LT1020
Micropower Regulator
and Comparator
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FEATURES
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DESCRIPTIO
The LT®1020 is a combination micropower positive regulator and free collector comparator on a single monolithic
chip. With only 40µA supply current, the LT1020 can
supply over 125mA of output current. Input voltage range
is from 4.5V to 36V and dropout voltage is 0.6V at 125mA.
Dropout voltage decreases with lower load currents. Also
included on the chip is a class B output 2.5V reference that
can either source or sink current. A dropout detector
provides an output current to indicate when the regulator
is about to drop out of regulation.
Input Voltage Range: 4.5V to 36V
40µA Supply Current
125mA Output Current
2.5V Reference Voltage
Reference Output Sources 1mA and Sinks 0.5mA
Dual Output Comparator
Comparator Sinks 10mA
Dropout Detector
0.2V Dropout Voltage
Thermal Limiting
Available in SO Package
The dual output comparator can be used as a comparator
for system or battery monitoring. For example, the comparator can be used to warn of low system voltage while
the dropout detector shuts down the system to prevent
abnormal operation. Frequency compensation of the comparator for amplifier applications can be obtained by
adding external output capacitance. Dual output or positive and negative regulators can also be made.
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APPLICATIO S
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Battery Systems
Battery Backup Systems
Portable Terminals
Portable Instruments
The 2.5V reference will source or sink current. This allows
it to be used as a supply splitter or auxiliary output.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
5V Regulator
VOUT
VIN
GND
9
FB
1M
11
+
10µF
1M
1020 TA01
0.1
0.01
0.1
1
10
1
100
OUTPUT CURRENT (mA)
SUPPLY CURRENT (mA)
10µF
10
5V
0.001µF
LT1020
+
1
2
DROPOUT VOLTAGE (V)
3
VIN > 5.2V
IQ = 40µA
Dropout Voltage and Supply Current
0.1
1000
1020 TA02
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LT1020
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ABSOLUTE
RATI GS (Note 1)
Input Voltage .......................................................... 36V
NPN Collector Voltage ............................................ 36V
PNP Collector Voltage ............................. Supply – 36V
Output Short Circuit Duration ......................... Indefinite
Power Dissipation .............................. Internally Limited
Storage Temperature Range ................ – 65°C to 150°C
Operating Temperature Range
LT1020C ............................................. 0°C to 100°C
LT1020I ........................................ – 40°C to 100 °C
LT1020M (OBSOLETE) .................. – 55°C to 125°C
Lead Temperature (Soldering, 10 sec).................. 300°C
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PACKAGE/ORDER I FOR ATIO
TOP VIEW
NC
1
VOUT
2
VIN
3
REF OUT
4
COMP PNP
5
14 NC
DROPOUT
13 DETECTOR
12 SHUTDOWN
COMP NPN
6
11 FEEDBACK
CURRENT
10 LIMIT
9 GND
+INPUT
7
8
ORDER PART
NUMBER
ORDER PART
NUMBER
TOP VIEW
LT1020CN
LT1020IN
16 NC
15 DROPOUT
DETECTOR
14 SHUTDOWN
NC 1
VOUT 2
VIN 3
13 FEEDBACK
12 CURRENT
LIMIT
11 GND
REF OUT 4
COMP PNP 5
–INPUT
COMP NPN 6
N PACKAGE
14-LEAD PDIP
10 –INPUT
+INPUT 7
TJMAX = 110°C, θJA = 130°C/W
9
NC 8
LT1020CJ
LT1020IJ
LT1020MJ
J PACKAGE 14-LEAD CERDIP
TJMAX = 150°C, θJA = 80°C/W
LT1020CSW
LT1020ISW
NC
SW PACKAGE
