YEV09T20 20A DC-DC POL Converter
4.5V to 13.8V Input 0.59V to 5.1V Output
Data Sheet
ZD-02093 Rev. 1.2, 18-Jun-10
www.power-one.com
Page 10 of 12
6.4
Remote Sense (Pins 7 and 8)
The remote sense feature compensates for the
voltage drop between the output pins of the POL
converter and the load. The SENSE- (Pin 8) and
SENSE+ (Pin 7) pins should be connected at the
load or at the point where regulation is required
(refer to Figure 21).
If remote sensing is not required, the SENSE pins
must be connected to the VOUT and GND pins
directly at the output of the POL converter.
Figure 21. Remote Sense Circuit Configuration
Because the sense leads carry minimal current,
large traces on the end-user board are not required.
The voltage sense traces should be located close to
a ground plane to minimize system noise.
When using remote sense, the output voltage at the
converter can be increased by up to 0.2V in order to
maintain the required voltage at the load. However,
the maximum output voltage measured directly
between the VOUT and GND pins shall not exceed
5.0V. In addition, it is the user’s responsibility to
ensure the POL converter’s actual output power
always remains at or below the maximum allowable
output power obtained from the derating curves.
6.5
Protections
6.5.1
Power Good (Pin 4)
Power Good pin (Pin 4) is an open drain output. The
Power Good pin is high when the output voltage is
within the regulation band. The Power Good pin is at
logic low during start-up, undervoltage, overvoltage
or overcurrent conditions, or when the POL converter
is disabled via the ON/OFF signal.
6.5.2
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.
6.5.3
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.
6.5.4
Output Overvoltage Protection
The POL converter is protected against overvoltage
on the output. If the output voltage is higher than
115% of its nominal value set by the RTRIM, the high
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 22.
Figure 22. Test Setup For Measuring Input Reflected-Ripple
Current And Output Voltage Ripple
8.
Safety
The YEV09T20-0 POL converters do not provide
isolation from input to output. The input devices
powering
YEV09T20-0
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.
Vin
VIN
GND
ON/OFF
YEV09T20
VOUT
3
6
1
5
PGOOD
4
TRIM
2
SENSE+
7
Rload
SENSE-
8
RW
Vout
V source
22
F
ceramic
capacitor
1
H
DC/DC
Converter
100 F
tantalum
+2x10F
ceramic
CIN
YEV09T20