19-2072; Rev 0; 1/02
500mA Low-Dropout Linear Regulator in UCSP
General Description
The MAX1819 low-dropout linear regulator operates from
a 2.5V to 5.5V supply and delivers a guaranteed 500mA
load current with low 120mV dropout. The high-accuracy
(±1%) output voltage is preset at an internally trimmed
voltage (see the
Selector Guide)
or can be adjusted from
1.25V to 5V with an external resistive-divider.
An internal PMOS pass transistor allows the low 125µA
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 that indicates when the output is out of regula-
tion, a 0.1µA shutdown, short-circuit protection, and
thermal shutdown protection. The device is available in
a miniature 6-pin UCSP™ package.
♦
Guaranteed 500mA Output Current
♦
Low 90mV Dropout at 500mA
♦
±1% Initial Output Accuracy
♦
Preset Output at 1.5V, 1.8V, 2V, 2.5V, 3.3V, 5V
♦
Adjustable Output from 1.25V to 5V
♦
Power-OK Output
♦
Low 125µA Ground Current
♦
0.1µA Shutdown Current
♦
Thermal Overload Protection
♦
Output Current Limit
♦
Tiny 840mW 6-Pin UCSP Package
Features
MAX1819
Ordering Information
PART
MAX1819EBL_ _ -T*
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
6 UCSP
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.
Selector Guide
PART AND
SUFFIX
MAX1819EBL 15
MAX1819EBL 18
MAX1819EBL 20
V
OUT
1.5V or Adj
1.8V or Adj
2V or Adj
2.5V or Adj
3.3V or Adj
5V or Adj
UCSP MARK
AAH
AAG
AAC
AAD
AAE
AAF
UCSP is a trademark of Maxim Integrated Products, Inc.
MAX1819EBL 25
MAX1819EBL 33
MAX1819EBL 50
Pin Configuration
TOP VIEW
(TOP OF PC BOARD/
BALLS SOLDERED DOWN)
A
1
IN
A1
2
POK
A2
3
SHDN
A3
Typical Operating Circuit
V
IN
= 2.5V TO 5.5V
IN
NC
C
IN
1µF
OUT
V
OUT
C
OUT
3.3µF
MAX1819
B
MAX1819
OUT
SET
C2
GND
C3
R
POK
100kΩ
POK
TO
µC
ON
SHDN
OFF
C
C1
SET
UCSP
GND
________________________________________________________________
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.
500mA Low-Dropout Linear Regulator in UCSP
Linear Regulator in
MAX1819
ABSOLUTE MAXIMUM RATINGS
IN,
SHDN,
POK, SET to GND ...................................-0.3V to +6V
OUT to GND ................................................-0.3V to (V
IN
+ 0.3V)
Output Short-Circuit Duration ...............................................1min
Continuous Power Dissipation (T
A
= +70°C) (Note 1)
6-Pin UCSP (derate 10.5mW/°C above +70°C) ............840mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Soldering Temperature (10s) ...........................................+300°C
Note 1:
Thermal properties are specified with product mounted on PC board with one square-inch of copper area and still air.
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
+ 500mV) or V
IN
= 2.5V, whichever is greater;
SHDN
= IN, T
A
= -40°C to +85°C, unless otherwise noted. Typical values
are at T
A
= +25°C.) (Note 2)
PARAMETER
Input Voltage
Input Undervoltage Lockout
SYMBOL
V
IN
V
UVLO
Rising, 75mV hysteresis
I
OUT
= 100mA, T
A
= +25°C, V
OUT
≥
2V
Output Voltage Accuracy
(Preset Mode)
I
OUT
= 100mA, T
A
= +25°C, V
OUT
< 2V
V
OUT
I
OUT
= 100mA, T
A
= -40°C to +85°C
I
OUT
= 1mA to 500mA, V
IN
> V
OUT
+ 0.5V,
T
A
= -40°C to +85°C
Adjustable Output
Voltage Range
SET Voltage Threshold
(Adjustable Mode)
Guaranteed Output Current
(RMS)
Short-Circuit Current Limit
In-Regulation Current Limit
SET Dual Mode™ Threshold
SET Input Bias Current
Ground-Pin Current
I
SET
I
Q
V
SET
= 1.25V
I
OUT
= 100µA
I
OUT
= 500mA
V
OUT
= 5V
Dropout Voltage (Note 3)
V
IN
- V
OUT
I
OUT
= 500mA
V
OUT
= 3.3V
V
OUT
= 2.5V
Line Regulation
∆V
LNR
V
IN
from (V
OUT
+ 100mV) to 5.5V,
I
LOAD
= 5mA
-0.15
V
SET
V
IN
= 2.7V,
I
OUT
= 100mA,
V
OUT
set to 2V
V
IN
≥
2.7V
V
OUT
= 0, V
IN
≥
2.7V
V
OUT
> 96% of nominal value, V
IN
≥
2.7V
50
-100
125
150
125
133
165
0
220
232
280
+0.15
%/V
mV
T
A
= 0°C to +85°C
T
A
= -40°C to +85°C
CONDITIONS
MIN
2.5
2.0
-1
-1.5
-2.5
-3
1.25
1.225
1.213
500
0.55
1.39
2
100
150
+100
250
2.50
1.250
2.15
TYP
MAX
5.5
2.3
+1
+1.5
+2.5
+3
5.00
1.275
V
1.288
mA
A
A
mV
nA
µA
V
%
UNITS
V
V
I
OUT
I
LIM
Dual Mode is a trademark of Maxim Integrated Products, Inc.
