_______________General Description
The MAX8863T/S/R and MAX8864T/S/R low-dropout lin-
ear regulators operate from a +2.5V to +6.5V input
range and deliver up to 120mA. A PMOS pass transis-
tor allows the low, 80µA supply current to remain inde-
pendent of load, making these devices ideal for
battery-operated portable equipment such as cellular
phones, cordless phones, and modems.
The devices feature Dual Mode™ operation: their out-
put voltage is preset (at 3.15V for the T versions, 2.84V
for the S versions, or 2.80V for the R versions) or can be
adjusted with an external resistor divider. Other fea-
tures include low-power shutdown, short-circuit protec-
tion, thermal shutdown protection, and reverse battery
protection. The MAX8864 also includes an auto-dis-
charge function, which actively discharges the output
voltage to ground when the device is placed in shut-
down mode. Both devices come in a miniature 5-pin
SOT23 package.
________________________Applications
Cordless Telephones Modems
PCS Telephones Hand-Held Instruments
Cellular Telephones Palmtop Computers
PCMCIA Cards Electronic Planners
____________________________Features
oLow Cost
oLow, 55mV Dropout Voltage @ 50mA IOUT
oLow, 68µA No-Load Supply Current
Low, 80µA Operating Supply Current (even in
dropout)
oLow, 350µVRMS Output Noise
oMiniature External Components
oThermal Overload Protection
oOutput Current Limit
oReverse Battery Protection
oDual Mode™ Operation: Fixed or Adjustable
(1.25V to 6.5V) Output
oLow-Power Shutdown
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
SOT23
TOP VIEW
GND
OUT
IN
15SET
SHDN
MAX8863
MAX8864
2
34
__________________Pin Configuration
MAX8863
MAX8864
OUT
GND SET
IN
SHDN
COUT
1µF
CIN
1µF
BATTERY
OUTPUT
VOLTAGE
__________Typical Operating Circuit
19-0466; Rev 4; 7/12
1
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
______________Ordering Information
Dual Mode is a trademark of Maxim Integrated Products.
*
Alternate marking information: CY_ _ = MAX8863T,
CZ_ _ = MAX8863S, DA_ _ = MAX8864T, DB_ _ = MAX8864S
+
Denotes a lead(Pb)-free/RoHS-compliant package.
PART
TEMP RANGE
PIN-
PACKAGE
SOT TOP
MARK*
MAX8863TEUK+T
-40°C to +85°C 5 SOT23
AABE
MAX8863SEUK+T
-40°C to +85°C 5 SOT23
AABF
MAX8863REUK+T
-40°C to +85°C 5 SOT23
AABV
MAX8864TEUK+T
-40°C to +85°C 5 SOT23
AABG
MAX8864SEUK+T
-40°C to +85°C 5 SOT23
AABH
MAX8864REUK+T
-40°C to +85°C 5 SOT23
AABW
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
2
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN = +3.6V, VGND = 0V, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
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.
VIN to GND ..................................................................-7V to +7V
Output Short-Circuit Duration ............................................Infinite
SET to GND ..............................................................-0.3V to +7V
SHDN to GND..............................................................-7V to +7V
SHDN to IN ...............................................................-7V to +0.3V
OUT to GND ................................................-0.3V to (VIN + 0.3V)
Continuous Power Dissipation (multilayer board, TA= +70°C)
SOT23 (3.9mW/°C above +70°C).............................312.6mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
SOT23
Junction-to-Ambient Thermal Resistance (θJA)...............255.9°C/W
Junction-to-Case Thermal Resistance (θJC)......................81°C/W
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Input Voltage (Note 3) VIN 2.5 6.5 V
MAX886_T 3.05 3.15 3.25
MAX886_S 2.75 2.84 2.93Output Voltage VOUT 0mA ≤ IOUT ≤ 50mA,
SET = GND MAX886_R 2.70 2.80 2.88
V
Adjustable Output Voltage
Range (Note 4) VOUT VSET 6.5 V
Maximum Output Current 120 mA
Current Limit (Note 5) ILIM 280 mA
ILOAD = 0mA 68 150
Ground Pin Current IQSET = GND ILOAD = 50mA 80 µA
IOUT = 1mA 1.1
D r op out V ol tag e ( N ote 6) IOUT = 50mA 55 120 mV
Line Regulation ∆VLNR VIN = 2.5V to 6.5V, SET tied to OUT,
IOUT = 1mA -0.15 0 +0.15 %/V
SET = GND 0.011 0.040
Load Regulation ∆VLDR IOUT = 0mA to 50mA S E T ti ed to O U T 0.006 %/mA
COUT = 1µF 350
Output Voltage Noise 10Hz to 1MHz COUT = 100µF 220 µV
RM S
SHUTDOWN
VIH 2.0
SHDN Input Threshold VIL 0.4 V
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
3
__________________________________________Typical Operating Characteristics
(VIN = +3.6V, CIN = 1µF, COUT = 1µF, TA= +25°C, MAX886_T, unless otherwise noted.)
