Mercury Green 320, Service Manual

Page: 17 / 85

17
DDR_VTT
Scope:
• This voltage is for the DDR DIMM Voltage for termination resistor
•
This is convert DDR_DIMM to 1.25V by LDO.
General characteristics:
Input voltage range Load/Line regulation Ripple
voltage
Maximum
load current
Efficiency
2.5V +5% ~ -5% 50mV 1.5 A 50%
• Over current protection (OCP): NO.
• Thermal protect: YES.
•
Short circuit protection: YES.
•
Turn on time: 100ms.
• Dynamic response: The voltage keeps 5% regulation when the load changing from 10% to 90%
• Operating temperature: 5 ° C to 35 ° C.
• Test condition and instruments:
9
Ripple & Noise: Measuring with bypass capacitors 0.1uf/10uf at output terminal and oscilloscope time-base set at
20MHz. (Tested by the oscilloscope and refer to figure 1.)
9
Input voltage set at 2.5V. (DC Power supply)
9
Electronic load: Chroma 63030 or Equivalent
9
Multimeter: FLUKE 87 or Equivalent
9
All measuring refer to figure 2.
+5V
GND
0.1U
10U
PROBE
GND
Figure 1.
DC
POWER
SUPPLY
DC/DC
CONVERTER
ELE.
LOAD
A
V V
A
GND
Figure 2.