19-0629; Rev 1; 1/07
Ultra-Low-Noise, High PSRR, Low-Dropout,
150mA Linear Regulators in µDFN
General Description
The MAX8840/MAX8841/MAX8842 ultra-low-noise, low-
dropout (LDO) linear regulators are designed to deliver
up to 150mA continuous output current. These regula-
tors achieve a low 120mV dropout for 120mA load cur-
rent. The MAX8840 uses an advanced architecture to
achieve ultra-low output voltage noise of 11µV
RMS
and
PSRR of 54dB at 100kHz.
The MAX8841 does not require a bypass capacitor,
hence achieving the smallest PC board area. The
MAX8842 output voltage can be adjusted with an exter-
nal divider.
The MAX8840/MAX8841 are preset to a variety of volt-
ages in the 1.5V to 4.5V range. Designed with a p-channel
MOSFET series pass transistor, the MAX8840/MAX8841/
MAX8842 maintain very low ground current (40µA).
The regulators are designed and optimized to work with
low-value, low-cost ceramic capacitors. The MAX8840
requires only 1µF (typ) of output capacitance for stability
with any load. When disabled, current consumption drops
to below 1µA.
The MAX8840/MAX8841/MAX8842 are available in a tiny
1.0mm x 1.5mm x 0.8mm µDFN.
Features
♦
Space-Saving 1.0mm x 1.5mm x 0.8mm µDFN
♦
11µV
RMS
Output Noise at 100Hz to 100kHz
Bandwidth (MAX8840)
♦
78dB PSRR at 1kHz (MAX8840)
♦
120mV Dropout at 120mA Load
♦
Stable with 1µF Ceramic Capacitor for Any Load
♦
Guaranteed 150mA Output
♦
Only Need Input and Output Capacitors (MAX8841)
♦
Output Voltages: 1.5V, 1.8V, 2.5V, 2.6V, 2.7V, 2.8V,
2.85V, 3V, 3.3V, 4.5V (MAX8840/MAX8841) and
Adjustable (MAX8842)
♦
Low 40µA Ground Current
♦
Excellent Load/Line Transient
♦
Overcurrent and Thermal Protection
MAX8840/MAX8841/MAX8842
Ordering Information
PART*
MAX8840ELTxy+T
MAX8841ELTxy+T
MAX8842ELT+T
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
6 µDFN-6
1.5mm x 1.0mm
6 µDFN-6
1.5mm x 1.0mm
6 µDFN-6
1.5mm x 1.0mm
Applications
Cellular and Cordless Phones
PDA and Palmtop Computers
Base Stations
Bluetooth Portable Radios and Accessories
Wireless LANs
Digital Cameras
Personal Stereos
Portable and Battery-Powered Equipment
*xy
is the output voltage code (see the Output Voltage Selector
Guide). Other versions between 1.5V and 4.5V are available in
100mV increments. Contact factory for other versions.
+Denotes
lead-free package.
Output Voltage Selector Guide appears at end of data sheet.
Typical Operating Circuits
TOP VIEW
INPUT
2V TO 6V
C
IN
1µF
ON
OFF
IN
OUT
OUTPUT PRESET
1.5V TO 4.5V
C
BP
10nF
BP
SHDN
GND
C
OUT
1µF
Pin Configuration
IN
1
6
OUT
MAX8840
GND
2
MAX8840
MAX8841
MAX8842
5
N.C.
BP (MAX8840)
4
N.C. (MAX8841)
FB (MAX8842)
SHDN
3
Typical Operating Circuits continued at end of data sheet.
µDFN
(1.5mm x 1.0mm)
1
________________________________________________________________
Maxim Integrated Products
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.
