IRDC3802

Rev 0.1

6/16/2008

2

A well regulated +12V input supply should be connected to VIN+ and VIN-.

A maximum 4A load

should be connected to VOUT+ and VOUT-. The connection diagram is shown in Fig. 1 and inputs

and outputs of the board are listed in Table I.

IR3802 has two input supplies, one for biasing (Vcc) and the other as input voltage (Vin). These

inputs are connected on the board with a 330 ohm resistor (R13). Separate supplies can be applied

regulated 5V-12V supply and it would be connected to Vcc+ and Vcc-.

CONNECTIONS and OPERATING INSTRUCTIONS

Table I. Connections

Ground for Optional Vcc input

Vcc-

Optional Vcc input

Vcc+

V

VOUT+

Ground of V

out

VOUT-

Ground of V

in

VIN-

V

VIN+

Signal Name

Connection

LAYOUT

The PCB is a 4-layer board. All of layers are 2 Oz. copper. The IR3802A SupIRBuck and all of

the passive components are mounted on the bottom side of the board. The Inductor, Input and

Output Bulk Capacitors are located on the top side of the board.

Power supply decoupling capacitors, the charge-pump capacitor and feedback components are

located close to IR3802A. The feedback resistors are connected to the output voltage at the point

of regulation and are located close to the SupIRBuck.

To improve efficiency, the circuit board is designed to minimize the length of the on-board power

ground current path.