SIPEX SPX2947U3

SPX2945
®
400mA Low Dropout Voltage Regulator with Shutdown
FEATURES
8
+VIN
■ Output 3.3V, 5.0V at 400mA Output
1.2V to 20V
1
+VIN
VOUT
+
100K
■ Very Low Quiescent Current, 100µA
SPX2945
■ Low Dropout Voltage, 420mV at 400mA
SHUTDOWN
INPUT
■ Extremely Tight Load and Line Regulation
3
SD
GND
OFF
7
0.01µF
10µF
ERROR
5
VREF
4
ON
■ Very Low Temperature Coefficient
FB
______
ERROR
R1
OUTPUT
R2
■ Current & Thermal Limiting
Adjustable Regulator
■ Error Flag Warns Of Output Dropout
■ Logic-Controlled Electronic Shutdown
5V
VIN
■ Output Programmable From 1.24V to 20V
(for SO-8)
OUT
IN
SPX2945
+
+
2.2 µF
GND
0.1 µF
5V Regulator Circuit
DESCRIPTION
The SPX2945 is a low power voltage regulator. This device is an excellent choice for use in battery-powered
applications such as cordless telephones, radio control systems, and portable computers. The SPX2945
features very low quiescent current (100µA Typ.) and very low dropout voltage. This includes a tight initial
tolerance of 1% max and very low output temperature coefficient, making the SPX2945 useful as a lowpower voltage reference.
The error flag output feature is used as power-on reset for warning of a low output voltage, due to a falling
voltage input of batteries. Another feature is the logic-compatible shutdown input which enables the
regulator to be switched on and off. The SPX2945 is offered in 3-pin TO-220 package, SO-8 (same pin
out as SPX2951), SOT-223, surface mount 3-Pin TO-252, 3-Pin TO-263 packages and 5-Pin TO-263.
The regulator output voltage (of the 8-pin SO-8) may be pin-strapped for a 3.3V and 5.0V or programmed
from 1.24V to 20V with an external pair of resistors. Look for SPX2951 for 150mA and SPX2954 for 250mA
applications.
TO-220-3 (U)
TO-263-3 (T)
SPX2945
SPX2945
1
1
2
2
3
3
TO-252 (R)
TO-263-5 (T5)
SPX2945
SPX2945
5 Pin TO-263
1
2
1 2 3 4 5
Rev. B Date:01/20/04
1
2
7
FEEDBACK
3
6
5V/ 3.3V TAP
8
SPX2945
V IN
GN
4
5
SOT-223 (M3)
SPX2945
ERRO
1
2
VIN GN
3
V OU
VOU
SD
Er
VIN
VOU
GND
VOUT
V IN GN
VOU
VOU
SENS
3
SHUTDOWN
V IN GN
VIN GN
8-Pin Surface Mount (S)
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
1
©Copyright 2004 Sipex Corporation
ABSOLUTE MAXIMUM RATINGS
Feedback Input Voltage ................................................ -1.5V to +26V
Shutdown Input Voltage ................................................ -0.3V to +26V
Error Comparator Output .............................................. -0.3V to +26V
ESD Rating ............................................................................ 2kV Min
Power Dissipation ........................................................ Internally Limited
Lead Temp. (Soldering, 5 Seconds) ............................................. 260°C
Storage Temperature Range ........................................ -65°C to +150°C
Operating Junction Temperature Range ....................... -40°C to +125°C
Input Supply Voltage ......................................................... -20V to +26V
ELECTRICAL CHARACTERISTICS
Electrical characteristics at VIN = VO+1V, IO = 1mA, COUT = 2.2µF, TA = 25°C, unless otherwise specified. The ♦ denotes
the specifications wich apply over full operating tempeture range -40°C to +85°C, unless noted.
