Sample Circuit That Makes Use of VBIAS (2)
LA5683T
This IC can be used to implement the circuit that is shown below since the power to the channels 3 and 4 output stages
is supplied via VBIAS.
Apply the power voltage to VBIAS through the path that is made up of VCC, L to Schottky diode (through path formation).
Then feed the stabilized voltage VO3 that is raised to 3.3V in channel 3 to VBIAS.
A voltage of approx. VBIAS3-1 volt develops at VOUT3, so that the IC can drive MOS transistors in a low-voltage
environment like this sample circuit.
VBIAS
Fed to VBIAS
Schottky barrier diode
VCC
L
OUT3
VO3=3.3V
SW
VOUT3
MCH3409
to IN3−
VBIAS Circuit Example 2
Using the IC in a Step-down Circuit (CH1 and CH2)
The IC detects a short-circuit condition and activates the SCP when VCC falls below the preset voltage VO+VF in such
a step-down application as the one shown below.
VCC
OUT
VF (diode forward voltage)
VO1
VO1
VF
IN+
VCC
SCP activated
1.8V
VCC
When stepping down VCC<V0+VF
No.8214-11/12