Datasheet MAX8885EUK50, MAX8885EUK33, MAX8885EUK30, MAX8885EUK25, MAX8885EUK27 Datasheet (Maxim)
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
General Description
The MAX8885 low-dropout (LDO) linear regulator operates
from a +2.5V to +6.5V input voltage range and delivers up
to 150mA. It uses a P-channel MOSFET pass transistor to
allow a low 85µA supply current—which is independent of
the load—as well as LDO voltage. The MAX8885 is optimized to operate with low-cost, high-ESR output capacitors such as small case-size tantalum capacitors. It is ideal
for cost-sensitive portable equipment such as PCS and
cellular phones. For a pin-compatible, functionally equivalent device for use with a low-ESR, ceramic output capacitor, refer to the MAX8875 data sheet.
The MAX8885 features a power-OK output that indicates
when the output is out of regulation, and is available in
preset output voltage versions of 5.0V, 3.3V, 3.0V, 2.7V,
and 2.5V. Other features include 1µA (max) shutdown current, short-circuit protection, thermal shutdown protection,
and reverse-battery protection. The MAX8885 is available
in a miniature 5-pin SOT23 package.
Applications
PCS Phones Modems
Cellular Phones Hand-Held Instruments
Cordless Phones Palmtop Computers
PCMCIA Cards Electronic Planners
Features
♦ Optimized for Low-Cost Tantalum Capacitors
♦ Pin Compatible with MIC5206
♦ Undervoltage Power-OK Output
♦ Preset Output Voltages (±1% accuracy)
♦ Guaranteed 150mA Output Current
♦ 85µA No-Load Supply Current
♦ Low 110mV Dropout at 100mA Load (165mV at
150mA load)
♦ Thermal-Overload and Short-Circuit Protection
♦ Reverse-Battery Protection
♦ 60dB PSRR at 100Hz
♦ 1µA max Shutdown Current
MAX8885
150mA, Low-Dropout Linear Regulator
with Power-OK Output
________________________________________________________________ Maxim Integrated Products 1
Typical Operating Circuit
19-1576; Rev 0; 10/99
PART
MAX8885EUK25
MAX8885EUK27
MAX8885EUK30 -40°C to +85°C
-40°C to +85°C
-40°C to +85°C
TEMP. RANGE PIN-PACKAGE
5 SOT23-5
5 SOT23-5
5 SOT23-5
Note: See Output Voltage Selector Guide for more information.
Pin Configuration
Ordering Information
MAX8885EUK33
MAX8885EUK50 -40°C to +85°C
-40°C to +85°C 5 SOT23-5
5 SOT23-5
Output Voltage Selector Guide
Note: Other output voltages between 2.5V and 5.0V are available in 100mV increments—contact factory for information.
Minimum order quantity is 25,000 units.
PART
MAX8885EUK25
MAX8885EUK27
MAX8885EUK30
MAX8885EUK33
MAX8885EUK50
V
OUT
(V)
2.5
2.7
3.0
3.3
5.0
TOP MARK
ADLE
ADLF
ADLG
ADLH
ADLJ
TOP VIEW
SHDN
GND
1
IN
MAX8885
2
3
5
OUT
POK
4
OUTPUT
100k
PRESET
2.5V TO 5.0V
150mA
C
OUT
4.7µF
TO
µC
INPUT
+2.5V TO +6.5V
C
IN
1µF
ON
OFF
IN OUT
MAX8885
SHDN
POK
GND
SOT23-5
MAX8885
150mA, Low-Dropout Linear Regulator
with Power-OK Output
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= V
OUT(NOMINAL)
+ 1V, SHDN = IN, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
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.
