MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
General Description
Features
The MAX603/MAX604 low-dropout, low quiescent current,
linear regulators supply 5V, 3.3V, or an adjustable output
for currents up to 500mA. They are available in a 1.8W SO
package. Typical dropouts are 320mV at 5V and 500mA,
or 240mV at 3.3V and 200mA. Quiescent currents are
15μA typ and 35μA max. Shutdown turns off all circuitry
and puts the regulator in a 2μA off mode. A unique protection
scheme limits reverse currents when the input voltage falls
below the output. Other features include foldback current
limiting and thermal overload protection.
The output is preset at 3.3V for the MAX604 and 5V
for the MAX603. In addition, both devices employ Dual
Mode™ operation, allowing user-adjustable outputs from
1.25V to 11V using external resistors. The input voltage
supply range is 2.7V to 11.5V.
The MAX603/MAX604 feature a 500mA P-channel
MOSFET pass transistor. This transistor allows the devices
to draw less than 35μA over temperature, independent
of the output current. The supply current remains low
because the P-channel MOSFET pass transistor draws
no base currents (unlike the PNP transistors of conventional
bipolar linear regulators). Also, when the input-to-output
voltage differential becomes small, the internal P-channel
MOSFET does not suffer from excessive base current
losses that occur with saturated PNP transistors.
Typical Operating Circuit
OUT
IN
MAX603
MAX604
BATTERY
CIN
10µF
OFF
GND
●● 500mA Output Current, with Foldback Current
Limiting
●● High-Power (1.8W) 8-Pin SO Package
●● Dual Mode™ Operation: Fixed or Adjustable Output
from 1.25V to 11V
●● Large Input Range (2.7V to 11.5V)
●● Internal 500mA P-Channel Pass Transistor
●● 15μA Typical Quiescent Current
●● 2μA (Max) Shutdown Mode
●● Thermal Overload Protection
●● Reverse-Current Protection
Applications
●●
●●
●●
●●
●●
●●
5V and 3.3V Regulators
1.25V to 11V Adjustable Regulators
Battery-Powered Devices
Pagers and Cellular Phones
Portable Instruments
Solar-Powered Instruments
Ordering Information appears at end of data sheet.
Pin Configuration
OUTPUT
VOLTAGE
TOP VIEW
IN 1
COUT
10µF
SET
GND 2
GND 3
MAX603
MAX604
OFF 4
DIP/SO
Dual Mode is a trademark of Maxim Integrated Products.
19-0269; Rev 1; 4/17
8
OUT
7
GND
6
GND
5
SET
MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
Absolute Maximum Ratings
Supply Voltage (IN or OUT to GND)......................-0.3V to +12V
Output Short-Circuit Duration.............................................. 1 min
Continuous Output Current...............................................600mA
SET, OFF Input Voltages........................... -0.3V to the greater of
(IN + 0.3V) or (OUT + 0.3V)
Continuous Power Dissipation (TA = +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C).............727mW
SO (derate 23.6mW/°C above +70°C).............................1.8W
CERDIP (derate 8.00mW/°C above +70°C).................640mW
Operating Temperature Ranges
MAX60_C_A........................................................0°C to +70°C
MAX60_E_A.................................................... -40°C to +85°C
MAX60_MJA.................................................. -55°C to +125°C
Junction Temperature.......................................................+150°C
Storage Temperature Range............................. -65°C to +160°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
(VIN = 6V (MAX603) or 4.3V (MAX604), CIN = COUT = 10μF, OFF = VIN, SET = GND, TJ = TMIN to TMAX, unless otherwise noted.
