LT1020
Micropower Regulator
and Comparator
FEATURES
s
s
s
s
s
s
s
s
s
s
DESCRIPTIO
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 LT1020 is a combination micropower positive regula-
tor 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.
The dual output comparator can be used as a comparator
for system or battery monitoring. For example, the com-
parator 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 com-
parator for amplifier applications can be obtained by
adding external output capacitance. Dual output or posi-
tive and negative regulators can also be made.
The 2.5V reference will source or sink current. This allows
it to be used as a supply splitter or auxiliary output.
APPLICATI
s
s
s
s
S
Battery Systems
Battery Backup Systems
Portable Terminals
Portable Instruments
TYPICAL APPLICATI
5V Regulator
Dropout Voltage and Supply Current
1
10
LT1020
0.001µF
FB
11
+
10µF
GND
9
1M
+
10µF
DROPOUT VOLTAGE (V)
V
IN
> 5.2V
I
Q
= 40µA
3
V
IN
V
OUT
2
5V
SUPPLY CURRENT (mA)
1M
1020 TA01
0.1
0.01
0.1
U
1
10
1
100
OUTPUT CURRENT (mA)
0.1
1000
1020 TA02
UO
UO
1
LT1020
ABSOLUTE
AXI U
RATI GS
Operating Temperature Range
LT1020C ............................................. 0°C to 100°C
LT1020I ........................................ – 40°C to 100
°C
LT1020M ....................................... – 55°C to 125°C
Lead Temperature (Soldering, 10 sec).................. 300°C
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
PACKAGE/ORDER I FOR ATIO
TOP VIEW
NC
V
OUT
V
IN
REF OUT
COMP PNP
COMP NPN
+INPUT
1
2
3
4
5
6
7
14 NC
DROPOUT
13 DETECTOR
12 SHUTDOWN
11 FEEDBACK
CURRENT
10 LIMIT
9 GND
8
–INPUT
ORDER PART
NUMBER
LT1020CJ
LT1020CN
LT1020IJ
LT1020IN
LT1020MJ
J PACKAGE
14-LEAD CERAMIC DIP
N PACKAGE
14-LEAD PLASTIC DIP
T
JMAX
= 150°C,
θ
JA
= 80°C/W (J)
T
JMAX
= 110°C,
θ
JA
= 130°C/W (N)
ELECTRICAL CHARACTERISTICS
PARAMETER
Reference
Reference Voltage
Line Regulation
Load Regulation
Output Source Current
Output Sink Current
Temperature Stability
Regulator
Supply Current
CONDITIONS
T
J
= 25°C
MIN
2.46
TYP
2.50
0.01
0.2
4
2
1
45
75
11
125
0.2
0.01
0.02
0.4
2.5
20
0.5
0.015
0.05
0.65
2.56
MAX
2.54
0.015
0.3
UNITS
V
%/V
%
mA
mA
%
µA
µA
mA
mA
%
%/V
V
V
V
µA
4.5V
≤
V
IN
≤
36V
4.5V
≤
V
IN
≤
36V
– 0.5mA
≤
I
REF
≤
1mA, V
IN
= 12V
V
IN
= 5V
V
IN
= 5V
Output Current
Load Regulation
Line Regulation
Dropout Voltage
Feedback Sense Voltage
Dropout Detector Current
V
IN
= 6V, I
OUT
≤
100µA
V
IN
= 36V, I
OUT
≤
100µA
V
IN
= 12V, I
OUT
= 125mA
(V
IN
– V
OUT
)
≥
1V, V
IN
≥
6V
(V
IN
– V
OUT
)
