NCP148

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11

configuration on the PCB, the board material, and the

ambient temperature affect the rate of junction temperature

rise for the part.

The maximum power dissipation the NCP148 can handle

is given by:

P

* T

A

q

JA

(eq. 1)

The power dissipated by the NCP148 for given

application conditions can be calculated from the following

equations:

P

(eq. 2)

Figure 38.

0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

80

90

100

110

120

130

140

150

160

0

100

200

300

400

500

600

700

Reverse Current

The PMOS pass transistor has an inherent body diode

Due to this fact in cases, where the extended reverse current

condition can be anticipated the device may require

additional external protection.

Power Supply Rejection Ratio

The NCP148 features very high Power Supply Rejection

ratio. If desired the PSRR at higher frequencies in the range

capacitor and proper PCB layout.

PCB Layout Recommendations

To obtain good transient performance and good regulation

device pins and make the PCB traces wide. In order to

minimize the solution size, use 0402 or 0201 capacitors with

appropriate capacity. Larger copper area connected to the

pins will also improve the device thermal resistance. The

actual power dissipation can be calculated from the equation

above (Equation 2). Expose pad can be tied to the GND pin

for improvement power dissipation and lower device

temperature.

ORDERING INFORMATION

Device

Nominal Output Voltage

Description

Marking

Rotation

Package

Shipping

NCP148AFCT180T2G

1.8 V

450 mA, Active

Discharge

T

270

°

567JZ

5000 /

Tape &

Reel

NCP148AFCT250T2G

2.5 V

V

0

°

NCP148AFCT255T2G

2.55 V

4

180

°

NCP148AFCT260T2G

2.6 V

V

90

°

NCP148AFCT270T2G

2.7 V

Y

0

°

NCP148AFCT280T2G

2.8 V

6

0

°