IN, SHDN, POK to GND...............................................-7V to +7V
SHDN to IN ...............................................................-7V to +0.3V
OUT to GND ................................................-0.3V to (V
IN
+ 0.3V)
Output Short-Circuit Duration ........................................Indefinite
Continuous Power Dissipation (T
A
= +70°C)
5-Pin SOT23 (derate 7.1mW/°C above +70°C)..........571mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
θ
JA
..................................................................................140°C/W
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
TA= +25°C
TA= -40°C to +85°C, I
OUT
= 100µA
VIN= 2.5V to 5.5V
TA= +25°C, I
OUT
= 100µA
SHDN = GND
f = 100Hz
I
OUT
= 100mA
I
OUT
= 50mA
C
OUT
= 10µF, f = 10Hz to 100kHz
I
OUT
= 100µA to 120mA, C
OUT
= 4.7µF
I
OUT
= 100µA
I
OUT
= 150mA
TA= -40°C to +85°C,
I
OUT
= 100µA to 120mA
VIN= (V
OUT
+ 0.1V) to 6.5V, I
OUT
= 1mA
I
OUT
= 100µA
I
OUT
= 150mA
CONDITIONS
0.05
nA
0 100
I
SHDN
SHDN Input Bias Current
0.4
V
IL
V
2.0
V
IH
SHDN Input Threshold
0.02
µA
0.005 1
I
OFF
Shutdown Supply Current
dB
60
PSRR
Output Voltage AC PowerSupply Rejection Ratio
µV
RMS
170
Output Voltage Noise
%/mA
0.01
∆V
LDR
Load Regulation
%/V
-0.15 0 0.15
∆V
LNR
Line Regulation
165
%
-2 2
-1 1
V
2.5 6.5
V
IN
Input Voltage
Output Voltage Accuracy
110 220
mV
50
0.1
VIN-
V
OUT
Dropout Voltage (Note 2)
100
-3 2
mA
150
I
OUT
Maximum Output Current
mA
160 390
I
LIM
Current Limit
µA
85 180
I
Q
Ground Pin Current
UNITSMIN TYP MAXSYMBOLPARAMETER
TA= +25°C
TA= +85°C
V
SHDN
= 5.5V or GND
TA= +85°C
SHUTDOWN
MAX8885
150mA, Low-Dropout Linear Regulator
with Power-OK Output
_______________________________________________________________________________________ 3
Note 1: Limits are 100% production tested at TA= +25°C. Limits over the operating temperature range are guaranteed through cor-
relation using Statistical Quality Control (SQC) methods.
Note 2: Dropout voltage is defined as V
IN
- V
OUT
, when V
OUT
is 100mV below the value of V
OUT
for VIN= V
OUT
+ 0.5V.
ELECTRICAL CHARACTERISTICS (continued)
(VIN= V
OUT(NOMINAL)
+ 1V, SHDN = IN, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER
I
SINK
= 1mA
Hysteresis, I
OUT
= 0
In dropout, V
OUT
falling
(1 - V
OUT
/ V
OUT(NOMINAL)
)100, V
OUT
falling,
I
OUT
= 0
V
0.4
V
OL
POK Output Voltage Low
1
-5.3
%
-3 -5 -8
V
POK
Power-OK Voltage Threshold
0 ≤ V
POK
≤ 6.5V, V
OUT
in regulation
°C
20
∆T
SHDN
Thermal Shutdown Hysteresis
°C
170
T
SHDN
Thermal Shutdown Temperature
µA
1
POK Output Leakage Current
Typical Operating Characteristics
(MAX8885EUK30, VIN= +3.6V, CIN= 1µF, C
OUT
= 4.7µF, SHDN = IN, TA= +25°C, unless otherwise noted.)
0
40
20
80
60
100
120
0231 456
GROUND PIN CURRENT
vs. INPUT VOLTAGE
MAX8885toc01
INPUT VOLTAGE (V)
GROUND PIN CURRENT (µA)
I
OUT
= 0
I
OUT
= 150mA
85
100
95
90
105
110
115
0604515 30 75 90 105 120 135 150
GROUND PIN CURRENT vs.
OUTPUT LOAD
MAX8885toc02
OUTPUT LOAD (mA)
GROUND PIN CURRENT (µA)
VIN = 3.5V
VIN = 5.0V
85
100
105
95
90
110
115
120
0604515 30 75 90 105 120 135 150
GROUND PIN CURRENT vs.