16-LEAD PLASTIC (WIDE) SO
TJMAX = 110°C, θJA = 150°C/W
OBSOLETE PACKAGE
Consider the N14 Package for Alternate Source
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
PARAMETER
Reference
Reference Voltage
Line Regulation
Load Regulation
Output Source Current
Output Sink Current
Temperature Stability
Regulator
Supply Current
Output Current
Load Regulation
Line Regulation
Dropout Voltage
TJ = 25°C
CONDITIONS
MIN
TYP
MAX
UNITS
4.5V ≤ VIN ≤ 36V
4.5V ≤ VIN ≤ 36V
– 0.5mA ≤ IREF ≤ 1mA, VIN = 12V
VIN = 5V
VIN = 5V
2.46
2.50
0.01
0.2
4
2
1
2.54
0.015
0.3
V
%/V
%
mA
mA
%
45
75
11
80
120
20
0.2
0.01
0.02
0.4
0.5
0.015
0.05
0.65
µA
µA
mA
mA
%
%/V
V
V
VIN = 6V, IOUT ≤ 100µA
VIN = 36V, IOUT ≤ 100µA
VIN = 12V, IOUT = 125mA
(VIN – VOUT) ≥ 1V, VIN ≥ 6V
(VIN – VOUT) ≥ 1V, VIN ≥ 6V
6V ≤ VIN ≤ 36V
IOUT = 100µA
IOUT = 125mA
1
0.5
125
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LT1020
ELECTRICAL CHARACTERISTICS
PARAMETER
Regulator
Feedback Sense Voltage
Dropout Detector Current
Feedback Bias Current
Minimum Load Current
Short-Circuit Current
Comparator
Offset Voltage
Bias Current
Offset Current
Gain-NPN Pull-Down
Common Mode Rejection
Power Supply Rejection
Output Sink Current
NPN Saturation Voltage
Output Source Current
Input Voltage Range
Response Time
Leakage Current (NPN)
TJ = 25°C
CONDITIONS
MIN
TYP
MAX
UNITS
VIN = 12V
∆VOUT = – 0.05V, IOUT = 500µA
2.44
3
2.5
20
15
1
300
30
2.56
V
µA
nA
µA
mA
mA
3
15
4
10000
94
96
18
0.4
200
7
40
15
VIN = 36V
VIN = 36V
Pins 9 and 10 Shorted, VIN = 4.5V
3
0V ≤ VCM ≤ 35V, VIN = 36V
0V ≤ VCM ≤ 35V, VIN = 36V
0V ≤ VCM ≤ 35V, VIN = 36V
∆VOUT = 29V, RL = 20k
0V ≤ VCM ≤ 35V, VIN = 36V
4.5V ≤ VS ≤ 36V
VIN = 4.5V
IOUT = 1mA
2000
80
80
10
60
0
40
5
400
mV
nA
nA
V/ V
dB
dB
mA
V
µA
V
µs
µA
0.6
VIN – 1
5
2
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C.
PARAMETER
Reference
Reference Voltage
Line Regulation
Load Regulation
Output Source Current
Output Sink Current
Regulator
Supply Current
Output Current
Load Regulation
Line Regulation
Dropout Voltage
Feedback Sense Voltage
Dropout Detector Current
Feedback Bias Current
Minimum Load Current
Short-Circuit Current
Comparator
Offset Voltage
Bias Current
CONDITIONS
4.5V ≤ VIN ≤ 36V
4.5V ≤ VIN ≤ 36V
– 0.5mA ≤ IREF ≤ 1mA, VIN = 12V
VIN = 5V
VIN = 5V
●
VIN = 6V, IOUT ≤ 100µA
VIN = 36V, IOUT ≤ 100µA
VIN = 12V, IOUT = 125mA
(VIN – VOUT) ≥ 1V, VIN ≥ 6V
(VIN – VOUT) ≥ 1V, VIN ≥ 6V
6V ≤ VIN ≤ 36V
IOUT = 100µA
IOUT = 125mA
VIN = 12V
∆VOUT = – 0.05V, IOUT = 500µA
●
●
●
MIN
TYP
MAX
UNITS
2.40
2.50
0.01
0.3
2.55
0.02
0.4
V
%/V
%
mA
mA
65
85
11
95
120
20
2.5
1
0.02
0.06
0.85
2.57
µA
µA
mA
mA
%
%/ V
V
V
V
µA
nA
µA
mA
mA
●
●
●
●
●
1
0.5
125
●
●
●
●
●
●
2.38
3
●
VIN = 36V
VIN = 36V
Pins 9 and 10 Shorted, VIN = 4.5V
●
0V ≤ VCM ≤ 35V, VIN = 36V
0V ≤ VCM ≤ 35V, VIN = 36V (Note 2)
●
●
●
●
2.5
300
30
15
50
50
400
10
60
mV
nA
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LT1020
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TJ = 25°C.
PARAMETER
Comparator
Offset Current
Gain-NPN Pull-Down
Common Mode Rejection
Power Supply Rejection
Output Sink Current
Output Source Current
Input Voltage Range
Leakage Current (NPN)
CONDITIONS
MIN
0V ≤ VCM ≤ 35V, VIN = 36V
∆VOUT = 29V, RL = 20k
0V ≤ VCM ≤ 35V, VIN = 36V
4.5V ≤ VIN ≤ 36V
VIN = 4.5V (Note 3)
TYP
●
●
●
●
●
VIN = 36V
UNITS
20
●
●
1000
80
80
5
40
0
nA
V/ V
dB
dB
mA
µA
V
µA
10
120
VIN – 1
8
●
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
MAX
Note 2: For 0V ≤ VCM ≤ 0.1V and T > 85°C IBIAS(MAX) is 100nA.