PARAMETER
CONDITIONS
(Note 2)
MIN
TYP
MAX
UNITS
3.267
3.217
3.3
3.3
3.333
3.382
♦
4.950
4.880
5.0
5.0
5.050
5.120
♦
100
♦
1.5
20
♦
6
20
30
♦
3.3V Version
Output Voltage
1mA ≤ IL ≤ 400mA
V
5.0V Version
Output Voltage
1mA ≤ IL ≤ 400mA
V
All Voltage Options
Output Voltage
Temperature Coefficient
(Note1)
Line Regulation (Note 3)
6V ≤ VIN ≤ 20V (Note 4)
Load Regulation (Note 3)
IL=1 to 400mA
Dropout Voltage (Note5)
Ground Current
20
IL=1mA
60
IL=400mA
360
IL=1mA
100
IL=150mA
Current Limit
2
IL=300mA
4
IL=400mA
8
VOUT=0
Thermal Regulation
Output Noise, 10Hz to 100kHz,
IL=100mA
CL=2.2µF
CL=33µF
PSRR at 100KHz
IL=100mA
CL=10µF
100
150
450
700
200
300
4
6
8
12
15
25
330
800
0.05
0.2
ppm/°C
mV
mV
mV
♦
♦
µA
♦
mA
♦
♦
♦
♦
mA
%/W
400
260
µVRMS
31
dB
Adjustable 8 Pin Version only
Reference Voltage
Reference Voltage
1.210
Over Temperature
1.235
1.185
20
Reference Voltage Temp.
Coefficient
20
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
2
V
1.285
Feedback Pin Bias Current
Rev. B Date:01/20/04
1.260
40
60
V
nA
♦
ppm/°C
©Copyright 2004 Sipex Corporation
ELECTRICAL CHARACTERISTICS: Continued
Electrical characteristics at VIN = VO+1V, IO = 1mA, COUT = 2.2µF, TA = 25°C, unless otherwise specified. ♦ applies over the
full operating temperature range.
PARAMETER
CONDITIONS
(Note 2)
MIN
Feedback Pin Bieas Current
Temperature Coefficient
Output Leakage Current
Output Low Voltage
V0H=20V
0.01
VIN=4.5V
I0L=400µA
(Note 6)
Lower Threshold Voltage
(Note 6)
150
40
25
♦
(Note 6)
Input Logic Voltage
Low (Regulator ON)
High (Regulator OFF)
1
2
♦
250
400
♦
µA
mV
mV
95
140
♦
mV
0.7
2.0
♦
♦
15
1.3
VS=2.4V
30
VS=26V
450
(Note 7)
10
20
UNITS
nA/°C
60
75
Hysteresis
Regulator Output Current
in Shutdown
MAX
0.1
Upper Threshold Voltage
Shutdown Pin Input Current
TYP
mV
50
100
600
750
V
µA
♦
♦
3
µA
♦
Note 1: Output or reference voltage temperature coefficients defined as the worst case voltage change divided by
the total temperature range.
Note 2: Unless otherwise specified all limits are guaranteed for Tj = 25°C, VIN = 6V, IL = 1mA and CL = 2.2µF. Additional
conditions for the 8-pin versions are feedback tied to 5V/3.3V tap and output tied to output sense (VOUT = 5V) and
VSHUTDOWN ≤ 0.8V.
Note 3: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes
in output voltage due to heating effects are covered under the specification for thermal regulation.
Note 4: Line regulation for the SPX2945 is tested at 150°C for IL = 1 mA. For TJ = 125°C, line regulation is guaranteed
by design.
Note 5: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below
its nominal value measured at 1V differential at very low values of programmed output voltage, the minimum input
supply voltage of 2V ( 2.3V over temperature) must be taken into account.
Note 6: Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the
nominal reference voltage measured at 6V input. To express these thresholds in terms of output voltage change,
multiply by the error amplifier gain = VOUT/VREF = (R1 + R2)/R2. For example, at a programmed output voltage of 5V,
the Error output is guaranteed to go low when the output drops by 95 mV x 5V/1.235 = 384 mV. Thresholds remain
constant as a percent of VOUT as VOUT is varied, with the dropout warning occurring at typically 5% below nominal, 7.5%
guaranteed.
Note 7: VSHUTDOWN ≥ 2V, VIN ≤ 26V, VOUT = 0, Feedback pin tied to 5V/3.3V Tap.
Rev. B Date:01/20/04
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
3
©Copyright 2004 Sipex Corporation
SPX2945 - 5.0V BLOCK DIAGRAM
UNREGULATED DC
7
+
FEEDBACK
5V at 400mA
MAX
1
8
OUTPUT
INPUT
2
SENSE
+
_
FROM
CMOS OR
TTL
180kΩ
.
ERROR
AMPLIFIER
3
6
5V TAP
330kΩ .
