LD3985
SERIES
ULTRA LOW DROP-LOW NOISE BICMOS VOLTAGE
REGULATORS LOW ESR CAPACITORS COMPATIBLE
■ INPUT VOLTAGE FROM 2.5V TO 6V
■ STABLE WITH LOW ESR CERAMIC
CAPACITORS
■ ULTRA LOW DROPO UT VOLTAGE (100mV
TYP. AT 150mA LOAD, 0.4mV TYP. AT 1mA
LOAD)
■ VERY LOW QUIESCENT CURRENT (85µA
TYP. AT NO LOAD, 170µA TY P. AT 150mA
LOAD; MAX 1.5µA IN OFF MODE)
■ GUARANTEED OUTPUT CURRENT UP TO
150mA
■ WIDE RANGE OF OUTPUT VOLTAGE: 1.2V;
1.22V; 1.25V; 1.35V; 1.5V; 1.8V; 2V; 2.1V;
2.2V; 2.4V; 2.5V; 2.6V; 2.7V; 2.8V; 2.85V;
2.9V; 3V; 3.1V; 3.2V; 3.3V; 4.7V; 5V
■ FAST TURN-ON TIME: TYP. 200µs [C
C
= 10nF AND IO=1mA]
BYP
■ LOGIC-CONTROLLED ELECTRONIC
=1µF,
O
SHUTDOWN
■ INTERNAL CURRENT AND THERMAL LIMIT
■ OUTPUT LOW NOISE VOLTAGE 30µVRMS
OVER 10Hz to 100KHz
■ S.V.R. OF 60dB AT 1KHz, 50dB AT 10KHz
■ TEMPERATURE RANGE: -40°C TO 125°C
DESCRIPTION
The LD3985 provides u p to 150mA, from 2.5V to
6V input voltage.
Flip-Chip
(1.57x1.22)
TSOT23-5LSOT23-5L
The ultra low drop-voltage, low quiescent current
and low noise make it suitable for low power
applications and in battery powered systems.
Regulator ground current increases only slightly in
dropout, further prolonging th e battery life. P ower
supply rejection is better than 60 dB at low
frequencies and starts to roll off at 10KHz. High
power supply rejection is maintained do wn to low
input voltage levels common to battery operated
circuits. 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. The LD3985 is designed to work
with low ESR ceramic capacitors. Typical
applications are in mobile phone and similar
battery powered wireless systems.
Figure 1: Schematic Diagram
Rev. 9
1/14March 2005
LD3985 SERIES
Table 1: Absolute Maximum Ratings
Symbol Parameter Value Unit
V
V
V
INH
I
P
T
STG
T
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is
not implied.
(*) The in put pin is able to withstand non repet iti ve spike of 6. 5V for 200ms .
Table 2: Thermal Data
DC Input Voltage
I
DC Output Voltage -0.3 to VI+0.3
O
INHIBIT Input Voltage -0.3 to VI+0.3
Output Current
O
Power Dissipation
D
Storage Temperature Range
Operating Junction Temperature Range
OP
-0.3 to 6 (*) V
V
V
Internally limited
Internally limited
-65 to 150 °C
-40 to 125 °C
Symbol Parameter
R
thj-case
R
thj-amb
Thermal Resistance Junction-case
Thermal Resistance Junction-ambient
SOT23-5L/
TSOT23-5L
81 °C/W
255 170 °C/W
Table 3: Order Codes
SOT23-5L TSOT23-5L Flip-Chip OUTPUT VOLTAGES
LD3985M12R (*) LD3985G12R (*) LD3985J12R (*) 1.20 V
LD3985M122R LD3985G122R (*) LD3985J122R 1.22 V
LD3985M125R (*) LD3985G125R (*) LD3985J125R 1.25 V
LD3985M135R (*) LD3985G135R (*) LD3985J135R 1.35 V
LD3985M15R LD3985G15R (*) LD3985J15R (*) 1.5 V
LD3985M18R LD3985G18R LD3985J18R 1.8 V
LD3985M20R (*) LD3985G20R (*) LD3985J20R (*) 2.0 V
LD3985M21R (*) LD3985G21R (*) LD3985J21R (*) 2.1 V
LD3985M22R (*) LD3985G22R (*) LD3985J22R (*) 2.2 V
LD3985M24R (*) LD3985G24R (*) LD3985J24R 2.4 V
LD3985M25R LD3985G25R LD3985J25R 2.5 V
LD3985M26R (*) LD3985G26R (*) LD3985J26R 2.6 V
LD3985M27R LD3985G27R LD3985J27R 2.7 V
LD3985M28R (*) LD3985G28R (*) LD3985J28R 2.8 V
LD3985M285R (*) LD3985G285R (*) LD3985J285R (*) 2.85 V
LD3985M29R LD3985G29R LD3985J29R 2.9 V
LD3985M30R (*) LD3985G30R (*) LD3985J30R 3.0 V
LD3985M31R (*) LD3985G31R (*) LD3985J31R 3.1 V
LD3985M32R (*) LD3985G32R (*) LD3985J32R (*) 3.2 V
LD3985M33R LD3985G33R (*) LD3985J33R 3.3 V
LD3985M44R (*) LD3985G44R (*) LD3985J44R (*) 4.4 V
LD3985M47R LD3985G47R (*) LD3985J47R 4.7 V
LD3985M48R (*) LD3985G48R (*) LD3985J48R 4.8 V
LD3985M49R (*) LD3985G49R (*) LD3985J49R (*) 4.9 V
LD3985M50R (*) LD3985G50R (*) LD3985J50R (*) 5.0 V
Flip-Chip Unit
(*) Avai l abl e on reque st .