Note 3: For TA ≤ – 40°C output ISINK(MIN) is 2.5mA.
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TYPICAL PERFOR A CE CHARACTERISTICS
Regulator Load Regulation
Supply Current
100
PRELOAD = 100µA
TJ = –55°C TO 125°C
0.1
TJ = 25°C
0
TJ = 125°C
–0.1
SHORT-CIRCUIT CURRENT (mA)
TJ = –55°C
10
1
0.1
–0.2
–0.3
0.1
10
100
1
OUTPUT CURRENT (mA)
0.01
0.1
1000
200
150
100
10
1000
1
100
REGULATOR OUTPUT CURRENT (mA)
1020 G04
–10
70
110
30
TEMPERATURE (°C)
1
Dropout Voltage
1
DROPOUT DETECTOR = 5µA
0.1
0.01
0.1
150
1020 G03
INPUT/OUTPUT DIFFERENTIAL (V)
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
0.1
CURRENT LIMIT TIED TO GROUND
50
Dropout Voltage
∆VOUT = 100mV
0.01
0.1
250
1020 G02
Dropout Voltage
1
300
0
–50
1
10
100
1000
REGULATOR OUTPUT CURRENT (mA)
1020 G01
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
Regulator Short-Circuit Current
350
0.2
SUPPLY CURRENT (mA)
OUTPUT VOLTAGE CHANGE (%)
0.3
I DROPOUT DETECTOR = 0.1% IOUT
0.1
I DROPOUT DETECTOR = 1% IOUT
0.01
10
1000
1
100
REGULATOR OUTPUT CURRENT (mA)
1020 G05
0.1
1
10
100
REGULATOR OUTPUT CURRENT (mA)
1020 G06
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LT1020
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TYPICAL PERFOR A CE CHARACTERISTICS
Dropout Detector Current
Dropout Detector Current
1
0.1
VDIFF = 1V
IOUT = 100mA
10
100
REGULATOR OUTPUT CURRENT (mA)
IOUT = 25mA
100
IOUT = 5mA
10
IOUT = 1mA
1
0.01
100
1000
70
80
90 100 110 120 130 140
TEMPERATURE (°C)
Supply Current
Regulator Ripple Rejection
Supply Current at Dropout
10
10
IOUT = 100mA
150
1020 G09
1020 G08
70
65
10
1
0.1
0
0.2
0.3
0.4
0.5
0.6
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
1020 G07
TJ = –55°C TO 125°C
IOUT = 100mA
IOUT = 100mA
55
IOUT = 1mA
50
45
40
VIN = 100VDC, 1VP-P
35 V
OUT = 5V
COUT = 10µF
30
10
10k
100
1k
RIPPLE FREQUENCY (Hz)
1
IOUT = 10mA
0.1
0.01
100k
IOUT = 1mA
VOUT = 5V
TJ = –55°C TO 125°C
1020 G10
IOUT = 10mA
0.1
Reference Regulation
3
90
INPUT BIAS CURRENT (nA)
100
1
0
–1
–2
–3
Feedback Pin Current
80
70
60
40
35
TJ = 125°C
TJ = 25°C
TJ = –55°C
50
40
30
20
1.5
1020 G13
0
–1.0
30
25
TJ = –55°C
20
15
TJ = 25°C
10
TJ = 125°C
5
10
0.5
1.0
–1.0 –0.5
0
REFERENCE OUTPUT CURRENT (mA)
0.1
0
0.2
0.3
0.4
0.5
0.6
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
1020 G12
Comparator Input Bias Current
2
IOUT = 1mA
1020 G11
4
–4
–1.5
1
0.01
5
1
10
15
20
25
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
FEEDBACK PIN CURRENT (nA)
60
SUPPLY CURRENT (mA)
IOUT = 10mA
SUPPLY CURRENT (mA)
RIPPLE REJECTION (dB)
MINIMUM LOAD CURRENT (µA)
DROPOUT DETECTOR CURRENT (µA)
DROPOUT DETECTOR CURRENT (µA)
VDIFF = 500mV
10
REFERENCE VOLTAGE CHANGE (mV)
Regulator Minimum Load Current
1000
100
0
–0.6
0.6
–0.2 GND 0.2
COMMON MODE VOLTAGE (V)
REFERRED TO PIN 9 (GND)
1.0
0.1
100
1000
1
10
REGULATOR OUTPUT CURRENT (mA)
1020 G15
1020 G14
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LT1020
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TYPICAL PERFOR A CE CHARACTERISTICS
LT1020 Turn-On Characteristic
5.5
VIN = 15V
VOUT = 5V
0
–0.1
OUTPUT
CURRENT (mA)
VOUT = 5V
5.0
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE
CHANGE (%)
Regulator Thermal Regulation
0.1
4.5
4.0
NO LOAD
3.5
RL = 50Ω
3.0
RL = 500Ω
2.5
50
2.0
0
0
20 40 60 80 100 120 140 160 180
TIME (ms)
0
0
1
1020 G16
2
5
6
3
4
INPUT VOLTAGE (V)
7
8
1020 G17
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PI FU CTIO S
Pins 1, 14: No Internal Connection.
