YEV09T10 10A DC-DC POL Converter

Data Sheet

ZD-02092 Rev 1.1, 25-Mar-09

www.power-one.com

Page 10 of 12

6.4

Protections

6.4.1

Input Undervoltage Lockout

The POL converter will shut down when the input

voltage drops below a predetermined voltage. It will

start automatically when the input voltage exceeds

the specified threshold.

6.4.2

Output Overcurrent Protection

The POL converter is protected against overcurrent

and short circuit conditions.

Upon sensing an

overcurrent condition, the POL converter will enter

hiccup mode of operation. Once the overload or

short circuit condition is removed, the POL converter

will automatically restart and Vout will return to its

nominal value.

6.4.3

Output Overvoltage Protection

The POL converter is protected against overvoltage

on the output. If the output voltage is higher than

side MOSFET will be immediately turned off and the

low side MOSFET will be turned on.

The POL

converter will remain in the state until the output

voltage reduces below 115% of its nominal value. At

that point the POL converter will automatically

restart.

7.

Characterization

7.1

Ripple and Noise

The output voltage ripple and input reflected ripple

current waveforms are measured using the test

setup shown in Figure 21.

Figure 21. Test Setup For Measuring Input Reflected-Ripple

Current And Output Voltage Ripple

8.

Safety

The YEV09T10 POL converters do not provide

isolation from input to output. The input devices

powering YEV09T10 must provide relevant isolation

requirements according to all IEC60950 based

standards. Nevertheless, if the system using the

converter needs to receive safety agency approval,

certain rules must be followed in the design of the

system.

In particular, all of the creepage and

clearance requirements of the end-use safety

requirements

must

be

observed.

These

requirements are included in UL60950 - CSA60950-

00 and EN60950, although specific applications may

have other or additional requirements.

The YEV09T10 POL converters have no internal

fuse.

If required, the external fuse needs to be

provided to protect the converter from catastrophic

failure. Refer to the “Input Fuse Selection for DC/DC

for proper selection of the input fuse. Both input

traces and the chassis ground trace (if applicable)

must be capable of conducting a current of 1.5 times

the value of the fuse without opening.

To comply with safety agencies’ requirements, a

recognized fuse must be used in series with the input

line. The fuse must not be placed in the grounded

input line. Abnormal and component failure tests

were conducted with the POL input protected by a

fast-acting 25A fuse. If a fuse rated greater than 25A

is used, additional testing may be required.

The maximum DC voltage between any two pins is

Vin under all operating conditions. In order for the

output of the YEV09T10 POL converter to be

considered as SELV (Safety Extra Low Voltage),

according to all IEC60950 based standards, the input

to the POL needs to be supplied by an isolated

secondary source providing a SELV also.

Vout

V source

22

F

ceramic

capacitor

1H

DC/DC

Converter

100 F

tantalum

+2x10F

ceramic

YEV09T10