LP2950AC [CALOGIC]
100mA Low Dropout Voltage Regulators; 100mA时的低压差稳压器
| 型号： | LP2950AC |
| 厂家： | 
CALOGIC, LLC |
| 描述： | 100mA Low Dropout Voltage Regulators |
| 文件： | 总10页 (文件大小：144K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
100mA Low Dropout
Voltage Regulators
CORPORATION
LP2950 / LP2951
FEATURES
PRODUCT DESCRIPTION
5V, 3.3V, and 3.0V Versions at 100mA Output
Very Low Quiescent Current
Low Dropout Voltage
Extremely Tight Load and Line Regulation
Very Low Temperature Coefficient
Current and Thermal Limiting
Needs Only 1µF for Stability
The Calogic LP2950 and LP2951 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 LP2950
and LP2951 features very low quiescent current and very low
dropout voltage (Typ. 50mV at light load and 380mV at 100mA).
This includes a tight initial tolerance of 0.5% typ., extremely
good load and line regulation 0.05% typ. and very low output
temperature coefficient, making the LP2950/LP2951 useful
as a low-power voltage reference.
•
•
•
•
•
•
•
LP2951 Versions Only
Error Flag Warns of Output Dropout
Logic-Controlled Electronic Shutdown
Output Programmable from 1.24 to 29V
•
The error flag output feature is used as power-on reset for
warning of a low output voltage, due to falling voltage input of
batteries. Another feature is the logic-compatible shutdown
input which enables the regulator to be switched on and off.
The LP2950 is offered in a 3-pin TO-92 package compatible
with other 5V, 3.0V, 3.3V regulators. The LP2951 is also available
in 8-pin plastic and SO-8.
•
•
APPLICATIONS
Battery Powered Systems
Cordless Telephones
Radio Control Systems
Portable / Palm Top / Notebook Computers
Portable Consumer Equipment
Portable Instrumentation
Avionics
SMPS Post-Regulator
•
•
•
The regulator output voltage may be pin-strapped for 5V, 3V
or 3.3 volts or programmed from 1.24 volt to 29 volts with an
external pair of resistors. Use of AS’s design, processing and
testing techniques make our LP2950 and LP2951 superior
over similar products.
•
•
•
•
•
Voltage Reference
Automotive Electronics
•
ORDERING INFORMATION
•
PART
PACKAGE
TEMPERATURE RANGE
LP2950ACN-X
LP2950CN-X
LP2951ACP-X
LP2951CP-X
LP2951ACS-X
LP2951CS-X
TO-92 (3-Pin)
TO-92 (3-Pin)
Plastic DIP (8-Pin)
Plastic DIP (8-Pin)
Plastic SOIC (8-Pin)
Plastic SOIC (8-Pin)
IND.
IND.
IND.
IND.
IND.
IND.
X = 3.0V, 3.3V or 5.0V
PIN CONNECTIONS
8-PIN SURFACE MOUNT
TO-92
OUTPUT
SENSE
1
2
3
4
8
7
6
5
INPUT
1
2
3
1. OUTPUT
2. GROUND
3. INPUT
FEEDBACK
5V OR 3.3V TAP
ERROR
LP2951
SHUTDOWN
GROUND
BOTTOM VIEW
1D-20
TOP VIEW
1D-19
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
LP2950 / LP2951
CORPORATION
ABSOLUTE MAXIMUM RATINGS
Power Dissipation . . . . . . . . . . . . . . . . . . . . . Internally Limited
Lead Temp. (Soldering, 5 Seconds) . . . . . . . . . . . . . . . 260oC
Storage Temperature Range . . . . . . . . . . . . . . . -65 to +150oC
Operating Junction Temperature Range
Input Supply Voltage . . . . . . . . . . . . . . . . . . . . . . -0.3 to +30V
Feedback Input Voltage. . . . . . . . . . . . . . . . . . . . -1.5 to +30V
Shutdown Input Voltage. . . . . . . . . . . . . . . . . . . . -0.3 to +30V
Error Comparator Output. . . . . . . . . . . . . . . . . . . -0.3 to +30V
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2KV Min
LP2951. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55 to +150oC
LP2950AC/LP2950C
LP2951AC/LP2951C . . . . . . . . . . . . . . . . . . . -40 to +125oC
ELECTRICAL CHARACTERISTICS: VS = 15V, TA = 25oC, unless otherwise specified.