Pin 9: Ground.
Pin 2: Regulator Output. Main output, requires 10µF
output capacitor. Can be shorted to VIN or ground without
damaging the device.
Pin 10: Current Limit. Connecting this pin to ground
decreases the regulator current limit to 3mA minimum.
Leave open when not used.
Pin 3: Input Supply. Bypass with 10µF capacitor. Must
always be more positive than ground.
Pin 11: Feedback. This is the feedback point of the regulator. When operating, it is nominally at 2.5V. Optimum
source resistance is 200k to 500k. The feedback pin
should not be driven below ground or more positive than
5V.
Pin 4: Reference. 2.5V can source or sink current. May be
shorted to ground or up to 5V. Voltages in excess of 5V can
damage the device.
Pin 5: Comparator PNP Output. Open Collector PNP
Output. Pull-up current source for the comparator. May be
connected to any voltage from VIN to 36V more negative
than VIN (operates below ground). Short-circuit protected.
For example, if VIN is 6V then pin 5 will operate to – 30V.
Pin 6: Comparator NPN Output. Open Collector NPN
Output. May be connected to any voltage from ground to
36V more positive than ground (operates above VIN).
Short-circuit protected.
Pin 12: Shutdown. Turns output off.
Pin 13: Dropout Detector. This pin acts like a current
source from VIN which turns on when the output transistor
goes into saturation. The magnitude of the current depends on the magnitude of the output current and the
input/output voltage differential. Pin current ranges from
5µA to about 300µA.
Pins 7, 8: Comparator Inputs. Operates from ground to
VIN – 1V. Comparator inputs will withstand 36V even with
VIN of 0V.
sn1020 1020fcs
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LT1020
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BLOCK DIAGRA
REF OUT 4
10
–
PNP OUT
5
NPN OUT
6
CURRENT
LIMIT
3
VIN
2
VOUT
13
DROPOUT
DETECTOR
+
REF
2.5V
NONINVERTING
7
INVERTING
8
11 FB
9
GND
1020 BD
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APPLICATIO S I FOR ATIO
The LT1020 is especially suited for micropower system
applications. For example, the comparator section of the
LT1020 may be used as a battery checker to provide an
indication of low battery. The dropout detector can shut
down the system when the battery voltage becomes too
low to regulate. Another type of system application for the
LT1020 would be to generate the equivalent of split
supplies from a single power input. The regulator section
provides regulated output voltage and the reference, which
can both source and sink current, is then an artificial
system ground providing a split supply for the system.
If the PNP output is being used, to maximize the gain a 1µA
to 5µA load should be placed upon the NPN output
collector. This is easily done by connecting a resistor
between the NPN collector and the reference output.
(Providing this operating current to the NPN side increases the internal emitter base voltages and maximizes
the gain of the PNP stage.) Without this loading on the
NPN collector, at temperatures in excess of 75°C, the gain
of the PNP collector can decrease by a factor of 2 or 3.
For many applications the comparator can be frequency
compensated to operate as an amplifier. Compensation
values for various gains are given in the data sheet. The
comparator gain is purposely low to make it easier to
frequency compensate as an amplifier. Two outputs are
available on the comparator, the NPN output is capable of
sinking 10mA and can drive loads connected to voltages
in excess of the positive power supply. This is useful for
driving switches or linear regulators from a higher input
voltage. The PNP output, which is capable of sourcing
100µA can drive loads below ground. It can be used to
make negative regulators with the addition of an external
pass transistor. Both outputs can be tied together to
provide an output that swings from rail-to-rail for comparator or amplifier applications. Although it is not specified, the gain for the PNP output is about 500 to 1000.
