LP2950-xx/LP2951-xx
APPLICATION HINTS
(Continued)
+V
IN
OUTPUT
VOLTAGE
4.75V
100k
ERROR*
ERROR
OUPUT
**SHUTDOWN
INPUT
5 ERROR*
3
8
+V
IN
V
OUT
1
V
OUT
1.2
30V
LP2951
SD
GND
4
FB
7
R
1
INPUT
VOLTAGE
1.3V
5V
* +
.01
μF
3.3μF
1.23V
V
REF
R
2
FIGURE 1. ERROR Output Timing
*When V
IN
1.3V the error flag pin becomes a high impedance,
and the error flag voltage rises to its pull-up voltage. Using V
out
as the pull-up voltage (see Figure 2), rather than an external 5V
source, will keep the error flag voltage under 1.2V (typ.) in this
condition. The user may wish to drive down the error flag
voltage using equal value resistors (10 k suggested), to ensure
a low-level logic signal during any fault condition, while still
allowing a valid high logic level during normal operation.
FIGURE 2. Adjustable Regulator
*See Application Hints.
V
out
= V
REF
×
(1 + R
1
/ R
2
)
**Drive with TTL- high to shut down. Ground or leave if shutdown
feature is not used.
Note:
Pins 2 and 6 are left open.
TYPICAL APPLICATIONS
300 mA Regulator with 0.75 Dropout
UNREGULATED
INPUT
8
IN
LP2951
6
V
TAP
FB
7
SENSE
GND
4
2
4.7μF
OUT
1
330Ω
27kΩ
5V OUTPUT
LOAD
50mA TO
300mA
2N5432 (2)
Wide Input Voltage Range Current Limiter
+V
IN
8
+V
IN
ERROR
OUPUT
5
ERROR
LP2951
V
OUT
1
*V
OUT
≈
V
ΙΝ
SHUTDOWN 3
SD
INPUT
GND
4
FB
7
*Minimum Input-Output voltage ranges from 40mV to 400mV, depending on load
current. Current limit is typically 160 mA
:
ADD.: RM. 4004,
88
BLOCK B,
B
4004
,
:210008
(TEL.): (86)-25-68853600
(FAX): (86)-25-68853600-810
WEB-SITE: WWW.HN-ELEC.COM
NEW WORLD CENTRE,
NO. 88 ZHUJIANG ROAD,
9
NANJING 210008,
CHINA
HN [ NANJING HONANO ELECTRONIC CO., LTD. ]