2
_______________________________________________________________________________________
500mA Low-Dropout Linear Regulator in UCSP
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= (V
OUT
+ 500mV) or V
IN
= 2.5V, whichever is greater;
SHDN
= IN, T
A
= -40°C to +85°C, unless otherwise noted. Typical values
are at T
A
= +25°C.) (Note 2)
PARAMETER
Load Regulation
Output Voltage Noise
SHUTDOWN
Shutdown Supply Current
SHDN
Input Threshold
SHDN
Input Bias Current
POK OUTPUT
POK Output Low Voltage
Operating Voltage Range for
Valid POK
POK Output High
Leakage Current
POK Threshold
THERMAL PROTECTION
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
T
SHDN
∆T
SHDN
170
20
°C
°C
V
OL
POK sinking 1mA
POK sinking 100µA
POK = 5.5V, T
A
= +25°C
T
A
= +85°C
Rising edge, referred to V
OUT(NOMINAL)
90
1.0
1
5
93
96
0.01
0.1
5.5
30
V
V
nA
%
I
OFF
V
IH
V
IL
I
SHDN
SHDN
= GND, V
IN
= 5.5V
2.5V < V
IN
< 5.5V
2.5V < V
IN
< 5.5V
SHDN
= IN or GND, T
A
= +25°C
T
A
= +85°C
1
5
1.6
0.6
70
0.1
15
µA
V
nA
SYMBOL
∆V
LDR
CONDITIONS
I
OUT
= 1mA to 500mA
10Hz to 1MHz, C
OUT
= 3.3µF (ESR < 0.1Ω)
MIN
TYP
0.4
115
MAX
1.0
UNITS
%
µV
RMS
MAX1819
Note 2:
All devices are 100% production tested at T
A
= +25°C and up to 100mA. Limits over the operating temperature range and
above 100mA are guaranteed by design.
Note 3:
The dropout voltage is defined as V
IN
- V
OUT
, when V
OUT
is 100mV below the value of V
OUT
measured for V
IN
= V
OUT(NOM)
+ 500mV. 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 = -40mV/V
✕
V
OUT(NOM)
+ 265mV;
Guaranteed Maximum Dropout = -60mV/V
✕
V
OUT(NOM)
+ 430mV. For V
OUT(NOM)
> 3.5V, Typical Dropout = 125mV;
Maximum Dropout = 220mV.
Typical Operating Characteristics
(V
IN
= (V
OUT
+ 500mV) or 2.5V, whichever is greater;
SHDN
= IN, C
IN
= 3.3µF, C
OUT
= 3.3µF, T
A
= +25°C, unless otherwise noted.)
GROUND-PIN CURRENT
vs. INPUT VOLTAGE
MAX1819 toc01
GROUND-PIN CURRENT
vs. LOAD CURRENT
MAX1819 toc02
GROUND-PIN CURRENT
vs. TEMPERATURE
I
LOAD
= 150mA
GROUND-PIN CURRENT (µA)
170
5V OUTPUT
160
MAX1819 toc03
250
225
GROUND-PIN CURRENT (µA)
200
175
150
125
100
75
50
25
0
I
OUT
= 150mA
3.3V OUTPUT
180
175
GROUND-PIN CURRENT (µA)
165
155
145
135
125
115
0
3.3V OUTPUT
2.5V OUTPUT
2.5V OUTPUT
1.8V OUTPUT
150
1.5V OUTPUT
1.8V OUTPUT
140
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
INPUT VOLTAGE (V)
130
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
LOAD CURRENT (A)
-40
-15
10
35
60
85
TEMPERATURE (°C)
_______________________________________________________________________________________
3
500mA Low-Dropout Linear Regulator in UCSP
MAX1819
Typical Operating Characteristics (continued)
(V
IN
= (V
OUT
+ 500mV) or 2.5V, whichever is greater;
SHDN
= IN, C
IN
= 3.3µF, C
OUT
= 3.3µF, T
A
= +25°C, unless otherwise noted)
DROPOUT VOLTAGE
vs. LOAD CURRENT
260
240
220
200
180
160
140
120
100
80
60
40
20
0
0
100 200 300 400 500 600 700 800
LOAD CURRENT (A)
MAX1819 toc04
OUTPUT VOLTAGE ACCURACY
vs. LOAD CURRENT
MAX1819 toc05
OUTPUT VOLTAGE ACCURACY
vs. TEMPERATURE
0.4
OUTPUT VOLTAGE ACCURACY (%)
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
-40
-15
10
35
60
85
I
LOAD
= 150mA
MAX1819 toc06
MAX1819 toc09
1.0
OUTPUT VOLTAGE ACCURACY (%)
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
0
V
OUT
= 3.3V
V
OUT
= 0.5V
V
OUT
= 1.8V
0.5
V
OUT
= 3.3V
T
A
= +85°C
DROPOUT VOLTAGE (mV)
T
A
= +25°C
T
A
= -40°C
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
