SIPEX SPX2951ACS-3.3

SPX2950/SPX2951
®
150mA Low Dropout Voltage Regulator
FEATURES
APPLICATIONS
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5.0V and 3.3V at 150mA Output
Accurate: 0.5% for SPX2950A/SPX2951A
Very Low Quiescent Current
Low Dropout Voltage: 300mV at 150mA
Extremely Tight Load and Line Regulation
Very Low Temperature Coefficient
Current & Thermal Limiting
Need Only 1µF for Stability
Offered in TO-92 (SPX2950) and SOIC
(SPX2951)
■ Direct Replacement for LP2950/LP2951
Battery Powered Systems
Cordless Telephones
Radio Control Systems
Portable/Palm Top/Notebook Computers
Portable Consumer Equipment
Portable Instrumentation
Avionics
SMPS Post-Regulator
Voltage Reference
Automotive Electronics
SPX2951 versions only
■ Error Flag Warns of Output Dropout
■ Logic-Controlled Electronic Shutdown
■ Output Programmable From 1.24 to 30V
DESCRIPTION
The SPX2950 and SPX2951 are low power voltage regulators. These devices are an excellent choice for
use in battery-powered applications such as cordless telephones, radio control systems, and portable
computers. The SPX2950 and SPX2951 feature low quiescent current and low dropout voltage (typ. 20mV
at 100µA and 300mV at 150mA). This includes a tight initial tolerance of (0.5% for SPX2950A/SPX2951A),
extremely good load and line regulation (0.05% typ.), and very low output temperature coefficient (20ppm/
°C typ.), making the SPX2950/SPX2951 useful as a low-power voltage reference.
The error flag output feature is used as a power-on reset for warning of a low output voltage, due to a falling
voltage. The logic compatible shutdown feature enables the regulator to be switched ON and OFF. The
SPX2950 is offered in a 3-pin TO-92 package compatible with other 5.0V, 3.3V regulators. The SPX2951
is availiable in an 8-lead SOIC package.
UNREGULATED DC
5V
8
1
INPUT
OUTPUT
7
+
FEEDBACK
2
SENSE
+
_
FROM
CMOS OR
TTL
3
180kΩ
6
ERROR
AMPLIFIER
330kΩ
5V TAP
SHUTDOWN
+
60kΩ
60 mV
+
______
+
_
+ 1.23V
5
ERROR DETECTION
COMPARATOR
ERROR
1µF
.
.
TO CMOS OR
TTL
4
REFERENCE
GROUND
Block Diagram of SPX2951, 8 Lead 5V Version
Rev. 3/6/03
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
1
©Copyright 2003 Sipex Corporation
ABSOLUTE MAXIMUM RATINGS
Feedback Input Voltage ................................................ -1.5V to +30V
Shutdown Input Voltage ................................................ -0.3V to +30V
Error Comparator Output .............................................. -0.3V to +30V
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 ........................................................ -0.3V to +30V
ELECTRICAL CHARACTERISTICS
Electrical characteristics at VIN = VO+1V, IL=100µA, CL=1µF (note 2) TA=25°C, unless otherwise specified. Boldface applies over the full
operating temperature range.
