MAX8875EUK27+ [MAXIM]
Fixed Positive LDO Regulator, 2.7V, 0.22V Dropout, PDSO5, SOT-23, 5 PIN;
| 型号： | MAX8875EUK27+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Fixed Positive LDO Regulator, 2.7V, 0.22V Dropout, PDSO5, SOT-23, 5 PIN 光电二极管 |
| 文件： | 总9页 (文件大小：257K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-1556; Rev 1; 12/00
150mA, Low-Dropout Linear Regulator
with Power-OK Output
General Description
Features
The MAX8875 low-dropout linear regulator operates from
a +2.5V to +6.5V input range and delivers up to 150mA.
A P-channel MOSFET pass transistor allows its 85µA sup-
ply current to remain independent of the load, making this
device ideal for battery-operated portable equipment
such as PCS phones, cellular phones, cordless phones,
and modems.
o Power-OK Output
o Small Output Capacitor (1µF ceramic)
o Preset Output Voltages ( 1ꢀ accuracꢁ)
o Guaranteed 150mA Output Current
o 85µA No-Load Supplꢁ Current
o Low 110mV Dropout at 100mA Load (165mV at
150mA load)
The MAX8875 features a power-OK (POK) output that indi-
cates when the output is out of regulation. The device is
available in several preset output voltage versions: 5.0V,
3.3V, 3.0V, 2.7V, 2.5V, or 1.5V. Other features include 1µA
(max) shutdown current, short-circuit protection, thermal
shutdown protection, and reverse-battery protection. The
device comes in a miniature 5-pin SOT23 package.
o Thermal-Overload and Short-Circuit Protection
o Reverse-Batterꢁ Protection
o 60dB PSRR at 100Hz
o 1µA max Shutdown Current
The MAX8875 is optimized for use with a 1µF ceramic out-
put capacitor. For a pin-compatible, functionally equivalent
device for use with a higher ESR output capacitor, see the
MAX8885 data sheet.
Ordering Information
*
PART
TEMP. RANGE
PIN-PACKAGE
MAX8875EUKxy-T
-40°C to +85°C
5 SOT23-5
*
xy is the output voltage code (see Output Voltage Selector
Guide).
Applications
Output Voltage Selector Guide
PCS Telephones
Cellular Telephones
Cordless Telephones
PCMCIA Cards
Hand-Held Instruments
Palmtop Computers
Electronic Planners
Modems
PART
V
(V)
TOP MARK
ADQI
OUT
MAX8875EUK15-T
MAX8875EUK25-T
MAX8875EUK27-T
MAX8875EUK30-T
MAX8875EUK33-T
MAX8875EUK50-T
1.5
2.5
2.7
3.0
3.3
5.0
ADKZ
ADLA
ADLB
ADLC
ADLD
Note: Other output voltages between 1.5V and 5.0V are avail-
able in 100mV increments—contact the factory for information.
Minimum order quantity is 25,000 units.
Typical Operating Circuit
OUTPUT
PRESET
INPUT
+2.5V TO +6.5V
1.5V TO 5.0V
Pin Configuration
150mA
IN
OUT
POK
C
OUT
1µF
TOP VIEW
C
IN
1µF
1
2
3
5
OUT
IN
GND
MAX8875
100k
MAX8875
ON
TO µC
SHDN
OFF
GND
SHDN
4
POK
SOT23-5
________________________________________________________________ Maxim Integrated Products
1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
150mA, Low-Dropout Linear Regulator
with Power-OK Output
ABSOLUTE MAXIMUM RATINGS
IN, SHDN, POK to GND...............................................-7V to +7V
SHDN to IN...............................................................-7V to +0.3V
OUT to GND ................................................-0.3V to (V + 0.3V)