Internal to the LT1020 is a 2.5V trimmed class B output
reference. The reference was designed to be able to source
or sink current so it could be used in supply splitting
applications as well as a general purpose reference for
external circuitry. The design of the reference allows it to
source typically 4mA or 5mA and sink 2mA. The available
source and sink current decreases as temperature increases. It is sometimes desirable to decrease the AC
output impedance by placing an output capacitor on them.
The reference in the LT1020 becomes unstable with large
capacitive loads placed directly on it. When using an
output capacitor, about 20Ω should be used to isolate the
capacitor from the reference pin. This 20Ω resistor can be
placed directly in series with the capacitor or alternatively
the reference line can have 20Ω placed in series with it and
then a capacitor to ground. This is shown in Figure 1. Other
Reference
sn1020 1020fcs
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LT1020
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APPLICATIO S I FOR ATIO
than placing large capacitive loads on the reference, no
other precautions are necessary and the reference is
stable with nominal stray capacitances.
REF
4
REF
4
OUTPUT
20Ω
20Ω
OR
+
OUTPUT
+
10µF
10µF
1020 F01
Figure 1. Bypassing Reference
Overload Protection
The main regulator in the LT1020 is current limited at
approximately 350mA. The current limit is stable with both
input voltage and temperature. A current limit pin, when
strapped to ground, decreases the output current. This
allows the output current to be set to a lower value than
250mA. The output current available with the current limit
pin strapped to ground is not well controlled so if precise
current limiting is desired it should be provided externally
as is shown in some of the application circuits.
If the device is overloaded for long periods of time, thermal
shutdown turns the output off. In thermal shutdown, there
may be some oscillations which can disturb external
circuitry. A diode connected between the reference and
feedback terminal provides hysteresis under thermal shutdown, so that the device turns on and off with about a 5
second period and there are no higher frequency oscillations. This is shown in Figure 2. This diode is recommended for most applications. Thermal shutdown
temperature is set at approximately 145°C.
VOUT
2
0.001µF
LT1020
REF
FB
11
+
10µF
4
*
* DIODE ADDS FEEDBACK
1020 F02
Figure 2. Minimizing Oscillation in Thermal Shutdown
Like most other IC regulators, a minimum load is required
on the output of the LT1020 to maintain regulation. For
most standard regulators this is normally specified at
5mA. Of course, for a micropower regulator this would be
a tremendously large current. The output current must be
large enough to absorb all the leakage current of the pass
transistor at the maximum operating temperature. It also
affects the transient response; low output currents have
long recovery times from load transients. At high operating temperatures the minimum load current increases and
having too low of a load current may cause the output to
go unregulated. Devices are tested for minimum load
current at high temperature. The output voltage setting
resistors to the feedback terminal can usually be used to
provide the minimum load current.
Frequency Compensation
The LT1020 is frequency compensated by a dominant pole
on the output. An output capacitor of 10µF is usually large
enough to provide good stability. Increasing the output
capacitor above 10µF further improves stability. In order
to insure stability, a feedback capacitor is needed between
the output pin and the feedback pin. This is because stray
capacitance can form another pole with the large value of
feedback resistors used with the LT1020. Also, a feedback
capacitor minimizes noise pickup and improves ripple
rejection.
With the large dynamic operating range of the output
current, 10000:1, frequency response changes widely.
Low AC impedance capacitors are needed to insure stability. While solid tantalum are best, aluminum electrolytics
can be used but larger capacitor values may be needed.
The CURRENT LIMIT pin allows one of the internal nodes
to be rolled off with a 0.05µF capacitor to ground. With this
capacitor, lower values of regulator output capacitance
can be used (down to 1µF) for low ( 5.2V
IQ = 40µA
VOUT
VIN
2
5V
0.001µF
LT1020
LT1020
+
10µF
DROPOUT
FB
GND
+
10µF
9
500k
TO
2M
1M
11
1M
1020 TA07
3M
1020 TA04
Regulator with Improved Transient Response
VIN > 5.2V
3
VIN
VOUT
2
GND
9
5V
0.001µF
LT1020
FB
Compensating the Comparator As an Op Amp
1M
11
7
+
5
+
10µF
8
0.001µF
22k
1M
6
–
1M
AT AV = 100,
SLEW RATE = 0.05V/µs
–6V/µs
1020 TA08
R2
R1
C2
AV
1
10
100
R1
33Ω
100Ω
10k
C1
C1
C2
R2
0.1µF 0.001µF
–
0.047µF
–
100k
0.002µF
–
10k
1020 TA05
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LT1020
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TYPICAL APPLICATIO S
1 Amp Low Dropout Regulator
VIN
VOUT
*
2
LT1020
10k*
FB
CL
3
9
GND
8
–INPUT
MJE2955
3
0.001µF
100k
+
11
VOUT
5V
VIN
VOUT
220µF†
0.001µF
1M
*FOR CURRENT LIMIT ≈ 1.5A
†
MUST HAVE LOW ESR.
