Mar12-07 RevD

SP7663 Evaluation Board Manual

©2007 Sipex Corp.

Page 3 of 16

Adjusting the current downwards is controlled by adjusting R8.













•

•

+

⋅

=

DCR)

(Imax

-

60mV

DCR)

(Imax

60mV)

-

(Vout

R8

4

R

Equation 3

Where:

DCR is the Inductor winding resistance

is the desired output current

Further details on the current limit can be found in the SP7663 data sheet.

POWER SUPPLY DATA

The SP7663ER is designed with an accurate 2.0% reference over line, load and

temperature. Figure 1 data shows a typical SP7663 evaluation board efficiency plot, with

efficiencies up to 90% and output currents up to 6A. The output voltage ripple of less

than 50mV at full load and the LX node are shown in figure 2. Figures 3 and 4 illustrate a

3A-to-6A and 0A-to-6A Load Step. Short circuit and current limit are shown in Figures 5

and 6. Typical startup characteristics into a full load and no load are shown in figure 7

While data on individual power supply boards may vary, the capability of the

SP7663ER of achieving high accuracy over a range of load conditions shown here is

quite impressive and desirable for accurate power supply design.

SP7663 Efficiency

12Vin - 3.3Vout - 6Amp

70.00

75.00

80.00

85.00

90.00

95.00

0.00

1.00

2.00

3.00

4.00

5.00

6.00

Iout (Amps)

Figure 1. Efficiency vs. Load