19-1699; Rev 2; 11/11
500mA Low-Dropout
Linear Regulator in µMAX
General Description
The MAX1792 low-dropout linear regulator operates
from a +2.5V to +5.5V supply and delivers a guaran-
teed 500mA load current with low 130mV dropout. The
high-accuracy (±1%) output voltage is preset at an
internally trimmed voltage (see
Selector Guide)
or can
be adjusted from 1.25V to 5.0V with an external resis-
tive divider.
An internal PMOS pass transistor allows the low 80µA
supply current to remain independent of load, making
this device ideal for portable battery-operated equip-
ment such as personal digital assistants (PDAs), cellu-
lar phones, cordless phones, base stations, and
notebook computers.
Other features include an active-low open-drain reset
output with a 4ms timeout period that indicates when
the output is out of regulation, a 0.1µA shutdown mode,
short-circuit protection, and thermal shutdown protec-
tion. The device is available in a miniature 1.3W, 8-pin
power-µMAX package with a metal pad on the under-
side of the package.
♦
Guaranteed 500mA Output Current
♦
Low 130mV Dropout at 500mA
♦
Up to ±1% Output Voltage Accuracy
Preset at 1.5V, 1.8V, 2.5V, 3.3V, or 5.0V
Adjustable from 1.25V to 5.0V
♦
Reset Output with 4ms Timeout Period
♦
Low 80µA Ground Current
♦
0.1µA Shutdown Current
♦
Thermal Overload Protection
♦
Output Current Limit
♦
Tiny 1.3W Power-µMAX Package
Features
MAX1792
Ordering Information
PART*
MAX1792EUA_ _+
MAX1792EUA_ _/V+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 Power-μMAX
8 Power-μMAX
________________________Applications
Notebook Computers
Cellular and Cordless Telephones
Personal Digital Assistants (PDAs)
Palmtop Computers
Base Stations
USB Hubs
Docking Stations
*Insert
the desired two-digit suffix (see Selector Guide) into the
blanks to complete the part number.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.
Contact factory for other preset output voltages.
Selector Guide
PART AND SUFFIX
MAX1792EUA15+
MAX1792EUA18+
MAX1792EUA25+
MAX1792EUA33+
MAX1792EUA50+
MAX1792EUA33/V+
V
OUT
1.5V or Adj.
1.8V or Adj.
2.5V or Adj.
3.3V or Adj.
5.0V or Adj.
3.3V or Adj.
μMAX TOP MARK
AAAE
AAAA
AAAB
AAAC
AAAD
AACP
Typical Operating Circuit
V
IN
= +2.5V TO +5.5V
C
IN
1μF
IN
NC
IN
OUT
OUT
V
OUT
C
OUT
3.3μF
R
RST
100k
RST
TO
μC
Pin Configuration
TOP VIEW
+
IN
IN
RST
1
2
3
EP
8
OUT
OUT
SET
GND
MAX1792
ON
SHDN
OFF
MAX1792
7
6
5
SHDN
4
SET
GND
POWER-μMAX
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim's website at www.maxim-ic.com.
500mA Low-Dropout
Linear Regulator in µMAX
MAX1792
ABSOLUTE MAXIMUM RATINGS
IN,
SHDN, RST,
SET to GND ....................................-0.3V to +6V
OUT to GND ................................................-0.3V to (V
IN
+ 0.3V)
Output Short-Circuit Duration ........................................Indefinite
Continuous Power Dissipation (T
A
= +70°C)
8-Pin Power-µMAX (derate 17mW/°C above +70°C) .......1.3W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°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
(V
IN
= V
OUT(NOM)
+ 500mV, or V
IN
= +2.5V (whichever is greater),
SHDN
= IN,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical
values are at T
A
= +25°C.)
