DocID025078 Rev 1

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AN4345

Board testing

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4.3

Standby performance

As explained in Section 2, two different settings of the IC biasing are possible in the present

product evaluation board.

If low standby power loss is a priority, J1 should be selected; it connects diode D6 and

disables the HV current generator during steady-state operation. If standby loss is not the

main focus, the IC can be self-biased (by deselecting J1), saving the cost of the D6 diode.

The standby performance is shown in the figure below for both cases, with linear regulator

disconnected and a 15 V Zener diode across the 12 V output to avoid overvoltage in no load

conditions.

The highest line represents the consumption of the converter in those cases where diode

D6 is not assembled (IC self-biased), the lower line is the consumption of the converter with

diode D6 (IC externally biased).

Figure 17. No load consumption

4.4

Efficiency

The active mode efficiency is defined as the average of efficiency measured at 25%, 50%,

External power supplies (those contained in a separate housing from the end-use devices

they are powering) need to comply with the Code of Conduct, version 5 active mode

efficiency criterion, which, for a power throughput of 1.5 W, states the active mode efficiency

is higher than 67.4% (CoC5 Tier 1, entered into force in january 2014); this limit should

increase to 70% starting from january 2016 (CoC5 Tier 2).

DOE (department of energy) recommendation is another standard, whose active mode

efficiency requirement for the same power throughput is 69.9%.

The above requirements refer to single output converters and they do not apply to the

presented evaluation board, which has two outputs. However, due to the following setting,

this board can be evaluated as a single output converter:

•

power throughput of the board when loaded on both outputs)

•

AM13822V1

0

25

50

75

100

125

150

175

200

225

250

80

105

130

155

180

205

230

255

Vin[V]

external biasing

self biasing