Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com
SPX5205
150mA, LOW-NOISE LDO VOLTAGE REGULATOR
JULY 30, 2008 REV. H
DESCRIPTION
FEATURES
■Low Noise Output LDO: 40μVRMS Possible
■1% Initial Accuracy
■Very Low Quiecent Current: 70μA
■Low Dropout Voltage (210mV at 150mA)
■Current and Thermal Limiting
■Reverse-Battery Protection
■Wide Range of Fix Output Voltages:1.2V, 1.5V,
1.8V, 2.0V, 2.5V, 2.8V, 3.0V, 3.3V and 5.0V
■Zero Off-Mode Current
■Small 5-Pin SOT-23
■Pin Compatible to MIC5205/MAX8877
(fixed Options Only) and AS3815
The SPX5205 is a positive voltage regulator with very low dropout voltage, output noise and ground current
(750μA at 100mA). VOUT has a tolerance of less than 1% and is temperature compensated. Fixed output
voltages 1.2V, 1.5V, 1.8V, 2.0V, 2.5V, 2.8V, 3.0V, 3.3V, and 5.0V and an adjustable version are available
in a small 5-pin SOT-23 package. Other key features include zero off-mode current, reverse battery
protection, thermal shutdown and current limit. The SPX5205 is an excellent choice for use in battery-
powered applications, and where powe
r conservation is desired such as: cellular/ cordless telephones, radio
control systems, and portable computers.
APPLICATIONS
■PDA
■Battery Powered Systems
■Cellular Phone
■Cordless Telephones
■Radio Control Systems
■Laptop, Palmtop, and Notebook Computers
+
+
GND
EN BYP
(Optn)
ENABLE may be tied directly to V
IN
SPX5205
1
2
3 4
5
V
IN
V
OUT
TOP View
1.0μF
TYPICAL APPLICATION CIRCUIT
54
123
SPX5205
5 Pin SOT-23
VIN
BYP
GND EN
VOUT
54
123
SPX5205
5 Pin SOT-23
VIN
ADJ/BYP
GND EN
VOUT
Fixed Output Voltage
Adjustable Output Voltage
Now Available in Lead Free Packaging
■Portable Consumer Equipment
■Portable Instrumentation
■Bar Code Scanners
■SMPS Post-Regulator
SPX5205
2
150mA, Low-Noise LDO Voltage Regulator REV. H
Thermal Shutdown .................................................................... Internally Limited
Lead Temperature (Soldering, 5 seconds) ................................................. 260°C
Operating Junction Temperature Range .................................... -40°C to +125°C
ELECTRICAL CHARACTERISTICS
T
J
=25°C, V
IN
= V
OUT
+ 1V, I
L
= 100μA, C
L
= 1μF, and V
ENABLE
* 2.4V. The z denotes the specifications which
apply over full temperature range -40°C to +85°C, unless otherwise specified.
PARAMETER MIN TYP MAX UNITS CONDITIONS
Output Voltage Tolerance (V
OUT
) -1 +1 %V
NOM
-2 +2 z
Line Regulation 0.03 0.1 %/V
0.2 z
Load Regulation 0.1 0.2 %
0.5 z IL = 1mA to 150mA
Dropout Voltage (See Note 2) 30 50 mV I
L
= 100μA
(V
IN
- V
O
) 70 z
140 190 mV I
L
= 50mA
230 z
180 250 mV I
L
= 100mA
300 z
210 275 mV I
L
= 150mA
350 z
Quiescent Current (I
GND
) 0.05 1 μA V
ENABLE
) 0.4V
5 zV
ENABLE
) 0.25V
Ground Pin Current 70 125 μA I
L
= 100μA
(I
GND
) 150 z
350 600 I
L
= 50mA
800 z
750 1000 I
L
= 100mA
1500 z
1300 1900 I
L
= 150mA
2500 z
Ripple Rejection (PSRR) 70 dB
Current Limit (I
LIMIT
) 360 500 mA V
OUT
= 0V
Output Noise (e
NO
) 300 μV
RMS
I
L
= 10mA, C
L
= 1μF, C
IN
= 1μF
(10Hz - 100kHz.)