SEVERAL 100µF CAPACITORS
CAN BE PARALLELED
150Ω* 100k
0.01µF
SEE LT1129 DATA SHEET FOR 700mA OUTPUT
VOUT
9
6
10µF
+
100k
10µF
–5V REG
10mA
–VIN
Dual Output 150mA Regulator
VIN > 5.2V
2
5V
0.001µF
LT1020
GND
+
500k
2N3904
1020 TA06
Maintaining Lowest IQ at Dropout
VIN
0.001µF
500k
COMP FB 11
NPN
REF
OUT
4
500k
5V
1020 TA09
51k
3
2
LT1020
5 COMP
PNP
+INPUT
7
10
9
VIN > 5.2V
VIN
2.2k
GND
Dual Output Regulator
1M
11
DROPOUT FB
3
VIN
9
GND
8
–INPUT
+
VOUT
10µF
13
1M
LT1020
5 COMP
PNP
+INPUT
1M
2N3904*
1020 TA11
REF
OUT
4
7
NC
*TRANSISTOR USED BECAUSE OF
LOW LEAKAGE CHARACTERISTICS
0.001µF
200k
2
100k
5V
0.001µF
500k
COMP FB 11
NPN
6
100k
+
10µF
500k
+
10µF
1020 TA10
–5V REG
150mA
2N3904
*FOR TEMPERATURES GREATER THAN
70°C, REDUCE 51k RESISTORS TO 15k.
IQ WILL INCREASE
51k*
2N3904
4.7k
51k*
0.0047µF
–VIN
Dual Output Positive Regulator
3
51k
VIN ≥ 12.3V
VIN
–
2N2907
12VOUT
VOUT
6
0.01µF
190k
+
10µF
50k
2
5V
0.001µF
LT1020
1M
+
11
+
FB
+IN
–IN
7
8
REF
GND
4
9
10µF
1M
1020 TA12
sn1020 1020fcs
10
LT1020
U
TYPICAL APPLICATIO S
Battery Backup Regulator
VOUT
5V
BATTERY
INPUT
3
VIN
2
2
VOUT
+
0.001µF
LT1020
GND
LT1020
11
9
MAIN
POWER
INPUT
3
VIN
10µF
1M
11
FB
VOUT
FB
GND
9
50k
1020 TA13
INTERNAL PARASITIC
DIODES OF LT1020
1M
VOUT
VIN
5V Regulator with Shutdown
3
VIN > 5.2V
IQ = 40µA
VOUT
VIN
2
LT1020
10µF
0.001µF
GND
5V
+
NC
1M
FB
9
11
500k
100k
2N3904*
LOGIC INPUT
1020 TA14
1M
*TRANSISTOR USED BECAUSE OF LOW LEAKAGE
CHARACTERISTICS. TO TURN OFF THE OUTPUT
OF THE LT1020, FORCE FB (PIN 11) > 2.5V
Turn-Off at Dropout
R1
1.5M
R2
1M
VIN
8
3
–
VOUT
2
+
5
FB
DROPOUT
13
7
6
1M
0.001µF
LT1020
9
VOUT*
+
11
10µF
REF
4
1M
1020 TA15
1M
1.5M
*VOUT TURNS OFF AT DROPOUT.
