zm7100 Power-One, zm7100 Datasheet - Page 24

• Manufacturer Part Number: zm7100
• Description: Zm7100 Series Digital Power Manager
• Manufacturer: Power-One

When the IBV decreases below the IBV Low Threshold, the DPM will pull all OK lines low turning off all POL
converters. The POL converters will enter regular turn-off sequence. Contents of the Ring Buffer will be saved in
non-volatile memory. When the IBV recovers, the DPM will first reprogram all POL converters and then turn them
on, if the Auto Turn On is enabled in the GUI POL Group Configuration Window.
When the IBV exceeds the IBV High Threshold, the DPM will pull all OK lines low turning off all POL converters.
The POL converters will enter regular turn-off sequence. Contents of the Ring Buffer will be saved in non-volatile
memory. After a delay (typically 50ms), the DPM will turn off the front end. If the voltage does not decrease below
the threshold within the next 50ms, the DPM will trigger the crowbar protection. One second after clearing the IBV
High fault, the DPM will attempt to turn on the front end. If the IBV is within limits, the DPM will reprogram all POL
converters and then turn them on, if the Auto Turn On is enabled in the GUI POL Group Configuration Window.
10.4.2
The AC_Fail signal is generated by a main AC-DC source supplying 48V backplane voltage that in turn powers the
DC-DC Front End. Whenever the AC voltage disappears, the AC-Fail signal will be set low. If there is no battery
backup, it means the 48V will disappear after 20ms. When DPM receives the AC_Fail signal, it will pull all OK
lines low, turning off all POL converters. The POL converters will enter regular turn-off sequence. Contents of the
Ring Buffer will be saved in non-volatile memory. When the AC voltage recovers and the AC_Fail goes high, the
DPM will reprogram all POL converters and then turn them on, if the Auto Turn On is enabled in the GUI POL
Group Configuration Window.
10.5 Controls
10.5.1
The FE_EN pin is dedicated to the control of a DC-DC Front End. The Front End is typically used to convert the
48V into the intermediate bus voltage. If the DPM is powered from an auxiliary source, not from the IBV, it can
control the Front End.
When FE_EN is internally pulled up to 3V, the Front End is enabled. The FE_EN output can provide up to 10mA
of current. When the FE_EN goes below 0.5V, the Front End is disabled. The Front End can be enabled and
disabled via the GUI IBS Monitoring Window or directly via the I
The FE_EN pin should not be directly connected to the Front End Enable pin. Typically, the Enable pin is
referenced to the primary side of the Front End that is isolated from low voltage secondary side. In addition, the
Enable pin can be pulled up internally to a voltage potentially damaging to the DPM FE_EN output. The best
method is to interface the DPM with the Front End through an optocoupler as shown in Figure 22.
configuration provides interface for negative logic front ends. The 3.3k resistor was added between the FE_EN pin
and the ground to avoid a glitch during application of input voltage to the DPM.
REV. 4.0 JUL 28, 2006
Bit 7:0 IBL[7:0]: IBV low threshold
Full Scale = 14.19V
W/R-0
IBL7
Bit 7
00h = 0
01h = 1/256 of full scale voltage
02h = 2/256 of full scale voltage
FEh = 254/256 of full scale voltage
FFh = 255/256 of full scale voltage
AC_Fail Protection
Front End Enable
W/R-0
IBL6
W/R-0
IBL5
Figure 21. IBV Low Threshold Register IBL (left) and IBV High Threshold Register IBH
W/R-0
IBL4
W/R-0
IBL3
W/R-0
IBL2
www.power-one.com
W/R-0
IBL1
W/R-0
IBL0
Bit 0
ZM7100 Series Digital Power Manager
Bit 7:0 IBH[7:0]: IBV high threshold
Full scale = 14.19V
W/R-1
IBH7
Bit 7
2
C bus using high and low level commands.
00h = 0
01h = 1/256 of full scale voltage
02h = 2/256 of full scale voltage
FEh = 254/256 of full scale voltage
FFh = 255/256 of full scale voltage
W/R-1
IBH6
W/R-1
IBH5
W/R-1
IBH4
W/R-1
IBH3
W/R-1
IBH2
Page 24 of 29
Data Sheet
W/R-1
IBH1
W/R-1
IBH0
Bit 0
This