IN
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
...............................................................................+140°C/W
θ
JA
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Output Short-Circuit Duration ........................................Indefinite
Continuous Power Dissipation (T = +70°C)
A
5-Pin SOT23 (derate 7.1mW/°C above +70°C)..........571mW
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
V
IN = OUT(NOMINAL)
+ 1V, SHDN = IN, T = -40°C to +85°C, unless otherwise noted. Typical values are at T = +25°C.) (Note 1)
A
A
PARAMETER
SYMBOL
CONDITIONS
MIN
2.5
-1.0
-2
TYP
MAX
6.5
1.0
2
UNITS
Input Voltage
V
IN
V
T
T
= +25°C, I
= 100µA
A
OUT
I
I
= 100µA
OUT
Output Voltage Accuracy
%
= -40°C to +85°C
A
= 100µA to
OUT
-3
2
120mA
Maximum Output Current
Current Limit
I
150
160
mA
mA
OUT
I
390
85
LIM
I
I
I
= 100µA
= 150mA
= 100µA
= 50mA
180
OUT
OUT
OUT
OUT
OUT
Ground Pin Current
I
Q
µA
100
0.1
50
I
I
Dropout Voltage (Note 2)
V
- V
OUT
mV
IN
= 100mA
= 150mA
110
165
0
220
I
OUT
Line Regulation
∆V
∆V
V
= 2.5V or (V
+ 0.1V) to 6.5V, I = 1mA
OUT
-0.15
0.15
%/V
LNR
IN
OUT
Load Regulation
Output Voltage Noise
I
= 100µA to 120mA, C
= 1µF
0.01
170
%/mA
LDR
OUT
OUT
C
= 10µF, f = 10Hz to 100kHz
µV
RMS
OUT
Output Voltage AC Power-
Supply Rejection Ratio
PSRR
f = 100Hz
60
dB
SHUTDOWN
T
T
= +25°C
0.005
0.02
1
A
Shutdown Supply Current
I
SHDN = GND
µA
V
OFF
= +85°C
A
V
2.0
IH
V
IN
= 2.5V to 5.5V
SHDN Input Threshold
V
IL
0.4
T
T
= +25°C
= +85°C
0
100
A
I
nA
SHDN Input Bias Current
SHDN = IN or GND
SHDN
0.05
A
2
_______________________________________________________________________________________
150mA, Low-Dropout Linear Regulator
with Power-OK Output
ELECTRICAL CHARACTERISTICS (continued)
(V = V
IN
OUT(NOMINAL)
+ 1V, SHDN = IN, T = -40°C to +85°C, unless otherwise noted. Typical values are at T = +25°C.) (Note 1)
A
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POWER-OK OUTPUT
1 - V
/V
falling, V
100, I
= 0,
OUT
OUT OUT(NOMINAL)
-3
-5
-8
V
OUT
≥ 2.5V
OUT
1 - V
100, I
/V
= I
falling,
< 2.5V
OUT OUT(NOMINAL)
T
= 0°C to +85°C
-8.5
-7
-10.5
-13.5
-15
A
,
OUT
LIM
Power-OK Voltage Threshold
V
POK
%
V
OUT
V
OUT
T = -40°C to +85°C
A
In dropout, V
falling, V
≥ 2.5V
OUT
-5.3
1
OUT
Hysteresis, I
= 1mA
= 0
OUT
POK Output Voltage Low
V
I
0.4
1
V
OL
SINK
POK Output Leakage Current
THERMAL PROTECTION
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
0 ≤ V
≤ 6.5V, V
in regulation
OUT
µA
POK
T
170
20
°C
°C
SHDN
∆T
SHDN
Note 1: Limits are 100% production tested at T = +25°C. Limits over the operating temperature range are guaranteed through
A
correlation using Statistical Quality Control (SQC) methods.
Note 2: Dropout voltage is defined as V - V
, when V
is 100mV below the value of V
for V = V
+ 0.5V. Applies only
IN
OUT
OUT
OUT
IN
OUT
for output voltages ≥ 2.5V.
Typical Operating Characteristics
(MAX8875EUK30, V = +3.6V, C = C
= 1µF, SHDN = IN, T = +25°C, unless otherwise noted.)
IN
IN
OUT
A
GROUND PIN CURRENT vs.
INPUT VOLTAGE
GROUND PIN CURRENT vs.
OUTPUT LOAD
GROUND PIN CURRENT vs.