Typical values are at TJ = +25°C.) (Note 1)
PARAMETER
Input Voltage
Output Voltage (Note 2)
Load Regulation
SYMBOL
VIN
VOUT
∆VLDR
CONDITIONS
SET = OUT, RL = 1kΩ
∆VLNR
∆VDO
OFF Quiescent Current
Minimum Load Current
IQ
IQ OFF
IOUT MIN
11.5
MAX60_E
2.9
11.5
11.5
3.0
MAX603
4.75
5.00
5.25
IOUT = 20μA to 300mA,
4.3V < VIN < 11.5V
MAX604
3.15
3.30
3.45
60
100
IOUT = 1mA to 500mA
MAX603C/E
MAX603M
150
30
100
(VOUT + 0.5V) ≤ VIN ≤ 11.5V, IOUT = 25mA
7
40
130
220
320
550
240
410
480
820
15
35
IOUT = 500mA
IOUT = 200mA
3.0V ≤ VIN ≤ 11.5V, SET = OUT
OFF ≤ 0.4V, RL = 1kΩ,
(VOUT + 1V) ≤ VIN ≤ 11.5V
VIN = 11.5V, SET = OUT
UNITS
V
V
MAX604
IOUT = 400mA
Quiescent Current
MAX
MAX60_M
IOUT = 200mA
Dropout Voltage (Note 3)
TYP
2.7
IOUT = 20μA to 500mA,
6.0V < VIN < 11.5V
IOUT = 1mA to 300mA
Line Regulation
MIN
MAX60_C
MAX603
MAX604
MAX60_C/E
MAX60_M
MAX60_C
40
0.01
10
MAX60_M
20
MAX60_C
2
MAX60_E
6
MAX60_M
20
350
VOUT > 0.8V and VIN - VOUT > 0.7V
1200
mV
mV
μA
2
MAX60_E
VOUT < 0.8V
mV
µA
µA
Foldback Current Limit
(Note 4)
ILIM
Thermal Shutdown Temperature
TSD
160
°C
∆TSD
10
°C
Thermal Shutdown Hysteresis
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mA
Maxim Integrated │ 2
MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
Electrical Characteristics (continued)
(VIN = 6V (MAX603) or 4.3V (MAX604), CIN = COUT = 10μF, OFF = VIN, SET = GND, TJ = TMIN to TMAX, unless otherwise noted.
Typical values are at TJ = +25°C.) (Note 1)
PARAMETER
Reverse-Current Protection
Threshold (Note 5)
Reverse Leakage Current
SYMBOL
∆VRTH
IRVL
TYP
MAX
VOUT = 4.5V
CONDITIONS
MAX603
6
20
VOUT = 3.0V
MAX604
6
20
0.01
10
VIN = 0V, VOUT = 4.5V
(MAX603) VOUT = 3.0V
(MAX604)
MIN
MAX60_C
MAX60_E
MAX60_M
Start-Up Overshoot
VOSH
RL = 1kΩ, COUT = 10μF, OFF rise time ≤ 1μs
Time Required to Exit Shutdown
tSTART
VIN = 9V, RL = 18Ω, VOFF switched from
0V to VIN, time from 0% to 95% of VOUT
Dual-Mode SET Threshold
VSET TH
150
1.16
VSET
SET = OUT, RL = 1kΩ
ISET
VSET = 1.5V or 0V
IOUT LKG
VIL OFF
OFF Threshold Voltage
OFF Input Leakage Current
Output Noise (Note 6)
VIH OFF
IOFF
en
VIN = 11.5V, VOUT = 2V,
SET = OUT
MAX60_C
%VOUT
200
µs
30
80
1.20
1.24
V
±10
nA
0.01
2
6
MAX60_M
20
Off
μA
0.4
On, SET = OUT, VIN = 4V
2.0
On, SET = OUT, VIN = 6V
3.0
On, SET = OUT, VIN = 11.5V
4.0
10Hz to 10kHz, SET = OUT, RL = 1kΩ,
COUT = 10μF
mV
±0.01
MAX60_E
VOFF = VIN or GND
µA
2
80
For external feedback
SET Input Leakage Current
mV
100
For internal feedback
SET Reference Voltage
OUT Leakage Current
20
UNITS
V
±0.01
250
±10
nA
μVRMS
Note 1: Electrical specifications are measured by pulse testing and are guaranteed for a junction temperature (TJ) equal to the
operating temperature range. C and E grade parts may be operated up to a TJ of +125°. Expect performance similar to M
grade specifications. For TJ between +125°C and +150°C, the output voltage may drift more.
Note 2: (VIN - VOUT) is limited to keep the product (IOUT x (VIN - VOUT)) from exceeding the package power dissipation limits.
Note 3: Dropout Voltage is (VIN - VOUT) when VOUT falls to 100mV below its nominal value at VIN = VOUT + 2V. For example, the
MAX603 is tested by measuring the VOUT at VIN = 7V, then VIN is lowered until VOUT falls 100mV below the measured
value. The difference (VIN - VOUT) is then measured and defined as ∆VDO.
Note 4: Foldback Current Limit was characterized by pulse testing to remain below the maximum junction temperature.
Note 5: The Reverse-Current Protection Threshold is the output/input differential voltage (VOUT - VIN) at which reverse-current
protection switchover occurs and the pass transistor is turned off.
Note 6: Noise is tested using a bandpass amplifier with two poles at 10Hz and two poles at 10kHz.
