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Enpirion Power Datasheet ES1022SI Adjustable Quad Sequencer

May 2014

Altera Corporation

Application Recommendations

Coupling from the EN_X pins to the sensitive UV and OV pins can cause false OV/UV events to be detected. This is

relevant due to the EN_A and OV pins being adjacent. This coupling can be reduced by adding a ground trace

between UV and the EN/FAULT signals, as shown in Figure 14. The PCB traces on OV and UV should be kept as small

as practical and the EN_X and FAULT traces should ideally not be routed under/over the OV/UV traces on different

PCB layers unless there is a ground or power plane in between. Other methods that can be used to eliminate this issue

are by reducing the value of the resistors in the network connected to UV and OV (R2, R3, R5 in Figure 15) or by

adding small decoupling capacitors to OV and UV (C2 and C7 in Figure 15). Both these methods act to reduce the AC

impedance at the nodes, although the latter method acts to filter the signals which will also cause an increase in the

time that a UV/OV fault takes to be detected

.

When the ES1022SI is implemented on a hot swappable card that is plugged into an always powered passive back

capacitor the addition of a small series R (>50

Ω) to provide a time constant >50μs is all that is necessary.

FIGURE 14. LAYOUT DETAIL OF GND BETWEEN PINS 4 AND 5

PIN 4

PIN 5

GND

10037

May 28, 2014

Rev A