ELECTRICAL CHARACTERISTICS (continued)
(VIN = +3.6V, VGND = 0V, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)
Note 2: 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 3: Guaranteed by line regulation test.
Note 4: Adjustable mode only.
Note 5: Not tested. For design purposes, the current limit should be considered 120mA minimum to 420mA maximum.
Note 6: The dropout voltage is defined as (VIN - VOUT) when VOUT is 100mV below the value of VOUT for VIN = VOUT +2V.
3.00
3.05
3.10
3.15
3.20
3.25
3.30
0 20 60 100
OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX8863/4-01
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
40 8010 30 7050 90
100
50
020 60 100
SUPPLY CURRENT
vs. LOAD CURRENT
60
90
MAX8863/4-02
LOAD CURRENT (mA)
SUPPLY CURRENT (µA)
40 8010 30 7050 90
80
70
95
55
85
75
65
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
012 4 6
OUTPUT VOLTAGE
vs. INPUT VOLTAGE
MAX8863/4-03
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
35
NO LOAD
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
TA = +25°C 0 100
SHDN Input Bias Current I SHDN V SHDN = VIN TA = TMAX 0.05 nA
TA = +25°C 0.0001 1
Shutdown Supply Current IQSHDN VOUT = 0V TA = TMAX 0.02 µA
Shutdown Discharge Resistance
(MAX8864) 300 Ω
SET INPUT
TA = +25°C 1.225 1.25 1.275
Set Reference Voltage
(Note 4) VSET VIN = 2.5V to 6.5V,
IOUT = 1mA TA = TMIN to 1.215 1.25 1.285 V
TA = +25°C 0.015 2.5
Set Input Leakage Current
(Note 4) ISET VSET = 1.3V TA = TMAX 0.5 nA
THERMAL PROTECTION
Thermal Shutdown Temperature TSHDN 170 °C
Thermal Shutdown Hysteresis ∆TSHDN 20 °C
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
4
____________________________Typical Operating Characteristics (continued)
(VIN = +3.6V, CIN = 1µF, COUT = 1µF, MAX886_T, TA= +25°C, unless otherwise noted.)
