19-1422; Rev 2; 1/01
Low-Dropout, 300mA
Linear Regulator in µMAX
General Description
The MAX8860 low-noise, low-dropout linear regulator
operates from a 2.5V to 6.5V input and is guaranteed to
deliver 300mA. Typical output noise for this device is
60µV
RMS
, and typical dropout is 105mV at 200mA. In
addition to the six available preset output voltages
(1.8V, 2.5V, 2.77V, 2.82V, 3V, and 3.3V), the Dual
Mode™ feature allows the device to be configured as
an adjustable output regulator from 1.25V to 6.5V.
Designed with an internal P-channel MOSFET pass tran-
sistor, the MAX8860 has a low 120µA supply current. An
output fault-detection circuit indicates loss of regulation.
Other features include a 10nA, logic-controlled shut-
down mode, short-circuit and thermal-shutdown protec-
tion, and reverse battery protection. The MAX8860 is
available in a miniature 8-pin µMAX package.
o
High Output Current (300mA)
o
Low Output Voltage Noise: 60µV
RMS
o
Low 105mV Dropout at 200mA Output
o
Low 120µA No-Load Supply Current
o
Thermal Overload and Short-Circuit Protection
o
Reverse Battery Protection
o
10nA Logic-Controlled Shutdown
o
FAULT Indicator
o
Small, Space-Saving µMAX Package
(1.1mm max height)
o
Small 2.2µF Output Capacitor
Saves Space and Cost
Features
MAX8860
Applications
Wireless Handsets
DSP Core Power
PCMCIA Cards
Hand-Held Instruments
Palmtop Computers
Electronic Planners
PART
MAX8860EUA18
MAX8860EUA25
MAX8860EUA27
MAX8860EUA28
MAX8860EUA30
MAX8860EUA33
Ordering Information
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-
PACKAGE
8 µMAX
8 µMAX
8 µMAX
8 µMAX
8 µMAX
8 µMAX
V
OUT
(V)
+1.80
+2.50
+2.77
+2.82
+3.00
+3.30
Typical Operating Circuit
INPUT
+2.5V TO
+6.5V
OUTPUT
UP TO
300mA
R1
100kΩ
C2
2.2µF
IN
OUT
Pin Configuration
TOP VIEW
OUT
IN
GND
OUT
1
2
3
4
8
FAULT
SHDN
CC
SET
MAX8860
C1
2.2µF
SHDN
SET
GND
OUT
FAULT
CC
FAULT-
DETECT
OUTPUT
C3
33nF
MAX8860
7
6
5
µMAX
Dual Mode is a trademark of Maxim Integrated Products.
________________________________________________________________
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-Dropout, 300mA
Linear Regulator in µMAX
MAX8860
ABSOLUTE MAXIMUM RATINGS
IN,
SHDN
to GND .......................................................-7V to +7V
SHDN
to IN ...............................................................-7V to +0.3V
SET, CC,
FAULT
to GND ..........................................-0.3V to +7V
OUT to GND .............................................. -0.3V to (V
IN
+ 0.3V)
FAULT
Sink Current ...........................................................20mA
Continuous Output Current ..............................................330mA
Output Short-Circuit Duration ....................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX (derate 4.1mW/°C above +70°C) ............330mW
Thermal Resistance (θ
JA
)
8-Pin µMAX ............................................................+244°C/W
Operating Temperature Range
MAX8860EUA_ _ ...........................................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range ............................-65°C to +150°C
Lead Temperature (soldering, 10sec) ............................+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
= 3.6V, C
CC
= 33nF, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Input Voltage (Note 2)
MAX8860EUA33
MAX8860EUA30
100µA < I
OUT
< 300mA,
V
IN
= V
OUT
1V,
SET = GND
MAX8860EUA28
MAX8860EUA27
MAX8860EUA25
MAX8860EUA18
SET Threshold Voltage
Adjustable Output Voltage
