YV12T25 Datasheet, PDF (5/12 Pages) Power-One – YV12T25 DC-DC Converter

YV12T25 DC-DC Converter
10 - 14 VDC Input; 0.8 - 5.5 VDC Programmable @ 25 A
Operations
Input and Output Impedance
The YV-Series converter should be connected via a
low impedance to the DC power source. In many
applications, the inductance associated with the
distribution from the power source to the input of the
converter can affect the stability of the converter. It is
recommended to use low - ESR tantalum, POS or
ceramic decoupling capacitors (minimum 150 μF)
placed as close as possible to the converter input
pins in order to ensure stability of the converter and
reduce input ripple voltage. Internally, the converter
has 40 μF (low ESR ceramics) of input capacitance.
The YV12T25-0 has been designed for stable
operation with or without external output
capacitance.
It is important to keep low resistance and low
inductance PCB traces for connecting load to the
output pins of the converter in order to maintain good
load regulation.
SEQ/ENA (Pin 13)
The SEQ/ENA pin is used to turn the power
converter on or off remotely via a system signal. If
not using the remote ON/OFF, leave the pin open
(module will be on). The SEQ/ENA signal is
referenced to ground. The typical connections are
shown in Fig. A.
The converter is ON when the SEQ/ENA pin is at a
logic low or left open, and OFF when the SEQ/ENA
pin is at a logic high (3.5V min) or connected to Vin.
The external resistor R1 should be chosen to
maintain 3.5V minimum on the SEQ/ENA pin to
insure that the unit is OFF when Q1 is turned OFF.
Note that the external diode is required for proper
operation.
Data Sheet
Remote Sense (Pins 1 and 2)
The remote sense feature of the converter
compensates for voltage drops occurring between
the output pins of the converter and the load. The
SENSE(-) (Pin 2) and SENSE(+) (Pin 1) pins should
be connected at the load or at the point where
regulation is required (see Fig. B).
Fig. B: Remote sense circuit configuration.
Because the sense lead carries minimal current,
large trace on the end-user board are not required.
However, sense trace should be located close to a
ground plane to minimize system noise and ensure
the optimum performance.
When utilizing the remote sense feature, care must
be taken not to exceed the maximum allowable
output power capability of the converter, which is
equal to the product of the nominal output voltage
and the allowable output current for the given
conditions.
When using remote sense, the output voltage at the
converter can be increased up to 0.5 V above the
nominal rating in order to maintain the required
voltage across the load. Therefore, the designer
must, if necessary, decrease the maximum current
(originally obtained from the derating curves) by the
same percentage to ensure output power remains at
or below the maximum allowable output power.
Fig. A: Circuit configuration for ON/OFF function.
ZD-01983 Rev. 2.1, 25-Jun-10
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