SPX1117M3-1.5 Ver la hoja de datos (PDF) - Signal Processing Technologies
Número de pieza
componentes Descripción
Fabricante
SPX1117M3-1.5 Datasheet PDF : 15 Pages
| |||
APPLICATION INFORMATION: Continued
TABLE 1
PC BOARD
mm2
2500
2500
2500
2500
2500
1600
2500
2500
1600
900
900
TOPSIDE COPPER BACKSIDE COPPER
mm2
2500
1250
950
2500
1800
600
1250
915
600
240
240
mm2
2500
2500
2500
0
0
1600
0
0
0
900
0
THERMAL RESISTANCE
JUNC. TO AMB.
°C/W
46
47
49
51
53
55
58
59
67
72
85
Output Voltage
The output of the adjustable regulator can be set
to any voltage between 1.25V and 15V. The
value of V can be quickly approximated using
OUT
the formula
VOUT = VREF(1+ (R2/R1)) + IADJ * R2,
where
V =1.25V.
REF
VOUT=1.25 *(R1 + R2)/R1.
A small correction to this formula is required
depending on the values of resistors R and R ,
1
2
since the adjustable pin current (approx 50µA)
flows through R2. When IADJ is taken into ac-
count, the formula becomes
Layout Considerations
Parasitic line resistance can degrade load regu-
lation. In order to avoid this, connect R directly
1
to V as illustrated in Figure 25. For the same
OUT
reason, R should be connected to the negative
2
side of the load.
V IN
IN
4.7µF + C 1
SPX1117
ADJ
IOUT =
VREF
R1
OUT
VOUT
C2
R1
IOUT
LOAD
VIN
IN
4.7µF + C1
SPX1117
ADJ
I ADJ
50µA
VOUT = V REF (1+R 2 /R1) +IADJ R 2
OUT
VREF R1
VOUT
C2
R2
Figure 21. Current Source
Figure 22. Typical Adjustable Regulator
Date: 8/25/04
SPX1117 800mA Low Dropout Voltage Regulator
8
© Copyright 2004 Sipex Corporation
Share Link: 