Datasheet

February 2012 Doc ID 2572 Rev 31 1/41
41
LD1117xx
Adjustable and fixed low drop positive voltage regulator
Features
Low dropout voltage (1 V typ.)
2.85 V device performances are suitable for
SCSI-2 active termination
Output current up to 800 mA
Fixed output voltage of: 1.2 V, 1.8 V, 2.5 V,
3.3 V, 5.0 V
Adjustable version availability (V
REF
= 1.25 V)
Internal current and thermal limit
Available in ± 1 % (at 25 °C) and 2 % in full
temperature range
Supply voltage rejection: 75 dB (typ.)
Description
The LD1117 is a low drop voltage regulator able
to provide up to 800 mA of output current,
available even in adjustable version (V
REF
=
1.25 V). Concerning fixed versions, are offered
the following output voltages: 1.2 V, 1.8 V, 2.5 V,
2.85 V, 3.3 V and 5.0 V. The 2.85 V type is ideal
for SCSI-2 lines active termination. The device is
supplied in: SOT-223, DPAK, SO-8 and TO-220.
The SOT-223 and DPAK surface mount packages
optimize the thermal characteristics even offering
a relevant space saving effect. High efficiency is
assured by NPN pass transistor. In fact in this
case, unlike than PNP one, the quiescent current
flows mostly into the load. Only a very common
10 µF minimum capacitor is needed for stability.
On chip trimming allows the regulator to reach a
very tight output voltage tolerance, within ± 1 % at
25 °C. The adjustable LD1117 is pin to pin
compatible with the other standard. Adjustable
voltage regulators maintaining the better
performances in terms of drop and tolerance.
DPAK
SO-8
TO-220
SOT-223
Table 1. Device summary
Part numbers
LD1117XX12 LD1117XX25 LD1117XX50
LD1117XX12C LD1117XX25C LD1117XX50C
LD1117XX18 LD1117XX33 LD1117XX
LD1117XX18C LD1117XX33C LD1117XXC
www.st.com

Summary of content (41 pages)