User`s guide

Power and Cooling Systems
4.1.3 H7214 Power Regulator
The H7214 inputs 300V DC and +14V bias. A 30 kHz clock synchronizes
this to all other power components. Outputs are 130 A of +5V DC and 0.5
A of +13.5V DC for Ethernet transceivers. A green LED on the regulator
lights to indicate that the +5V output is present.
4.1.4 H7215 Power Regulator
The H7215 inputs 300V DC and outputs 20 A of –5V DC,7Aof–2VDC,4
A of +12V DC, and 2.5 A of –12V DC. A green LED on the regulator lights
to indicate that the outputs are present. An internal overtemperature
switch asserts the OVERTEMP signal when necessary, which causes an
orderly system shutdown.
4.1.5 H7242 Power Regulator
The H7242 inputs 300V DC and outputs 80 A of +3.3V DC and 0.5 A of
+13.5V DC for Ethernet transceivers. A green LED on the regulator lights
to indicate that the outputs are present.
4.1.6 XTC Power Sequencer
The XTC power sequencer contains:
• XMI reset timing control logic
• Time-of-year (TOY) clock power circuits
• EIA RS-232/RS-423-compatible console line driver and receiver
4.1.6.1 XMI Reset Timing Control Logic
The XMI reset timing control logic handles these sequences:
• Cold start power-up
• Warm start power-up
• Loss of AC power followed by a cold start power-up
• Reset, which mimics a power-down and then a cold start power-up
4.1.6.2 TOY Circuits
The TOY circuits consist of a battery charger circuit that trickle charges
the TOY clock battery and a voltage-level detection circuit that monitors
the TOY BBU battery voltage.
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