PARAMETER
Input Voltage
Input Undervoltage Lockout
SYMBOL
V
IN
V
UVLO
Rising, 75mV hysteresis
I
OUT
= 100mA,
T
A
= +85°C
Output Voltage Accuracy
(Preset Mode)
V
OUT
Preset V
OUT
2.5V
Preset V
OUT
< 2.5V
I
OUT
= 100mA, T
A
= 0°C to +85°C
I
OUT
= 1mA to 500mA, V
IN
> V
OUT
+ 0.5V,
T
A
= 0°C to +85°C
Adjustable Output Voltage
Range
SET Voltage Threshold
(Adjustable Mode)
Maximum Output Current
Short-Circuit Current Limit
In-Regulation Current Limit
SET Dual Mode™ Threshold
SET Input Bias Current
Ground-Pin Current
I
SET
I
Q
V
IN
-
V
OUT
V
LNR
V
LDR
V
SET
= 1.25V
I
OUT
= 1mA
I
OUT
= 500mA
V
OUT
= 5.0V
I
OUT
= 500mA
V
OUT
= 3.3V
V
OUT
= 2.5V
V
IN
from (V
OUT
+ 100mV) to 5.5V,
I
LOAD
= 5mA
I
OUT
= 1mA to 500mA
10Hz to 1MHz, C
OUT
= 3.3μF (ESR < 0.1 )
I
OFF
V
IH
V
IL
SHDN
= GND, V
IN
= 5.5V
2.5V < V
IN
< 5.5V
2.5V < V
IN
< 5.5V
SHDN
= IN or GND
10
1.6
0.6
100
-0.15
V
SET
I
OUT
I
LIM
V
IN
= +2.7V,
V
OUT
set to 2.0V,
I
OUT
= 100mA
V
IN
2.7V
2.7V
50
-100
80
110
120
130
210
0
0.4
115
0.1
15
225
250
360
+0.15
1.0
%/V
%
μV
RMS
μA
V
nA
mV
T
A
= +85°C
T
A
= 0°C to +85°C
CONDITIONS
MIN
2.5
2.0
-1
-1.5
-2
-3
1.25
1.229
1.219
500
0.55
0.8
1.6
100
150
+100
250
1.8
1.250
2.15
TYP
MAX
5.5
2.3
+1
+1.5
+2
+3
5
1.271
V
1.281
mA
RMS
A
A
mV
nA
μA
%
UNITS
V
V
%
V
V
OUT
= 0V, V
IN
2.7V
V
OUT
> 96% of nominal value, V
IN
Dropout Voltage (Note 1)
Line Regulation
Load Regulation
Output Voltage Noise
SHUTDOWN
Shutdown Supply Current
SHDN
Input Threshold
SHDN
Input Bias Current
Dual Mode is a trademark of Maxim Integrated Products.
2 _______________________________________________________________________________________
500mA Low-Dropout
Linear Regulator in µMAX
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
OUT(NOM)
+ 500mV, or V
IN
= +2.5V (whichever is greater),
SHDN
= IN,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical
values are at T
A
= +25°C.)
