Linear Technology 1823B Manual

Description
Demonstration circuit 1823B features the ideal diode
bridge controller LT 4320
®
require high current AC to DC full-wave rectification or
DC polarity correction (see Table 2).
The LT4320 drives four N-channel MOSFETs to perform
full-wave rectification functionally similar to a diode bridge
but with much lower power dissipation. This topology eases
thermal design, and increases usable output voltage. In
addition, an all N-channel topology has benefits over a
P-channel topology such as a wider selection of MOSFETs,
lower cost, lower R
DS(ON)
Only a few essential components are required to oper-
ate the LT4320 as an ideal diode bridge: four N-channel
MOSFETs, a bypass ceramic capacitor, and an AC
performance summary
Table 1. DC Efficiency of the DC1823B at Various Load Currents
DC INPUT VOLTAGE (V)
20.004
20.005
20.006
suitable for applications that
, and smaller footprint.
DC OUTPUT VOLTAGE (V)
19.966
19.906
19.825
DEMO MANUAL DC1823B
Ideal Diode Bridge Controller
smoothing capacitor (C
very low R N-channel MOSFETs (2.5mΩ typical) to
DS(ON)
support high current applications. When an AC voltage
source is used, the onboard C
for up to 1.5A of average output current. Add additional
C capacitance to support higher current AC applica-
LOAD
tions. A unidirectional TVS (D1) is included to protect the
application from brief overvoltage events up to the part
rating. A footprint for bidirectional TVS (D3) is also included
and is recommended for electrically harsh conditions.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1823B
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
DC LOAD CURRENT (A)
10.008
20.013
30.012
LT4320
). The DC1823B includes four
LOAD
(C2) capacitor allows
LOAD
EFFICIENCY (%) (TYPICAL)
99.81
99.51
99.10
dc1823bfb
1