110
MAX8863/4-08
FREQUENCY (kHz)
PSRR (dB)
70
60
50
40
30
20
10
0
100 1000
0.10.01
VOUT = 3.15V
RL = 100W
COUT = 10µF
COUT = 1µF
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
10
0.01
0.1 10 1001 1000
OUTPUT SPECTRAL NOISE DENSITY
vs. FREQUENCY
0.10
MAX8863/64-8A
FREQUENCY (kHz)
OUTPUT SPECTRAL NOISE DENSITY (µV/÷Hz)
1
RL = 50Ω
COUT = 1µF
COUT = 100µF
1000
0.01
0506070809010 20 30 40 100
REGION OF STABLE COUT ESR
vs. LOAD CURRENT
0.1
MAX8863/64-8B
LOAD CURRENT (mA)
COUT ESR (Ω)
1
10
100
INTERNAL FEEDBACK
STABLE REGION
COUT = 1µF
EXTERNAL FEEDBACK
0
20
40
60
80
100
120
140
0 20 60 100
DROPOUT VOLTAGE
vs. LOAD CURRENT
MAX8863/4-07
LOAD CURRENT (mA)
DROPOUT VOLTAGE (mV)
40 8010 30 7050 90
TA = +85°C
TA = +25°C
TA = -40°C
ILOAD = 50mA, VOUT IS AC COUPLED
OUTPUT NOISE DC TO 1MHz
VOUT
1ms/div
0
10
20
30
40
50
60
70
80
90
012 4 6
SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX8863/4-04
INPUT VOLTAGE (V)
35
SUPPLY CURRENT (µA)
ILOAD = 0mA
ILOAD = 50mA
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
5
ILOAD = 0mA to 50mA, CIN = 10µF, VOUT IS AC COUPLED
LOAD TRANSIENT
3.16V
VOUT 3.15V
3.14V
ILOAD
10µs/div
VIN = VOUT + 0.2V, ILOAD = 0mA to 50mA, CIN = 10µF,
VOUT IS AC COUPLED
LOAD TRANSIENT
ILOAD
3.16V
VOUT 3.15V
3.14V
10µs/div
____________________________Typical Operating Characteristics (continued)
(VIN = +3.6V, CIN = 1µF, COUT = 1µF, MAX886_T, TA= +25°C, unless otherwise noted.)
ILOAD = 50mA, VOUT IS AC COUPLED
LINE TRANSIENT
3.16V
VOUT 3.15V
3.14V
4.6V
3.6V
VIN
50µs/div
VIN = VOUT + 0.1V, ILOAD = 0mA to 50mA, CIN = 10µF,
VOUT IS AC COUPLED
LOAD TRANSIENT
0mA
50mA
10µs/div
3.16V
VOUT 3.15V
3.14V
ILOAD
NO LOAD
MAX8864 SHUTDOWN (NO LOAD)
0V
VSHDN
4V
VOUT
0V
2V
2V
500µs/div
ILOAD = 50mA
MAX8864 SHUTDOWN
0V
VSHDN
VOUT
4V
2V
0V
2V
200µs/div
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
6
_______________Detailed Description
The MAX8863/MAX8864 are low-dropout, low-quiescent-
current linear regulators designed primarily for battery-
powered applications. They supply an adjustable 1.25V to
6.5V output or a preselected 2.80V (MAX886_R), 2.84V
(MAX886_S), or 3.15V (MAX886_T) output for load currents
up to 120mA. As illustrated in Figure 1, these devices con-
sist of a 1.25V reference, error amplifier, MOSFET driver, P-
channel pass transistor, Dual Mode™ comparator, and
internal feedback voltage divider.
The 1.25V bandgap reference is connected to the error
amplifier’s inverting input. The error amplifier compares this
reference with 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 refer-
ence, the pass-transistor gate is pulled lower, allowing more
current to pass and increasing 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 internal
resistor voltage divider connected to the OUT pin, or an
external resistor network connected to the SET pin. The
Dual Mode comparator examines the SET voltage and
selects the feedback path. If SET is below 60mV, internal
feedback is used and the output voltage is regulated to the
preset output voltage. Additional blocks include a current
limiter, reverse battery protection, thermal sensor, and shut-
down logic.
SHUTDOWN
LOGIC
ERROR
AMP
1.25V
REF
P
N
*
OUT
SET
DUAL-MODE
COMPARATOR 60mV
* AUTO-DISCHARGE, MAX8864 ONLY
GND
IN
SHDN
MAX8863
MAX8864
MOS DRIVER
WITH ILIMIT
THERMAL
SENSOR
REVERSE
BATTERY
PROTECTION
______________________________________________________________Pin Description
Active-Low Shutdown Input. A logic low reduces the supply current to 0.1nA. On the MAX8864, a logic low
also causes the output voltage to discharge to GND. Connect to IN for normal operation.
SHDN1
PIN FUNCTIONNAME
GND2Ground. This pin also functions as a heatsink. Solder to large pads or the circuit board ground plane to max-
imize thermal dissipation.
3Regulator Input. Supply voltage can range from +2.5V to +6.5V. Bypass with 1µF to GND (see
Capacitor
Selection and Regulator Stability
).