PARAMETER
RESET OUTPUT
Reset Output Low Voltage
Operating Voltage Range for
Valid Reset
RST
Output High Leakage
Current
RST
Threshold
RST
Release Delay
THERMAL PROTECTION
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
T
SHDN
T
SHDN
170
20
°C
°C
t
RP
V
OL
RST
sinking 1mA
RST
sinking 100μA
V
RST
= +5.5V
Rising edge, referred to V
OUT(NOMINAL)
Rising edge of OUT to rising edge of
RST
90
1.5
93
4.5
1.0
0.01
0.1
5.5
100
96
8
V
V
nA
%
ms
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX1792
ELECTRICAL CHARACTERISTICS
(V
IN
= V
OUT(NOM)
+ 500mV, or V
IN
= +2.5V (whichever is greater),
SHDN
= IN,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 2)
PARAMETER
Input Voltage
Input Undervoltage Lockout
Output Voltage Accuracy
(Preset Mode)
Adjustable Output Voltage
Range
SET Voltage Threshold
(Adjustable Mode)
Maximum Output Current
Short-Circuit Current Limit
SET Dual Mode Threshold
SET Input Bias Current
Ground-Pin Current
Dropout Voltage (Note 1)
I
SET
I
Q
V
IN
-
V
OUT
V
LNR
V
LDR
I
OFF
V
IH
V
IL
I
SHDN
V
SET
= 1.25V
I
OUT
= 1mA
V
OUT
= 5.0V
I
OUT
= 500mA
V
OUT
= 3.3V
V
OUT
= 2.5V
V
IN
from (V
OUT
+ 100mV) to 5.5V,
I
LOAD
= 5mA
I
OUT
= 1mA to 500mA
SHDN
= GND, V
IN
= +5.5V
2.5V < V
IN
< 5.5V
2.5V < V
IN
< 5.5V
SHDN
= IN or GND
1.6
0.6
100
-0.15
V
SET
I
OUT
I
LIM
V
OUT
= 0V
I
OUT
= 100mA
SYMBOL
V
IN
V
UVLO
V
OUT
Rising or falling
I
OUT
= 100mA
I
OUT
= 1mA to 500mA
CONDITIONS
MIN
2.5
2.0
-2
-3
1.25
1.212
500
0.55
50
-100
1.8
150
+100
250
225
250
360
+0.15
1.0
15
mV
%/V
%
μA
V
nA
MAX
5.5
2.3
+2
+3
5
1.288
UNITS
V
V
%
V
V
mA
RMS
A
mV
nA
μA
Line Regulation
Load Regulation
SHUTDOWN
Shutdown Supply Current
SHDN
Input
Threshold
SHDN
Input Bias Current
_______________________________________________________________________________________
3
500mA Low-Dropout
Linear Regulator in µMAX
MAX1792
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
OUT(NOM)
+ 500mV, or V
IN
= +2.5V (whichever is greater),
SHDN
= IN,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 2)
PARAMETER
RESET OUTPUT
Reset Output Low Voltage
Operating Voltage Range for
Valid Reset
RST
Output High Leakage
Current
RST
Threshold
RST
Release Delay
t
RP
V
OL
RST
sinking 1mA
RST
sinking 100μA
V
RST
= +5.5V
Rising edge, referred to V
OUT(NOMINAL)
Rising edge of OUT to rising edge of
RST
90
1.5
1.0
0.1
5.5
100
96
8
V
V
nA
%
ms
SYMBOL
CONDITIONS
MIN
MAX
UNITS
Note 1:
Dropout voltage is defined as V
IN
- V
OUT
, when V
OUT
is 100mV below the value of V
OUT
measured when V
IN
= V
OUT(NOM)
+ 0.5V. Since the minimum input voltage is 2.5V, this specification is only meaningful when V
OUT(NOM)
≥
2.5V. For V
OUT(NOM)
between 2.5V and 3.5V, use the following equations: Typical Dropout = -93mV/V
✕
V
OUT(NOM)
+ 445mV; Guaranteed Maximum
Dropout = -137mV/V
✕
V
OUT(NOM)
+ 704mV. For V
OUT(NOM)
≥
3.5V: Typical Dropout = 120mV; Guaranteed Maximum Dropout
= 225mV.
Note 2:
Specifications to -40°C are guaranteed by design, not production tested.
Typical Operating Characteristics
(MAX1792EUA33, V
IN
= V
OUT
+ 500mV,
SHDN
= IN, C
IN
= 1µF, C
OUT
= 3.3µF, T
A
= +25°C, unless otherwise noted.)