≥
1V, V
IN
≥
6V
6V
≤
V
IN
≤
36V
I
OUT
= 100µA
I
OUT
= 125mA
V
IN
= 12V
∆V
OUT
= – 0.05V, I
OUT
= 500µA
2
U
U
W
W W
U
W
TOP VIEW
NC 1
V
OUT
2
VI
N
3
REF OUT 4
COMP PNP 5
COMP NPN 6
+INPUT 7
NC 8
16 NC
15 DROPOUT
DETECTOR
14 SHUTDOWN
13 CURRENT
LIMIT
12 FEEDBACK
11 GND
10 –INPUT
9
NC
ORDER PART
NUMBER
LT1020CS
LT1020IS
S PACKAGE
16-LEAD PLASTIC SOIC
T
JMAX
= 110°C,
θ
JA
= 150°C/W
1
0.5
80
120
20
2.44
3
LT1020
ELECTRICAL CHARACTERISTICS
PARAMETER
Regulator
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)
CONDITIONS
T
J
= 25°C
MIN
TYP
15
1
300
30
3
15
4
10000
94
96
18
0.4
200
5
2
MAX
40
5
400
UNITS
nA
µA
mA
mA
mV
nA
nA
V/ V
dB
dB
mA
V
µA
V
µs
µA
V
IN
= 36V
V
IN
= 36V
Pins 9 and 10 Shorted, V
IN
= 4.5V
0V
≤
V
CM
≤
35V, V
IN
= 36V
0V
≤
V
CM
≤
35V, V
IN
= 36V
0V
≤
V
CM
≤
35V, V
IN
= 36V
∆V
OUT
= 29V, R
L
= 20k
0V
≤
V
CM
≤
35V, V
IN
= 36V
4.5V
≤
V
S
≤
36V
V
IN
= 4.5V
I
OUT
= 1mA
3
7
40
15
2000
80
80
10
60
0
0.6
V
IN
– 1
ELECTRICAL CHARACTERISTICS
PARAMETER
Reference
Reference Voltage
Line Regulation
Load Regulation
Output Source Current
Output Sink Current
Regulator
Supply Current
CONDITIONS
4.5V
≤
V
IN
≤
36V
4.5V
≤
V
IN
≤
36V
– 0.5mA
≤
I
REF
≤
1mA, V
IN
= 12V
V
IN
= 5V
V
IN
= 5V
V
IN
= 6V, I
OUT
≤
100µA
V
IN
= 36V, I
OUT
≤
100µA
V
IN
= 12V, I
OUT
= 125mA
(V
IN
– V
OUT
)
≥
1V, V
IN
≥
6V
(V
IN
– V
OUT
)
≥
1V, V
IN
≥
6V
6V
≤
V
IN
≤
36V
I
OUT
= 100µA
I
OUT
= 125mA
V
IN
= 12V
∆V
OUT
= – 0.05V, I
OUT
= 500µA
V
IN
= 36V
V
IN
= 36V
Pins 9 and 10 Shorted, V
IN
= 4.5V
0V
≤
V
CM
≤
35V, V
IN
= 36V
0V
≤
V
CM
≤
35V, V
IN
= 36V (Note 1)
0V
≤
V
CM
≤
35V, V
IN
= 36V
∆V
OUT
= 29V, R
L
= 20k
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
q
MIN
2.40
TYP
2.50
0.01
0.3
MAX
2.55
0.02
0.4
UNITS
V
%/V
%
mA
mA
µA
µA
mA
mA
%
%/ V
V
V
V
µA
nA
µA
mA
mA
mV
nA
nA
V/ V
1
0.5
65
85
11
125
1
0.02
0.06
0.85
2.57
50
50
400
95
120
20
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
Offset Current
Gain-NPN Pull-Down
2.38
3
2.5
2.5
300
30
15
1000
10
60
20
3
LT1020
ELECTRICAL CHARACTERISTICS
PARAMETER
Comparator
Common-Mode Rejection
Power Supply Rejection
Output Sink Current
Output Source Current
Input Voltage Range
Leakage Current (NPN)
CONDITIONS
0V
≤
V
CM
≤
35V, V
IN
= 36V
4.5V
≤
V
IN
≤
36V
V
IN
= 4.5V (Note 2)
q
q
q
q
q
MIN
80
80
5
40
0
TYP
MAX
UNITS
dB
dB
mA
µA
V
µA
10
120
V
IN
– 1
8
V
IN
= 36V
q
The
q
denotes specifications which apply over the full operating
temperature range.
Note 1:
For 0V
≤
V
CM
≤
0.1V and T > 85°C I
BIAS(MAX)
is 100nA.
Note 2:
For T
A
≤
– 40°C output I
SINK(MIN)
is 2.5mA.