Ultra-Low-Noise, High PSRR, Low-Dropout,
150mA Linear Regulators in µDFN
MAX8840/MAX8841/MAX8842
ABSOLUTE MAXIMUM RATINGS
IN to GND .................................................................-0.3V to +7V
Output Short-Circuit Duration ............................................Infinite
OUT,
SHDN
to GND ......................................-0.3V to (IN + 0.3V)
FB, BP, N.C. to GND..................................-0.3V to (OUT + 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
6-Pin µDFN (derate 2.1mW/°C above +70°C) .............0.168W
θ
JA
..................................................................................477°C/W
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
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
+ 0.5V, T
A
= -40°C to +85°C, unless otherwise noted. C
IN
= 1µF, C
OUT
= 1µF, C
BP
= 10nF. Typical values are at +25°C;
the MAX8842 is tested with 2.45V output, unless otherwise noted.) (Note 1)
PARAMETER
Input Voltage Range
Output Voltage Accuracy
Maximum Output Current
Current Limit
I
OUT
I
LIM
OUT = 90% of nominal value
V
OUT
≥
3V, I
OUT
= 80mA
V
OUT
≥
3V, I
OUT
= 120mA
Dropout Voltage (Note 2)
2.5V
≤
V
OUT
< 3V, I
OUT
= 80mA
2.5V
≤
V
OUT
< 3V, I
OUT
= 120mA
2V
≤
V
OUT
< 2.5V, I
OUT
= 80mA
2V
≤
V
OUT
< 2.5V, I
OUT
= 120mA
Ground Current
Line Regulation
Load Regulation
Shutdown Supply Current
I
Q
V
LNR
V
LDR
I
SHDN
I
OUT
= 0.05mA
V
IN
= V
OUT(nom)
- 0.1V, I
OUT
= 0mA
V
IN
= (V
OUT
+ 0.5V) to 6V, I
OUT
= 0.1mA
I
OUT
= 1mA to 80mA
SHDN
= 0V
f = 1kHz, I
OUT
= 10mA
Ripple Rejection
PSRR
f = 10kHz, I
OUT
= 10mA
f = 100kHz, I
OUT
= 10mA
T
A
= +25°C
T
A
= +85°C
MAX8840
MAX8841/MAX8842
MAX8840
MAX8841/MAX8842
MAX8840
MAX8841/ MAX8842
SYMBOL
V
IN
I
OUT
= 1mA, T
A
= +25°C
I
OUT
= 100µA to 80mA, T
A
= +25°C
I
OUT
= 100µA to 80mA
CONDITIONS
MIN
2
-1
-2
-3
150
150
200
80
120
90
135
120
180
40
220
0.001
0.003
0.003
0.05
78
72
75
65
54
46
dB
1
90
500
µA
%/V
%/mA
µA
250
200
mV
300
170
TYP
MAX
6
+1
+2
+3
mA
mA
%
UNITS
V
2
_______________________________________________________________________________________
Ultra-Low-Noise, High PSRR, Low-Dropout,
150mA Linear Regulators in µDFN
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
OUT
+ 0.5V, T
A
= -40°C to +85°C, unless otherwise noted. C
IN
= 1µF, C
OUT
= 1µF, C
BP
= 10nF. Typical values are at +25°C;
the MAX8842 is tested with 2.45V output, unless otherwise noted.) (Note 1)
PARAMETER
Output Noise Voltage
(RMS)
Shutdown Exit Delay
SHDN
Logic-Low Level
SHDN
Logic-High Level
SHDN
Input Bias Current
FB Input Bias Current
(MAX8842)
Thermal Shutdown
Thermal-Shutdown
Hysteresis
SYMBOL
CONDITIONS
f = 100Hz to 100kHz,
I
LOAD
= 10mA
f = 100Hz to 100kHz,
I
LOAD
= 80mA
R
LOAD
= 50Ω (Note 3)
V
IN
= 2V to 6V
V
IN
= 2V to 6V
V
IN
= 6V,
SHDN
= 0V or
6V
V
IN
= 6V, V
FB
= 1.3V
T
A
= +25°C
T
A
= +85°C
T
A
= +25°C
T
A
= +85°C
0.01
0.006
0.01
160
10
0.1
1.5
MAX8840
MAX8841/MAX8842
MAX8840
MAX8841/MAX8842
MIN
TYP
11
230
13
230
300
0.4
µs
V
V
µA
µA
°C
°C
µV
MAX
UNITS
MAX8840/MAX8841/MAX8842
Note 1:
Limits are 100% tested at +25°C. Limits over operating temperature range are guaranteed by design.
Note 2:
Dropout is defined as V
IN
- V
OUT
when V
OUT
is 100mV below the value of V
OUT
for V
IN
= V
OUT
+ 0.5V.
Note 3:
Time needed for V
OUT
to reach 90% of final value.
Typical Operating Characteristics
(V
IN
= V
OUT
+ 0.5V, C
IN
= 1µF, C
OUT
= 1µF, C
BP
= 10nF, T
A
= +25°C, unless otherwise noted.)
MAX8840
OUTPUT VOLTAGE ACCURACY
vs. LOAD CURRENT
MAX8840 toc01
MAX8840 toc02
MAX8840
OUTPUT VOLTAGE vs. INPUT VOLTAGE
3.5
3.0
I
OUT
= 0mA
OUTPUT VOLTAGE (V)
2.5
2.0
1.5
I
OUT
= 150mA
1.0
0.5
0.0
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
0.6
0.4
% DEVIATION (%)
0.2
0
-0.2
-0.4
-0.6
0
MAX8840
OUTPUT VOLTAGE ACCURACY
vs. TEMPERATURE
0.8
0.6
% DEVIATION (%)
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
IOUT = 1mA
MAX8840 toc03
1.0
25
50
75
100
125
150
-40
-15
10
35
60
85
LOAD CURRENT (mA)
TEMPERATURE (°C)
_______________________________________________________________________________________
3
Ultra-Low-Noise, High PSRR, Low-Dropout,
150mA Linear Regulators in µDFN
MAX8840/MAX8841/MAX8842
Typical Operating Characteristics (continued)
(V
IN
= V
OUT
+ 0.5V, C
IN
= 1µF, C
OUT
= 1µF, C
BP
= 10nF, T
A
= +25°C, unless otherwise noted.)