SHUTDOWN
60kΩ .
+
60 mV
+
_
ERROR DETECTION
COMPARATOR
+ 1.23V
+
5
______
ERROR
1µF
TO CMOS OR
TTL
4
REFERENCE
GROUND
APPLICATION INFORMATION
External Capacitors
The stability of the SPX2945 requires a 2.2µF or
greater capacitor between output and ground.
Oscillation could occur without this capacitor.
Most types of tantalum or aluminum electrolytic
works fine here. For operations of below -25°C
solid tantalum is recommended since the many
aluminum types have electrolytes that freeze at
about -30°C. The ESR of about 5Ω or less and
resonant frequency above 500kHz are the most
important parameters in the value of the capacitor. The capacitor value can be increased without limit.
The SPX2945, unlike other low dropout regulators will remain stable and in regulation with
no load in addition to the internal voltage divider. This feature is especially important in
applications like CMOS RAM keep-alive.
If there is more than 10 inches of wire between
the input and the AC filter capacitor, or if a
battery is used as the input, then a 0.1µF tantalum or aluminum electrolytic capacitor should
be placed from the input to the ground.
Instability can occur if there is stray capacitance to the SPX2945 feedback terminal (pin 7).
This could cause more problems when using a
higher value of external resistors to set the
output voltage.
At lower values of output current, less output
capacitance is required for stability. For the
currents below 10mA the value of the capacitor
can be reduced to 0.5µF and 0.15µF for 1mA.
More output capacitance needed for the 8-pin
version at voltages below 5V since it runs the
error amplifier at lower gain. At worst case
4.7µF or greater must be used for the condition
of 250mA load at 1.23V output.
Rev. B Date:01/20/04
This problem can be fixed by adding a 100pF
capacitor between output and feedback and
increasing the output capacitor to at least 3.3µF.
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
4
©Copyright 2004 Sipex Corporation
Error Detection Comparator Output
The Comparator produces a logic low output
whenever the SPX2945 output falls out of regulation by more than around 5%. This is around
60mV offset divided by the 1.235 reference
voltage. This trip level remains 5% below
normal regardless of the programmed output
voltage of the regulator. Figure 1 shows the
timing diagram depicting the ERROR signal
and the regulator output voltage as the SPX2945
input is ramped up and down. The ERROR
signal becomes low at around 1.3V input, and
goes high around 5V input (input voltage at
which VOUT = 4.75). Since the SPX2945’s
dropout voltage is load dependent, the input
voltage trip point (around 5V) will vary with the
load current. The output voltage trip point
(approx. 4.75V) does not vary with load.
2% in VOUT, which may be eliminated at room
temperature by trimming R1. To improve the
accuracy choose the value of R2 = 100k; this
reduces the error by 0.17% and increases the
resistor program current by 12µA. Since the
SPX2945 typically draws 60 µA at no load with
Pin 2 open-circuited this is a small price to pay.
Reducing Output Noise
It may be an advantage to reduce the AC noise
present at the output. One way is to reduce the
regulator bandwidth by increasing the size of
the output capacitor. This is the only way that
noise can be reduced on the 3 lead SPX2945 but
is relatively inefficient, as increasing the capacitor from 1µF to 220µF only decreases the
noise from 430µV to 160µV Vrms for a 100kHz
bandwidth at 5V output. Noise could also be
reduced fourfold by a bypass capacitor across
R1, since it reduces the high frequency gain from
4 to unity. Pick
The error comparator has an open-collector output, which requires an external pull-up resistor.
Depending on the system requirements the resistor may be returned to 5V output or other
supply voltage. In determining the value of this
resistor, note that the output is rated to sink
400µA; this value adds to battery drain in a low
battery condition. Suggested values range from
100K to 1MΩ. If the output is unused this
resistor is not required.
CBYPASS ≅1 / 2πR1 x 200 Hz
or choose 0.01µF. When doing this, the output
capacitor must be increased to 3.3µF to maintain stability. These changes reduce the output
noise from 430µV to 100µV Vrms for a 100kHz
bandwidth at 5V output. With the bypass capacitor added, noise no longer scales with output voltage so that improvements are more dramatic at higher output voltages.