LOAD CURRENT (A)
TEMPERATURE (°C)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX1819 toc07
LINE TRANSIENT
MAX1819 toc08
LOAD TRANSIENT RESPONSE
V
IN
= 3.8V
V
OUT
= 3.3V
10mV/div
I
OUT
380mA
50mA
80
70
60
PSRR (dB)
50
40
30
20
10
0
0.01
0.1
1
10
100
C
OUT
= 3.3µF
V
OUT
= 3.3V
R
LOAD
= 100Ω
V
OUT
= 2.5V
I
OUT
= 5mA
V
OUT
3.5V
V
IN
3V
V
OUT
20mV/div
1000
100µs/div
40µs/div
FREQUENCY (kHz)
LOAD TRANSIENT RESPONSE
NEAR DROPOUT
MAX1819 toc10
POWER-ON RESET
MAX1819 toc11
V
IN
= 3.35V
V
OUT
= 3.5V
V
OUT
V
POK
50mV/div
0
V
OUT
2V/div
I
OUT
200mA
20mA
V
IN
0
0
40µs/div
10ms/div
4
_______________________________________________________________________________________
500mA Low-Dropout Linear Regulator in UCSP
MAX1819
Typical Operating Characteristics (continued)
(V
IN
= (V
OUT
+ 500mV) or 2.5V, whichever is greater;
SHDN
= IN, C
IN
= 3.3µF, C
OUT
= 3.3µF, T
A
= +25°C, unless otherwise noted)
SHUTDOWN WAVEFORM
MAX1819 toc12
SHORT-CIRCUIT CURRENT LIMIT
vs. SUPPLY VOLTAGE
V
OUT(NOM)
= 2V
SHORT-CIRCUIT CURRENT LIMIT (A)
MAX1819 toc13
1.40
SHUTDOWN
VOLTAGE
0
1.39
1.38
V
OUT
0
2V/div
1.37
1.36
P
OK
200µs/div
0
1.35
2.5
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY VOLTAGE (V)
Pin Description
PIN
A1
A2
A3
C1
C2
C3
NAME
IN
POK
SHDN
OUT
SET
GND
FUNCTION
Regulator Input. Supply voltage can range from 2.5V to 5.5V. Bypass with a 1µF capacitor to GND (see the
Capacitor Selection and Regulator Stability
section).
Open-Drain POK Output. POK remains low while the output voltage (V
OUT
) is below the POK threshold.
Connect a 100kΩ pullup resistor from POK to OUT to obtain an output voltage.
Active-Low Shutdown Input. A logic low reduces supply current below 15µA. In shutdown, the POK and
OUT are low. Connect to IN for normal operation.
Regulator Output. Sources up to 500mA. Bypass with a 3.3µF low-ESR capacitor to GND. Use a 4.7µF
capacitor for output voltages below 2V.
Voltage-Setting Input. Connect to GND for preset output. Connect to a resistive voltage-divider between
OUT and GND to set the output voltage between 1.25V and 5V.
Ground
Detailed Description
The MAX1819 is a low-dropout, low-quiescent-current
linear regulator designed primarily for battery-powered
applications. The device supplies loads up to 500mA
and is available with preset output voltages. As illustrat-
ed in Figure 1, the MAX1819 consists of a 1.25V refer-
ence, error amplifier, P-channel pass transistor, and
internal feedback voltage-divider.
The 1.25V reference is connected to the error amplifier,
which compares this reference with the feedback volt-
age and amplifies the difference. If the feedback voltage
is lower than the reference voltage, the pass-transistor
gate is pulled lower, which allows more current to pass
to the output and increases the output voltage. If the
feedback voltage is too high, the pass-transistor gate is
pulled up, allowing less current to pass to the output.
The output voltage is fed back through either an inter-
nal resistive-divider connected to OUT or an external
resistor network connected to SET. The Dual Mode
comparator examines V
SET
and selects the feedback
path. If V
SET
is below 50mV, the internal feedback path
is used and the output is regulated to the factory-preset
voltage.
_______________________________________________________________________________________
5
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