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
SPX2950AC
SPX2951AC
TYP
MAX
UNITS
SPX2950C
SPX2951C
3.3V Version
Output Voltage
TJ=25°C
-25°C≤TJ≤85°C
Full Operating Temperature
3.284
3.267
3.260
3.3
3.3
3.3
3.317
3.333
3.340
3.267
3.251
3.324
3.3
3.3
3.3
3.333
3.350
3.366
V
Output Voltage
100µA≤ IL ≤150mA
TJ≤TJMAX
3.254
3.3
3.346
3.221
3.3
3.379
V
Output Voltage
TJ=25°C
-25°C≤TJ≤85°C
Full Operating Temperature
4.975
4.950
4.940
5.0
5.0
5.0
5.025
5.050
5.060
4.950
4.925
4.900
5.0
5.0
5.0
5.050
5.075
5.100
V
Output Voltage
100µA≤IL≤150mA
TJ≤TJMAX
4.925
5.0
5.075
4.880
5.0
5.120
V
20
100
50
150
ppm/°C
5.0V Version
All Voltage Options
Output Voltage
Temperature Coefficient
(Note1)
Line Regulation (Note 3)
VO+1V ≤ VIN ≤ 30V (Note 4)
0.03
0.1
0.04
0.2
%
Load Regulation (Note 3) 100µA≤IL≤150mA
0.04
0.1
0.1
0.2
%
Dropout Voltage (Note5)
IL=100µA
IL=100mA
IL=150mA
20
270
300
80
450
500
20
270
300
80
450
500
mV
mV
mV
Ground Current
IL=100µA
IL=100mA
IL=150mA
150
3
5
170
6
8
150
3
5
170
6
8
µA
mA
mA
Current Limit
VOUT=0
0.2
0.05
0.2
%/W
230
Thermal Regulation
Output Noise,
10Hz to 100kHz
CL=1µF
CL=200µF
CL=3.3µF, Bypass=0.01µF
from pin 7 to pin1 (SPX2951)
430
160
100
8-Pin Version only
1.220
Over Temperature (Note 6)
1.235
1.190
mA
430
160
100
SPX2951AC
Reference Voltage
Reference Voltage
230
0.05
µVrms
µVrms
µVrms
SPX2951C
1.250
1.210
1.270
1.185
V
1.285
V
60
nA
40
Reference Voltage
Temperature Coefficient
20
50
ppm/°C
Feedback Pin Bias Current
Temperature Coefficient
0.1
0.1
nA/°C
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
2
40
1.260
Feedback Pin Bias Current
Rev. 3/6/03
60
1.235
©Copyright 2003 Sipex Corporation
ELECTRICAL CHARACTERISTICS: Continued
Electrical characteristics at VIN = VO+1V, IL=100µA, CL=1µF (note 2) TA=25°C, unless otherwise specified. Boldface applies over
the full operating temperature range.
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
Error Comparator
Output Leakage Current
V0H=30V
0.01
1
0.01
1
µA
Output Low Voltage
VIN=VO-0.5V
I0L=400µA
150
250
150
250
mV
Upper Threshold Voltage (Note 7)
40
60
Lower Threshold Voltage (Note 7)
75
Hysteresis
15
(Note 7)
40
95
60
75
mV
95
15
mV
mV
Shutdown Input
Input Logic Voltage
Low (Regulator ON)
High (Regulator OFF)
1.3
0.7
2.0
1.3
0.7
V
V
2.0
Shutdown Pin Input Current VS=2.4V
VS=30V
30
400
50
800
30
400
50
800
µA
µA
Regulator Output Current (Note 8)
in Shutdown
3
10
3
10
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 = VO +1V, IL = 100µA and CL = 1µF.
Additional conditions for the 8-pin versions are feedback tied to 5V 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 SPX2951 is tested at IL = 1mA. See typical performance characteristics for line
regulation versus temperature and load current.
Note 5: Dropout voltage is defined as the input to output differential at which the output voltage drops 100mV 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: VREF≤VOUT≤(VIN -1V),2.3≤VIN≤30V, 100µA≤IL≤150mA, TJ≤TJMAX.
Note 7: 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 95mV x 5V/1.235 = 384mV. 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 8: VSHUTDOWN ≥ 2V, VIN ≤ 30V, VOUT = 0, Feedback pin tied to 5V/ 3.3V tap.