LP2951
TYP
LP2950AC / LP2951AC LP2950C / LP2951C
CONDITIONS
PARAMETER
3V VERSIONS
UNITS
(Note 2)
MIN
MAX
MIN
TYP
MAX
MIN
TYP MAX
2.985
3.0
3.015 2.985
2.970
3.036 2.964
3.0
3.0
3.0
3.015 2.970
3.030 2.955
3.036 2.940
3.0 3.030
3.0 3.045
3.0 3.060
V
V
V
TJ = 25oC
Output Voltage
-25oC ≤ TJ ≤ 85oC
2.964
2.955
Full Operating Temperature
100µA ≤ IL ≤ 100mA
TJ ≤TJMAX
Output Voltage
3.0
3.3
3.045 2.958
3.0
3.042 2.928
3.0 3.072
V
3.3V VERSIONS
3.284
3.260
3.251
3.317 3.284
3.267
3.340 3.260
3.3
3.3
3.3
3.317 3.267
3.333 3.251
3.340 3.234
3.3 3.333
3.3 3.350
3.3 3.366
V
V
V
TJ = 25oC
Output Voltage
-25oC ≤ TJ ≤ 85oC
Full Operating Temperature
100µA ≤ IL ≤ 100mA
TJ ≤TJMAX
Output Voltage
3.3
5.0
3.350 3.254
3.3
3.346 3.221
3.3 3.379
V
5V VERSIONS
4.975
4.94
5.025 4.975
4.95
5.0
5.0
5.0
5.025 4.95
5.050 4.925
5.0
5.05
V
V
V
TJ = 25oC
Output Voltage
5.0 5.075
-25oC ≤ TJ ≤ 85oC
Full Operating Temperature
5.06
4.94
5.06
4.90
5.0
5.0
5.10
5.12
100µA ≤ IL ≤ 100mA
TJ ≤ TJMAX
Output Voltage
4.925
5.0
20
5.075 4.93
5.0
5.07
4.88
V
ALL VOLTAGE OPTIONS
Output Voltage
Temperature Coefficient
120
20
50
ppm/oC (Note 1)
Line Regulation (Note 3)
Load Regulation (Note 3)
0.03
0.04
0.1
0.1
0.03
0.04
0.1
0.1
0.04
0.1
0.2
0.2
%
%
6V ≤ VIN ≤ 30V (Note 4)
100µA ≤ IL ≤ 100mA
Dropout Voltage
(Note 5)
50
380
80
450
50
380
80
450
50
380
80
450
mV
mV
IL = 100µA
IL = 100mA
150
8
170
12
150
8
170
12
150
8
170
12
µA
mA
IL = 100µA
IL = 100mA
Ground Current
Current Limit
130
200
0.2
130
200
0.2
130
200
0.2
mA
VOUT = 0
Thermal Regulation
0.05
0.05
0.05
%/W
430
160
100
430
160
100
430
160
100
CL = 1µF
CL = 200µF
CL = 13.3µF
(Bypass = 0.01µF pins 7 to 1 (LP2951))
µVrms
µVrms
µVrms
Output Noise,
10Hz to 100KHz
8-PIN VERSIONS ONLY
Reference Voltage
LP2951
LP2951AC
LP2951C
1.22 1.235 1.25
1.22
1.19
1.235 1.25
1.27 1.185
60
1.21 1.235 1.26
V
V
Reference Voltage
1.19
1.27
60
1.285
60
Over Temperature (Note 6)
Feedback Pin Bias Current
40
20
40
20
40
50
nA
Reference Voltage
Temperature Coefficient
ppm/oC (Note 7)
Feedback Pin Bias Current
Temperature Coefficient
0.1
0.1
0.1
nA/oC
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
LP2950 / LP2951
CORPORATION
ELECTRICAL CHARACTERISTICS (continued)
LP2951
LP2950AC / LP2951AC LP2950C / LP2951C
CONDITIONS
PARAMETER
UNITS
(Note 2)
MIN
TYP
MAX
MIN
TYP
MAX
MIN
TYP MAX
ERROR COMPARATOR
Output Leakage Current
Output Low Voltage
Upper Threshold Voltage
Lower Threshold Voltage
Hysteresis
0.01
150
60
1
0.01
150
60
1
0.01
150
60
1
µA
mV
mV
mV
mV
VOH = 30V
250
250
250
VIN = 4.5V, IOL = 400µA
(Note 7)
40
40
40
75
95
75
95
75
95
(Note 7)
15
15
15
(Note 7)
SHUTDOWN INPUT
1.3
0.6
1.3
0.7
1.3
0.7
V
V
Low (Regulator ON)
High (Regulator OFF)
Input Logic Voltage
2
2
2
Shutdown Pin
Input Current
30
675
50
800
30
675
50
800
30
675
50
800
µA
µA
V
V
S = 2.4V
S = 30V
Regulator Output Current
in Shutdown
3
10
3
10
3
10
µA
(Note 9)
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 guaranteed for TJ = 25oC, VIN = 6V, 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 LP2951 is tested at 150oC for IL = 1mA. For IL = 100µA and TJ = 125oC, line regulation is guaranteed by design to
