Global Mixed-mode Technology Inc.
Layout Guide
An input capacitance of
≅
1
µ
F is required between the
G923 input pin and ground (the amount of the capaci-
tance may be increased without limit), This capacitor
must be located a distance of not more than 1cm from
the input and return to a clean analog ground.
G923
Input capacitor can filter out the input voltage spike
caused by the surge current due to the inductive effect
of the package pin and the printed circuit board’s rout-
ing wire. Otherwise, the actual voltage at the IN pin
may exceed the absolute maximum rating.
The output capacitor also must be located a distance
of not more than 1cm from output to a clean analog
ground. Because it can filter out the output spike
caused by the surge current due to the inductive effect
of the package pin and the printed circuit board
’
s rout-
ing wire. Figure 6 is adjustable mode of G923 PCB
layout. Figure 7 is a PCB layout of G923 fixed mode.
Figure 3. Recomme nded Minimum Footprint
Safe Operating Area of G923 [ Power Diss ipation Limit]
200
Maximum Recommended Outp ut Curren t
Maximum Power Dissipation of SOT-23-5
0.7
Still Air
Air
St ill
0.6
0.5
TA=25℃
Power Dissipation (W)
0.4
0.3
0.2
0.1
0
1oz Copper on SOT-23-5
Package
1oz copper on SOT-23-5
Package
Mount ed on rec omm end mim imum f oot print (R JA=240°C/W
Mounted on recommended foorprint (R?
JA
=240°C/W)
θ
150
Output C
urrent (mA)
)
100
TA=55℃
TA=85℃
50
T
A
=25°C,Still Air
1oz Copper on SOT
-23-5 Package
Mounted on recommended mimimum footprint (R
θ
JA=240
°
C/ W)
Figure 4 Safe Operating Area
0
0.0
0 .5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
25
35
45
55
65
75
85
95
105
115
125
Input-Output Voltage Differential V
I N
-V
OUT
(V)
Note : V
IN(m ax )
<=5.5V
Amibent Temperature T
A
T
(°C)
Amibent T emperature
A
(°C)
Figure 4 Safe O perating Area
Figure 5 Power Dissipation vs. Tem perature
Figure 6. Adjustable Mode
*Distance between pin & capacitor must no more than 1cm
Figure 7. Fixed Mode
*Distance between pin & capacitor must no more than 1cm
Ver: 1.1
Jan 19, 2006
TEL: 886-3-5788833
http://www.gmt.com.tw
8
INTERPOINT [ INTERPOINT CORPORATION COMPANY ]