OUTPUT LOAD
MAX8885toc03
OUTPUT LOAD (mA)
GROUND PIN CURRENT (µA)
VIN = V
OUT(NOMINAL)
+ 0.5V
V
OUT
= 5.0V
MAX8885EUK50
V
OUT
= 3.0V
MAX8885EUK30
POWER-OK OUTPUT
THERMAL PROTECTION
MAX8885
150mA, Low-Dropout Linear Regulator
with Power-OK Output
4 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(MAX8885EUK30, VIN= +3.6V, CIN= 1µF, C
OUT
= 4.7µF, SHDN = IN, TA= +25°C, unless otherwise noted.)
60
80
70
100
90
120
110
130
-40 10-15 35 60 85
GROUND PIN CURRENT
vs. TEMPERATURE
MAX8885toc04
TEMPERATURE (°C)
GROUND PIN CURRENT (µA)
VIN = 5.0V
I
OUT
= 150mA
VIN = 3.6V
I
OUT
= 150mA
VIN = 3.6V OR 5.0V
I
OUT
= 0
0
1.0
0.5
2.0
1.5
3.0
2.5
3.5
0231 456
OUTPUT VOLTAGE vs.
INPUT VOLTAGE
MAX8885toc05
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
I
OUT
= 0
I
OUT
= 150mA
0604515 30 75 90 105 120 135 150
2.90
2.95
3.00
3.05
3.10
OUTPUT VOLTAGE vs. OUTPUT LOAD
MAX8885toc06
OUTPUT LOAD (mA)
OUTPUT VOLTAGE (V)
VIN = 3.6V
VIN = 5.0V
60
80
110
130
OUTPUT VOLTAGE vs. TEMPERATURE
OUTPUT VOLTAGE (V)
MAX8885toc07
TEMPERATURE (°C)
120
100
90
70
-40 -15
10
35
60
85
VIN = 5.0V
I
OUT
= 150mA
VIN = 3.6V OR 5.0V
I
OUT
= 0
VIN = 3.6V
I
OUT
= 150mA
0604515 30 75 90 105 120 135 150
0
150
100
50
200
250
DROPOUT VOLTAGE vs.
OUTPUT LOAD
MAX8885toc08
OUTPUT LOAD (mA)
DROPOUT VOLTAGE (mV)
TA = +25°C
T
A
= -40°C
T
A
= +85°C
0.01 0.1 1 10 100 1000
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
40
45
30
35
20
25
50
55
60
65
MAX8885toc09
FREQUENCY (kHz)
PSRR (dB)
R
OUT
= 60Ω
C
OUT
= 10µF
C
OUT
= 1µF
10
0.01
0.1 10 100 1000
OUTPUT NOISE SPECTRAL DENSITY
vs. FREQUENCY
0.1
1
MAX8885toc10
FREQUENCY (kHz)
OUTPUT NOISE SPECTRAL DENSITY (µV/
Hz
)
1
I
OUT
= 50mA
C
OUT
= 10µF
C
OUT
= 1µF
10ms/div
OUTPUT NOISE (10Hz TO 100kHz)
V
OUT
500µV/div
MAX8885toc11
C
OUT
= 10µF
I
LOAD
= 50mA
16030 12090 150
REGION OF STABLE C
OUT
ESR vs.
LOAD CURRENT
MAX8885toc12
LOAD CURRENT (mA)
C
OUT
ESR (Ω)
1000
0.1
1
10
100
STABLE REGION: C
OUT
= 4.7µF TO 10µF
150mA, Low-Dropout Linear Regulator
with Power-OK Output
_______________________________________________________________________________________ 5
Typical Operating Characteristics (continued)
(MAX8885EUK30, VIN= +3.6V, CIN= 1µF, C
OUT
= 4.7µF, SHDN = IN, TA= +25°C, unless otherwise noted.)