0.2%. 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 input account.
Note 6: VREF ≤ VOUT ≤ (VIN - 1V), 2.3 ≤ VIN ≤ 30V, 100µA ≤ IL ≤ 100mA, 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 Tap.
Note 9: All typical values are not guaranteed.
BLOCK DIAGRAM
UNREGULATED DC
5V @ 100mA
MAX
7
8
1
+
FEEDBACK
INPUT
OUTPUT
2
SENSE
+
–
180kΩ
60kΩ
6
ERROR
AMPLIFIER
3
330kΩ
5V TAP
FROM
CMOS
OR TTL
SHUTDOWN
+
5
1µF
+
+
–
60mV
ERROR
ERROR DETECTION
COMPARATOR
TO CMOS OR
TTL
+
1.23V
REFERENCE
LP2950 AND LP2951 BLOCK DIAGRAM
4
GROUND
1D-21
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
LP2950 / LP2951
CORPORATION
APPLICATION HINTS
EXTERNAL CAPACITORS
The error comparator has an open-collector output which
requires an external pullup 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.
• The stability of the LP2950/LP2951 requires a 1.0µF or
greater capacitor between output and ground. Oscillation
could occur without this capacitor. Most types of tantalum
or aluminum electrolytic are acceptable. For operations
below -25oC a solid tantalum is recommended since the
many aluminum types have electrolytes that freeze at about
-30oC. The ESR of about 5Ω or less and resonant
frequency about 500kHz are the most important parameters
in the value of the capacitor. The capacitors value may be
increased without limit.
PROGRAMMING THE OUTPUT VOLTAGE OF LP2951
The LP2951 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.
• At lower values of output current, less output capacitance is
required for stability. For 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.
Refer to the equation below for the programming of the output
voltage:
• At worst case 3.3µF or greater must be used for the
condition of 100mA load at 1.23V output.
VOUT = VREF × (1 + R1\R2) + IFBR1
• The LP2950, 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 circuits. When
setting the output voltage of the LP2951 version with
external resistors, a minimum load of 1µA is recommended.
The VREF is 1.235 and IFB is the feedback bias current,
nominally -20nA. The minimum recommended load current of
1µA 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 LP2951 typically draws
60µA at no load with Pin 2 open-circuited this is a small price
to pay.
• 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 1µA tantalum or aluminum electrolytic capacitor
should be placed from the input to the ground.
REDUCING OUTPUT NOISE
• Instability can occur if there is a stray capacitance to the
LP2951 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 eliminated by
adding a 100pF capacitor between output and feedback
and increasing the output capacitor to at least 3.3µF.
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 lead 3 of LP2950, 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.
ERROR DETECTION COMPARATOR OUTPUT
The Comparator produces a logic low output whenever the
LP2951 output falls out of regulation by more than around 5%.