OUTPUT VOLTAGE
OUTPUT VOLTAGE
OUTPUT VOLTAGE
vs. INPUT VOLTAGE
vs. TEMPERATURE
vs. LOAD CURRENT
MAX1792-01
MAX1792-02
3.0
OUTPUT VOLTAGE (V)
2.5
2.0
1.5
1.0
0.5
0
2.0
I
OUT
= 0A
I
OUT
= 500mA
3.32
OUTPUT VOLTAGE (V)
3.31
3.30
3.29
3.28
3.27
3.32
OUTPUT VOLTAGE (V)
3.31
3.30
3.29
3.28
3.27
V
IN
= V
OUT
+ 500mV
I
OUT
= 0A
2.5
3.0
3.5
4.0
4.5
5.0
5.5
0
100 200 300 400 500 600 700 800
LOAD CURRENT (mA)
-40
-15
10
35
60
85
INPUT VOLTAGE (V)
TEMPERATURE (°C)
DROPOUT VOLTAGE
vs. LOAD CURRENT
MAX1792-04
GROUND-PIN CURRENT
vs. INPUT VOLTAGE
MAX1792-05
GROUND-PIN CURRENT
vs. LOAD CURRENT
130
GROUND-PIN CURRENT (μA)
120
110
100
90
80
70
60
V
IN
= 3.8V
MAX1792-06
250
T
A
= +85°C
DROPOUT VOLTAGE (mV)
200
140
I
OUT
= 500mA
120
GROUND-PIN CURRENT (μA)
100
80
60
40
20
140
V
IN
= 5.5V
150
T
A
= +25°C
I
OUT
= 0A
100
T
A
= -40°C
50
0
0
100 200 300 400 500 600 700 800
LOAD CURRENT (mA)
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
INPUT VOLTAGE (V)
0
100 200 300 400 500 600 700 800
LOAD CURRENT (mA)
4
_______________________________________________________________________________________
MAX1792-03
3.5
3.33
3.33
500mA Low-Dropout
Linear Regulator in µMAX
Typical Operating Characteristics (continued)
(MAX1792EUA33, V
IN
= V
OUT
+ 500mV,
SHDN
= IN, C
IN
= 1µF, C
OUT
= 3.3µF, T
A
= +25°C, unless otherwise noted.)
GROUND-PIN CURRENT
vs. TEMPERATURE
MAX1792-07
MAX1792
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
-70
-60
PSRR (dB)
-50
-40
-30
C
OUT
= 3.3μF
I
OUT
= 50mA
MAX1792-08
MAX1792-10
95
90
GROUND-PIN CURRENT (μA)
85
80
75
70
65
60
-40
V
IN
= V
OUT
+ 500 mV
I
OUT
= 0A
-80
-20
-10
0
-15
10
35
60
85
0.01
0.1
1
10
100
1000
TEMPERATURE (°C)
FREQUENCY (kHz)
OUTPUT SPECTRAL NOISE DENSITY
vs. FREQUENCY
OUTPUT SPECTRAL NOISE DENSITY (μV/√Hz)
C
OUT
= 3.3μF
I
OUT
= 50mA
MAX1792-09
OUTPUT NOISE DC TO 1MHz
10
1
0.1
V
OUT
200μV/div
0.01
0.001
0.1
1
10
FREQUENCY (kHz)
100
1000
V
OUT
= 3.3V
R
OUT
= 66Ω (50mA)
20ms/div
REGION OF STABLE C
OUT
ESR
vs. LOAD CURRENT
MAX1792-11
LOAD-TRANSIENT RESPONSE
MAX1792-12
100
10
C
OUT
ESR (Ω)
C
OUT
= 3.3μF
1
C
OUT
= 10μF
0.1
STABLE REGION
V
IN
= V
OUT
+ 500mV
C
IN
= 10μF
R
OUT
= 660Ω TO 6.6Ω (5mA TO 500mA)
0
100 200 300 400
500
600 700
800
10μs/div
I
OUT
500mA/div
V
OUT
20mV/div
0.01
LOAD CURRENT (mA)
_______________________________________________________________________________________
5
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