ZHCSJY8E june 2019 – february 2021 UCC256402 , UCC256403 , UCC256404
PRODUCTION DATA
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
BLK | 4 | I | This pin is used to sense the LLC stage input voltage level. A resistor divider should be used to attenuate the signal before it is applied to this pin. The voltage level on this pin will determine when the LLC converter starts/stops switching. |
BW | 8 | I | This pin is used to sense the output voltage through the bias winding. The sensed voltage is used for output over voltage protection. During startup, the pin is also used to program the ratio between the two burst mode thresholds (BMTL and BMTH). |
FB | 5 | I | LLC stage control feedback input. The amount of current sourced from this pin will determine the LLC input power level. |
GND | 11 | G | Ground reference for all signals. |
HB | 14 | I | High-side gate-drive floating supply voltage. The bootstrap capacitor is connected between this pin and HS pin. A high voltage, high speed diode should be connected from RVCC to this pin to supply power to the high-side gate-driver during the period when the low-side MOSFET is conducting. |
HO | 15 | O | High-side floating gate-drive output. |
HS | 16 | I | High-side gate-drive floating ground. Current return for the high-side gate-drive current. |
HV | 1 | I | Connects to internal HV startup JFET. For UCC256402 and UCC256404, this pin provides start up power for both PFC and LLC stage. This pin also monitors the AC line voltage for x-capacitor discharge function. For UCC256403, this pin needs to be connected to ground. |
ISNS | 6 | I | Resonant current sense. The resonant capacitor voltage is differentiated with a first order filter to measure the resonant current. |
LL/SS | 9 | I | The capacitance value connected from this pin to ground will impact the duration of the soft-start period. The resistor divider connected to the pin will define the initial voltage applied on the pin for startup. After system startup, this pin is used to program the burst mode threshold. |
LO | 10 | O | Low-side gate-drive output. |
Removed | 2 | N/A | Functional creepage and clearance |
Removed | 13 | N/A | Functional creepage and clearance |
RVCC | 12 | P | Regulated 13-V supply. This pin is used to supply the gate driver and PFC controller. |
VCC | 3 | P | Supply input. |
VCR | 7 | I | Resonant capacitor voltage sense. |