19-2560; Rev 0; 7/02
IT
TION K
VALUA
E
BLE
AVAILA
Low-Voltage, Low-Dropout Linear Regulators
with External Bias Supply
General Description
The MAX1982/MAX1983 are low-voltage, low-dropout
linear regulators with an external bias supply input. The
5V bias supply drives the gate of the internal N-channel
pass transistor, making these devices ideal for applica-
tions that require low-voltage outputs from low-voltage
inputs. The MAX1982 delivers 1.2V (±3%) at 300mA
from an input voltage of 1.25V to 5.5V. The MAX1983
delivers an adjustable output voltage from 0.8V to 2V.
The MAX1982/MAX1983 include a current-limit and
thermal shutdown that protects the regulator in the
event of a fault condition. Both devices are offered in a
6-pin SOT23 package and are specified over the
extended (-40°C to +85°C) temperature range.
o
Low-Cost 1.2V, 300mA VID Supply
o
±3% Output Voltage Accuracy
o
No Minimum Load Current Required
o
1.25V to 5.5V Input Supply Voltage
o
5V Input Bias Supply Voltage
o
Power-Good (PGOOD) Open-Drain Output with
1ms Rising Edge Propagation Delay (MAX1982)
o
Adjustable Output Voltage (MAX1983)
o
Low Supply Current (I
BIAS
+ I
IN
= 165µA typ)
o
5µA (max) Shutdown Supply Current
o
Tiny 6-Pin SOT23 Package
Features
MAX1982/MAX1983
Applications
Notebook Computers
VID Power Supplies
PDAs
Cell Phones
Low-Dropout Regulators with External Bias
Supply
Ordering Information
PART
MAX1982EUT-T
MAX1983EUT-T
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-
PACKAGE
6 SOT23-6
6 SOT23-6
TOP
MARK
ABEA
ABEB
Typical Operating Circuit
TOP VIEW
4.5V TO 5.5V
BIAS
IN
1.25V TO 5.5V
10µF
Pin Configurations
BIAS
1
GND
2
6
IN
OUT
PGOOD
MAX1982
0.1µF
GND
OUT
MAX1982
5
4
1.2V
10µF
SHDN
3
ON
SHDN
OFF
PGOOD
PGOOD
SOT23-6
Fixed Output Voltage
100kΩ
BIAS
1
GND
2
SHDN
3
6
IN
OUT
ADJ
MAX1983
5
4
SOT23-6
Adjustable Output
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Low-Voltage, Low-Dropout Linear Regulators
with External Bias Supply
MAX1982/MAX1983
ABSOLUTE MAXIMUM RATINGS
ADJ, IN, BIAS, PGOOD,
SHDN,
OUT to GND..........-0.3V to +6V
Output Short-Circuit Duration ............................................Infinite
Continuous Power Dissipation (T
A
= +70°C)
6-Pin SOT23 (derate 8.7mW/
o
C above +70°C)............696mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65
o
C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 3, V
IN
= 1.8V, I
LOAD
= 1mA, C
LOAD
= 10µF,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 1)
PARAMETER
Input Voltage
BIAS Voltage
V
OUT
Voltage Range
BIAS Input Undervoltage Lockout
Shutdown Supply Current
Quiescent BIAS Current
Shutdown BIAS Current
V
OUT
Input Bias Current
MAX1983 ADJ Input Current
REGULATOR CHARACTERISTICS
Line Regulation
MAX1982 1.20V
Output Voltage Accuracy
∆V
OUT
/
∆V
IN
V
OUT
I
LOAD
= 10mA, 1.5V < V
IN
< 5.5V
T
A
= +25°C, I
OUT
= 100mA
T
A
= 0°C to +85°C, I
OUT
= 1mA to 300mA,
V
OUT
+ 0.5V < V
IN
< 5.5V
T
A
= +25°C, I
OUT
= 100mA
V
OUT
T
A
= 0°C to +85°C, I
OUT
= 1mA to 300mA,
V
OUT
+ 0.5V < V
IN
< 5.5V
I
LOAD
= 300mA
I
LOAD
= 150mA
V
IN
- V
OUT
= 1.3V
330
600
160
20
10Hz to 100kHz
% of regulated output voltage
V
HYST
-12.5
65
-9
10
-6
-0.15
-1
-3
-1
-3
+0.15
+1
+3
+1
+3
350
175
1400
%
%
%/V
I
IN
I
Q
I
SHDN
1.25V < V
IN
< 5.5V
4.5V < V
BIAS
< 5.5V
4.5V < V
BIAS
< 5.5V
MAX1982: V
IN
= open, V
OUT
= 1.20V
MAX1983: V
IN
= open, 0.8V < V
OUT
< 2.0V
0V < V
ADJ
< 2.0V
SYMBOL
V
IN
V
BIAS