10µs/div
POK AND SHUTDOWN RESPONSE
2V
0
2V
0
0
2V
4V
V
POK
V
OUT
MAX8885toc19
V
SHDN
R
LOAD
= 60Ω
MAX8885
3.02V
3.00V
2.98V
3V
0
2V
0
LINE-TRANSIENT RESPONSE
5V
4V
R
= 60Ω
OUT
SHUTDOWN DELAY
R
= 60Ω
LOAD
100µs/div
100
µs/div
MAX8885toc13
MAX8885toc16
V
IN
V
OUT
V
OUT
1V/div
V
SHDN
1V/div
LOAD-TRANSIENT RESPONSE
NEAR DROPOUT
0
POK STARTUP RESPONSE
0
0
0
5µs/div
10ms/div
VIN = V
C
50mA
3.05V
3.0V
4V
3V
2V
LOAD-TRANSIENT RESPONSE
0
POK OUTPUT
0
0
5µs/div
200µs/div
VIN = V
= 1µF
C
IN
MAX8885toc14
OUT +
MAX8885toc17
0.5V
I
LOAD
25mA/div
V
OUT
25mV/div
V
OUT
2V/div
V
POK
2V/div
V
IN
1V/div
50mA
3.05V
3.0V
5V
2.5V
2.5V
5V
2.5V
IN
= 1µF
MAX8885toc15
OUT +
MAX8885toc18
0.1V
I
LOAD
25mA/div
V
OUT
25mV/div
V
IN
2.5V/div
V
OUT
2.5V/div
V
POK
2.5V/div
MAX8885
150mA, Low-Dropout Linear Regulator
with Power-OK Output
6 _______________________________________________________________________________________
Pin Description
FUNCTION
Regulator Output. Fixed 5.0V, 3.3V, 3.0V, 2.7V, or 2.5V output. Sources up to 150mA. Bypass
with 4.7µF (>0.5Ω typ ESR) tantalum capacitor to GND.
OUT5
Power-OK Output. Active low, open-drain output indicates an out-of-regulation condition.
Connect a 100kΩ pull-up resistor to OUT for logic levels. If not used, leave this pin unconnected.
POK4
Active-Low Shutdown Input. A logic low reduces the supply current to below 1µA. Connect to IN
for normal operation.
SHDN
3
PIN
Ground. This pin also functions as a heatsink. Solder to a large pad or the circuit-board ground
plane to maximize power dissipation.
GND2
Regulator Input. Supply voltage can range from +2.5V to +6.5V. Bypass with 1µF capacitor to GND
(see Capacitor Selection and Regulator Stability).
IN1
NAME
Detailed Description
The MAX8885 is a low-dropout, low-quiescent-current
linear regulator designed primarily for battery-powered
applications using low-cost, high-ESR tantalum capacitors. The device delivers up to 150mA and is available
with preset output voltages of 2.5V, 2.7V, 3.0V, 3.3V, or
5.0V. The MAX8885 consists of a 1.25V reference, error
amplifier, P-channel pass transistor, power-OK comparator, 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 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 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 an internal resistor voltage
divider connected to the OUT pin.
Additional blocks include a current limiter, reverse-battery protection, thermal sensor, and shutdown logic.
Output Voltage
The MAX8885 is supplied with factory-set output voltages of 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 MAX8885EUK33 indicates a
preset output voltage of 3.3V (see Output Voltage
Selector Guide).
Internal P-Channel Pass Transistor
The MAX8885 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 significantly. PNP-based regulators waste considerable current in dropout when the pass transistor saturates. They
also use high base-drive currents under large loads.
The MAX8885 does not suffer from these problems and
consumes only 100µA of quiescent current whether in
dropout, light-load, or heavy-load applications (see
Typical Operating Characteristics).
Power-OK Output (POK)
When the output voltage goes out of regulation—as during 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 resis-
tor works well for most applications. The POK function is
not active during shutdown. A capacitor to GND may be
added to generate a power-on-reset (POR) delay, which
can operate down to VIN≤ 1V. (See POK Startup
Response in the Typical Operating Circuit.)