Range (Note 3)
Maximum Output Current
Output Current Limit
Supply Current
Shutdown Supply Current
SET = GND
V
OUT
= 0,
SHDN
= GND
I
OUT
= 1mA
Dropout Voltage (Note 4)
Line Regulation
Load Regulation
I
OUT
= 200mA
I
OUT
= 300mA
V
IN
= 2.5V to 6.5V, SET = OUT, I
OUT
= 1mA
I
OUT
= 100µA to 300mA
SET = OUT
SET = GND
-0.1
I
OUT
= 0
I
OUT
= 300mA
T
A
= +25°C
T
A
= +85°C
DC average current rating
SET = OUT, V
IN
= 2.5V to 6.5V,
I
OUT
= 1mA
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
CONDITIONS
MIN
2.5
3.24
3.21
2.95
2.92
2.78
2.75
2.73
2.70
2.46
2.43
1.77
1.755
1.230
1.220
1.25
300
330
770
120
165
0.01
0.05
0.6
105
155
0.01
0.0001
0.0006
0.1
%/V
%/mA
220
mV
1
270
1.248
1.80
2.50
2.77
2.82
3.00
3.3
TYP
MAX
6.5
3.35
3.38
3.05
3.08
2.87
2.90
2.81
2.84
2.54
2.57
1.83
1.845
1.267
1.275
6.5
V
V
mA
mA
µA
µA
V
UNITS
V
Output Voltage
2
_______________________________________________________________________________________
Low-Dropout, 300mA
Linear Regulator in µMAX
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 3.6V, C
CC
= 33nF, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Output Voltage Noise
Output Voltage Noise Density
SHDN
Input Threshold
SHDN
Input Bias Current
SET Input Leakage Current (Note 3)
FAULT
Detection Voltage (Note 5)
FAULT
Output Low Voltage
FAULT
Output Off-Leakage Current
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
Start-Up Time
Note 1:
Note 2:
Note 3:
Note 4:
C
OUT
= 10µF, V
OUT
to 90% of final value
I
OUT
= 10mA,
10Hz < f < 100kHz
CONDITIONS
C
OUT
= 2.2µF
C
OUT
= 10µF
C
OUT
= 100µF
10Hz < f < 100kHz, C
OUT
= 10µF
V
IH
, 2.5V
≤
V
IN
≤
5.5V
V
IL
, 2.5V
≤
V
IN
≤
5.5V
SHDN
= GND or IN
V
SET
= 1.3V
SET = GND, I
OUT
= 200mA
V
IN
= 2.5V, I
SINK
= 2mA
V
FAULT
= 3.6V
T
A
= +25°C
T
A
= +85°C
0.01
0.5
170
20
120
T
A
= +25°C
T
A
= +85°C
T
A
= +25°C
T
A
= +85°C
0.01
0.5
0.01
0.5
130
280
0.25
100
2.5
2.0
0.4
100
MIN
TYP
65
60
55
190
nV√Hz
V
V
nA
nA
mV
V
nA
°C
°C
µs
µV
RMS
MAX
UNITS
MAX8860
Specifications to -40°C are guaranteed by design and not production tested.
Guaranteed by line-regulation test.
Adjustable mode only.
The dropout voltage is defined as V
IN
- V
OUT
when V
OUT
is 100mV below the value of V
OUT
for V
IN
= V
OUT
2V. Since the
minimum input voltage is 2.5V, this is applicable only for voltages of 2.5V or higher.
Note 5:
The
FAULT
detection voltage is the difference from input to output voltage. Maintain the input above this level to ensure
good line and load regulation.
Typical Operating Characteristics
(V
IN
= V
OUT
+ 0.5V, C
IN
= C
OUT
= 2.2µF, C
CC
= 33nF, T
A
= +25°C, unless otherwise noted.)
NORMALIZED OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX8860 toc01
NORMALIZED OUTPUT VOLTAGE
vs. TEMPERATURE
MAX8860 toc02
SUPPLY CURRENT vs. LOAD CURRENT
180
160
SUPPLY CURRENT (µA)
140
120
100
80
60
40
20
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
MAX8860 toc03
0.4
V
OUT
NORMALIZED AT I
OUT
= 0
OUTPUT VOLTAGE (%)
0.2
0.3
V
OUT
NORMALIZED AT +25°C, I
OUT
= 0
0.2
OUTPUT VOLTAGE (%)
0.1
0
-0.1
-0.2
I
OUT
= 200mA
200
I
OUT
= 0
I
OUT
= 100mA
0
-0.2
-0.4
0
50
100
150
200
250
300
LOAD CURRENT (mA)
-0.3
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
0
0
50
100
150
200
250
300
LOAD CURRENT (mA)
_______________________________________________________________________________________
3
Low-Dropout, 300mA
Linear Regulator in µMAX
MAX8860
Typical Operating Characteristics (continued)
(V
IN
= V
OUT
+ 0.5V, C
IN
= C
OUT
= 2.2µF, C
CC
= 33nF, T
A
= +25°C, unless otherwise noted.)