OUTPUT LOAD
115
110
105
100
95
120
100
80
60
40
20
0
120
115
110
105
100
95
V
IN
= V
+ 0.5V
OUT(NOMINAL)
I
= 150mA
OUT
V
OUT
= 5.0V
MAX8875EUK50
V
IN
= 5.0V
= 3.5V
I
= 0
OUT
V
IN
V
OUT
= 3.0V
MAX8875EUK30
90
90
85
85
0
15 30 45 60 75 90 105 120 135 150
OUTPUT LOAD (mA)
0
1
2
3
4
5
6
0
15 30 45 60 75 90 105 120 135 150
OUTPUT LOAD (mA)
INPUT VOLTAGE (V)
_______________________________________________________________________________________
3
150mA, Low-Dropout Linear Regulator
with Power-OK Output
Typical Operating Characteristics (continued)
(MAX8875EUK30, V = +3.6V, C = C
= 1µF, SHDN = IN, T = +25°C, unless otherwise noted.)
IN
IN
OUT
A
OUTPUT VOLTAGE vs.
INPUT VOLTAGE
GROUND PIN CURRENT vs.
TEMPERATURE
OUTPUT VOLTAGE vs. OUTPUT LOAD
3.10
3.05
3.00
2.95
2.90
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
130
120
110
100
90
V
OUT
= 5.0V
IN
I
= 0
OUT
I
= 150mA
V
OUT
= 3.6V
IN
I
= 150mA
OUT
V
= 3.6V
IN
I
= 150mA
V
I
= 3.6V OR 5.0V
OUT
IN
80
= 0
V
IN
= 5.0V
70
60
0
15 30 45 60 75 90 105 120 135 150
OUTPUT LOAD (mA)
0
1
2
3
4
5
6
-40
-15
10
35
60
85
INPUT VOLTAGE (V)
TEMPERATURE (°C)
DROPOUT VOLTAGE vs.
OUTPUT LOAD
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
OUTPUT VOLTAGE vs. TEMPERATURE
3.10
3.05
3.00
2.95
2.90
250
200
150
100
50
70
60
V
OUT
= 3.6V OR 5.0V
IN
50
40
30
I
= 0
C
OUT
= 10µF
T
A
= +85°C
V
OUT
= 3.6V
IN
T
A
= +25°C
C
OUT
= 1µF
I
= 150mA
20
10
T
A
= -40°C
V
OUT
= 5.0V
IN
I
= 150mA
0
0
0.01
-40
-15
10
35
60
85
0
15 30 45 60 75 90 105 120 135 150
OUTPUT LOAD (mA)
0.1
1
10
100
1000
TEMPERATURE (°C)
FREQUENCY (kHz)
OUTPUT NOISE SPECTRAL DENSITY
vs. FREQUENCY
OUTPUT NOISE
LINE-TRANSIENT RESPONSE
10
f = 10Hz TO 100kHz
C
= 10µF
OUT
= 50mA
C
OUT
= 10µF
OUT
= 50mA
I
OUT
5V
4V
I
1
V
OUT
500µV/div
3.02V
0.1
3.00V
2.98V
0.01
0.1
1
10
100
10ms/div
10µs/div
FREQUENCY (kHz)
I
= 50mA
OUT
4
_______________________________________________________________________________________
150mA, Low-Dropout Linear Regulator
with Power-OK Output
Typical Operating Characteristics (continued)
(MAX8875EUK30, V = +3.6V, C = C
= 1µF, SHDN = IN, T = +25°C, unless otherwise noted.)
IN
IN
OUT
A
LOAD-TRANSIENT RESPONSE
LOAD-TRANSIENT RESPONSE
NEAR DROPOUT
3.01V
3.01V
3.00V
2.99V
3.00V
2.99V
50mA
0
50mA
0
10µs/div
10µs/div
V
IN
= V + 0.5V, I
OUT
= 0 TO 50mA
OUT
V
IN
= V + 0.1V, I
= 0 TO 50mA
OUT
OUT
SHUTDOWN DELAY
POK OUTPUT
3V
V
OUT
2V/div
0
0
V
OUT
1V/div
V
POK
2V/div
0
2V
4V
3V
V
SHDN
1V/div
V
IN
1V/div
0
2V
100µs/div
200µs/div
MAX8875EUK30, R
= 60Ω
R
POK
= 100kΩ
OUT
POK STARTUP RESPONSE
POK AND SHUTDOWN RESPONSE
5.0V
V
IN
V
SHDN
2V/div
2.5V/div
2V
0
0
2.5V
0
V
OUT
2.5V/div
2V
0
V
OUT
2V/div
4V
5.0V
V
POK
2V/div
V
POK
2.5V/div
0
0
R
LOAD
= 60Ω
10ms/div
10µs/div
R
POK
= 100kΩ
R
POK
= 100kΩ
_______________________________________________________________________________________
5
150mA, Low-Dropout Linear Regulator
with Power-OK Output
Pin Description
PIN
NAME
FUNCTION
Regulator Input. Supply voltage can range from 2.5V to 6.5V. Bypass with 1µF to GND (see the Capacitor
Selection and Regulator Stability section).
