MAX8863
19-0466; Rev 4; 7/12
Low-Dropout, 120mA Linear Regulators
The MAX8863T/S/R and MAX8864T/S/R low-dropout linear regulators operate from a +2.5V to +6.5V input
range and deliver up to 120mA. A PMOS pass transistor allows the low, 80µA supply current to remain independent 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 output 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 features include low-power shutdown, short-circuit protection, thermal shutdown protection, and reverse battery
protection. The MAX8864 also includes an auto-discharge function, which actively discharges the output
voltage to ground when the device is placed in shutdown mode. Both devices come in a miniature 5-pin
SOT23 package.
____________________________Features
o Low Cost
o Low, 55mV Dropout Voltage @ 50mA IOUT
o Low, 68µA No-Load Supply Current
Low, 80µA Operating Supply Current (even in
dropout)
o Low, 350µVRMS Output Noise
o Miniature External Components
o Thermal Overload Protection
o Output Current Limit
o Reverse Battery Protection
o Dual Mode™ Operation: Fixed or Adjustable
(1.25V to 6.5V) Output
o Low-Power Shutdown
______________Ordering Information
PART
TEMP RANGE
PINPACKAGE
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
________________________Applications
Cordless Telephones
Modems
PCS Telephones
Hand-Held Instruments
Cellular Telephones
Palmtop Computers
PCMCIA Cards
Electronic Planners
__________Typical Operating Circuit
MAX8864REUK+T -40°C to +85°C
5 SOT23
AABW
*Alternate marking information: CY_ _ = MAX8863T,
CZ_ _ = MAX8863S, DA_ _ = MAX8864T, DB_ _ = MAX8864S
+Denotes a lead(Pb)-free/RoHS-compliant package.
__________________Pin Configuration
TOP VIEW
OUT
IN
BATTERY
CIN
1µF
MAX8863
MAX8864
SHDN
GND
OUTPUT
VOLTAGE
COUT
1µF
SHDN 1
GND 2
5
SET
MAX8863
MAX8864
SET
OUT
IN 3
4
SOT23
Dual Mode is a trademark of Maxim Integrated Products.
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.
1
MAX8863T/S/R, MAX8864T/S/R
_______________General Description
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
ABSOLUTE MAXIMUM RATINGS
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
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)
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.
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
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(VIN = +3.6V, VGND = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER
Input Voltage (Note 3)
Output Voltage
Adjustable Output Voltage
Range (Note 4)
SYMBOL
CONDITIONS
VIN
VOUT
Ground Pin Current
TYP
MAX
UNITS
6.5
V
2.5
0mA ≤ IOUT ≤ 50mA,
SET = GND
MAX886_T
3.05
3.15
3.25
MAX886_S
2.75
2.84
2.93
MAX886_R
2.70
2.80
2.88
VOUT
VSET
Maximum Output Current
Current Limit (Note 5)
MIN
6.5
120
ILIM
IQ
Dropout Voltage (Note 6)
ILOAD = 0mA
68
ILOAD = 50mA
80
IOUT = 1mA
1.1
55
120
0
+0.15
SET = GND
0.011
0.040
SET tied to OUT
0.006
∆VLNR
VIN = 2.5V to 6.5V, SET tied to OUT,
IOUT = 1mA
Load Regulation
∆VLDR
IOUT = 0mA to 50mA
Output Voltage Noise
mA
150
IOUT = 50mA
Line Regulation
10Hz to 1MHz
-0.15
V
mA
280
SET = GND
V
COUT = 1µF
350
COUT = 100µF
220
µA
mV
%/V
%/mA
µVRMS
SHUTDOWN
SHDN Input Threshold
2
VIH
VIL
2.0
0.4
V
Low-Dropout, 120mA Linear Regulators
MAX8863T/S/R, MAX8864T/S/R
ELECTRICAL CHARACTERISTICS (continued)
(VIN = +3.6V, VGND = 0V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
SHDN Input Bias Current
I SHDN
V SHDN = VIN
Shutdown Supply Current
IQSHDN
VOUT = 0V
TYP
MAX
TA = +25°C
MIN
0
100
TA = TMAX
0.05
TA = +25°C
0.0001
TA = TMAX
0.02
Shutdown Discharge Resistance
(MAX8864)
SET INPUT
Set Reference Voltage
(Note 4)
Set Input Leakage Current
(Note 4)
UNITS
nA
1
µA
Ω
300
VSET
VIN = 2.5V to 6.5V,
IOUT = 1mA
ISET
VSET = 1.3V
TA = +25°C
1.225
1.25
1.275
TA = TMIN to
1.215
1.25
1.285
TA = +25°C
0.015
2.5
TA = TMAX
0.5
V
nA
THERMAL PROTECTION
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
TSHDN
170
°C
∆TSHDN
20
°C
Note 2: Limits are 100% production tested at TA = +25°C. Limits over the operating temperature range are guaranteed through correlation 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.