Rev. 3/6/03
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
3
©Copyright 2003 Sipex Corporation
TYPICAL PREFORMANCE CHARACTERISTICS
6
10
250
225
R L =50kΩ
3
R L =50kΩ
2
R L = 50kΩ
175
150
125
100
RL =
8
4
GROUND PIN CURRENT (mA)
200
INPUT CURRENT (µA)
OUTPUT VOLTAGE (VOLTS)
5
75
50
1
1
0.1
25
0
0
2
3
4
5
0
6
1
2
320
240
INPUT CURRENT (mA)
GROUND CURRENT (µA)
280
I L = 1mA
200
160
IL= 0
120
80
40
1
2
3
5
6
7
8
0.01
0.1
9 10
4
5
6
7
8
100
6
R L =50 Ω
VOUT = 5V
5
V IN = 6V
I L = 100mA
4
3
0
1
2
3
4
5
6
7
8
-75 -50 -25
9 10
0
25 50
75 100 125 150
TEMPERATURE (ºC)
INPUT VOLTAGE (VOLTS)
Ground Current
10
Quiescent Current
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
INPUT VOLTAGE (VOLTS)
1
LOAD CURRENT (mA)
Input Current
Dropout Characteristics
0
4
INPUT VOLTAGE (VOLTS)
INPUT VOLTAGE (VOLTS)
0
3
GROUND CURRENT (mA)
1
0
Ground Current
Input Current
190
8
6
QUIESCENT CURRENT (µA)
GROUND CURRENT (mA)
7
I L =100mA
5
4
3
2
1
170
V IN =6V
I L =100uA
150
130
0
0
1
2
3
4
5
6
7
-75 -50 -25
8
Ground Current
Rev. 3/6/03
0
25 50
75 100 125 150
TEMPERATURE (ºC)
INPUT VOLTAGE
Quiescent Current
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
4
©Copyright 2003 Sipex Corporation
TYPICAL PREFORMANCE CHARACTERISTICS: (Continued)
500
500
240
I L = 150mA
230
300
200
~
~
40
20
I L = 100µA
SHORT CIRCUIT CURRENT (mA)
400
DROP-OUT VOLTAGE (mV)
300
200
TJ = 25ºC
100
0
0
-75 -50 -25
0
25 50
100µA
75 100 125 150
1mA
TEMPERATURE (ºC)
10mA
210
200
190
180
170
-75 -50 -25
100mA
OUTPUT CURRENT
Drop-Out Voltage
2.5
50
mV
SINK CURRENT (mA)
2.0
HYSTERESIS
2
0
1.5
T A = 25ºC
1.0
T A = -55ºC
0.5
0.0
0
1
2
3
4
5
0
8V
4V
0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
INPUT VOLTAGE (V)
C L = 1µF
I L = 1mA
V OUT = 5V
-50
mV ~
~
6V
PULLUP RESISTOR TO
SEPARATE 5V SUPPLY
-2
200
OUTPUT LOW VOLTAGE (V)
Error Comparator Output
400
600
800
TIME(µs)
SPX2951 Comparator Sink Current
10
75 100 125 150
100
mV
T A = 125ºC
4
25 50
Short Circuit Current
V OUT = 5V
6
0
TEMPERATURE (ºC)
Drop-Out Voltage
8
COMPARATOR OUTPUT (V)
220
INPUT OUTPUT VOLTAGE
VOLTAGE CHANGE
DROP-OUT VOLTAGE (mV)
400
Line Transient Response
90
90
80
80
70
70
I O = 1mA
2
I O = 100mA
1
0.5
V OUT = 5V
C L = 1µF
0.2
0.1
0.05
IL = 0
60
50
40
I L = 100µA
C L = 1µF
V IN = 6V
V OUT = 5V
30
0.02
RIPPLE REJECTION (dB)
5
RIPPLE REJECTION (dB)
OUTPUT IMPEDANCE (OHMS)
IO = 100µA
10
100
1K
10K
FREQUENCY (Hz)
Output Impedance
Rev. 3/6/03
100K
1M
60
50
40
30
20
0.01
C L = 1µF
V IN = 6V
V OUT = 5V
I L = 1mA
I L = 10mA
20
10 1
10 2
10 3
10 4
10 5
10 1
10 6
FREQUENCY (Hz)
Ripple Rejection
10 2
10 3
10 4
10 5
10 6
FREQUENCY (Hz)
Ripple Rejection
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
5
©Copyright 2003 Sipex Corporation
TYPICAL PREFORMANCE CHARACTERISTICS: (Continued)
20
50
1.9
FEEDBACK CURRENT (µA)
2.1
0
-10
-20
0
-50 -25
25
-75 -50 -25
75 100 125 150
50
0
25 50
-2.0
6
150
40
