Datasheet

1
2
3
6
5
4
VS
GND
CS
CBC (00)
NTC (01)
VDD
DRV
DBV Package
(Top View)
UCC28700, UCC28701
UCC28702, UCC28703
www.ti.com SLUSB41 – JULY 2012
Table 2. TERMINAL FUNCTIONS
PIN
DESCRIPTION
NAME NO. I/O
CBC CaBle Compensation is a programming pin for compensation of cable voltage drop.
1 I
(UCC28700) Cable compensation is programmed with a resistor to GND.
Current Sense input connects to a ground-referenced current-sense resistor in series
with the power switch. The resulting voltage is used to monitor and control the peak
CS 4 I
primary current. A series resistor can be added to this pin to compensate the peak
switch current levels as the AC-mains input varies.
DRriVe is an output used to drive the gate of an external high voltage MOSFET
DRV 3 O
switching transistor.
The GrouND pin is both the reference pin for the controller and the low-side return for
the drive output. Special care should be taken to return all AC decoupling capacitors as
GND 5 —
close as possible to this pin and avoid any common trace length with analog signal
return paths.
NTC NTC is an interface to an external NTC (negative temperature coefficient) resistor for
1 I
(UCC28701/2/3) remote temperature sensing. Pulling this pin low shuts down PWM action.
VDD is the bias supply input pin to the controller. A carefully-placed bypass capacitor
VDD 2 —
to GND is required on this pin.
Voltage Sense is an input used to provide voltage and timing feedback to the controller.
This pin is connected to a voltage divider between an auxiliary winding and GND. The
VS 6 I
value of the upper resistor of this divider is used to program the AC-mains run and stop
thresholds and line compensation at the CS pin.
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