LD1117S18TR STMicroelectronics, LD1117S18TR Datasheet - Page 25

• Manufacturer Part Number: LD1117S18TR
• Description: IC REG LDO POS 800MA 1.8V SOT223
• Manufacturer: STMicroelectronics

Specifications of LD1117S18TR

• Regulator Topology: Positive Fixed
• Voltage - Output: 1.8V
• Voltage - Input: Up to 15V
• Voltage - Dropout (typical): 1.1V @ 800mA
• Number Of Regulators: 1
• Current - Output: 950mA
• Operating Temperature: 0°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: SOT-223 (3 leads + Tab), SC-73, TO-261
• Number Of Outputs: 1
• Polarity: Positive
• Input Voltage Max: 15 V
• Output Voltage: 1.8 V
• Output Type: Fixed
• Dropout Voltage (max): 1.1 V
• Output Current: 950 mA
• Line Regulation: 6 mV
• Load Regulation: 10 mV
• Voltage Regulation Accuracy: 1 %
• Maximum Power Dissipation: 12 W
• Maximum Operating Temperature: + 150 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Limit (min): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-7308-2; LD1117S18TR

LD1117xx
7
Figure 11. Adjustable output voltage application
Figure 12. Adjustable output voltage application with improved ripple rejection
LD1117 adjustable: application note
The LD1117 adjustable has a thermal stabilized 1.25 ± 0.012 V reference voltage between
the OUT and ADJ pins. I
R
V
In normal application R
be considered in the V
V
In order to have the better load regulation it is important to realize a good Kelvin connection
of R
ADJ pin, while R
Load pin. Ripple rejection can be improved by introducing a 10 µF electrolytic capacitor
placed in parallel to the R
OUT
OUT
1
is normally fixed to 120 Ω. From
1
= V
= V
and R
REF
REF
2
+ R
resistors. In particular R
(1 + R
2
2
ground connection must be placed as near as possible to the negative
(I
2
ADJ
/ R
OUT
2
+I
1
ADJ
value is in the range of few kΩ, so the R
).
2
R1
calculation; then the above expression becomes:
resistor (see
) = V
is 60 µA typ. (120 µA max.) and ΔI
Doc ID 2572 Rev 29
REF
Figure 10
+ R
1
connection must be realized very close to OUT and
Figure
2
(I
ADJ
we obtain:
11).
+V
REF
LD1117 adjustable: application note
/R
1
) = V
ADJ
REF
2
x I
is 1 µA typ. (5 µA max.).
(1 + R
ADJ
product could not
2
/ R
1
) + R
2
x I
25/42
ADJ
.