V
OUT
MAX1983
CONDITIONS
MIN
1.25
4.5
0.8
3.8
4.1
1
140
1
TYP
MAX
5.5
5.5
2.0
4.35
5
250
5
30
2
1
UNITS
V
V
V
V
µA
µA
µA
µA
µA
MAX1983 0.80V
Output Voltage Accuracy
Dropout Voltage
Current Limit
Thermal-Shutdown Temperature
Thermal-Shutdown Hysteresis
RMS Output Noise
PGOOD COMPARATOR
Comparator Threshold
Comparator Hysteresis
V
DO
I
LIM
T
SHDN
mV
mA
°C
°C
µV
RMS
%
mV
2
_______________________________________________________________________________________
Low-Voltage, Low-Dropout Linear Regulators
with External Bias Supply
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 3, V
IN
= 1.8V, I
LOAD
= 1mA, C
LOAD
= 10µF,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 1)
PARAMETER
LOGIC AND I/O
SHDN
Input High Voltage
SHDN
Input Low Voltage
SHDN
Input Current
PGOOD Output Low Voltage
PGOOD Output
High Leakage Current
DYNAMICS
Positive Load Step
Negative Load Step
Ripple Rejection at V
IN
Startup Response Time
Startup Overshoot
PGOOD Propagation Delay
t
PD
t
ON
t
RISE
t
FALL
I
LOAD
= 1mA to full load, C
LOAD
= 10µF
I
LOAD
= full load to 1mA, C
LOAD
= 10µF
10Hz < f < 10kHz, I
LOAD
= 300mA,
C
LOAD
= 10µF
I
LOAD
= 300mA, C
LOAD
= 10µF, 0% to 90%
of nominal output voltage
I
LOAD
= 300mA, C
LOAD
= 10µF
Falling edge, 3mV under trip threshold
Rising edge within 5% of regulation level
1
10
50
-60
100
0.5
10
4
µs
µs
dB
µs
%
µs
ms
PGOOD sinking 1mA
0 < V
PGOOD
< V
IN
-1
V
IH
V
IL
-1
2.4
0.8
+1
0.1
+1
V
V
µA
V
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX1982/MAX1983
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 3, V
IN
= 1.8V, I
LOAD
= 1mA, C
LOAD
= 10µF,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
Input Voltage
BIAS Voltage
V
OUT
Voltage Range
BIAS Input Undervoltage Lockout
Shutdown Supply Current
Quiescent BIAS Current
Shutdown BIAS Current
V
OUT
Input Bias Current
REGULATOR CHARACTERISTICS
Line Regulation
MAX1982 1.20V
Output Voltage Accuracy
∆V
OUT
/
∆V
IN
V
OUT
I
LOAD
= 10mA, 1.5V < V
IN
< 5.5V
I
OUT
= 1mA to 300mA,
V
OUT
+ 0.5V < V
IN
< 5.5V
-0.15
-3
+0.15
+3
%/V
%
I
IN
I
Q
I
SHDN
1.25V < V
IN
< 5.5V
4.5V < V
BIAS
< 5.5V
4.5V < V
BIAS
< 5.5V
MAX1982: V
IN
= open, V
OUT
= 1.20V
MAX1983: V
IN
= open, 0.8V < V
OUT
< 2.0V
SYMBOL
V
IN
V
BIAS
V
OUT
MAX1983
CONDITIONS
MIN
1.25
4.5
0.8
3.8
MAX
5.5
5.5
2.0
4.2
5
250
5
30
2
UNITS
V
V
V
V
µA
µA
µA
µA
_______________________________________________________________________________________
3
Low-Voltage, Low-Dropout Linear Regulators
with External Bias Supply
MAX1982/MAX1983
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 3, V
IN
= 1.8V, V
OUT
= 1.2V, I
LOAD
= 1mA, C
LOAD
= 10µF,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
MAX1983 0.80V
Output Voltage Accuracy
Dropout Voltage
Current Limit
PGOOD COMPARATOR
Comparator Threshold
LOGIC AND I/O
SHDN
Input High Voltage
SHDN
Input Low Voltage
SHDN
Input Current
PGOOD Output Low Voltage
PGOOD Output High Leakage
Current
DYNAMICS
PGOOD Propagation Delay
t
PD
Rising edge within 5% of regulation level
1
4
ms
PGOOD sinking 1mA
0 < V
PGOOD
< V
IN
-1
V
IH
V
IL
-1
2.4
0.8
+1
0.1
+1
V
V
µA
V
µA
% of regulated output voltage
-12.5
-6
%
SYMBOL
V
OUT
V
DO
I
LIM
CONDITIONS
I
OUT
= 1mA to 300mA,
V
OUT
+ 0.5V < V
IN
< 5.5V
I
LOAD
= 300mA
I
LOAD
= 150mA
V
IN
- V
OUT
= 1.3V
330
MIN
-3
MAX
+3
350
175
1400
UNITS
%
mV
mA
Note 1:
Specifications over temperature are guaranteed by design, not production tested.