MAX8440
DROPOUT VOLTAGE vs. LOAD CURRENT
MAX8840 toc04
MAX8840
DROPOUT VOLTAGE vs. OUTPUT VOLTAGE
MAX8840 toc05
MAX8840
GROUND PIN CURRENT vs. INPUT VOLTAGE
MAX8840 toc06
200
180
DROPOUT VOLTAGE (mV)
160
140
120
100
80
60
40
20
0
0
25
50
75
100
125
T
A
= -40°C
T
A
= +85°C
T
A
= +25°C
250
I
OUT
= 80mA
DROPOUT VOLTAGE (mV)
200
350
300
GROUND PIN CURRENT (µA)
250
200
150
100
50
I
LOAD
= 0mA
I
LOAD
= 150mA
150
100
50
0
150
2.0
2.2
2.4
2.6
2.8
3.0
3.2
INPUT VOLTAGE (V)
OUTPUT (V)
0
0
1
2
3
4
5
INPUT VOLTAGE (V)
MAX8840
GROUND PIN CURRENT vs. LOAD CURRENT
MAX8840 toc 07
MAX8840
GROUND PIN CURRENT vs. TEMPERATURE
MAX8840 toc08
MAX8840
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
80
70
60
PSRR (dB)
50
40
30
MAX8840 toc09
350
300
GROUND PIN CURRENT (µA)
V
IN
= 5.5V
250
200
150
100
50
0
0
25
50
75
100
125
V
IN
= 3.8V
50
90
GROUND PIN CURRENT (µA)
45
40
35
20
10
I
LOAD
= 10mA
C
BP
= 10nF
0.01
0.1
1
10
100
1000
30
150
-40
-15
10
35
60
85
LOAD CURRENT (mA)
TEMPERATURE (°C)
0
FREQUENCY (kHz)
MAX8841
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX8840 toc10
MAX8840
OUTPUT NOISE
MAX8840 toc11
MAX8840
OUTPUT NOISE-SPECTRAL DENSITY
vs. FREQUENCY
10,000
OUTPUT NOISE DENSITY (nV/√Hz)
MAX8840 toc12
90
80
70
60
PSRR (dB)
50
V
IN
= 3.8V
I
LOAD
= 10mA
V
NOISE
= 11µV
RMS
1000
20µV/div
40
30
20
10
0
0.01
0.1
1
10
100
1000
400µs/div
FREQUENCY (kHz)
I
LOAD
= 10mA
100
10
0.01
0.1
1
10
100
1000
FREQUENCY (kHz)
4
_______________________________________________________________________________________
Ultra-Low-Noise, High PSRR, Low-Dropout,
150mA Linear Regulators in µDFN
Typical Operating Characteristics (continued)
(V
IN
= V
OUT
+ 0.5V, C
IN
= 1µF, C
OUT
= 1µF, C
BP
= 10nF, T
A
= +25°C, unless otherwise noted.)
MAX8840
OUTPUT NOISE vs. BP CAPACITANCE
MAX8840 toc13
MAX8840/MAX8841/MAX8842
MAX8840
LOAD-TRANSIENT RESPONSE
MAX8840 toc14
MAX8840
LOAD-TRANSIENT RESPONSE NEAR DROPOUT
MAX8840 toc15
25
20
OUTPUT NOISE (µV)
V
IN
= 3.5V
I
LOAD
= 0 TO 50mA
V
IN
= 3.1V
I
LOAD
= 0 TO 50mA
15
10
V
OUT
10mV/div
5
V
OUT
10mV/div
0
1
10
BP CAPACITANCE (nF)
100
1ms/div
1ms/div
MAX8840
LINE-TRANSIENT RESPONSE
MAX8840 toc16
MAX8840
EXITING SHUTDOWN WAVEFORM
MAX8840 toc17
MAX8840
ENTERING SHUTDOWN DELAY
MAX8840 toc18
V
IN
= 3.5V TO 4V
V
OUT
= 2.85V
R
LOAD
= 47Ω
C
BP
= 0.01µF
SHUTDOWN
VOLTAGE
SHUTDOWN
VOLTAGE
V
OUT
2mV/div
OUTPUT
VOLTAGE
2V/div
OUTPUT
VOLTAGE
2V/div
200µs/div
20µs/div
40µs/div
MAX8840
SHUTDOWN EXIT DELAY
MAX8840 toc19
MAX8840
REGION OF STABLE C
OUT
ESR
vs. LOAD CURRENT
MAX8840 toc20
100
V
OUT
1V/div
C
OUT
ESR (Ω)
V
OUT
= 3V
C
BP
= 100nF
10
1
SHUTDOWN
VOLTAGE
0.1
0.01
20µs/div
0
25
50
75
100
125
150
LOAD CURRENT (mA)
_______________________________________________________________________________________
5
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