OUT4Regulator Output. Fixed or adjustable from 1.25V to +6.5V. Sources up to 120mA. Bypass with a 1µF, <0.2Ω
typical ESR capacitor to GND.
IN
SET5
Feedback Input for Setting the Output Voltage. Connect to GND to set the output voltage to the preset 2.80V
(MAX886_R), 2.84V (MAX886_S), or 3.15V (MAX886_T). Connect to an external resistor divider for
adjustable-output operation.
Figure 1. Functional Diagram
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
7
Internal P-Channel Pass Transistor
The MAX8863/MAX8864 feature a 1.1Ωtypical P-chan-
nel MOSFET pass transistor. This provides several
advantages over similar designs using PNP pass tran-
sistors, including longer battery life.
The P-channel MOSFET requires no base drive current,
which reduces quiescent current considerably. PNP-
based regulators waste considerable amounts of cur-
rent in dropout when the pass transistor saturates. They
also use high base-drive currents under large loads.
The MAX8863/MAX8864 do not suffer from these prob-
lems, and consume only 80µA of quiescent current,
whether in dropout, light load, or heavy load applica-
tions (see
Typical Operating Characteristics
).
Output Voltage Selection
The MAX8863/MAX8864 feature Dual Mode operation:
they operate in either a preset voltage mode or an
adjustable mode.
In preset voltage mode, internal, trimmed feedback
resistors set the MAX886_R output to 2.80V, the
MAX886_S output to 2.84V, and the MAX886_T output to
3.15V. Select this mode by connecting SET to ground.
In adjustable mode, select an output between 1.25V
and 6.5V using two external resistors connected as a
voltage divider to SET (Figure 2). The output voltage is
set by the following equation:
VOUT = VSET (1 + R1 / R2)
where VSET = 1.25V. To simplify resistor selection:
Choose R2 = 100kΩto optimize power consumption,
accuracy, and high-frequency power-supply rejection.
The total current through the external resistive feedback
and load resistors should not be less than 10µA. Since
the VSET tolerance is typically less than ±25mV, the out-
put can be set using fixed resistors instead of trim pots.
Connect a 10pF to 25pF capacitor across R1 to com-
pensate for layout-induced parasitic capacitances.
In preset voltage mode, impedances between SET and
ground should be less than 100kΩ. Otherwise, spurious
conditions could cause the voltage at SET to exceed
the 60mV Dual Mode threshold.
Shutdown
A low input on the SHDN pin shuts down the
MAX8863/MAX8864. In shutdown mode, the pass tran-
sistor, control circuit, reference, and all biases are
turned off, reducing the supply current to typically
0.1nA. Connect SHDN to IN for normal operation. The
MAX8864 output voltage is actively discharged to
ground when the part is placed in shutdown (see
Typical Operating Characteristics
).
Current Limit
The MAX8863/MAX8864 include a current limiter that
monitors and controls the pass transistor’s gate volt-
age, estimating the output current and limiting it to
about 280mA. For design purposes, the current limit
should be considered 120mA (min) to 420mA (max).
The output can be shorted to ground for an indefinite
time period without damaging the part.
Thermal Overload Protection
Thermal overload protection limits total power dissipa-
tion in the MAX8863/MAX8864. When the junction tem-
perature exceeds TJ= +170°C, the thermal sensor
sends a signal to 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 typically cools by 20°C,
resulting in a pulsed output during continuous thermal
overload conditions.
Thermal overload protection is designed to protect the
MAX8863/MAX8864 in the event of fault conditions.
Stressing the device with high load currents and high
input-output differential voltages (which result in die tem-
peratures above +125°C) may cause a momentary over-
shoot (2% to 8% for 200ms) when the load is completely
removed. This can be remedied by raising the minimum
load current from 0µA (+125°C) to 100µA (+150°C). For
continuous operation, do not exceed the absolute maxi-
mum junction temperature rating of TJ= +150°C.
