January 28, 2014

12

IDTP9167

Advanced Datasheet

DESIGN OF COMPONENTS

Suggested Components

Depending on the expected input and output voltage requirement for the application, the recommended inductor and output

capacitor values are provided in Table 7. These component values will nominally provide the best stability and transient

response. It is recommended that the 47µF output capacitors for all DPUs be clustered together at the point-of-load where the

feedback connection is, with the optional 10µF capacitor placed next to the DPU’s inductor to absorb ripple current.

VO (V)

PVIN (V)

L (µH)

CO (µF)

3.3

12 ± 10%

1.0

10 + 2 x 47

< 2V

5.6 to 12.6

0.47

10 + 2 x 47

Table 7 – Recommended component values

Component Selection

If deviation from the recommended components is desired to further optimize the regulator response for a specific application,

guidelines are provided in the following section to aid in the component selection process.

Inductor – L

L is the inductor connected to the switch node of the IDTP9167. The inductor physical size selection should consider its

temperature rise and current saturation for the expected operating conditions. The maximum current through the inductor is

typically 5.9A. The inductor value chosen should take into account ripple current consideration which can affect peak current

handling capability, efficiency and board EMI performance.

The inductor ripple current can be calculated from the following equation:

∆������������=������.������×������������������−������������������������������×������������������������������������������

where: L (µH) = Inductor value

VIN (V) = Input voltage

VOUT (V) = Output voltage

∆IL (A) = Inductor current ripple

For typical application as described in the EC table, the ripple current equates to 931mA(pp).

For an inductor current limit specification of 5.9A, this translates to a maximum load current capability of 5.44A.