TYPICAL PERFOR A CE CHARACTERISTICS
Regulator Load Regulation
0.3
PRELOAD = 100µA
OUTPUT VOLTAGE CHANGE (%)
SUPPLY CURRENT (mA)
T
J
= –55°C
0.1
0
–0.1
–0.2
–0.3
0.1
T
J
= 125°C
T
J
= 25°C
10
SHORT-CIRCUIT CURRENT (mA)
0.2
1
10
100
OUTPUT CURRENT (mA)
Dropout Voltage
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
∆V
OUT
= 100mV
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
1
INPUT/OUTPUT DIFFERENTIAL (V)
0.1
0.01
0.1
1
100
10
1000
REGULATOR OUTPUT CURRENT (mA)
1020 G04
4
U W
1020 G01
Supply Current
100
T
J
= –55°C TO 125°C
Regulator Short-Circuit Current
350
300
250
200
150
100
50
0
–50
CURRENT LIMIT TIED TO GROUND
1
0.1
1000
0.01
0.1
10
100
1000
1
REGULATOR OUTPUT CURRENT (mA)
1020 G02
–10
70
110
30
TEMPERATURE (°C)
150
1020 G03
Dropout Voltage
1
DROPOUT DETECTOR = 5µA
1
Dropout Voltage
I DROPOUT DETECTOR = 0.1% I
OUT
0.1
0.1
I DROPOUT DETECTOR = 1% I
OUT
0.01
0.1
0.01
1
100
10
1000
REGULATOR OUTPUT CURRENT (mA)
1020 G05
0.1
1
10
100
REGULATOR OUTPUT CURRENT (mA)
1020 G06
LT1020
TYPICAL PERFOR A CE CHARACTERISTICS
Dropout Detector Current
100
DROPOUT DETECTOR CURRENT (µA)
1000
DROPOUT DETECTOR CURRENT (µA)
MINIMUM LOAD CURRENT (µA)
V
DIFF
= 500mV
10
1
0.1
V
DIFF
= 1V
0.01
10
100
REGULATOR OUTPUT CURRENT (mA)
1000
Regulator Ripple Rejection
70
65
I
OUT
= 100mA
I
OUT
= 10mA
SUPPLY CURRENT (mA)
1
10
RIPPLE REJECTION (dB)
SUPPLY CURRENT (mA)
60
55
I
OUT
= 1mA
50
45
40
35
30
10
V
IN
= 100VDC, 1V
P-P
V
OUT
= 5V
C
OUT
= 10µF
10k
100
1k
RIPPLE FREQUENCY (Hz)
Reference Regulation
4
REFERENCE VOLTAGE CHANGE (mV)
3
INPUT BIAS CURRENT (nA)
2
1
0
–1
–2
–3
–4
–1.5
0.5
1.0
–1.0 –0.5
0
REFERENCE OUTPUT CURRENT (mA)
1.5
80
70
60
50
40
30
20
10
0
–1.0
FEEDBACK PIN CURRENT (nA)
U W
1020 G07
1020 G10
Dropout Detector Current
100
I
OUT
= 100mA
100
I
OUT
= 25mA
Regulator Minimum Load Current
10
10
I
OUT
= 5mA
I
OUT
= 1mA
1
0
0.2
0.3
0.4
0.5
0.6
0.1
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
1020 G08
1
70
80
90 100 110 120 130 140
TEMPERATURE (°C)
150
1020 G09
Supply Current
10
Supply Current at Dropout
T
J
= –55°C TO 125°C
I
OUT
= 100mA
I
OUT
= 100mA
1
I
OUT
= 10mA
0.1
I
OUT
= 10mA
0.1
I
OUT
= 1mA
V
OUT
= 5V
T
J
= –55°C TO 125°C
I
OUT
= 1mA
100k
0.01
1
10
15
20
25
5
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
1020 G11
0.01
0.2
0.3
0.4
0.5
0.6
0.1
0
REGULATOR INPUT/OUTPUT DIFFERENTIAL (V)
1020 G12
Comparator Input Bias Current
100
90
T
J
= 125°C
T
J
= 25°C
T
J
= –55°C
40
35
30
25
20
15
10
5
0
Feedback Pin Current
T
J
= –55°C
T
J
= 25°C
T
J
= 125°C
1020 G13
–0.6
0.6
–0.2 GND 0.2
COMMON-MODE VOLTAGE (V)
REFERRED TO PIN 9 (GND)
1.0
1020 G14
0.1
100
1000
1
10
REGULATOR OUTPUT CURRENT (mA)
1020 G15
5
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