This occurs at approximately 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
LP2951 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 LP2951’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.
Noise could also be reduced fourfold by a bypass capacitor
across R1, since it reduces the high frequency gain from 4 to
unity.
CBYPASS 1/2πR1 × 200Hz
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 voltages.
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
LP2950 / LP2951
CORPORATION
TYPICAL PERFORMANCE CHARACTERISTICS
DROPOUT
CHARACTERISTICS
QUIESCENT CURRENT
INPUT CURRENT
10
6
5
4
3
2
1
0
250
225
200
175
150
125
100
75
5V OUTPUT
5V OUTPUT
R
= 50kΩ
L
1
0.1
R
= 50kΩ
L
R
= 50Ω
L
R
∞
L
50
25
0.01
0.1
0
1.0
10
100
0
1
2
3
4
5
6
0
1
2
3
4
5
6
7
8
9 10
LOAD CURRENT (mA)
INPUT VOLTAGE (VOLTS)
INPUT VOLTAGE (VOLTS)
1D-22
1D-23
1D-24
OUTPUT VOLTAGE vs
TEMPERATURE OF 3
INPUT CURRENT
5V OUTPUT
REPRESENTATIVE UNITS
QUIESCENT CURRENT
5V OUTPUT
120
5.06
5.04
5.02
5.0
160
140
120
100
80
5V OUTPUT
110
100
90
80
70
60
50
40
30
20
10
0
R
= 50Ω
L
I
I
= 1mA
L
= 0
L
60
4.98
4.96
4.94
40
0.2%
20
0
0
1
2
3
4
5
6
7
8
9
10
–75 –50 –25
0
25 50 75 100 125 150
0
1
2
3
4
5
6
7
8
INPUT VOLTAGE (VOLTS)
TEMPERATURE (˚C)
INPUT VOLTAGE (VOLTS)
1D-25
1D-26
1D-27
SHORT CIRCUIT CURRENT
DROPOUT VOLTAGE
DROPOUT VOLTAGE
170
160
150
140
130
120
110
100
600
500
400
300
100
50
500
400
300
200
100
0
I
= 100mA
L
T
= 25˚C
1mA
J
I
= 100µA
L
0
–75 –50 –25
0
25 50 75 100 125 150
–75 –50 –25
0
25 50 75 100 125 150
100µA
10mA
100mA
TEMPERATURE (˚C)
TEMPERATURE (˚C)
OUTPUT CURRENT
1D-28
1D-29
1D-30
QUIESCENT CURRENT
5V OUTPUT
QUIESCENT CURRENT
5V OUTPUT
QUIESCENT CURRENT
5V OUTPUT
120
110
100
90
10
9
8
7
6
5
4
3
2
1
0
V
= 6V
IN
I
= 100mA
V
= 6V
L
IN
I
= 100µA
L
80
I
= 100mA
L
8
70
60
50
7
–75 –50 –25
0
25 50 75 100 125 150
–75 –50 –25
0
25 50 75 100 125 150
0
1
2
3
4
5
6
7
8
TEMPERATURE (˚C)
TEMPERATURE (˚C)
INPUT VOLTAGE (V)
1D-31
1D-32
1D-33
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
LP2950 / LP2951
CORPORATION
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
LP2951 MINIMUM
OPERATING VOLTAGE
LP2951 FEEDBACK
BIAS CURRENT
LP2951 FEEDBACK
PIN CURRENT
2.2
2.1
2.0
1.9
1.8
1.7
1.6
20
10
50
0
PIN 7 DRIVEN BY