40 μV
RMS
I
L
= 10mA, C
L
= 10μF, C
BYP
=
1μF,C
IN
=1μF,(10Hz - 100kHz)
Input Voltage Level Logic Low (VIL) 0.4 V OFF
Input Voltage Level Logic High (VIL) 2.0 ON
Input Supply Voltage ......................................... -20V to +20V
Enable Input Voltage ......................................... -20V to +20V
Input voltage ..................................................................................... +2.5V to 16V
Operating Junction Temperature Range .................................... -40°C to +125°C
Enable Input Voltage .............................................................................. 0V to V
IN
SOT-23-5 (e
JA
) ................................................................................... See Note 1
RECOMMENDED OPERATING CONDITIONS
Note 1: The maximum allowable power dissipation is a function of maximum operating junction temperature, T
J (max)
, the junction to ambient thermal
resistance, and the ambient, eJ
A
, and the ambient temperature T
A
. The maximum allowable power dissipation at any ambient temperature is
given: P
D (max)
= (T
J (max)
- T
A
)/eJ
A
, exceeding the maximum allowable power limit will result in excessive die temperature; thus, the
regulator will go into thermal shutdown. The eJ
A
of the SPX5205 is 220°C/W mounted on a PC board.
Note 2: Not applicable to output voltages of less than 2V.
ABSOLUTE MAXIMUM RATINGS
ENABLE Input Current 0.01 2 μA V
IL
) 0.4V
3 20 V
IH
* 2.0V
Output Voltage Temperature Coefficient 57 ppm/°C z
z
SPX5205
3
REV. H 150mA, Low-Noise LDO Voltage Regulator
TYPICAL PERFORMANCE CHARACTERISTICS
Ground Current vs Load Current Ground Current vs Input Voltage
1.40
1.20
1.00
0.80
0.60
0.40
0.20
0.00
0 50 100 150
I
L
(mA)
I
GND
(mA)
3.3V Device
V
IN
= 3.2V
C
L
= 1.0μF
110
100
90
80
70
60
50
40
30 4 6 8 10 12 14 16
V
IN
(V)
I
GND
(μA)
VO = 3.3V
CL = 1.0μF
IL = 100μA
Ground Current vs Load Current in Dropout Output Voltage vs Input Voltage
2.00
1.50
1.00
0.50
0.00
0 50 100 150
I
L
(mA)
I
GND
(mA)
3.3V Device
V
IN
= 4.3V
C
L
= 1.0μF
3.340
3.335
3.330
3.325
3.320
3.315
3.310
3.305
3.300
3.295
3.290
4 6 8 10 12 14 16
VIN (V)
V
OUT (V)
3.3V Device
C
L
= 1.0μF
I
L
= 100μA
SPX5205
4
150mA, Low-Noise LDO Voltage Regulator REV. H
Dropout Voltage vs Load Current Output Voltage vs Load Current
Ground Current vs Temperature at I
LOAD
=100μA Ground Current vs Temperature at I
LOAD
=100mA
200
150
100
50
0
0 50 100 150
I
L
(mA)
Dropout (mV)
V
O
=3.3V
V
IN
= 3.2V
C
L
= 1.0μF
3.310
3.308
3.306
3.304
3.302
3.300
0 50 100 150
I
L
(mA)
V
OUT
(V)
3.3V Device
V
IN
= 4.3V
C
L
= 1.0μF
90.0
80.0
70.0
60.0
50.0
-40 -20 0 20 40 60 80 100 120
Temperature (°C)
I
GND (μA)
V
OUT
= 3.3V
V
IN
= 4.3V
C
L
= 1.0μF
I
L
= 100μA
950
850
750
650
550
450
-40 -20 0 20 40 60 80 100 120
Temperature (°C)
I
GND
(μA)
V
OUT
= 3.3V
V
IN
= 4.3V
C
L
= 1.0μF
I
L
= 100mA
TYPICAL PERFORMANCE CHARACTERISTICS
4
SPX5205
5
REV. H 150mA, Low-Noise LDO Voltage Regulator
Ground Current in Dropout vs Temperature Output Voltage vs Temperature
