ORDER NUMBER | FEATURES | ||||
---|---|---|---|---|---|
ACTIVE-X CAPACITOR DISCHARGE | OVERLOAD TIMER | ADJUSTABLE CC LIMIT | FREQUENCY DITHER | SECONDARY-SIDE WAKE UP | |
UCC28630D | Yes | Yes | No | Yes | SD Pin |
UCC28631D | No | No | Yes | Yes | SD Pin |
UCC28632D | No | No | Yes | No | SD Pin |
UCC28633D | Yes | No | Yes | Yes | VSENSE Pin |
UCC28634D | No | No | Yes | Yes | SD Pin |
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
CS | 3 | I | Current sense input |
DRV | 5 | O | Output drive pin for the external flyback MOSFET |
GND | 4 | G | Ground reference connection for all signals |
HV | 8 | P | High-voltage connection to the internal high-voltage start-up current source |
SD | 2 | I | Latching fault shutdown input pin. May be connected to an external temperature sensor |
VDD | 6 | P | Bias supply input pin to the device. Decoupled with a 1-µF ceramic bypass capacitor, connect directly across pins 6-4. Connect an additional hold-up capacitor charged from the transformer auxiliary bias winding to this pin. |
VSENSE | 1 | I | Sense pin for the flyback transformer bias and sense winding for output feedback regulation, output OVP, and input voltage sense/UV protection |