LD2979
SERIES
VERY LOW DROP
VOLTAGE REGULATORS WITH INHIBIT
s
s
s
s
s
s
s
s
s
s
s
VERY LOW DROPOUT VOLTAGE
(0.2V TYP. AT 50mA LOAD)
VERY LOW QUIESCENT CURRENT
(TYP. 500µA AT 50mA LOAD)
OUTPUT CURRENT UP TO 50mA
LOGIC-CONTROLLED ELECTRONIC
SHUTDOWN
OUTPUT VOLTAGES OF 2.85; 3.0; 3.2; 3.3;
3.8; 5.0V
INTERNAL CURRENT AND THERMAL LIMIT
SUPPLY VOLTAGE REJECTION: 63dB (TYP)
ONLY 1µF FOR STABILITY
SELECTION AT 25°C
TEMPERATURE RANGE: -25°C TO 125°C
PACKAGE AVAILABLE: SOT23-5L AND
TO-92
SOT23-5L
DESCRIPTION
The LD2979 series are very Low Drop regulators
available in SOT23-5L and TO-92.
The very low drop-voltage and the very low
quiescent current make them particularly suitable
for low noise, low power applications and in
battery powered systems.
Shutdown Logic Control function is available on
five pin version (TTL compatible). This means that
TO-92
when the device is used as local regulator, it is
possible to put a part of the board in standby,
decreasing the total power consumption.
SCHEMATIC DIAGRAM
February 2003
1/10
LD2979 SERIES
ABSOLUTE MAXIMUM RATINGS
Symbol
V
I
V
INH
I
O
P
tot
T
stg
T
op
DC Input Voltage
DC Inhibit Input Voltage
Output Current
Power Dissipation
Storage Temperature Range
Operating Junction Temperature Range
Parameter
Value
16
V
IN
Internally limited
Internally limited
-40 to 150
-25 to 125
°C
°C
Unit
V
V
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is
not implied.
CONNECTION DIAGRAM
(top view)
SOT23-5L
TO-92
PIN DESCRIPTION
PIN NUMBER
SYMBOL
V
IN
GND
INHIBIT
NC
V
OUT
Input Voltage
Ground
Control Switch ON/OFF (*)
Not to be connected
Output Voltage
NAME AND FUNCTION
SOT23-5L
1
2
3
4
5
TO-92
3
2
1
(*) Only for the version in SOT23-5L package: Inhibit pin is not internally pulled-up then it must not be left floating. Connect to a positive
voltage higher than 2V to able the device.
ORDERING CODES
SOT23-5L (T&R)
LD2979M28TR
LD2979M30TR
LD2979M32TR
LD2979M33TR
LD2979M38TR
LD2979M50TR
TO-92
LD2979Z28
LD2979Z30
LD2979Z32
LD2979Z33
LD2979Z38
LD2979Z50
TO-92 (T&R)
LD2979Z28TR
LD2979Z30TR
LD2979Z32TR
LD2979Z33TR
LD2979Z38TR
LD2979Z50TR
TO-92 (Ammo Pack)
LD2979Z28AP
LD2979Z30AP
LD2979Z32AP
LD2979Z33AP
LD2979Z38AP
LD2979Z50AP
OUTPUT
VOLTAGES
2.85 V
3.0 V
3.2 V
3.3 V
3.8 V
5.0 V
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LD2979 SERIES
ELECTRICAL CHARACTERISTICS FOR LD2979
(refer to the test circuits, T
a
= 25°C, V
IN
=V
O(NOM)
+1V,
I
O
=1mA, V
INH
=2V
(*)
, C
O
= 1µF) (unless otherwise specified)
Symbol
V
O
V
O
V
O
V
O
V
O
V
O
I
out
∆V
O
I
d
Parameter
Output Voltage
Output Voltage
Output Voltage
Output Voltage
Output Voltage
Output Voltage
Output Current Limit
Line Regulation
V
IN
= V
O(NOM)
+1V to 16V, I
O
=
1mA
T
a
= -25 to 125
°C
80
T
a
= -25 to 125
°C
500
T
a
= -25 to 125
°C
0
T
a
= -25 to 125
°C
C
OUT
= 10µF
f = 120Hz
63
6
T
a
= -25 to 125
°C
30
T
a
= -25 to 125
°C
100
T
a
= -25 to 125
°C
200
T
a
= -25 to 125
°C
T
a
= -25 to 125
°C (*)
T
a
= -25 to 125
°C (*)
T
a
= -25 to 125
°C
C
O
= 10µF
2
0
5
160
-1
15
µV
12
18
60
90
200
300
400
600
0.18
V
V
µA
1
dB
mV
Test Conditions
V
IN
= 3.85 V
I
O
= 1 to 50mA
V
IN
= 4 V
I
O
= 1 to 50mA
V
IN
= 4.2 V
I
O
= 1 to 50mA
V
IN
= 4.3 V
I
O
= 1 to 50mA
V
IN
= 4.8 V
I
O
= 1 to 50mA
V
IN
= 6 V
I
O
= 1 to 50mA
T
a
= -25 to 125
°C
T
a
= -25 to 125
°C
T
a
= -25 to 125
°C
T
a
= -25 to 125
°C
T
a
= -25 to 125
°C
T
a
= -25 to 125
°C
Min.
2.793
2.736
2.940
2.880
3.136
3.072
3.234
3.168
3.724
3.648
4.9
4.8
100
0.028
0.064
110
170
700
1300
µA
µA
5
3.8
3.3
3.2
3
Typ.
2.85
Max.
2.907
2.964
3.060
3.120
3.264
3.328
3.366
3.432
3.876
3.952
5.1
5.2
mA
%/V
IN
V
V
V
V
V
Unit
V
Quiescent Current (On Mode) I
O
= 0
I
O
= 0
I
O
= 50mA
I
O
= 50mA
Quiescent Current (Off Mode) V
INH
< 0.18 V
(*)
V
INH
< 0.18 V
SVR
V
d
Supply Voltage Rejection
Dropout Voltage
I
O
= 50mA
I
O
= 0
I
O
= 0
I
O
= 1mA
I
O
= 1mA
I
O
= 10mA
I
O
= 10mA
I
O
= 50mA
I
O
= 50mA
V
IL
V
IH
I
I
eN
Inhibit Input Logic Low
Inhibit Input Logic High
Inhibit Input Current
Device Off
Device On
V
INH
= 0 V (*)
V
INH
= 5V
Output Noise Voltage (RMS)
BW= 300Hz to 50KHz
(*) Note: Only for types in SOT23-5L
3/10
LD2979 SERIES
TYPICAL CHARACTERISTICS
(unless otherwise specified T
a
= 25°C)
Figure 1 :
Output Voltage vs Temperature
Figure 4 :
Dropout Voltage vs Output Current
Figure 2 :
Output Voltage vs Input Voltage
Figure 5 :
Dropout Voltage vs Temperature
Figure 3 :
Output Voltage vs Input Voltage
Figure 6 :
Quiescent Current vs Temperature
4/10
LD2979 SERIES
Figure 7 :
Short Circuit Current vs Dropout
Voltage
Figure 10 :
Inhibit Voltage vs Temperature
Figure 8 :
Supply Voltage Rejection vs
Frequency
Figure 11 :
Load Transient Response
C
O
= 10µF (ESR = 1 at 1KHz)
Figure 9 :
Inhibit Current vs Temperature
Figure 12 :
Load Transient Response
C
O
= 10µF (ESR = 1 at 1KHz)
5/10
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