International Rectifier SupIRBuck IRDC3863, SupIRBuck IRDC3865 User Manual
IRDC3863
SupIRBuck
TM
USER GUIDE FOR IRDC3863 EVALUATION BOARD
DESCRIPTION
TM
The IR3863 SupIRBuck
fully integrated and highly efficient DC/DC
voltage regulator. The onboard constant on
time hysteretic controller and MOSFETs make
IR3863 a space-efficient solution that delivers
up to 6A of precisely controlled output voltage
in a 4mm x 5mm QFN package.
In addition to excellent light load and full load
efficiency, the IR3863 offers features such as:
a 0.5V reference, programmable switching
frequency, temperature compensated over
current protection, thermal shutdown and
optional forced continuous conduction mode.
is an easy-to-use,
Additional features include: pre-bias startup,
soft start, power good output, enable input with
voltage monitoring capability and over/under
voltage protection, making the device a very
flexible solution that is suitable for a broad
range of applications.
This user guide contains the schematic, bill of
materials, and operating instructions of the
IRDC3863 evaluation board. Detailed product
specifications, application information and
performance curves at different operating
conditions are available in the IR3863 data
sheet.
BOARD FEATURES
• V
= +12V
IN
• V
• V
• I
• F
= +5V
CC
= +1.05V
OUT
= 0 to 6A
OUT
= 300kHz @ CCM
S
• L = 2.2µH
• C
• C
= 22µF
IN
= 47µF (ceramic 0805) + 150µF (PC-CON)
OUT
(ceramic 1210) + 68µF (electrolytic)
1
IRDC3863
CONNECTIONS and OPERATING INSTRUCTIONS
An input supply in the range of 7 to 16V should be connected from VIN to PGND. A maximum load
of 6A may be connected to V
and PGND. The connection diagram is shown in Fig. 1,
OUT
inputs and outputs of the board are listed in Table 1.
IRDC3863 has two input supplies, one for biasing (VCC) and the other for input voltage (VIN).
Separate supplies should be applied to these inputs. VCC
5.5V supply connected to VCC and PGND. Enable (EN) is controlled
input should be a well regulated 4.5V to
by the first switch of SW1, and
FCCM option can be selected by the second switch of SW1. Toggle the switch to the ON position
(marked by a solid square) to enable switching or to select FCCM. The absolute maximum voltage
of the external signal applied to EN (TP4) and FCCM is +8V.
Table 1. Connections
Connection Signal Name
VIN (TP2) VIN
PGND (TP5) Ground for VIN
and the
VCC (TP16) VCC Input
PGND (TP17) Ground for VCC Input
VOUT (TP7) V
PGND (TP10) Ground for V
EN (TP4) Enable Input
OUT
(+1.05V)
OUT
LAYOUT
The PCB is a 4-layer board. All layers are 1 oz. copper.
on the top and bottom layers of the board.
The power supply decoupling capacitors, bootstrap capacitor and feedback components are located
close to IR3863. To improve efficiency, the circuit board is designed to minimize the length of the onboard power ground current path.
IR3863 and other components are
mounted
2
CONNECTION DIAGRAM
IRDC3863
Control Switch for:
EN
FCCM
GROUND
VCC = +5.0V
VIN
GROUND
VOUT = +1.05V
Fig. 1: Connection Diagram of IRDC3863 Evaluation Board
GROUND
3
PCB Board Layout
IRDC3863
Fig. 2: Board Layout, Top Components
Fig. 3: Board Layout, Bottom Components
4
PCB Board Layout
IRDC3863
Fig. 4: Board Layout, Top Layer
Fig. 5: Board Layout, Bottom Layer
5
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