Programming the Output Voltage of
SPX2945
The SPX2945 may be pin-strapped for 5V or
3.3V using its internal voltage divider by tying
Pin 1 (output) to Pin 2 (sense) and Pin 7 (feedback) to Pin 6 (5V/3.3V Tap).
Also, it may be programmed for any output
voltage between its 1.235V reference and its
20V maximum rating. As seen in Figure 2, an
external pair of resistors is required.
Refer to the below equation for the programming of the output voltage::
4.75V
OUTPUT
VOLTAGE
_______
ERROR*
VOUT = VREF x ( 1 + R1/ R2 )+ IFBR1
+5.0V
The VREF is 1.235 and IFB is the feedback bias
current, nominally -20nA. The minimum recommended load current of 1 µA forces an upper
limit of 1.2 MΩ on value of R2. If no load is
presented the IFB produces an error of typically
INPUT
VOLTAGE
+
+1.3V
+
* See Application Info.
Figure 1. ERROR Output Timing
Rev. B Date:01/20/04
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
5
©Copyright 2004 Sipex Corporation
PACKAGE: 3 PIN TO-252
-A-
E
b2
-BA
A1
C1
L2
A
4
SEATING
PLANE
D
1
2
L3
L1
H
3
L
-C-
b1
3 PLCS
.010
M
A M
c
e
C
A
8
e1
NOTES
1. Refer To Applicable Symbol List.
2. Dimensions And Tolerancing Per Ansi Y14.5m - 1982.
3. Lead Dimension Uncontrolled in L3
4. Tab Contour Optional Within Dim. b2 & L2 And E1 & D1
5. D1 & E1 Establishes A Minimum Mounting Surface for
Terminal 4.
6. L is the Termal Length for Soldering.
7. Controlling Dimension: Inch
8. 2 Mils Suggested For Postive Contact At Mounting.
D1
E1
TERM 4
BACK VIEW A-A
S
Y
M
B
O
L
A
A1
b
b1
b2
c
c1
D
D1
E
E1
e
e1
H
L
L1
L2
L3
Rev. B Date:01/20/04
INCHES
MAX
MIN.
0.086
0.035
0.025
0.300
0.205
0.018
0.018
0.235
0.170
0.250
0.170
0.094
0.045
0.035
0.045
0.215
0.023
0.023
0.245
0.265
-
MAX
MIN.
2.3876
1.143
0.889
1.143
5.461
0.5842
0.5842
6.223
6.731
-
2.184
0.889
0.635
7.620
5.207
0.457
0.457
5.969
4.318
6.350
4.318
0.098
0.180
0.370
0.020
0.025
0.035
0.045
N
O
T
E
MM
4
4,5
4,5
2.489
4.572
0.410
0.040
0.050
0.060
9.398
0.508
0.635
0.889
1.143
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
6
10.414
1.016
1.270
1.524
6
4
3
©Copyright 2004 Sipex Corporation
PACKAGE: 3 PIN TO-220
0.151D ± 0.002
(3.835 D ± 0.051)
0.180 ± 0.005
(4.572 ± 0.127)
0.408 ± 0.013
(10.36 ± 0.33)
0.110 ± 0.010
(2.794 ± 0.254)
0.050 ± 0.002
(1.270 ± 0.051)
0.250 ± 0.010
(6.350 ± 0.254)
Tapered 1°
2 Sides
0.340 ± 0.010
(8.636 ± 0.254)
SEATING
PLANE
1.020 ± 0.015
(25.910 ± 0.381)
0.150 MIN
(3.81 MIN)
7°Typ.
