ZY7007 Datasheet, PDF (18/35 Pages) Power-One – 7A DC-DC Intelligent POL 3V to 14V Input - 0.5V to 5.5V Output

ZY7007 7A DC-DC Intelligent POL Data Sheet
3V to 14V Input • 0.5V to 5.5V Output
8.1.1 Output Voltage Setpoint
The output voltage programming range is from 0.5V
to 5.5V. Within this range, there are 256 predefined
voltage setpoints. To improve resolution of the
output voltage settings, the voltage range is divided
into three sub-ranges as shown in Table 2.
Table 2. Output Voltage Adjustment Resolution
V_{OUT MIN}, V
V_{OUT MAX}, V
Resolution, mV
0.500
2.000
12.5
2.025
5.25
25
5.3
5.5
50
8.1.2 Output Voltage Margining
If the output voltage needs to be varied by a certain
percentage, the margining function can be utilized.
The margining can be programmed in the GUI
Output Configuration window or directly via the I²C
bus using high level commands as described in the
‘”DPM Programming Manual”.
In order to properly margin POLs that are connected
in parallel, the POLs must be members of one of the
Parallel Buses. Refer to the GUI System
Configuration Window shown in Figure 53.
8.1.3 Optimal Voltage Positioning
Optimal voltage positioning increases the voltage
regulation window by properly positioning the output
voltage setpoint. Positioning is determined by the
load regulation that can be programmed in the GUI
Output Configuration window shown in Figure 25 or
directly via the I²C bus by writing into the CLS
register shown in Figure 36.
Figure 27 illustrates optimal voltage positioning
concept. If no load regulation is programmed, the
headroom (voltage differential between the output
voltage setpoint and a regulation limit) is
approximately half of the voltage regulation window.
When load regulation is programmed, the output
voltage will decrease as the output current
increases, so the VI characteristic will have a
negative slope. Therefore, by properly selecting the
operating point, it is possible to increase the
headroom as shown in the picture.
VOUT
Upper Regulation
Limit
Operating
Point
VI Curve Without
Load Regulation
Lower Regulation
Limit
VI Curve With
Load Regulation
Headroom without
Load Regulation
Headroom with
Load Regulation
Light
Load
IOUT
Heavy
Load
Figure 27. Optimal Voltage Positioning Concept
Increased headroom allows tolerating larger voltage
deviations. For example, the step load change from
light to heavy load will cause the output voltage to
drop. If the optimal voltage positioning is utilized, the
output voltage will stay within the regulation window.
Otherwise, the output voltage will drop below the
lower regulation limit. To compensate for the voltage
drop external output capacitance will need to be
added, thus increasing cost and complexity of the
system.
The effect of optimal voltage positioning is shown in
Figure 28 and Figure 29. In this case, switching
output load causes large peak-to-peak deviation of
the output voltage. By programming load regulation,
the peak to peak deviation is dramatically reduced.
Figure 28. Transient Response without Optimal Voltage
Positioning
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