1/13
December 2004
s
INPUT VOLTAGE FROM 2.5V TO 6V
s
STABLE WITH LOW ESR CERAMIC
CAPACITORS
s
ULTRA LOW DROPOUT VOLTAGE (150mV
TYP. AT 300mA LOAD, 0.4mV TYP. AT 1mA
LOAD)
s
VERY LOW QUIESCENT CURRENT (85A
TYP. AT NO LOAD, 200A TYP. AT 300mA
LOAD; MAX 1.5A IN OFF MODE)
s
GUARANTEED OUTPUT CURRENT UP TO
300mA
s
WIDE RANGE OF OUTPUT VOLTAGE:
1.25V; 1.35; 1.5V; 1.8V; 2V; 2.1V; 2.2V; 2.5V;
2.6V; 2.7V; 2.8V; 2.85V; 2.9V; 3V; 3.1V; 3.2V;
3.3V; 4.7V
s
FAST TURN-ON TIME: TYP. 240s
[C
O
=2.2F, C
BYP
= 33nF AND I
O
=1mA]
s
LOGIC-CONTROLLED ELECTRONIC
SHUTDOWN
s
INTERNAL CURRENT AND THERMAL LIMIT
s
OUTPUT LOW NOISE VOLTAGE 30V
RMS
OVER 10Hz to 100KHz
s
S.V.R. OF 55dB AT 1KHz, 50dB AT 10KHz
s
TEMPERATURE RANGE: -40C TO 125C
DESCRIPTION
The LDS3985 provides up to 300mA, from 2.5V to
6V input voltage.
It is stable with ceramic and high quality tantalum
capacitor. The ultra low drop-voltage, low
quiescent current and low noise makes it suitable
for low power applications and in battery powered
systems. Regulator ground current increases only
slightly in dropout, further prolonging the battery
life. Shutdown Logic Control function is available,
this means that 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.
Typical applications are in mobile phone and
similar battery powered wireless systems,
portable information appliances.
LDS3985
SERIES
ULTRA LOW DROP-LOW NOISE BICMOS 300mA V.REG.
FOR USE WITH VERY LOW ESR OUTPUT CAPACITOR
Figure 1: Schematic Diagram
DFN6
SOT23-5L
Rev. 1
LDS3985 SERIES
2/13
Table 1: Absolute Maximum Ratings
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is
not implied.
(*) The input pin is able to withstand non repetitive spike of 6.5V for 200ms.
Table 2: Thermal Data
Table 3: Order Codes
(*) Available on request.
Symbol
Parameter
Value
Unit
V
I
DC Input Voltage
-0.3 to 6 (*)
V
V
O
DC Output Voltage
-0.3 to V
I
+0.3
V
V
INH
INHIBIT Input Voltage
-0.3 to V
I
+0.3
V
I
O
Output Current
Internally limited
P
D
Power Dissipation
Internally limited
T
STG
Storage Temperature Range
-65 to 150
C
T
OP
Operating Junction Temperature Range
-40 to 125
C
Symbol
Parameter
SOT23-5L
DFN6
Unit
R
thj-case
Thermal Resistance Junction-case
81
10
C/W
R
thj-amb
Thermal Resistance Junction-ambient
255
55
C/W
SOT23-5L
DFN6
OUTPUT VOLTAGES
LDS3985M125R (*)
LDS3985PM12R (*)
1.25 V
LDS3985M135R (*)
LDS3985PM13R (*)
1.35 V
LDS3985M15R (*)
LDS3985PM15R (*)
1.5 V
LDS3985M18R
LDS3985PM18R
1.8 V
LDS3985M20R (*)
LDS3985PM20R (*)
2.0 V
LDS3985M21R (*)
LDS3985PM21R (*)
2.1 V
LDS3985M22R (*)
LDS3985PM22R (*)
2.2 V
LDS3985M25R
LDS3985PM25R
2.5 V
LDS3985M26R (*)
LDS3985PM26R (*)
2.6 V
LDS3985M27R (*)
LDS3985PM27R (*)
2.7 V
LDS3985M28R
LDS3985PM28R
2.8 V
LDS3985M285R (*)
LDS3985PM285R (*)
2.85 V
LDS3985M29R
LDS3985PM29R (*)
2.9 V
LDS3985M30R (*)
LDS3985PM30R (*)
3.0 V
LDS3985M31R (*)
LDS3985PM31R (*)
3.1 V
LDS3985M32R (*)
LDS3985PM32R (*)
3.2 V
LDS3985M33R
LDS3985PM33R
3.3 V
LDS3985M47R (*)
LDS3985PM47R (*)
4.7 V
LDS3985M48R (*)
LDS3985PM48R (*)
4.8 V
LDS3985M49R (*)
LDS3985PM49R (*)
4.9 V
LDS3985M50R (*)
LDS3985PM50R (*)
5.0 V
LDS3985 SERIES
3/13
Figure 2: Connection Diagram (top view for SOT, top through view for DFN6)
Table 4: Pin Description
Figure 3: Typical Application Circuit
Pin N
SOT23-5L
Pin N
DFN6
Symbol
Name and Function
1
1
V
I
Input Voltage of the LDO
2
5
GND
Common Ground
3
6
V
INH
Inhibit Input Voltage: ON MODE when V
INH
1.2V, OFF MODE when V
INH
0.4V (Do not leave floating, not internally pulled down/up)
4
4
BYPASS
Bypass Pin: Connect an external capacitor (usually 10nF) to minimize noise
voltage
5
3
V
O
Output Voltage of the LDO
-
2
N.C.
