YB1683 Datasheet, PDF (5/9 Pages) YOBON TECHNOLOGIES,INC. – 3A 380KHz 28V PWM Buck DC/DC Converter

Function Block
YB1683
3A 380KHz 28V PWM Buck DC/DC Converter
Figure 3: Function Block
Functional Description
VIN
This is the positive input supply for the IC
switching regulator. A suitable input bypass
capacitor must be present at this pin to
minimize voltage transients and to supply
the switching currents needed by the
regulator.
Gnd
Circuit ground.
SW
Internal switch. The voltage at this pin
switches between (V_IN – V_GS) and
approximately – 0.5V, with a duty cycle of
approximately V_OUT / V_IN. To minimize
coupling to sensitive circuitry, the PC board
copper area connected to this pin should
be kept a minimum.
FB
Senses the regulated output voltage to
complete the feedback loop.
EN
Allows the switching regulator circuit to be
shutdown using logic level signals thus
dropping the total input supply current to
approximately 3 µA.Pulling this pin below a
threshold voltage of approximately 0.7 V
turns the regulator down, and pulling this
pin above 1.3V (up to a maximum of 12V)
shuts the regulator on.
For automatic star up condition, can be
implemented by the addition of a resistive
voltage divider from V_IN to GND.
YB1683 Rev.1.0
www.yobon.com.tw
5