ZM7300G Series Digital Power Manager
Data Sheet
10.4.4 IBV Monitoring
The DPM continuously monitors the intermediate bus voltage via the IBVS input and the built-in 10-bit
ADC. The digital representation of the bus voltage is stored in RAM and reported in the IBS Monitoring
window shown in Figure 11.
In addition, the DPM continuously compares the value of IBV to the Undervoltage and Overvoltage
thresholds programmed in the GUI Intermediate Bus Configuration Window shown in Figure 12.
Figure 12. Intermediate Bus Configuration Window
The thresholds have a symmetric, fixed size hysteresis as shown in Figure 13
Figure 13: Undervoltage (IBL) and Overvoltage (IBH) Protections Hysteresis
When the IBV decreases below the IBL threshold minus the hysteresis, the DPM will pull OK lines low
turning off all POL converters. The POL converters will execute regular turn-off ramping their output
voltages down according to the turn-off delay and falling slew rate settings. In addition, the DPM will
clear all bits in the POL Programming Status registers and save the content of the Run Time Counter
into the non-volatile memory. The IBV Low bit in the IBS Monitoring Window will change to red. When
the IBV recovers above the IBL threshold plus the hysteresis, the DPM will first program all POL
ZD-00896 Rev. 5.1, 13-Jul-10
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