__________________________________________Typical Operating Characteristics
(VIN = +3.6V, CIN = 1µF, COUT = 1µF, TA = +25°C, MAX886_T, unless otherwise noted.)
OUTPUT VOLTAGE
vs. LOAD CURRENT
OUTPUT VOLTAGE
vs. INPUT VOLTAGE
95
MAX8863/4-03
3.5
MAX8863/4-02
3.25
3.0
3.20
3.15
3.10
OUTPUT VOLTAGE (V)
90
SUPPLY CURRENT (µA)
OUTPUT VOLTAGE (V)
100
MAX8863/4-01
3.30
SUPPLY CURRENT
vs. LOAD CURRENT
85
80
75
70
65
2.5
2.0
NO LOAD
1.5
1.0
60
3.05
0.5
55
3.00
50
0
10 20 30 40 50 60 70 80 90 100
LOAD CURRENT (mA)
0
0
10 20 30 40 50 60 70 80 90 100
LOAD CURRENT (mA)
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
3
____________________________Typical Operating Characteristics (continued)
(VIN = +3.6V, CIN = 1µF, COUT = 1µF, MAX886_T, TA = +25°C, unless otherwise noted.)
OUTPUT VOLTAGE
vs. TEMPERATURE
ILOAD = 50mA
3.25
70
ILOAD = 0mA
60
50
40
30
100
ILOAD = 50mA
90
80
3.20
3.15
3.10
20
70
60
50
40
30
20
3.05
10
10
3.00
2
4
3
5
-20
0
20
40
80
60
100
-20
40
60
80
100
OUTPUT SPECTRAL NOISE DENSITY
vs. FREQUENCY
70
60
50
PSRR (dB)
TA = -40°C
40
VOUT = 3.15V
RL = 100W
COUT = 10µF
40
30
COUT = 1µF
20
20
10
0
0
10 20 30 40 50 60 70 80 90 100
0.1
1
10
FREQUENCY (kHz)
100
COUT = 1µF
1
COUT = 100µF
0.10
1000
0.1
100
INTERNAL FEEDBACK
10
EXTERNAL FEEDBACK
1
VOUT
STABLE REGION
0.1
0.01
10 20 30 40 50 60 70 80 90 100
LOAD CURRENT (mA)
1
10
OUTPUT NOISE DC TO 1MHz
MAX8863/64-8B
COUT = 1µF
RL = 50Ω
FREQUENCY (kHz)
REGION OF STABLE COUT ESR
vs. LOAD CURRENT
1000
10
0.01
0.01
LOAD CURRENT (mA)
OUTPUT SPECTRAL NOISE DENSITY (µV/÷Hz)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
60
COUT ESR (Ω)
20
DROPOUT VOLTAGE
vs. LOAD CURRENT
80
0
0
TEMPERATURE (°C)
TA = +25°C
0
-40
TEMPERATURE (°C)
TA = +85°C
100
0
-40
INPUT VOLTAGE (V)
140
120
6
MAX8863/4-08
1
MAX8863/4-07
0
MAX8863/64-8A
0
1ms/div
ILOAD = 50mA, VOUT IS AC COUPLED
4
MAX8863/4-06
3.30
SUPPLY CURRENT (µA)
ILOAD = 50mA
OUTPUT VOLTAGE (V)
SUPPLY CURRENT (µA)
80
MAX8863/4-04
90
SUPPLY CURRENT
vs. TEMPERATURE
MAX8863/4-05
SUPPLY CURRENT
vs. INPUT VOLTAGE
DROPOUT VOLTAGE (mV)
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
100
1000
Low-Dropout, 120mA Linear Regulators
LOAD TRANSIENT
LINE TRANSIENT
3.16V
3.16V
VOUT 3.15V
VOUT 3.15V
3.14V
3.14V
VIN
4.6V
ILOAD
3.6V
10µs/div
ILOAD = 0mA to 50mA, CIN = 10µF, VOUT IS AC COUPLED
50µs/div
ILOAD = 50mA, VOUT IS AC COUPLED
LOAD TRANSIENT
LOAD TRANSIENT
3.16V
3.16V
VOUT 3.15V
VOUT 3.15V
3.14V
3.14V
50mA
ILOAD
0mA
ILOAD
10µs/div
10µs/div
VIN = VOUT + 0.2V, ILOAD = 0mA to 50mA, CIN = 10µF,
VOUT IS AC COUPLED
VIN = VOUT + 0.1V, ILOAD = 0mA to 50mA, CIN = 10µF,
VOUT IS AC COUPLED
MAX8864 SHUTDOWN (NO LOAD)
MAX8864 SHUTDOWN
4V
VOUT
4V
2V
VOUT
0V
VSHDN
2V
0V
2V
VSHDN
0V
2V
0V
500µs/div
NO LOAD
200µs/div
ILOAD = 50mA
5
MAX8863T/S/R, MAX8864T/S/R
____________________________Typical Operating Characteristics (continued)
(VIN = +3.6V, CIN = 1µF, COUT = 1µF, MAX886_T, TA = +25°C, unless otherwise noted.)