EXTERNAL SOURCE
(REGULATROR RUN
OPEN LOOP)
–50
0
T
= 125˚C
A
–100
–150
–200
–250
–10
–20
–30
T
= 25˚C
A
T
= –55˚C
A
–75 –50 –25
0
25 50 75 100 125 150
–75 –50 –25
0
25 50 75 100 125 150
–2.0 –1.5 –1.0 –0.5
0
0.5
1.0
TEMPERATURE (˚C)
TEMPERATURE (˚C)
FEEDBACK VOLTAGE (V)
1D-34
1D-35
1D-36
LP2951 ERROR
LP2951 COMPARATOR
SINK CURRENT
LINE TRANSIENT
RESPONSE
COMPARATOR OUTPUT
8
6
2.5
2.0
1.5
1.0
0.5
0.0
100mV
50mV
0
V
= 5V
OUT
T
= 125˚C
A
4
T
= 25˚C
A
C
I
= 1µA
L
–50mV
8V
HYSTERESIS
= 1mA
L
2
V
= 5V
OUT
T
= –55˚C
A
0
6V
NOTE: PULLUP RESISTOR
TO SEPARATE 5V SUPPLY
–2
4V
0
1
2
3
4
5
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
0
200
400
600
800
INPUT VOLTAGE (V)
OUTPUT LOW VOLTAGE (V)
TIME (µs)
1D-37
1D-38
1D-39
OUTPUT IMPEDANCE
RIPPLE REJECTION
RIPPLE REJECTION
10
5
90
80
70
60
50
40
30
20
90
80
70
60
50
40
30
20
C
= 1µF
L
I
= 100µA
V
= 6V
= 5V
O
IN
V
2
1
OUT
I
= 1mA
I
= 100mA
O
O
I
= 1mA
L
I
= 0
L
0.5
0.2
0.1
V
= 5V
OUT
= 1µA
I
= 100µA
L
C
L
C
V
V
1
= 1µF
0.05
L
= 6V
IN
0.02
0.01
I
= 10mA
L
= 5V
2
OUT
3
4
5
6
1
2
3
4
5
6
10
10
100
1K
10K
100K
1M
10
10
10
10
10
10
10
10
10
10
10
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
1D-40
1D-41
1D-42
LP2951
LOAD TRANISENT
RESPONSE
LOAD TRANSIENT
RESPONSE
ENABLE TRANSIENT
7
6
250
80
60
C
= 1µF
L
200
150
100
50
40
5
20
4
I
= 10mA
L
0
3
V
V
= 8V
IN
OUT
0
–20
–40
–60
2
C
= 10µF
= 5V
L
–50
–100
1
C
V
= 1µF
C
V
= 10µF
L
L
0
= 5V
= 5V
OUT
OUT
2
100mA
100mA
0
100µA
100µA
–2
–100
0
100 200 300 400 500 600 700
0
1
2
3
4
5
0
4
8
12
16
20
TIME (µs)
1D-45
TIME (ms)
TIME (ms)
1D-43
1D-44
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
LP2950 / LP2951
CORPORATION
TYPICAL APPLICATIONS
+VIN
4.75V
OUTPUT
VOLTAGE
8
100K
+VIN
1.2 TO 30V
5
3
1
ERROR
ERROR
VOUT
ERROR*
OUTPUT
LP2951
+
3.3µF
R1
SHUTDOWN
INPUT
SD
GND
4
.01µF
FB
5.0V
7
1.23V
INPUT
VOLTAGE
1.3V
R2
VREF
*SEE APPLICATION INFO.
1F-44
1F-45
FIGURE 1. ERROR OUTPUT TIMING
FIGURE 2. ADJUSTABLE REGULATOR
+VIN
+VIN
8
8
470KΩ
+VIN
+VIN
VOUT
5
3
1
*VOUT = VIN
5
3
1
ERROR
ERROR
VOUT
ERROR
VOUT
OUTPUT
470KΩ
LP2951
LP2951
+
1µF
R1
SHUTDOWN
INPUT
SD
SD
GND
4
GND
4
FB
7
FB
7
R2
*MINIMUM INPUT - OUTPUT VOLTAGE RANGES FROM 4mV TO 400mV.
DEPENDING ON LOAD CURRENT. CURRENT LIMIT IS TYPICALLY 160mA.
