The LD2981 series are 100mA fixed-output
voltage regulator. The ultra drop-voltage and the
ultralow quiescentcurrent make them particularly
suitablefor low noise, lowpower applications and
in battery poweredsystems.
o
C
SERIES
VERY LOW DROP
SOT23-5LSOT-89
In sleep mode quiescent current is less than 1µA
when INHIBIT pis is pulled low. Shutdown Logic
Control function is available on pin n.3 (TTL
compatible). This means that when the device is
used aslocal regulator,it ispossible to put a part
of the board in standby, decreasing the total
power consumption. Typlical application are in
cellularphone,palmtop/laptopcomputer,
personal digital assistant (PDA), personalstereo,
camcorderand camera.
SCHEMATIC DIAGRAM
April 2000
1/12
Page 2
LD2981
ABSOLUTE MAXIMUM RATING
SymbolParameterValueUnit
V
DC InputVoltage16V
IN
V
THERMALDATA
SymbolParameterSOT-89SOT23-5LUnit
R
thj-cas e
INHBITInput Voltage16V
INH
OutputCurrentInternally limitedmA
I
o
P
PowerDissipationInternally limitedmW
tot
StorageTemperature Range- 55 to 150
T
stg
OperatingJunctionTemperatureRange- 40 to 125
T
op
Thermal ResistanceJunction-case1581
o
o
C
o
C
C/W
CONNECTION DIAGRAM
(*) Inhibitpin is not internallypulled-up then it must notbe left floating.Disable the device whenconnected to GND or to a positive voltage
less than 0.18V
ControlInput LogicHighHIGH = Output ON -40< TJ<125oC2V
V
ih
ControlInput CurrentV
I
i
=0 mA-40 <TJ< 125oC
I
o
=1mA
I
o
=1 mA-40 <TJ< 125oC
I
o
=25mA
I
o
=25 mA-40< TJ<125oC
I
o
=100 mA
I
o
=100 mA-40< TJ<125oC
I
o
=0 V ,-40< TJ<125oC
INH
=5 V,-40< TJ<125oC
V
INH
=10µF63dB
out
eNOutputNoise Voltage(RMS)BW = 300Hz to50 KHz, C
ShortCircuitCurrentRL=0150mA
I
SC
1
7
70
200
0
5
=10µF160 µV
out
0.8
2
3
5
10
15
100
150
250
375
-1
15
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
µA
µ
µA
µ
µA
µ
µA
µ
µ
µA
mV
mV
mV
mV
mV
mV
mV
mV
µA
µ
in
A
A
A
A
A
A
4/12
Page 5
LD2981
TYPICALPERFORMANCE CHARACTERISTICS
OutputVoltage vs Temperature
OutputVoltage vs Input Voltage
(unless otherwise specified T
OutputVoltage vs Temperature
OutputVoltage vs InputVoltage
=25oC, CIN=C
J
OUT
=1µF)
OutputVoltage vs Output Current
OutputVoltage vs OutputCurrent
5/12
Page 6
LD2981
TYPICALPERFORMANCE CHARACTERISTICS
Line Regulationvs Temperature
DropoutVoltagevs OutputCurrent
(continued)
Dropout Voltagevs Temperature
QuiescentCurrent vs Temperature
QuiescentCurrent vs Output Current
6/12
QuiescentCurrent vs Input Voltage
Page 7
LD2981
TYPICALPERFORMANCE CHARACTERISTICS
S.V.R.vs Frequency
S.V.R.vs Output Current
(continued)
S.V.R.vs Temperature
Stability
Short Circuit Current vs Droput Voltage
ReverseCurrentvs ReverseVoltage
7/12
Page 8
LD2981
TYPICALPERFORMANCE CHARACTERISTICS
OutputVoltage vs Inhibit Voltage
SupplyVoltage Rejectionat V
=2.85VSupplyVoltage Rejectionat V
OUT
(continued)
InhibitCurrent vs Temperature
OUT
=5V
VIN= 7.35±2.5V, I
=0.1A, f = 1KHzVIN=9±2.5V,I
OUT
Line TransientResponse
VIN= 4.75 to 5.25V,I
8/12
= 0.1A,CO=10µF (ESR=1Ω at 1KHz)VIN= 4.75 to 5.25V,I
OUT
= 0.1A, f = 1KHz
OUT
Line TransientResponse
= 0.1A,CO=10µF (ESR=1Ω at 1KHz)
OUT
Page 9
LD2981
TYPICALPERFORMANCE CHARACTERISTICS
LoadTransient Response
VCC= 5V, I
(ESR=1Ω at 1KHz)
= 1 to 100mA,CIN= 150nF C
OUT
OUT
=10µF
ShutdownTransient Response
(continued)
LoadTransient Response
= 5V, I
V
CC
(ESR=1Ω at 1KHz)
= 1 to100mA,CIN= 150nF C
OUT
OUT
=10µF
V
=5V, VIN= 6V, V
OUT
=0to5V,CIN=C
INH
=1µF (Tant.)
OUT
9/12
Page 10
LD2981
SOT-89 MECHANICAL DATA
DIM.
MIN.TYP.MAX.MIN.TYP.MAX.
A1.41.655.163.0
B0.440.5617.322.0
B10.360.4814.218.9
C0.350.4413.817.3
C10.350.4413.817.3
D4.44.6173.2181.1
D11.621.8363.872.0
E2.292.690.2102.4
e1.421.5755.961.8
e12.923.07115.0120.9
H3.944.25155.1167.3
L0.891.235.047.2
mmmils
10/12
P025H
Page 11
SOT23-5L MECHANICAL DATA
LD2981
DIM.
MIN.TYP.MAX.MIN.TYP.MAX.
A0.901.4535.457.1
A10.000.150.05.9
A20.901.3035.451.2
b0.350.5013.719.7
C0.090.203.57.8
D2.803.00110.2118.1
E2.603.00102.3118.1
E11.501.7559.068.8
L0.350.5513.721.6
e0.9537.4
e11.974.8
mmmils
11/12
Page 12
LD2981
Information furnished is believed to be accurate andreliable. However,STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implicationor otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in thispublication are
subject tochange without notice. Thispublication supersedes andreplaces allinformationpreviously supplied. STMicroelectronics products
are not authorized for use as critical components in life support devices or systems withoutexpress written approval of STMicroelectronics.
The ST logo isa registered trademark of STMicroelectronics