100
20
0
-50
C L = 1µF
V OUT = 5V
100
mA
SHUTDOWN OUTPUT
PINOUT VOLTAGE (V) VOLTAGE (V)
7
60
50
0
-20
C L = 10µF
V OUT = 5V
-40
-60
~
~
100
µA
100
100
µA
µA
2
3
4
5
0
4
8
12
16
40
T A =25 ºC
T A = 85 ºC
5
10
15
20
INPUT VOLTAGE (V)
SPX2950 Maxium Rated Output
Rev. 3/6/03
25
I L = 10mA
V IN = 8V
V OUT = 5V
1
C L = 10µF
0
2
0
0 100 200 300 400 500 600 700
Enable Transient
120
100
30
DIP SOLDERED
TO PC BOARD
T JMAX = 125º C
V OUT = 5V
300
200
100
80
60
T A = 25ºC
40
T A = 50ºC
20
0
0
0
2
TIME (us)
OUTPUT CURRENT (mA)
PIN 2 TO PIN 4 RESISTANCE (kΩ)
T JMAX = 125 ºC
20
3
8-PIN
MOLDED
Vout=5V
60
1.0
4
-100
400
TO-92 PACKAGE
0.25" LEADS SOLDERED
TO PC BOARD
80
0.5
5
20
Load Transient Response
120
0
C L = 1µF
TIME (ms)
Load Transient Response
-0.5
-2
TIME (ms)
100
-1.0
SPX2951 Feedback Pin Current
80
1
-1.5
FEEDBACK VOLTAGE (V)
200
0
T A = 55ºC
-200
250
~
~
T A = 25ºC
-150
75 100 125 150
SPX2951 Feedback Bias Current
LOAD OUTPUT VOLTAGE
CURRENT CHANGE (mV)
LOAD OUTPUT VOLTAGE
CURRENT CHANGE (mV)
SPX2951 Minimum Operating Voltage
-100
TA=1 25ºC
-100
TEMPEATURE (ºC)
TEMPERATURE
OUTPUT CURRENT (mA)
-50
-250
-30
1.7
-75
PIN 7 DRIVEN BY EXTERNAL
SOURCE (REGULATOR RUN
OPEN LOOP)
0
10
BIAS CURRENT (nA)
MINIMUM OPERATING VOLTAGE (V)
2.3
-75
T A = 85ºC
0
-50 -25
0
25
50
75 100 125 150
TEMPERATURE (ºC)
SPX2951 Divider Resistance
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
6
0
5
10
15
20
25
30
INPUT VOLTAGE (V)
SPX2950 Maxium Rated Output Current
©Copyright 2003 Sipex Corporation
TYPICAL APPLICATIONS:
1.8
5
3.5
1.6
4
3.0
2
2.5
0
2.0
-2
1.5
I L = 100mA
1.4
C L = 1µF
C L = 220µF
C L = 3.3µF
C BYP = 0.1µF
1.2
~~
1.0
1.0
1
1.25W
0.8
0.5
0
0.6
0.0
-1
-75 -50 -25
0 25
50
10
0
75 100 125 150
20
30
40
50
10 2
TIME (µs)
TEMPERATURE (ºC)
Shutdown Threshold Voltage
10 3
10 4
10 5
FREQUENCY (Hz), C BYP =0.1uF
Thermal Response
Output Noise
80
30
I L = 50mA
25
20
70
I L = 100µA
15
10
5
60
T J = 150 ºC
I L = 1mA
I L = 100mA
50
0
40
~~
10
C L = 1µF
VIN = 6V
VOUT = 5V
30
T J = 125 ºC
5
0
-5
I L = 100µA
20
10
-10
5
10
15
20
25
30
10 1
10 2
INPUT VOLTAGE (V)
Line Regulation
Rev. 3/6/03
10 3
10 4
10 5
10 6
FREQUENCY (Hz)
Ripple Rejection
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
7
©Copyright 2003 Sipex Corporation
APPLICATION HINTS
EXTERNAL CAPACITORS
The stability of the SPX2950/SPX2951 requires
a 1µF 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 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 capacitors value may be increased without limit.
4.75V
OUTPUT
VOLTAGE
_______
ERROR*
+5.0V
INPUT
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 0.33µF and 0.1µF for 1mA.
More output capacitance is needed for the 8-pin
version at voltages below 5V since it runs the
error amplifier at lower gain. At worst case 3.3µF
or greater must be used for the condition of
150mA load at 1.23V output.
+1.3V
+
* See Application Info.
