D12S2R550A Datasheet, PDF (7/11 Pages) Delta Electronics, Inc. – Non-Isolated Point of Load DC/DC Modules: 4.5V~13.8Vin, 0.6V~5.0Vout, 50A

DESIGN CONSIDERATIONS
FEATURES DESCRIPTIONS
The D12S2R550 uses a two phase and voltage mode
controlled buck topology. The output can be trimmed in the
range of 0.6Vdc to 5.0Vdc by a resistor from Trim pin to
Ground.
The converter can be turned ON/OFF by remote control.
Positive on/off (ENABLE pin) logic implies that the converter
DC output is enabled when the signal is driven high (greater
than 1.2V) or floating and disabled when the signal is driven
low (below 0.6V).
The converter provides an open collector Power Good signal.
The power good signal is pulled low when output is not within
±10% of Vout or Enable is OFF.
For output voltages above 1.8V, please refer to Figure 29
below for minimum input voltage requirement for proper
module operations.
The converter can protect itself by entering hiccup mode
against over current and short circuit condition.
Safety Considerations
It is recommended that the user to provide a fuse in the input
line for safety. The output voltage set-point and the output
current in the application could define the amperage rating of
the fuse.
5.5
Vo=5V
5.0
4.5
4.0
3.5
Vo=3. 3V
3.0
Vo=2. 5V
2.5
2.0
Vo=1. 8V
1.5
1.0
Vo=0. 6V
0.5
0.0
3.5 4.5 5.5 6.5 7.5 8.5 9.5 10.5 11.5 12.5 13.5 14.5
INPUT VOLTAGE(V)
Figure 25: minimum input voltage required for output
voltages above 1.8V
Enable (On/Off)
The ENABLE (on/off) input allows external circuitry to put the
D12S2R550 converter into a low power dissipation (sleep) mode.
Positive ENABLE is available as standard.
Positive ENABLE units of the D12S2R550 series are turned on if
the ENABLE pin is high or floating. Pulling the pin low will turn off
the unit. With the active high function, the output is guaranteed to
turn on if the ENABLE pin is driven above 1.2V. The output will
turn off if the ENABLE pin voltage is pulled below 0.6V.
Input Under-Voltage Lockout
The input under-voltage lockout prevents the converter from
being damaged while operating when the input voltage is too
low. The under-voltage lockout is adjustable by adding a resistor
(Figure 30) between Enable pin and ground pin per the following
equation:
Re n(K)  ³¹⁵
14Ven  3.8
Default lockout range is between 4.3V and 4.0V.
Unit
Vin
Vout
Enable Trim(+)
Ren
GND
GND
Figure 26: Enable input drive circuit example.
Reflected Ripple Current and Output Ripple and Noise
Measurement
The measurement set-up outlined in Figure 31 has been used for
both input reflected/ terminal ripple current and output voltage
ripple and noise measurements on D12S2R550 converters.
Input reflected current measurement point
Vin+
Ltest
DC-DC Converter
Cs
Cin
1uF
Ceramic
10uF
Tan
Load
Output voltage ripple noise measurement point
DS_D12S2R550_10182013
Cs=330μF OS-con cap x1, Ltest=1μH, Cin=330μF OS-con cap x1
Figure 27: Input reflected ripple/ capacitor ripple current and
output voltage ripple and noise measurement setup for
D12S2R550
7