VOUT TURN ON WHEN:
VIN × R2
= 2.5V
R1 + R2
0.047µF
Current Limited 1 Amp Regulator
2.2k
0.5Ω*
VIN
MJE2955
3
VIN
0.22µF
100k
VOUT 2
LT1020
GND
9
FB
11
2N3906*
+
VOUT
5V, 1A
220µF†
1020 TA16
270Ω
100k
*SETS CURRENT LIMIT BUT INCREASES
DROPOUT VOLTAGE BY 0.5V
†
MUST HAVE LOW ESR. SEVERAL 100µF
CAPACITORS CAN BE PARALLELED
sn1020 1020fcs
11
LT1020
U
TYPICAL APPLICATIO S
1 Amp Regulator with Precision Current Limit
VIN
12V
2.2k
+
100µF
MJE2955
8
–
VOUT
5V
1A
3
4
100k
+
LT1020
0.22µF
100k
220µF†
2
1.2k
7
FB
+
5
6
ISC
SENSE
0.03Ω
9
11
100k
270Ω
1N4148
RL
1020 TA17
†
MUST HAVE LOW ESR. SEVERAL 100µF
CAPACITORS CAN BE PARALLELED
Logic Output on Dropout
VIN
4
8
–
3
LT1020
2
7
VOUT
5V
1M
+
FB
5
6
9
0.001µF
+
11
10µF
1M
13
1020 TA18
1M
VIN
“DROPOUT”
TTL COMPATIBLE
0V
Charge Pump Negative Voltage Generator
VIN
1M
51k
8
–
3
5
0.0033µF
7
+
6
9
1M
VOUT (NL) ≅ – (VIN – 1V)
VOUT (5mA) ≅ – (VIN – 3V)
IQ ≅ 300µA
2N3904
22k
+
10µF
–VOUT
51k
1N5819
OR EQUIVALENT
+ 20µF
1020 TA19
sn1020 1020fcs
12
LT1020
U
TYPICAL APPLICATIO S
Charge Pump Voltage Doubler
VIN
1M
1N5819
OR EQUIVALENT
51k
VOUT
+
8
20µF
3
–
5
0.0033µF
6
+
10µF
+
7
2N3904
22k
9
VOUT (NL) ≅ 2VIN – 1V
VOUT (5mA) ≅ 2VIN – 3V
IQ ≅ 300µA
1M
1020 TA20
51k
50mA Battery Charger and Regulator
+
VIN*
+
10µF
10µF
51k
10µF
2N2905
20k
+
220k
8
4
–
3
VIN
2
VOUT
+
LT1020
6
5V
1M
2.5V
+
FB
0.001µF
6V
BATTERY
10µF
11
1M
9
7
*VIN MUST BE GREATER THAN THE
BATTERY VOLTAGE PLUS 1.3V
3.9Ω
1020 TA21
Switching Preregulator for Wide Input Voltage Range
7.5V TO 30V
VIN
100µF
30k
3.3M
SWITCHING
REGULATOR
OUTPUT
2N3906
2N3904
TO
VREF
(PIN4)
2N2222
10k
1.8M
2N3904
1M
4mH
3
100k
1k
LT1020
COMPARATOR
6
MAINTAINS LOW IQ (< 100µA)
FOR ALL INPUT VOLTAGES
SWITCHER EFFICIENCY = 85%
POST REGULATOR EFFICIENCY = 82%
OVERALL EFFICIENCY = 70%
SWITCHING REGULATOR OUTPUT =
2.5 × (1 + RA /RB). FOR A CLEAN OUTPUT
FROM THE LINEAR REGULATOR SET TO VOUT + 1.2V
POST REGULATOR
VIN
VREF
2M
–
8
30k
+
7
RA
1.5M
VOUT
LT1020
4
2
+
FB
VOUT
5V
100mA
22µF
11
0.01µF
220k
220k
2M
RB
1M
0.001µF
1020 TA22
+
30k
100µF
sn1020 1020fcs
13
6
Q5
NPN
OUTPUT
R1
25Ω
Q7
Q6
R36
60k
Q8
Q9
Q2
R2
50k
Q12
Q10
R37
110.8k
8
–INPUT
R6
3k
7
R5
3k
Q17 Q18
Q15 Q16
Q14
+INPUT
R3
50k
Q11
Q13
R35
42k
Q21
R7
6.8k
C1
10pF
Q20
Q19
Q22
Q23
15k
28k
Q64
C2
25pF
Q62
R38
20k
Q61
Q60
R10
75k
Q28
Q33
R14
15k
Q32
Q34
Q31
Q27
R11
15k
Q63
Q30
Q26
Q24
Q25
R8
40k
R15
80k
Q35
R8
100k
12
60k
100pF
Q65
125k
125k
Q42
R23
30k
60k
Q41
Q39
Q37
Q40
R22
30k
SHUTDOWN
R18
15k
Q36
C3
10pF
R16
6k
R17
100Ω
Q29
Q38
R19
40k
11 FEEDBACK
Q45
Q51
R26
15k
R27
15k
Q46
Q44
C5
100pF
Q43
R24
390k
R28
2k
Q47
C6
100pF
R29
5Ω
Q48
Q52
Q54
R32
2k
R31
10Ω
CURRENT
LIMIT
10
100pF
Q49
R30
2k
Q55
1020 SS
GND
9
Q56
R33 138.3k
47k
13
DROPOUT
DETECTOR
2
OUTPUT
Q58
3
VIN
SCHE ATIC DIAGRA
W
W
14
5
PNP
OUTPUT
Q1
R4
42k
REFERENCE 4
LT1020
sn1020 1020fcs