Current Limit
The MAX8885 includes a current limiter that monitors
and controls the pass transistor’s gate voltage, limiting
the output current to 390mA (typ). For design purposes, 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.
Thermal-Overload Protection
When the junction temperature exceeds TJ= +170°C,
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 thermaloverload conditions.
Thermal-overload protection is designed to protect the
MAX8885 in the event of fault conditions. For continuous
operation, do not exceed the absolute maximum
junction-temperature rating of TJ= +150°C.
Operating Region and Power Dissipation
The MAX8885’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 dissipation across the device is P = I
OUT(VIN
- V
OUT
). The
maximum power dissipation is:
P
MAX
= (TJ- TA) / ( θJB+ θBA)
where T
J
- TAis the temperature difference between the
MAX8885 die junction and the surrounding air; θJB(or
θJC) is the thermal resistance of the package; and θ
BA
is the thermal resistance through the printed circuit
board, copper traces, and other materials to the surrounding air.
The MAX8885’s GND pin 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.
Reverse-Battery Protection
The MAX8885 has a unique protection scheme that limits the reverse supply current to 1mA when either V
IN
or
V
SHDN
falls below ground. The circuitry monitors the
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
Capacitor Selection and
Regulator Stability
The MAX8885 is designed primarily for applications
using low-cost, high-ESR output capacitors such as
small case-size tantalum electrolytic capacitors. These
capacitors have ESR that can extend as high as 10Ω,
and their capacitance and ESR can vary widely over
their operating temperature range. For stable operation
over the full operating range, use a 4.7µF (1µF min)
capacitor with ESR > 0.5Ω (see the Region of Stable
C
OUT
ESR vs. Load Current graph in the Typical
Operating Characteristics). Ceramic output capacitors
should not be used with the MAX8885. For a pin-compatible, functionally equivalent linear regulator that is
suitable for ceramic output capacitors, refer to the
MAX8875 data sheet.
Bypass the MAX8885’s input with a 1µF or greater
capacitor to GND. Place this capacitor close to the
device (<5mm).
MAX8885
150mA, Low-Dropout Linear Regulator
with Power-OK Output
_______________________________________________________________________________________ 7
Figure 1. Functional Diagram
REVERSE
IN
SHDN
GND
BATTERY
PROTECTION
MAX8885
SHUTDOWN
LOGIC
THERMAL
SENSOR
1.25V
REF
P
OUT
POK
95%
REF
ERROR
AMP
POK
MOS DRIVER
WITH I
LIMIT
MAX8885
150mA, Low-Dropout Linear Regulator
with Power-OK Output
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.
8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
PSRR and Operation from Sources
Other than Batteries
The MAX8885 is designed to allow 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 MAX8885’s line- and load-transient responses.
Load-Transient Considerations
The MAX8885’s load-transient response graphs (see
Typical Operating Characteristics) show three components of the output response. The first (and most significant) component is the abrupt drop in output voltage
due to the capacitor’s ESR. The magnitude of the voltage
drop is directly proportional to the output capacitor's
ESR and the size of the load transient and is independent of the regulator’s transient response. The second
component is the output voltage recovery, which is a
function of the regulator’s loop response and the capacitance at the output. The third component is a DC shift in
the output voltage resulting from the regulator’s finite output impedance. To improve the MAX8885’s load-transient response, increase the output capacitor’s value
and decrease its ESR. Take care to ensure that the out-
put capacitor is chosen to comply with the Region of
Stable C
OUT
ESR vs. Load Current graph.
Dropout Voltage
A 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
MAX8885 uses a P-channel MOSFET pass transistor,
its dropout voltage is a function of drain-to-source onresistance (R
DS(ON)
) multiplied by the load current (see
Typical Operating Characteristics).
V
DROPOUT
= VIN- V
OUT
= R
DS(ON)
· I
OUT
Chip Information
TRANSISTOR COUNT: 266
Package Information
SOT5L.EPS
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