Not Connect.
SOT23-5L
DFN6
LDS3985 SERIES
4/13
Table 5: Electrical Characteristics For LDS3985 (T
j
= 25C, V
I
= V
O(NOM)
+0.5V, C
I
= 1
F, C
O
= 2.2
F
C
BYP
= 33nF, I
O
= 1mA, V
INH
= 1.4V, unless otherwise specified)
Note 1: For V
O(NOM)
< 2V V
I
= 2.5V
Note 2: For V
O(NOM)
=1.25V V
I
= 2.5V
Note 3: Dropout voltage is the input-to-output voltage difference at which the output voltage is 100mV below its nominal value. This specifi-
cation does not apply for input voltages below 2.5V.
Note 4: Turn -on time is time measured between the enable input just exceeding V
INH
High Value and the output voltage just reaching 95%
of its nominal value
Note 5: Typical thermal protection hysteresis is 20C
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
V
I
Operating Input Voltage
2.5
6
V
V
O
Output Voltage < 2.5V
I
O
= 1 mA
-50
50
mV
T
J
= -40 to 125C
-75
75
V
O
Output Voltage
2.5V
I
O
= 1 mA
-2
2
% of
V
O(NOM)
T
J
= -40 to 125C
-3
3
V
O
Line Regulation (Note 1)
V
I
= V
O(NOM)
+ 0.5 to 6 VT
J
= -40 to 125C
-0.1
0.1
%/V
V
O
= 4.7 to 5V
-0.19
0.19
V
O
Load Regulation
I
O
= 1 mA to 300mA
V
O
2.5V
T
J
= -40 to 125C
0.005
0.01
%/mA
V
O
Load Regulation
I
O
= 1 mA to 300mA
V
O
2.5V
T
J
= -40 to 125C
0.0008
0.004
%/mA
V
O
Output AC Line Regulation
(Note 2)
V
I
= V
O(NOM)
+ 1 V, I
O
= 300mA,
t
R
= t
F
= 30s
5
mV
PP
I
Q
Quiescent Current
ON MODE: V
INH
= 1.24V
I
O
= 0
85
A
I
O
= 0
T
J
= -40 to 125C
150
I
O
= 0 to 300mA
200
I
O
= 0 to 300mA
T
J
= -40 to 125C
300
OFF MODE: V
INH
= 0.4V
0.003
T
J
= -40 to 125C
1.5
V
DROP
Dropout Voltage (Note 3)
I
O
= 1mA
0.4
mV
I
O
= 1mA
T
J
= -40 to 125C
2
I
O
= 150mA
60
I
O
= 150mA
T
J
= -40 to 125C
100
I
O
= 300mA
150
I
O
= 300mA
T
J
= -40 to 125C
250
I
SC
Short Circuit Current
R
L
= 0
600
mA
SVR
Supply Voltage Rejection
V
I
= V
O(NOM)
+0.25V
V
RIPPLE
= 0.1V, I
O
= 50mA
For V
O(NOM)
< 2.5V, V
I
=2.55V
f = 1KHz
55
dB
f = 10KHz
50
I
O(PK)
Peak Output Current
V
O
V
O(NOM)
- 5%
300
550
mA
V
INH
Inhibit Input Logic Low
V
I
= 2.5V to 6V
T
J
= -40 to 125C
0.4
V
Inhibit Input Logic High
1.4
I
INH
Inhibit Input Current
V
INH
= 0.4V
V
I
= 6V
1
nA
eN
Output Noise Voltage
B
W
= 10 Hz to 100 KHz
C
O
= 2.2
F
30
V
RMS
t
ON
Turn On Time (Note 4)
C
BYP
= 33 nF
240
s
T
SHDN
Thermal Shutdown
Note 5
160
C
C
O
Output Capacitor
Capacitance (Note 6)
2.2
22
F
ESR
5
5000
m
LDS3985 SERIES
5/13
TYPICAL PERFORMANCE CHARACTERISTICS (T
j
= 25C, V
I
= V
O(NOM)
+0.5V, C
I
= 1
F, C
O
= 2,2
F,
C
BYP
= 33nF, I
O
= 1mA, V
INH
= 1.4V, unless otherwise specified)
Figure 4: Output Voltage vs Temperature
Figure 5: Output Voltage vs Temperature
Figure 6: Output Voltage vs Temperature
Figure 7: Shutdown Voltage vs Temperature
Figure 8: Shutdown Voltage vs Temperature
Figure 9: Line Regulation vs Temperature
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