1
IN
Ground. This pin also functions as a heatsink. Solder to a large pad or the circuit-board ground plane to
maximize power dissipation.
2
3
4
GND
SHDN
POK
Active-Low Shutdown Input. A logic low reduces the supply current to below 1µA. Connect to IN for normal
operation.
Power-OK Output. Active-low, open-drain output indicates an out-of-regulation condition. Connect a 100k
pull-up resistor to OUT for logic levels. If not used, leave this pin unconnected.
Regulator Output. Fixed 5.0V, 3.3V, 3.0V, 2.7V, 2.5V, or 1.5V output. Sources up to 150mA. Bypass with 1µF
5
OUT
(<0.2Ω typical ESR) ceramic capacitor to GND for V
≥ 2.5V. Bypass with 3.3µF (<0.2Ω typ ESR) ceramic
OUT
capacitor to GND for V
= 1.5V.
OUT
REVERSE-
BATTERY
PROTECTION
IN
SHDN
P
MOS DRIVER
WITH I
LIMIT
ERROR
AMP
SHUTDOWN
LOGIC
OUT
POK
MAX8875
POK
1.25V
REF
95%
REF
THERMAL
SENSOR
GND
Figure 1. Functional Diagram
this reference with the feedback voltage 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 volt-
age is too high, the pass-transistor gate is pulled up,
allowing less current to pass to the output. The output
voltage feeds back through an internal resistor voltage
divider connected to the OUT pin.
_______________Detailed Description
The MAX8875 is a low-dropout, low-quiescent-current
linear regulator designed primarily for battery-powered
applications. The device supplies loads up to 150mA
and is available with preset output voltages of 1.5V,
2.5V, 2.7V, 3.0V, 3.3V, or 5.0V. As illustrated in Figure
1, the MAX8875 consists of a 1.25V reference, error
amplifier, P-channel pass transistor, power-OK com-
parator, and internal feedback voltage divider.
Additional blocks include a current limiter, reverse-
battery protection, thermal sensor, and shutdown logic.
The 1.25V bandgap reference is connected to the error
amplifier’s inverting input. The error amplifier compares
6
_______________________________________________________________________________________
150mA, Low-Dropout Linear Regulator
with Power-OK Output
continuous operation, do not exceed the absolute maxi-
Output Voltage
The MAX8875 is supplied with factory-set output volt-
ages of 1.5V, 2.5V, 2.7V, 3.0V, 3.3V, or 5.0V. The part
number’s two-digit suffix identifies the nominal output
voltage. For example, the MAX8875EUK33 has a preset
output voltage of 3.3V (see Output Voltage Selector
Guide).
mum junction-temperature rating of T = +150°C.
J
Operating Region and Power Dissipation
The MAX8875’s maximum power dissipation depends
on the thermal resistance of the case and circuit board,
the temperature difference between the die junction
and ambient air, and the rate of air flow. The power dis-
Internal P-Channel Pass Transistor
sipation across the device is P = I (V - V
OUT IN
maximum power dissipation is:
). The
OUT
The MAX8875 features a 1.1Ω (typ) P-channel MOSFET
pass transistor. This provides several advantages over
similar designs using PNP pass transistors, including
longer battery life. The P-channel MOSFET requires no
base drive, which reduces quiescent current signifi-
cantly. PNP-based regulators waste considerable
current in dropout when the pass transistor saturates.
They also use high base-drive currents under large
loads. The MAX8875 does not suffer from these prob-
lems and consumes only 100µA of quiescent current
whether in dropout, light-load, or heavy-load applica-
tions (see Typical Operating Characteristics).
P
MAX
= (T - T ) / (θ + θ
)
BA
J
A
JB
where T - T is the temperature difference between
J
A
the MAX8875 die junction and the surrounding air, θ
JB
(or θ ) is the thermal resistance of the package, and
JC
θ
is the thermal resistance through the printed circuit
board, copper traces, and other materials to the sur-
rounding air.