ENABLE Voltage, ON threshold vs Input Voltage Output Noise vs. Bypass Capacitor Value
2.30
2.20
2.10
2.00
1.90
1.80
1.70
1.60
1.50
1.40
-40 -20 0 20 40 60 80 100 120
Temperature (°C)
I
GND
(mA)
V
OUT
= 3.3V
V
IN
= 4.3V
C
L
= 1.0μF
I
L
= 150mA
1.60
1.50
1.40
1.30
1.20
1.10
1.00
0.90
0.80
4 6 8 10 12 14 16
VIN (V)
V
EN, On Threshold (V)
VOUT =3.3V
CL= 1.0μA
IL = 100μA
3.400
3.380
3.360
3.340
3.320
3.300
3.280
3.260
3.240
3.220
3.200
-40 -20 0 20 40 60 80 100 120
Temperature (°C)
V
OUT
(V)
V
OUT
= 3.3V
V
IN
= 4.3V
C
L
= 1.0μF
TYPICAL PERFORMANCE CHARACTERISTICS
0
50
100
150
200
250
300
350
1 10 100 1000 10000 100000 1000000
Bypass Cap (pF)
uV RMS
Cin = 1uFT,
Cout = 1uFT
Cin = 1uFT,
Cout = 2.2uFT
Cin = 1uFT
Cout = 10uFT
SPX5205
6
150mA, Low-Noise LDO Voltage Regulator REV. H
+
+
GND
EN
BYP
(Optn)
Hi-ON
Lo-OFF
SPX5205
1
2
3 4
5
V
IN
V
OUT
R1
R2
ADJ
TOP View
Figure 1. Typical Adjustable Output Voltage.
APPLICATION INFORMATION
The SPX5205 requires an output capacitor for
device stability. Its value depends upon the
application circuit. In general, linear regulator
stability decreases with higher output currents.
In applications where the SPX5205 is putting
out less current, a lower output capacitance may
be sufficient. For example, a regulator sourcing
only 10mA, requires approximately half the
capacitance as the same regulator sourcing
150mA.
Bench testing is the best method for determining
the proper type and value of the capacitor since
the high frequency characteristics of electro-
lytic capacitors vary widely, depending on type
and manufacturer. A high quality 2.2μF alumi-
num electrolytic capacitor works in most appli-
cation circuits, but the same stability often can
be obtained with a 1μF tantalum electrolytic.
With the SPX5205 adjustable version, the mini-
mum value of output capacitance is a function of
the output voltage. The value decreases with
higher output voltages, since closed loop gain is
increased.
Typical Applications Circuits
A 10nF capacitor on BYP pin will significantly
reduce output noise but it may be left uncon-
nected if the output noise is not a major concern.
The SPX5205 start-up speed is inversely pro-
portional to the size of the BYP capacitor. Ap-
plications requiring a slow ramp-up of the out-
put voltage should use a larger CBYP. However,
if a rapid turn-on is necessary, the BYP capaci-
tor can be omitted.
The SPX5205’s internal reference is available
through the BYP pin.
The Typical Application Circuit shown on page
1 represents a SPX5205 standard application
circuit. The EN (enable) pin is pulled high
(>2.0V) to enable the regulator. To disable the
regulator, EN < 0.4V.
The SPX5205 in Figure 1 illustrates a typical
adjustable output voltage configuration. Two
resistors (R1 and R2) set the output voltage. The
output voltage is calculated using the formula:
VOUT = 1.235V x ( 1 + R1/R2)
R2 must be > 10 k1 and for best results, R2
should be between 22 k1 and 47k1. A capacitor
placed between adjustable and ground will pro-
vide improved noise performance.