LT1020
U
PACKAGE DESCRIPTIO
J Package
14-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
.785
(19.939)
MAX
.005
(0.127)
MIN
14
13
11
12
10
9
8
.220 – .310
(5.588 – 7.874)
.025
(0.635)
RAD TYP
1
2
3
4
5
6
7
.200
(5.080)
MAX
.300 BSC
(7.62 BSC)
.015 – .060
(0.381 – 1.524)
.008 – .018
(0.203 – 0.457)
0° – 15°
.045 – .065
(1.143 – 1.651)
.100
(2.54)
BSC
.014 – .026
(0.360 – 0.660)
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
.125
(3.175)
MIN
J14 0801
OBSOLETE PACKAGE
N Package
14-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
.770*
(19.558)
MAX
14
13
12
11
10
9
8
1
2
3
4
5
6
7
.255 ± .015*
(6.477 ± 0.381)
.130 ± .005
(3.302 ± 0.127)
.300 – .325
(7.620 – 8.255)
.045 – .065
(1.143 – 1.651)
.020
(0.508)
MIN
.065
(1.651)
TYP
.008 – .015
(0.203 – 0.381)
(
+.035
.325 –.015
8.255
+0.889
–0.381
NOTE:
1. DIMENSIONS ARE
)
.120
(3.048)
MIN
.005
(0.125) .100
MIN (2.54)
BSC
.018 ± .003
(0.457 ± 0.076)
INCHES
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
N14 1002
sn1020 1020fcs
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
LT1020
U
PACKAGE DESCRIPTIO
SW Package
16-Lead Plastic Small Outline (Wide .300 Inch)
(Reference LTC DWG # 05-08-1620)
.050 BSC .045 ±.005
.030 ±.005
TYP
.398 – .413
(10.109 – 10.490)
NOTE 4
16
N
15
14
13
12
11
10
9
N
.325 ±.005
.420
MIN
.394 – .419
(10.007 – 10.643)
NOTE 3
1
2
3
N/2
N/2
RECOMMENDED SOLDER PAD LAYOUT
1
.005
(0.127)
RAD MIN
.009 – .013
(0.229 – 0.330)
.291 – .299
(7.391 – 7.595)
NOTE 4
.010 – .029 × 45°
(0.254 – 0.737)
2
3
4
5
6
.093 – .104
(2.362 – 2.642)
7
8
.037 – .045
(0.940 – 1.143)
0° – 8° TYP
.050
(1.270)
BSC
NOTE 3
.016 – .050
(0.406 – 1.270)
NOTE:
1. DIMENSIONS IN
.004 – .012
(0.102 – 0.305)
.014 – .019
(0.356 – 0.482)
TYP
INCHES
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS.
THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS
4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
S16 (WIDE) 0502
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1120/LT1120A
125mA, Micropower Regulator and Comparators
VIN: 4.5V to 36V; VOUT(MIN): 2.50V, Dropout Voltage (V at IOUT): 0.40V;
IQ (Supply): 40µA; VOUT (V): Adj; ISD: 10µA; S8, N8; Comparator and
Reference, Logic Shutdown, Ref Sources and Sinks 2/4mA
LT1121/LT1121HV 150mA, Micropower, LDO
VIN: 4.2V to 30/36V; VOUT(MIN): 3.75V, Dropout Voltage (V at IOUT): 0.42V;
IQ (Supply): 30µA; VOUT (V): Adj, 3.3, 5; ISD: 16µA; SOT-223, S8, Z;
Reverse-Battery Protection
LT1129
700mA, Micropower, LDO
VIN: 4.2V to 30V; VOUT(MIN): 3.75V, Dropout Voltage (V at IOUT): 0.40V;
IQ (Supply): 50µA; VOUT (V): Adj, 3.3, 5; ISD: 16µA; DD, SOT-223, S8,
TO220-5, TSSOP20
LT1616
25V, 500mA (IOUT), 1.4MHz, High Efficiency
Step-Down DC/DC Converter
VIN: 3.6V to 25V, VOUT(MIN): 1.25V, IQ: 1.9mA, ISD:
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