Note 2:
V
OUT
is 1.2V for MAX1982. For MAX1983 V
OUT
is set to 1.2V with circuit of Figure 4.
Typical Operating Characteristics
(Circuit of Figure 3, T
A
= +25°C, unless otherwise noted.)
INPUT CURRENT vs. INPUT VOLTAGE
MAX1982/83 toc01
BIAS INPUT CURRENT
vs. INPUT VOLTAGE
MAX1982/83 toc02
GROUND CURRENT vs. OUTPUT CURRENT
MAX1982/83 toc03
30
150
175
BIAS INPUT CURRENT (µA)
29
INPUT CURRENT (µA)
28
140
GROUND CURRENT (µA)
145
170
165
27
26
V
BIAS
= 5V
1.5
2.5
3.5
INPUT VOLTAGE (V)
4.5
5.5
135
V
BIAS
= 5V
130
1.5
2.5
3.5
INPUT VOLTAGE (V)
4.5
5.5
160
V
BIAS
= 5V
V
IN
= 1.8V
155
0
50
100
150
200
250
300
OUTPUT CURRENT (mA)
25
4
_______________________________________________________________________________________
Low-Voltage, Low-Dropout Linear Regulators
with External Bias Supply
Typical Operating Characteristics (continued)
(Circuit of Figure 3, T
A
= +25°C, unless otherwise noted.)
INPUT CURRENT vs. TEMPERATURE
MAX1982/83 toc04
MAX1982/MAX1983
BIAS SUPPLY CURRENT vs. TEMPERATURE
MAX1982/83 toc05
DROPOUT VOLTAGE vs. OUTPUT CURRENT
V
BIAS
= 5V
DROPOUT VOLTAGE (mV)
150
MAX1982/83 toc06
28.0
V
BIAS
= 5V
27.5
27.0
150
V
BIAS
= 5V
145
140
I
BIAS
(µA)
135
130
125
120
115
200
I
IN
(µA)
26.5
26.0
25.5
25.0
-40
-15
10
35
60
85
TEMPERATURE (°C)
100
50
0
-40
-15
10
35
60
85
0
50
100
150
200
250
300
TEMPERATURE (°C)
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE ERROR
vs. OUTPUT CURRENT
MAX1982/83 toc07
OUTPUT VOLTAGE ERROR vs. TEMPERATURE
V
IN
= 1.8V
0.75
RELATIVE V
OUT
ERROR (%)
0.50
0.25
0
-0.25
-0.50
I
LOAD
= 0mA
-0.75
-1.00
I
LOAD
= 200mA
I
LOAD
= 300mA
MAX1982/83 toc08
SHORT-CIRCUIT CURRENT LIMIT
vs. INPUT VOLTAGE
SHORT-CIRCUIT CURRENT LIMIT (mA)
700
600
500
400
300
200
100
0
1.50
2.50
3.50
INPUT VOLTAGE (V)
4.50
5.50
MAX1982/83 toc09
1.00
0.75
0.50
V
OUT
ERROR (%)
0.25
0
V
BIAS
= 5V
V
IN
= 1.8V
1.00
800
-0.25
-0.50
-0.75
-1.00
0
50
100
150
200
250
300
OUTPUT CURRENT (mA)
-40
-15
10
35
60
85
TEMPERATURE (°C)
SHORT-CIRCUIT CURRENT LIMIT
vs. TEMPERATURE
MAX1982/83 toc10
POWER-SUPPLY REJECTION RATIO (V
IN
)
vs. FREQUENCY
-10
-20
-30
PSRR (dB)
-40
-50
-60
-70
-80
-90
V
IN
= 2.1V
V
P-P
= 0.6V
I
LOAD
= 0
MAX1982/83 toc11
700
SHORT-CIRCUIT CURRENT LIMIT (mA)
0
650
600
550
500
-40
-15
10
35
60
85
TEMPERATURE (°C)
-100
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
_______________________________________________________________________________________
5
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