SPX5205
7
REV. H 150mA, Low-Noise LDO Voltage Regulator
SPX5205
8
150mA, Low-Noise LDO Voltage Regulator REV. H
ORDERING INFORMATION
PART NUMBER TOP MARK ACC. OUTPUT VOLTAGE PACKAGE
SPX5205M5-L.............. H1WW ................. 1% ...................... Adj ................... 5 Pin SOT-23
SPX5205M5-L/TR ........ H1WW ................. 1% ...................... Adj ................... 5 Pin SOT-23
SPX5205M5-L-1-2 ......... R12 ................... 1% ..................... 1.2V .................. 5 Pin SOT-23
SPX5205M5-L-1-2/TR
.... R12 ................... 1% ..................... 1.2V .................. 5 Pin SOT-23
SPX5205M5-L-1-5 ......... R15 ................... 1% ..................... 1.5V .................. 5 Pin SOT-23
SPX5205M5-L-1-5/TR .... R15 ................... 1% ..................... 1.5V .................. 5 Pin SOT-23
SPX5205M5-L-1-8 ......... R18 ................... 1% ..................... 1.8V .................. 5 Pin SOT-23
SPX5205M5-L-1-8/TR .... R18 ................... 1% ..................... 1.8V .................. 5 Pin SOT-23
SPX5205M5-L-2-0 ......... R20 ................... 1% ..................... 2.0V .................. 5 Pin SOT-23
SPX5205M5-L-2-0/TR .... R20 ................... 1% ..................... 2.0V .................. 5 Pin SOT-23
SPX5205M5-L-2-5 ......... R25 ................... 1% ..................... 2.5V .................. 5 Pin SOT-23
SPX5205M5-L-2-5/TR .... R25 ................... 1% ..................... 2.5V .................. 5 Pin SOT-23
SPX5205M5-L-2-8 ......... R28 ................... 1%......................2.8V................... 5 Pin SOT-23
SPX5205M5-L-2-8/TR .... R28 ................... 1%......................2.8V................... 5 Pin SOT-23
SPX5205M5-L-3-0...........R30.....................1% .....................3.0V................... 5 PIN SOT-23
SPX5205M5-L-3-0/TR.....R30.....................1% .....................3.0V................... 5 PIN SOT-23
SPX5205M5-L-3-3 ......... R33 ................... 1% ..................... 3.3V .................. 5 Pin SOT-23
SPX5205M5-L-3-3/TR .... R33 ................... 1% ..................... 3.3V .................. 5 Pin SOT-23
SPX5205M5-L-5-0 ......... R50 ................... 1% ..................... 5.0V .................. 5 Pin SOT-23
SPX5205M5-L-5-0/TR .... R50 ................... 1% ..................... 5.0V .................. 5 Pin SOT-23
All Packaging is lead free. A bar is added to indicate lead-free parts and can be mistaken as a “1” or an “I”.
/TR = Tape and Reel. Pack quantity is 2,500 for 5pin SOT-23
For further assistance:
Email: customersupport@exar.com
EXAR Technical Documentation: http://www.exar.com/TechDoc/default.aspx?
Exar Corporation
Headquarters and
Sales Office
48720 Kato Road
Fremont, CA 94538
main: 510-668-7000
fax: 510-668-7030
EXAR Corporation reserves the right to make changes to the products contained in this publication in
order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the
use of any circuits described herein, conveys no license under any patent or other right, and makes no
representation that the circuits are free of patent infringement. Charts and schedules contained here in
are only for illustration purposes and may vary depending upon a user’s specific application. While the
information in this publication has been carefully checked; no responsibility, however, is assumed for
inaccuracies.
EXAR Corporation does not recommend the use of any of its products in life support applications where
the failure or malfunction of the product can reasonably be expected to cause failure of the life support
system or to significantly affect its safety or effectiveness. Products are not authorized for use in such
applications unless EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk
of injury or damage has been minimized; (b) the user assumes all such risks; (c) potential liability of
EXAR Corporation is adequately protected under the circumstances.