WIDE INPUT VOLTAGE RANGE CURRENT LIMITER
LATCH OFF WHEN ERROR FLAG OCCURS
1F-46
1F-47
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
LP2950 / LP2951
CORPORATION
TYPICAL APPLICATIONS (continued)
+
6V
120KΩ
1.5KΩ
8
SEALED
LEAD-
ACID
BATTERY
SOURCE
+V
IN457
IN
1
MAIN V-
VOUT
FB
CLM385
LP2951
MEMORY V+
SENSE
400KΩ
FOR 5.5V
+
3
1µF
20KΩ
SD
100KΩ
GND
4
NI-CAD
BACKUP
BATTERY
LOW BATTERY DISCONNECT
1G-24
8
2
39k
Ω
SENSE
+V
IN
= 5V
+VOUT
+
5
1
7
ERROR
VOUT
RESET
1µF
LP2951
–
+
3
C4
SD
GND
TAP
6
39k
Ω
4
100k
Ω
1%
1%
1%
100k
Ω
Ω
Ω
–
+
C1
6V
LEAD-
ACID
<5.8V**
<6.0V**
<6.2V**
1k
Ω
Ω
100k
–
+
C2
C3
BATTERY
1k
100k
–
+
10k
20k
Ω
R3
Ω
1%
*OPTIONAL LATCH OFF WHEN DROPOUT OCCURS. ADJUST R3 FOR C2 SWITCHING WHEN V IS 6.0V.
IN
**OUTPUTS GO LOW WHEN V DROPS BELOW DESIGNATED THRESHHOLDS.
IN
REGULATOR WITH STATE-OF-CHARGE INDICATOR
1G-25
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
LP2950 / LP2951
CORPORATION
TYPICAL APPLICATIONS (continued)
+VIN
8
10KΩ
+VIN
3
5
1
AUX SHUTDOWN
INPUT
5 DEGREE SHUTDOWN FLAG
SD
ERROR
OFF
ON
LP2951
VOUT
FB
GND
4
7
EXTERNAL CIRCUIT
PROTECTED FROM
OVER TEMPERATURE
(V+ GOES OFF WHEN
TEMP > 125)
+
AS35
–
OR
TEMP
SENSOR
RELAY
8.2KΩ
SYSTEM OVER TEMPERATURE PROTECTION CIRCUIT
1F-48
+5v
4.7mA
4
20mA
UNREGULATED INPUT
OUTPUT
8
+VIN
330KΩ
1
5
1
2
VOUT
IN
VOUT
2N5432
IN4001
27KΩ
LP2951
LP2951
0.1µF
7
3
5V
FB
2
VTAP
FB
SENSE
OUTPUT
GND
4
GND
+
7
4
4.7µF
360KΩ
IN457
LOAD 50mA
TO 300mA
MIN VOLTAGE = 4V
OPEN CIRCUIT DETECTOR FOR 4mA TO 20mA CURRENT LOOP
1F-49
300mA REGULATOR WITH 0.75 DROPOUT
1F-50
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
LP2950 / LP2951
CORPORATION
SCHEMATIC DIAGRAM
IN
FEEDBACK
R18
20k
Ω
Q15A
Q15B
24
Q24
3
Q26
Q25
3
OUT
Q9
Q7
Q3
Q4
SENSE
R11
18
R27
182k
Q5
Q8
R17
Ω
Q14
k
Ω
R11
20.6
12k
Ω
Q6
C1
Q16
1
Q17
1
5V TAP
20pF
k
Ω
R28
2
2
Q1
10
60k
Ω
Q2
Q20
R1
Q22
R10
150
20k
Ω
Q42
R8
31.4k
Ω
Q21
k
Ω
Q23
C2
40pF
R2
3
R15
100k
50k
Ω
Ω
R9
R5
180
R6
140
27.8k
Ω
R14
350
kΩ
Ω
Ω
k
k
R16
Ω
30k
Q40
Q13
Q12
R17
Q41
Q11
10
Ω
Q29
4
Q18
Q19
R30
30k
Q28
6
Ω
R3
50k
R4
13k
Ω
Ω
R21 8
Ω
Q30 Q31
SHDN
R23 60k
Ω
R22
150k
R24
50k
Q37
Q36
Ω
Ω
ERROR
Q38
Q34
5
4
R26
60k
Ω
R25
2.8
—
—
— DENOTES CONNECTION ON LP2950 ONLY
2
k
Ω
GND
1G-01
Q39
CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
相关型号：
©2020 ICPDF网 联系我们和版权申明