Mar 12, 2003
TEL: 886-3-5788833
http://www.gmt.com.tw
1
EV2995-10
Global Mixed-mode Technology
G2995 Evaluation Board Manual
Introduction
The G2995 evaluation board is designed to provide the design engineer with a fully functional prototype system
in which to evaluate the G2995 in both a static environment and with a complete memory system. It is one version
of the board, which SOP-8L(FD) is used. The application note contains information regarding the board,for more in-
formation regarding the G2995 please refer to the datasheet.
Schematic
The following schematic was used to create the layout.
Bill of Material
Name Qty Value
Description
Manufacturer
Model
Number
U1
1
G2995 DDR Linear Regulator
Global Mixed-mode Tech-
nology
http://www.gmt.com.tw
G2995
C3, C5
2
330uf 6.3V POSCAP Series
SANYO
6TPD330M
C6
1
68uf
6.3V POSCAP Series
SANYO
6TPB68M
C1, C2
2
0.1uf
0603 Ceramic Capacitor X7R 6.3V TDK
1068X7R1H104K
Application
The G2995 evaluation board can be used immediately in either a static test environment to check functionality
or in a memory termination scheme on a motherboard. In either implementation the following steps should be
taken to ensure correct operation.
1. Correct leads from the evaluation board. The board layout has been designed to allows sockets to be directly sol-
dered.
2. AVIN and PVIN should be connected to a 2.5V power supply.
3. The VDDQ input provides the internal divide by two reference voltage. Both VREF and VTT will track this
internal voltage, nominally a 2.5V will be applied.
4. The VREF pad is the output for the VREF from the G2995 after being bypassed by a ceramic capacitor.
This can be connected either to a multi-meter for confirmation or directly to the memory controller and DIMMS.
5. The remaining two pads are for the force and sense leads of the VTT output. These should be connected
directly to the termination plane or a multi-meter if interested in verification. The output will be regulated where the
VSENSE leads connect to the VTT leads permitting the connection to a motherboard without suffering from large
resistance drops.
Mar 12, 2003
TEL: 886-3-5788833
http://www.gmt.com.tw
2
EV2995-10
Global Mixed-mode Technology
Performance
The following series of scope plots shows the performance of the G2996 evaluation board when it is subjected
to various load tests. On each of the six scope plots there are two traces. The upper trace is the
V
TT
output
voltage that has been AC coupled with a scale of 20mV per division. The lower trace is the output current with
a scale of 500mA per division. All the load transients begin from an initial condition of zero current and show
magnitude. Please refer to the title to determine whether the current flow is into (sinking) or out from (sourcing)
the
V
TT
pin. The time scale for all the plots is 2mS per division.
I
Load=0.5A Transient(Sinking)
I
Load=1A Transient (Sinking)
I
Load=1.5A Transient (Sinking)
I
Load=0.5A Transient(Sourcing)
I
Load=1A Transient(Sourcing)
I
Load=1.5A Transient(Sourcing)
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