BA
The MAX8875’s ground pin (GND) performs the dual
function of providing an electrical connection to system
ground and channeling heat away. Connect GND to the
system ground using a large pad or ground plane.
Power-OK Output (POK)
When the output voltage goes out of regulation—as dur-
ing dropout, current limit, or thermal shutdown—POK
goes low. POK is an open-drain N-channel MOSFET. To
obtain a logic-level output, connect a pull-up resistor
from POK to OUT. To minimize current consumption,
make this resistor as large as practical. A 100kΩ resistor
works well for most applications. A capacitor to GND
may be added to generate a power-on-reset (POR)
delay. The POK function is not active during shutdown.
POK also provides a power-on-reset function that can
Reverse-Battery Protection
The MAX8875 has a unique protection scheme that lim-
its the reverse supply current to 1mA when either V or
IN
V
falls below ground. The circuitry monitors the
SHDN
polarity of these two pins and disconnects the internal
circuitry and parasitic diodes when the battery is
reversed. This feature prevents device damage.
__________Applications Information
operate down to V ≤ 1V. See POK Startup Response
Capacitor Selection and
Regulator Stability
For stable operation over the full temperature range
and with load currents up to 150mA, use a 1µF (min)
IN
in the Typical Operating Characteristics.
Current Limit
The MAX8875 includes a current limiter that monitors
and controls the pass transistor’s gate voltage, limiting
the output current to 390mA (typ). For design purpos-
es, consider the current limit to be 160mA min to
600mA max. The output can be shorted to ground for
an indefinite period of time without damaging the part.
ceramic output capacitor with an ESR <0.2Ω for V
OUT
≥ 2.5V, or an equivalent 3.3µF ceramic output capacitor
for V = 1.5V. To reduce noise and improve load-
OUT
transient response, stability, and power-supply rejec-
tion, use large output capacitor values, such as 10µF.
Note that some ceramic dielectrics exhibit large capac-
itance and ESR variation with temperature. With
dielectrics such as Z5U and Y5V, it may be necessary
to increase the capacitance by a factor of 2 or more to
ensure stability at temperatures below T = -10°C. With
A
X7R or X5R dielectrics, 1µF should be sufficient at all
Thermal-Overload Protection
When the junction temperature exceeds T = +170°C,
J
the thermal sensor signals the shutdown logic, turning
off the pass transistor and allowing the IC to cool. The
thermal sensor will turn the pass transistor on again after
the IC’s junction temperature cools by 20°C, resulting in
a pulsed output during continuous thermal-overload
conditions.Thermal-overload protection is designed to
protect the MAX8875 in the event of fault conditions. For
operating temperatures for V
patible, functionally equivalent device for use with a
higher ESR output capacitor, see the MAX8885.
≥ 2.5V. For a pin-com-
OUT
_______________________________________________________________________________________
7
150mA, Low-Dropout Linear Regulator
with Power-OK Output
PSRR and Operation from
Sources Other than Batteries
The MAX8875 is designed to deliver low dropout voltages
and low quiescent currents in battery-powered systems.
Power-supply rejection is 60dB at low frequencies. See
the Power-Supply Rejection Ratio vs. Frequency graph in
the Typical Operating Characteristics.
Improve supply-noise rejection and transient response
by increasing the values of the input and output bypass
capacitors. The Typical Operating Characteristics show
the MAX8875’s line- and load-transient responses.
Dropout Voltage
For versions with the output voltage greater than the
minimum input voltage (2.5V), the regulator’s minimum
input-output voltage differential (or dropout voltage)
determines the lowest usable supply voltage. In battery-
powered systems, this will determine the useful end-of-
life battery voltage. Because the MAX8875 uses a
P-channel MOSFET pass transistor, its dropout voltage
is a function of drain-to-source on-resistance (R
)
DS(ON)
multiplied by the load current (see Typical Operating
Characteristics):
V
= V - V
= R
✕ I
DS(ON) OUT
DROPOUT
IN
OUT
Chip Information
TRANSISTOR COUNT: 266
8
_______________________________________________________________________________________
150mA, Low-Dropout Linear Regulator
with Power-OK Output
Package Information
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
9 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2000 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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