NO LOAD SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX8860 toc04
DROPOUT VOLTAGE vs. LOAD CURRENT
160
DROPOUT VOLTAGE (mV)
140
120
100
80
60
40
20
0
0
0
50
100
150
200
250
300
0
T
A
= +85°C
T
A
= -40°C
T
A
= +25°C
MAX8860 toc05
FAULT DETECT THRESHOLD
vs. LOAD CURRENT
MAX8860 toc06
200
180
160
SUPPLY CURRENT (µA)
140
120
100
80
60
40
20
0
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
T
A
= -40°C
T
A
= +25°C
T
A
= +85°C
180
250
FAULT DETECT THRESHOLD (mV)
200
FAULT = HIGH
150
100
FAULT = LOW
50
50
100
150
200
250
300
LOAD CURRENT (mA)
LOAD CURRENT (mA)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX8860 toc07
OUTPUT NOISE SPECTRAL DENSITY
MAX8860 toc08
OUTPUT NOISE
(10Hz TO 1MHz)
MAX8860 toc09
0
-10
-20
-30
-40
-50
-60
-70
0.01
0.1
1
10
100
10
I
LOAD
= 10mA
NOISE (µV/√Hz)
1.0
C
OUT
= 2.2µF
0.1
C
OUT
= 10µF
V
OUT
500µV/div
I
LOAD
= 200mA
PSRR (dB)
0.01
1000
0.1
1
10
FREQUENCY (kHz)
100
1000
1ms/div
FREQUENCY (kHz)
LOAD-TRANSIENT RESPONSE
MAX8860 toc10
LINE-TRANSIENT RESPONSE
+4.3V
V
IN
+3.3V
MAX8860 toc12
200mA
I
LOAD
0
V
OUT
20mV/div
V
IN
= V
OUT
+ 200mV
V
OUT
2mV/div
I
LOAD
= 200mA
400µs/div
500µs/div
4
_______________________________________________________________________________________
Low-Dropout, 300mA
Linear Regulator in µMAX
Typical Operating Characteristics (continued)
(V
IN
= V
OUT
+ 0.5V, C
IN
= C
OUT
= 2.2µF, C
CC
= 33nF, T
A
= +25°C, unless otherwise noted.)
MAX8860
POWER-UP RESPONSE
MAX8860 toc13
POWER-DOWN RESPONSE
2V
0
FAULT
MAX8860 toc14
SHUTDOWN/POWER-UP
4V
SHDN
2V
0
3V
MAX8860 toc15
4V
2V
0
4V
3V
2V
1V
0
5ms/div
V
OUT
V
IN
FAULT
4V
4V
3V
2V
1V
0
V
IN
V
OUT
2V
V
OUT
1V
0
2ms/div
400µs/div
Pin Description
PIN
1, 4
2
3
5
6
7
8
NAME
OUT
IN
GND
SET
CC
SHDN
FAULT
FUNCTION
Regulator Output. Bypass with 2.2µF, low-ESR capacitor to GND for stable operation.
Supply Input. Connect to power source (2.5V to 6.5V). Bypass with 2.2µF capacitor to GND.
Ground
Output Voltage Set. Connect to GND for internally set threshold. Connect to resistor-divider for adjustable
output voltages. See
the Output Voltage Selection
section for more information.
Compensation Capacitor. Connect a 0.033µF capacitor from CC to GND.
Shutdown Input. Connect to IN for normal operation. Drive
SHDN
low to turn off the regulator.
Fault Output. A high-impedance, open-drain output. When the MAX8860 is out of regulation,
FAULT
goes
low. In shutdown, the
FAULT
pin is high impedance. Connect to GND if unused.
Detailed Description
The MAX8860 is a low-dropout, low-quiescent-current
linear regulator designed primarily for battery-powered
applications. It supplies an adjustable 1.25V to
6.5V output voltage or a fixed-voltage output of 1.8V
(MAX8860EUA18), 2.5V (MAX8860EUA25), 2.77V
(MAX8860EUA27), 2.82V (MAX8860EUA28), 3.0V
(MAX8860EUA30), or 3.3V (MAX8860EUA33) for load
currents up to 300mA. The devices with 2.77V and
2.82V nominal outputs are designed to guarantee mini-
mum output voltages of 2.70V and 2.75V, respectively.
The device consists of a 1.25V reference, error amplifi-
er, MOSFET driver, P-channel pass transistor, Dual
Mode comparator, fault detector, and internal-feedback
voltage divider (Figure 1).
The 1.25V bandgap reference is connected to the error
amplifier’s inverting input. The error amplifier compares
this reference to the selected feedback voltage and
amplifies the difference. The MOSFET driver reads the
error signal and applies the appropriate drive to the P-
channel pass transistor. If the feedback voltage is lower
than the reference voltage, the pass-transistor gate is
pulled lower, allowing more current to pass and
increasing the output voltage. If the feedback voltage
is higher than the reference voltage, the pass-transistor
gate is driven higher, allowing less current to pass to
the output. The output voltage is fed back through
either an internal resistor voltage 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 60mV, internal
feedback is used and the output voltage is regulated to
the preset output voltage. Additional blocks include an
output current limiter, reverse battery protection, a ther-
mal sensor, a fault detector, and shutdown logic.
5
_______________________________________________________________________________________
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