Fig. 1 ERROR Output Timing
ERROR DETECTION COMPARATOR
OUTPUT
The comparator produces a logic low output
whenever the SPX2951 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.
The SPX2950/51 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. When
setting the output voltage of the SPX2950/51
version with external resistors, a minimum load
of 1µA is recommended
Figure 1 shows the timing diagram depicting the
ERROR signal and the regulator output voltage
as the SPX2951 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
SPX2951’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.
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 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 SPX2951 feedback terminal (pin 7). This
could cause more problems when using a higher
value of external resistors to set the output
voltage. This problem can be fixed by adding a
100pF capacitor between output and feedback
and increasing the output capacitor to at least
3.3µF.
Rev. 3/6/03
+
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.
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
8
©Copyright 2003 Sipex Corporation
PROGRAMMING THE OUTPUT
VOLTAGE OF SPX2951
The SPX2951 may be pin-strapped for 5V using
its internal voltage divider by tying Pin 1 (output) to Pin 2 (sense) and Pin 7 (feedback) to Pin
6 (5V Tap). Also, it may be programmed for any
output voltage between its 1.235V reference
and its 30V 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:
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 SPX2950 but
is relatively inefficient, as increasing the capacitor from 1µF to 220µF only decreases the
noise from 430µV to 160µVRMS 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
VOUT = VREF × (1 + R1/R2)+ IFBR1
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 1.2MΩ on value of R2. If no load is
presented the IFB produces an error of typically
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
SPX2951 typically draws 60µA at no load with
Pin 2 open-circuited this is a small price to pay.
CBYPASS ≅ (1 / 2πR1 × 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 100µVRMS 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.
TYPICAL APPLICATIONS
+V IN
100K
8
5
ERROR
OUTPUT
+V IN
______
ERROR
V OUT
1.2 to 30V
1
SPX2951
SHUTDOWN
INPUT
+
R1
3
SD
FB
GND
3.3µF
.01µF
7
4
1.23V
V REF
R2
Figure 2. Adjustable Regulator
Rev. 3/6/03
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
9
©Copyright 2003 Sipex Corporation
TYPICAL APPLICATIONS: (Continued)
+V IN
470KΩ
+V IN
8
8
5
+V IN
______
ERROR
ERROR
V OUT
470kΩ
V OUT
1
5
OUTPUT
SPX2951
+
3
R1
SD
FB
SHUTDOWN
1µF
4
7
120kΩ
SD
FB
GND
7
4
*MINIMUM INPUT-OUTPUT VOLTAGE RANGES FROM 40mV to 400mV.
DEPENDING ON LOAD CURRENT.
Figure 4. Wide Input Voltage Range Current Limiter
Figure 3. Latch Off When Error Flag Occurs
6V
SEALED
LEADACID
BATTERY
SOURCE
3
INPUT
GND
R2
+
1.5kΩ
8
1N457
+V IN
FB
SPX385
V OUT
1
MAIN V+
SPX2951
FOR 5.5 V
*V OUT = V IN
1
V OUT
SPX2951
RESET
+V IN
______
ERROR
MEMORY V+
SENSE
400kΩ
2
3
1µF
SD
100kΩ
+
GND
4
20kΩ
NI-CAD
BACKUP
BATTERY
Figure 5.Low Battery Disconnect
Rev. 3/6/03
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
10
©Copyright 2003 Sipex Corporation
TYPICAL APPLICATIONS: (Continued)
39kΩ
8
5
+VIN
ERROR
RESET
2
SENSE
VOUT
+VOUT=5V
1
+
SPX2951
C4
+
3
SD
39kΩ
1µF
FB
GND
TAP
4
6
7
100kΩ
1%
C1
+
100kΩ
C2
+
100kΩ
<5.8V**
6V
LEADACID
BATTERY
1%
1kΩ
1%
1kΩ
<6.0V**
100kΩ
C3
+
<6.2V**
10kΩ
R1
* OPTIONAL LATCH OFF WHEN DROPOUT OCCURS.
ADJUST R3 FOR C2 SWITCHING WHEN VIN IA 6.0V
* OUTPUTS GO LOW WHEN VIN DROPS BELOW DESIGNATED THRESHOLDS
20kΩ
1%
Figure 6. Regulator with State-of Charge Indicator
+V IN
8
3
AUX SHUTDOW
INPUT
OFF
+V IN
SD
10K Ω.