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
______________________________________________________________Pin Description
PIN
NAME
FUNCTION
1
SHDN
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.
2
GND
Ground. This pin also functions as a heatsink. Solder to large pads or the circuit board ground plane to maximize thermal dissipation.
3
IN
4
OUT
Regulator 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.
5
SET
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.
Regulator Input. Supply voltage can range from +2.5V to +6.5V. Bypass with 1µF to GND (see Capacitor
Selection and Regulator Stability).
_______________Detailed Description
The MAX8863/MAX8864 are low-dropout, low-quiescentcurrent linear regulators designed primarily for batterypowered 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 consist of a 1.25V reference, error amplifier, MOSFET driver, Pchannel 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
IN
SHDN
and applies the appropriate drive to the P-channel pass
transistor. If the feedback voltage is lower than the reference, 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 shutdown logic.
REVERSE
BATTERY
PROTECTION
ERROR
AMP
MAX8863
MAX8864
SHUTDOWN
LOGIC
N
*
THERMAL
SENSOR
1.25V
REF
DUAL-MODE
COMPARATOR
GND
* AUTO-DISCHARGE, MAX8864 ONLY
Figure 1. Functional Diagram
6
P
MOS DRIVER
WITH ILIMIT
60mV
OUT
SET
Low-Dropout, 120mA Linear Regulators
MAX8863
MAX8864
SHDN
R1 20pF
SET
R2
GND
COUT
1µF
RL
Shutdown
Figure 2. Adjustable Output Using External Feedback
Resistors
Internal P-Channel Pass Transistor
The MAX8863/MAX8864 feature a 1.1Ω typical 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 current,
which reduces quiescent current considerably. PNPbased regulators waste considerable amounts of current 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 problems, and consume only 80µA of quiescent current,
whether in dropout, light load, or heavy load applications (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:
⎛V
R1 = R2 ⎜ OUT
⎜ VSET
⎝
⎞
− 1⎟
⎟
⎠
A low input on the SHDN pin shuts down the
MAX8863/MAX8864. In shutdown mode, the pass transistor, 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 voltage, 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 dissipation in the MAX8863/MAX8864. When the junction temperature exceeds T J = +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 temperatures above +125°C) may cause a momentary overshoot (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 maximum junction temperature rating of TJ = +150°C.
7
MAX8863T/S/R, MAX8864T/S/R
OUT
IN
CIN
BATTERY 1µF
OUTPUT
VOLTAGE
Choose R2 = 100kΩ to 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 output can be set using fixed resistors instead of trim pots.
Connect a 10pF to 25pF capacitor across R1 to compensate 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.
MAX8863T/S/R, MAX8864T/S/R
Low-Dropout, 120mA Linear Regulators
Operating Region and Power Dissipation
Maximum power dissipation of the MAX8863/MAX8864
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 = 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 surrounding 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 V SHDN falls below ground.
The circuitry monitors the polarity of these two pins, disconnecting 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 minimum 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
8
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 currents 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-supply 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 batterypowered systems. Power-supply rejection is 62dB at
low frequencies and rolls off above 300Hz. As the frequency 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 capacitors, 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.
Low-Dropout, 120mA Linear Regulators
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
9
MAX8863T/S/R, MAX8864T/S/R
Package Information
Input-Output (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
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).
Low-Dropout, 120mA Linear Regulators
MAX8863T/S/R, MAX8864T/S/R
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
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.
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