lt1529cq-trpbf Linear Technology Corporation, lt1529cq-trpbf Datasheet - Page 11

• Manufacturer Part Number: lt1529cq-trpbf
• Description: 3a Low Dropout Regulators With Micropower Quiescent Current And Shutdown
• Manufacturer: Linear Technology Corporation

PACKAGE DESCRIPTIO
A
In some applications it may be necessary to leave the input
to the LT1529 unconnected when the output is held high.
This can happen when the LT1529 is powered from a
rectified AC source. If the AC source is removed, then the
input of the LT1529 is effectively left floating. The reverse
output current also follows the curve in Figure 3 if the V
pin is left open. The state of the SHDN pin will have no
effect on the reverse output current when the V
floating.
When the input of the LT1529 is forced to a voltage below
its nominal output voltage and its output is held high, the
output current will follow the curve shown in Figure 3 . This
can happen if the input of the LT1529 is connected to a
discharged (low voltage) battery and the output is held up
by either a backup battery or by a second regulator circuit.
When the V
OUTPUT pin is pulled above the V
PPLICATI
IN
pin is forced below the OUTPUT pin or the
.080
O
(1.524)
FOR THICKER SOLDER PASTE APPLICATIONS
.060
.205
HATCHED AREA IS SOLDER PLATED
.320
RECOMMENDED SOLDER PAD LAYOUT
U
BOTTOM VIEW OF DD PAK
S
COPPER HEAT SINK
.067
(6.502)
(7.620)
I FOR ATIO
.256
.300
U
.420
.276
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of circuits as described herein will not infringe on existing patent rights.
IN
(1.524)
(1.905)
.075
.060
pin, the input current
(4.648)
W
.183
.042
U
.090
.325
.565
(1.524)
.060
TYP
(8.382 – 9.398)
(
3.632
.330 – .370
.143
+0.305
–0.508
U
+.012
–.020
IN
5-Lead Plastic DD Pak
(LTC DWG # 05-08-1461)
NOTE:
1. DIMENSIONS IN INCH/(MILLIMETER)
2. DRAWING NOT TO SCALE
pin is
)
Q Package
IN
(0.711 – 0.965)
.028 – .038
will typically drop to less than 2µA (see Figure 4). The state
of the SHDN pin will have no effect on the reverse output
current when the output is pulled above the input.
TYP
(9.906 – 10.541)
.390 – .415
(1.702)
.067
BSC
15° TYP
RECOMMENDED SOLDER PAD LAYOUT
5
4
2
1
0
3
0
V
V
OUT
OUT
.067
(4.191 – 4.572)
= 3.3V (LT1529-3.3)
= 5V (LT1529-5)
.165 – .180
Figure 4. Input Current
1
LT1529-3.3/LT1529-5
.420
(0.330 – 0.584)
.013 – .023
(1.499)
INPUT VOLTAGE (V)
.059
TYP
2
LT1529-3.3
.042
3
.090
.350
(1.143 – 1.397)
(
0.102
.045 – .055
(2.413 – 2.921)
.004
.565
(1.270 ± 0.305)
.095 – .115
.050 ± .012
LT1529-5
4
+0.203
–0.102
+.008
–.004
LT1529 • F04
Q(DD5) 0502
)
5
LT1529
11
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