DESCRIPTION

The UTC UCL1099 is a high-performance enhanced half-bridge

LLC resonant controller IC with high integration, high efficiency and

outstanding reliability.

The UTC UCL1099 regulates the output voltage by adjusting the

system operating frequency, and the operating frequency range can

be configured via external peripheral components connected to

dedicated pins. The device outputs two gate drive signals. The

high-side and low-side power switches turn on/off with a 180° phase

shift within one switching cycle. A fixed dead time is inserted

between the two non-overlapping drive signals to guarantee

soft-switching operation and superior high-frequency performance of

the power system.

An integrated soft-start circuit is implemented inside the chip. Upon power-up, the system starts at the pre-defined

maximum switching frequency, then the operating frequency gradually decreases until the control loop takes over

regulation. This mechanism effectively suppresses output voltage overshoot. The soft-start duration is configurable

through external peripheral components on the corresponding pin.

A high-side bootstrap charging diode with an equivalent series resistance of 100 Ω is integrated on-chip to

simplify system implementation. At light-load conditions, the controller operates in Burst mode to significantly cut

switching losses and boost light-load efficiency.

The UTC UCL1099 integrates comprehensive control and protection functions, including brown-in/brown-out

(BIBO) line voltage protection, two-stage overcurrent protection (OCP and AOCP), over-temperature protection

(OTP), as well as low-side and high-side under-voltage lockout protection (UVLO_LS, UVLO_HS).

Additionally, the chip incorporates an interface for communication with the PFC controller. It can rapidly disable

the PFC stage when abnormal operating conditions are detected, such as OCP triggering, the DIS pin being pulled

high, or operation under Burst mode.

FEATURES

* 700V high-side gate driver

* Integrated bootstrap charging diode

* 1.5A/2A source/sink capability for both high-side and low-side gate drivers

* Maximum operating frequency up to 600 kHz

* PFC interface

* Burst-mode operation at light-load

* Two-stage overcurrent protection with programmable OCP delay time

* Current hysteresis BIBO protection

* Programmable soft-start function

* Green & Pb Free