_______
ERROR
5 DEGREE SHUTDOWN FLAG
.
SPX2951
ON
V OUT
GND
+
TEMP
SENSOR
5
4
1
FB
EXTERNAL CIRCUIT
PROTECTED FROM
OVER TEMPERATURE
(V+ GOES OFF WHEN
TEMP > 125)
7
AS35
-
OR
RELAY
8.2K Ω
Figure 7. System Over Temperature Protection
Rev. 3/6/03
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
11
©Copyright 2003 Sipex Corporation
TYPICAL APPLICATIONS: (Continued)
+5V
4
4.7mA
20mA
UNREGULATED INPUT
8
OUTPUT
8
+V IN
IN
1
V OUT
330kΩ
1
1N4001
27kΩ
SPX2951
SPX2951
0.1µF
7
FB
2
5V
2
6
SENSE
V TAP
GND
360K Ω
4
2N5432
(2)
V OUT
FB
GND
7
4
OUTPUT
+
4.7µF
LOAD
50mA
TO
300 mA
1N457
MIN VOLTAGE = 4V
Figure 9. 300mA Regulator with 0.75V
Figure 8. Open Circuit Detector for 4mA to 20mA
Current Loop
IN
FEEDBACK
Q15A
R18
20kΩ
3
Q15B
24
Q24
Q25
3
Q26
3
Q9
Q4
Q3
R11
18kΩ
R27
1
Q8
Q5
C1
Q17
Q16
Q1
10
Q42
R1
20kΩ
R5
180kΩ
R9
27.8kΩ
R6
140kΩ
Q13
Q41
4
R28
C2
40pF
R10
150
kΩ
Q22
Q21
R13
100
kΩ
R12
110kΩ
Q23
R13
100kΩ
R14
350kΩ
Q12
Q18
Q11
R2
50kΩ
R30
30kΩ
VTAP
12kΩ
2
Q20
Q2
R8
31.4kΩ
Q40
2
R11
20.6kΩ
R17
Q14
1
Q6
20pF
OUT
SENSE
Q7
R16
30kΩ
Q19
R17
10Ω
Q29
R3
R4
50kΩ
13kΩ
3
Q28
6
R21
8Ω
R23
Q30
ERROR
Q37
Q38
R22
150kΩ
Q36
Q35
R26
60kΩ
2
4
Q31
R24
50kΩ
60kΩ
SHDN
Q34
5
DENOTES CONNECTION ON
LP2950 ONLY
R25
2.8kΩ
GND
Q39
Figure 10. Schematic Diagram
Rev. 3/6/03
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
12
©Copyright 2003 Sipex Corporation
PACKAGE DIAGRAM
8-Pin Surface Mount (S)
TO-92 (N)
2
1
OUTPUT
1
8
INPUT
SENSE
2
7
FEEDBACK
SHUTDOWN
3
6
5V or 3.3V Output
GROUND
4
5
ERROR
3
V
V
OUT
IN
GROUND
SPX2950 Bottom View
SPX2951 Top View
ORDERING INFORMATION
Ordering No.
Accuracy
Output Voltage
Packages
SPX2950ACN-3.3
0.5%
3.3V
3-Pin TO-92
SPX2950ACN-5.0
0.5%
5.0V
3-Pin TO-92
1%
3.3V
3-Pin TO-92
SPX2950CN-3.3
SPX2950CN-5.0
1%
5.0V
3-Pin TO-92
SPX2951ACS-3.3
0.5%
3.3V
8-Pin SOIC
SPX2951ACS-5.0
0.5%
5.0V
8-Pin SOIC
SPX2951CS-3.3
1%
3.3V
8-Pin SOIC
SPX2951CS-5.0
1%
5.0V
8-Pin SOIC
Corporation
SIGNAL PROCESSING EXCELLENCE
Sipex Corporation
Headquarters and
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sales Office
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: [email protected]
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. 3/6/03
SPX2950/SPX2951 150mA Low Dropout Voltage Regulator
13
©Copyright 2003 Sipex Corporation