iW1696

Low-Power Off-line Digital Green-Mode PWM Controller

iW1696

10 mA to 31 mA, and is dynamically controlled according to

the power supply load change. The higher the output power,

the higher the base current. Specifically, the base current is

related to V

0

5

10

15

20

25

30

35

0.1

0

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1

Figure 9.5: Base Drive Current vs. V

IPK

9.12 Cable Drop Compensation

The iW1696 incorporates an innovative method to

compensate for any IR drop in the secondary circuitry

including cable and cable connector. A 2.5 W adapter with

5 V DC output has 3% deviation at 0.5 A load current due to

the drop across a 24 AWG, 1.8 meter DC cable without cable

compensation. The iW1696 compensates for this voltage

drop by providing a voltage offset to the feedback signal

based on the amount of load current detected.

To calculate the amount of cable compensation needed, take

the resistance of the cable and connector and multiply by the

maximum output current.