0.540 ± 0.015
(13.720 ± 0.381)
0.050 TYP
(1.27 TYP)
0.200 ± 0.010
(5.080 ± 0.254)
Rev. B Date:01/20/04
0.410
(10.41)
0.015 ± 0.010/-0.015
(2.667± 0.254/-0.381)
0.100 ± 0.010
(2.540 ± 0.254)
0.032 ± 0.005
(0.813 ± 0.127)
0.015 ± 0.010/-0.002
(0.381± 0.254/-0.051)
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
7
©Copyright 2004 Sipex Corporation
PACKAGE: 5 PIN TO-263
0.055 (1.397)
0.176 ± 0.005 (4.470 ± 0.127)
0.050 ± 0.002 (1.270 ± 0.051)
0.405 ± 0.005
(10.287 ± 0.127)
0.356 ± 0.005
(9.042 ± 0.127)
0.600 ± 0.025
(15.24 ± 0.635)
0.100 ± 0.010
(2.540 ± 0.254)
0.067 ± 0.005
(1.702 ± 0.127)
0.015
(0.381
0.032 ± 0.003
(0.813 ± 0.076)
+- 0.003
+- 0.074)
0° 8°
PACKAGE: 3 PIN TO-263
0.405 ± 0.005
(10.287 ± 0.127)
0.176 ± 0.005 (4.470
0.050 ± 0.002 (1.270
0.055 (1.397)
0.356
(9.042
±
±
±
±
0.127)
0.051)
0.005
0.127)
0.600 ± 0.025
(15.24 ± 0.635)
0.100 ± 0.010
(2.540 ± 0.254)
0.103 BSC
(2.616)
Rev. B Date:01/20/04
0.015
(0.381
0.050 (1.270)
0.032 +- 0.001
(0.813 +- 0.025)
++
-
0.003
0.074)
0° 8°
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
8
©Copyright 2004 Sipex Corporation
PACKAGE: 3 PIN SOT-223
0.124
0.116
0.146 0.295
0.130 0.264
0.041
0.033
0.0905 NOM
0.181 NOM
0.067
0.028
0.0040
0.0008
0.264
0.248
10°C Max
0.014
0.010
16°C
10°C
0.033
0.025
Rev. B Date:01/20/04
16°C
10°C
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
9
©Copyright 2004 Sipex Corporation
PACKAGE: 8 PIN NSOIC
D
e
E/2
E1
E
E1/2
SEE VIEW C
1
b
INDEX AREA
(D/2 X E1/2)
Ø1
A
TOP VIEW
b
WITH PLATING
Gauge Plane
L2
Seating Plane
Ø1
Ø
L
L1
c
VIEW C
BASE METAL
DIMENSIONS
Minimum/Maximum
(mm)
CONTACT AREA
8 Pin NSOIC
(JEDEC MS-012,
AA - VARIATION)
COMMON HEIGHT DIMENSION
A2
A
SEATING PLANE
A1
SIDE VIEW
SYMBOL
A
A1
A2
b
c
D
E
E1
e
L
L1
L2
Ø
Ø1
MIN NOM MAX
1.75
1.35
0.25
0.10 1.25
1.65
0.31
0.51
0.17
0.25
4.90 BSC
6.00 BSC
3.90 BSC
1.27 BSC
0.40 1.27
1.04 REF
0.25 BSC
0º
8º
5º
15º
8 PIN NSOIC
Rev. B Date:01/20/04
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
10
©Copyright 2004 Sipex Corporation
ORDERING INFORMATION
Ordering No.
Top Mark
Accuracy
Output Voltage
SPX2945M3-3.3
2945M3
33YYWW
1%
3.3V
SPX2945M3-5.0
2945M3
50YYWW
1%
5.0V
SPX2945S-3.3
2945S33
33YYWW
1%
3.3V
SPX2945S-5.0
SPX2945R
50YYWW
1%
5.0V
1%
3.3V
1%
5.0V
1%
3.3V
1%
5.0V
1%
3.3V
SPX2945R-3.3
SPX2945R-5.0
SPX2945T-3.3
SPX2945T-5.0
SPX2945T5-3.3
SPX2945R
504YYWW
SPX2945R
YYWW
SPX2945T
33YYWW
SPX2945T5
50YYWW
SPX2945T5
33YYWW
SPX2945T5-5.0
SPX2945T
50YYWW
1%
5.0V
SPX2945U-3.3
SPX2945U
33YYWW
1%
3.3V
SPX2945U-5.0
SPX2945U
50YYWW
1%
5.0V
Packages
3-Pin SOT-223
3-Pin SOT-223
8-Pin SOIC
8-Pin SOIC
3-Pin TO-252
3-Pin TO-252
3-Pin TO-263
3-Pin TO-263
5-Pin TO-263
5-Pin TO-263
3-Pin TO-220
3-Pin TO-220
Corporation
ANALOG EXCELLENCE
Sipex Corporation
Sales Office
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: [email protected]
Headquarters and
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.
Rev. B Date:01/20/04
SPX2945 400mA Low Dropout Voltage Regulator with Shutdown
11
©Copyright 2004 Sipex Corporation