2/14
LD3985 SERIES
Figure 2: Connection Di agram (top view for SOT and TSOT, top through view for Flip-Chip)
TSOT23-5L/SOT23-5L Flip-Chip
Table 4: Pin Description
Pin N°
SOT23-5L/
TSOT23-5L
14V
Pin N°
Flip-Chip
Symbol Name and Function
Input Voltage of the LDO
I
2 2 GND Common Ground
31V
INH
Inhibit Input Voltage: ON MODE when V
≥ 1.2V, OFF MODE when V
INH
0.4V (Do not leave floating, not internally pulled down/up)
4 5 BYPASS Bypass Pin: Connect an external capacitor (usually 10nF) to minimize noise
voltage
53V
O
Output Voltage of the LDO
Figure 3: Typi cal Application Ci rcuit
INH
≤
3/14
LD3985 SERIES
Table 5: Electrical Characteristics For LD3985 (Tj = 25°C, VI = V
C
= 10nF, IO = 1mA, V
BYP
= 1.4V, unless otherwise specified)
INH
O(NOM)
+0.5V, CI = 1µF,
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VIOperating Input Voltage 2.5 6 V
V
Output Voltage < 2.5V IO = 1 mA -50 50 mV
O
= -40 to 125°C -75 75
T
J
Output Voltage ≥ 2.5V IO = 1 mA -2 2 % of
V
O
Line Regulation (Note 1) VI = V
∆V
O
Load Regulation IO = 1 mA to 150mA VO < 2.5V
∆V
O
Load Regulation IO = 1 mA to 150mA VO ≥ 2.5V
∆V
O
∆V
Output AC Line Regulation VI = V
O
I
Quiescent Current
V
DROP
Q
ON MODE: V
OFF MODE: V
Dropout Voltage (NOTE 1) IO = 1mA 0.4 mV
Short Circuit Current RL = 0 600 mA
I
SC
= 1.2V
INH
= 0.4V 0.003
INH
SVR Supply Voltage Rejection V
I
O(PK)
V
Peak Output Current VO ≥ V
Inhibit Input Logic Low VI = 2.5V to 6V TJ= -40 to
INH
Inhibit Input Logic High 1.2
I
Inhibit Input Current V
INH
eN Output Noise Voltage B
t
Turn On Time (Note 4) C
ON
T
Thermal Shutdown Note 5 160 °C
SHDN
TJ= -40 to 125°C -3 3
+ 0.5 to 6 VTJ= -40 to 125°C -0.1 0.1 %/V
O(NOM)
V
= 4.7 to 5V -0.19 0.19
O
0.002 0.008 %/mA
T
= -40 to 125°C
J
0.0004 0.002 %/mA
T
= -40 to 125°C (for Flip-Chip)
J
I
= 1 mA to 150mA, TJ= -40 to 125°C
O
(for SOT23-5L/TSOT23-5L), V
+ 1 V, IO = 150mA,
O(NOM)
t
= tF = 30µs
R
I
= 0 85 µA
O
I
= 0 TJ= -40 to 125°C 150
O
= 0 to 150mA 170
I
O
= 0 to 150mA TJ= -40 to 125°C 250
I
O
T
= -40 to 125°C 1.5
J
I
= 1mA TJ= -40 to 125°C 2
O
= 50mA 20
I
O
= 50mA TJ= -40 to 125°C 35
I
O
= 100mA 45
I
O
I
= 100mA TJ= -40 to 125°C 70
O
= 150mA 60
I
O
= 150mA TJ= -40 to 125°C 100
I
O
= V
I
V
RIPPLE
V
O(NOM)
+0.25V ±
O(NOM)
= 0.1V, IO= 50mA
< 2.5V, VI = 2.55V
- 5% 300 550 mA
O(NOM)
≥ 2.5V
O
f = 1KHz 60 dB
f = 10KHz 50
0.0025 0.005
1.5 mV
125°C
= 0.4V VI = 6V ±1 nA
INH
= 10 Hz to 100 KHz CO = 1 µF30µV
W
= 10 nF 100 250 µs
BYP
V
O(NOM)
0.4 V
PP
RMS
4/14
LD3985 SERIES
Symbol Parameter Test Conditions Min. Typ. Max. Unit
C
Output Capacitor Capacitance (Note 6) 1 22 µF
O
Note 1 – Fo r V
Note 2 – Fo r V
Note 3 – Dropout volt age is the inpu t- to-output voltage difference at which the output volta ge is 100mV be l ow its nomina l val ue. This specification does not apply for input voltages bel ow 2.5V.
Note 4 – Turn-on time is time measured between the enable input just exceeding V
of its nomi nal value
Note 5 – Typi cal therm al protection hysteresis i s 20°C
Note 6 - The minimum capacitor value is 1µF, anyway the LD3985 is still stable if the compensation capacitor has a 30% tolerance in all
temperature range.
< 2V, VI = 2.5V
O(NOM)
= 1.25V , VI = 2.5V
O(NOM)
ESR 5 5000 mΩ
High Value and the output voltage just reaching 95%
INH
TYPICAL PERFORMANCE CHARACTERISTICS (Tj = 25°C, VI = V
= 10nF, IO = 1mA, V
C
BYP
Figure 4: Output Voltage vs Temperature
Figure 5: Output Voltage vs Temperature
= 1.4V, unless otherwise specified)
INH
Figure 6: Output Voltage vs Temperature
Figure 7: Shutdown Voltage vs Temperature
O(NOM)
+0.5V, CI = CO = 1µF,
5/14