MAX8863
MAX8864
OUT
SET
GND
IN
SHDN
COUT
1µF
CIN
1µF
BATTERY
OUTPUT
VOLTAGE
R1 20pF
R2
RL
Figure 2. Adjustable Output Using External Feedback
Resistors
R1 R2 V
V1
OUT
SET
=−
⎛
⎝
⎜
⎜
⎞
⎠
⎟
⎟
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
8
Operating Region and Power Dissipation
Maximum power dissipation of the MAX8863/MAX8864
depends on the thermal resistance of the case and cir-
cuit 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 = IOUT (VIN -
VOUT). The resulting maximum power dissipation is:
PMAX = (TJ- TA) / θJA
where (TJ- TA) is the temperature difference between
the MAX8863/MAX8864 die junction and the surround-
ing air, and θJA is the thermal resistance of the chosen
package to the surrounding air.
The GND pin of the MAX8863/MAX8864 performs the
dual function of providing an electrical connection to
ground and channeling heat away. Connect the GND
pin to ground using a large pad or ground plane.
Reverse Battery Protection
The MAX8863/MAX8864 have a unique protection
scheme that limits the reverse supply current to less
than 1mA when either VIN or VSHDN falls below ground.
The circuitry monitors the polarity of these two pins, dis-
connecting the internal circuitry and parasitic diodes
when the battery is reversed. This feature prevents the
device from overheating and damaging the battery.
VIN > 5.5V Minimum Load Current
When operating the MAX8863/MAX8864 with an input
voltage above 5.5V, a minimum load current of 20µA is
required to maintain regulation in preset voltage mode.
When setting the output with external resistors, the min-
imum current through the external feedback resistors
and load must be 30µA.
__________Applications Information
Capacitor Selection and
Regulator Stability
Normally, use a 1µF capacitor on the input and a 1µF
capacitor on the output of the MAX8863/MAX8864.
Larger input capacitor values and lower ESR provide
better supply-noise rejection and transient response. A
higher-value input capacitor (10µF) may be necessary
if large, fast transients are anticipated and the device is
located several inches from the power source. Improve
load-transient response, stability, and power-supply
rejection by using large output capacitors. For stable
operation over the full temperature range, with load cur-
rents up to 120mA, a minimum of 1µF is recommended.
Noise
The MAX8863/MAX8864 exhibit 350µVRMS noise during
normal operation. When using the MAX8863/MAX8864
in applications that include analog-to-digital converters
of greater than 12 bits, consider the ADC’s power-sup-
ply rejection specifications (see the Output Noise DC to
1MHz photo in the
Typical Operating Characteristics
).
Power-Supply Rejection and Operation
from Sources Other than Batteries
The MAX8863/MAX8864 are designed to deliver low
dropout voltages and low quiescent currents in battery-
powered systems. Power-supply rejection is 62dB at
low frequencies and rolls off above 300Hz. As the fre-
quency increases above 20kHz, the output capacitor is
the major contributor to the rejection of power-supply
noise (see the Power-Supply Rejection Ratio vs.
Ripple Frequency graph in the
Typical Operating
Characteristics
).
When operating from sources other than batteries,
improve supply-noise rejection and transient response
by increasing the values of the input and output capac-
itors, and using passive filtering techniques (see the
supply and load-transient responses in the
Typical
Operating Characteristics
).
Load Transient Considerations
The MAX8863/MAX8864 load-transient response
graphs (see
Typical Operating Characteristics
) show
two components of the output response: a DC shift of
the output voltage due to the different load currents,
and the transient response. Typical overshoot for step
changes in the load current from 0mA to 50mA is
12mV. Increasing the output capacitor’s value and
decreasing its ESR attenuates transient spikes.
Input-Output (Dropout) Voltage
A regulator’s minimum input-output voltage differential
(or dropout voltage) determines the lowest usable sup-
ply voltage. In battery-powered systems, this will deter-
mine the useful end-of-life battery voltage. Because the
MAX8863/MAX8864 use a P-channel MOSFET pass
transistor, their dropout voltage is a function of RDS(ON)
multiplied by the load current (see
Electrical
Characteristics
).
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
9
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
5 SOT23 U5+1 21-0057 90-0174
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
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. The parametric values (min and max limits) shown in
the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
10
_______________Maxim Integrated Products, Inc. 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
© 2012 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
3 5/11 Added lead-free designation and updated continuous power dissipation and
θJA specs 1, 2
4 7/12 Corrected units for TOC 7 4