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Maxim Integrated │ 3
MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
Typical Operating Characteristics
(VIN = 7V for MAX603, VIN = 5.3V for MAX604, OFF = VIN, SET = GND, CIN = COUT = 10μF, RL = 1kΩ, TJ = +25°C, unless otherwise noted.)
NORMALIZED TO
OUTPUT VOLTAGE
AT 1mA
0.96
0.95
0.1
100
QUIESCENT CURRENT vs.
TEMPERATURE
102
101
100
99
98
10
MAX603
20
MAX604
15
0
8
2
3
5
4
7
6
0.9
25 45
5
65
85 105 125
10
5
TEMPERATURE (°C)
10Hz TO 10kHz OUTPUT NOISE
0
-55 -35 -15
5
25 45
65
9
8
10 11 12
6
DROPOUT VOLTAGE vs. LOAD CURRENT
MAX604
VOUT = 3.3V
0.8
0.7
0.6
85 105 125
MAX603
VOUT = 5V
0.5
.2Ω
0.4
0.3
R
0.2
)
ON
(
DS
=1
N)
(O
R DS
0
.65Ω
=0
N)
R DS(O
Ω
= 0.4
MAX603, VOUT = 10V,
SET EXTERNALLY
0.1
-55 -35 -15
12
2
SUPPLY VOLTAGE (V)
25
97
14
IQ
700
100
OUTPUT VOLTAGE vs.
TEMPERATURE
103
16
04
, MAX6
1
10
1
MAX604, VOUT = 3.3V I Q, MA
0
100
TEMPERATURE (°C)
200
300 400
500
600
700
LOAD CURRENT (mA)
LINE-TRANSIENT RESPONSE
OUTPUT NOISE (1mV/div)
A
B
MAX603
VOUT = 5V
tR = 10µs, tF = 70µs
MAX603
VOUT = 5V
10ms/div
2ms/div
A: VIN = 8V (HIGH), VIN = 7V (LOW)
B: OUTPUT VOLTAGE (50mV/div)
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Maxim Integrated │ 4
MAX1603/4 TOC-03
MAX603/4-TOC-02
0.1
18
X603
3
UPWARD CURVE IS
THERMAL EFFECT
LOAD CURRENT (mA)
MAX603/4-TOC-04
NORMALIZED OUTPUT VOLTAGE (%)
0
700
MAX604, VIN = 5.3V, VOUT = 3.3V
10
LOAD CURRENT (mA)
104
96
15
5
10
1
MAX603, VIN = 7V, VOUT = 5V
20
4
QUIESCENT CURRENT (µA)
VOUT = 3.3V, 5V, 10V
QUIESCENT CURRENT (µA)
0.97
MAX603, VIN = 12V, VOUT = 10V
OUTPUT VOLTAGE (V)
0.98
20
22
MAX603, VOUT = 5V
5
MAX603/4-TOC-05
0.99
25
24
6
DROPOUT VOLTAGE (V)
1.00
30
QUIESCENT CURRENT (µA)
MAX603/4-TOC-01
NORMALIZED OUTPUT VOLTAGE
1.01
OUTPUT VOLTAGE AND
QUIESCENT CURRENT vs. SUPPLY VOLTAGE
QUIESCENT CURRENT vs. LOAD CURRENT
MAX603/4-TOC-06
OUTPUT VOLTAGE vs. LOAD CURRENT
MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
Typical Operating Characteristics (continued)
(VIN = 7V for MAX603, VIN = 5.3V for MAX604, OFF = VIN, SET = GND, CIN = COUT = 10μF, RL = 1kΩ, TJ = +25°C, unless otherwise noted.)
OVERSHOOT AND TIME
EXITING SHUTDOWN MODE
LOAD-TRANSIENT RESPONSE
B
5V
A
A
B
MAX603
VOUT = 5V
0V
2ms/div
500µs/div
A: OFF PIN VOLTAGE (1V/div)
RISE TIME = 13µs
B: MAX603 OUTPUT VOLTAGE (1V/div)
DELAY = 4.936ms, OVERSHOOT = 1%, RISE TIME = 55µs
A: OUTPUT VOLTAGE (100mV/div)
B: IOUT = 500mA (HIGH), IOUT = 5mA (LOW)
Pin Description
PIN
NAME
DESCRIPTION
1
IN
2, 3, 6, 7
GND
Ground. These pins function as heatsinks, only in the SOIC package. All GND pins must be soldered to the
circuit board for proper power dissipation. Connect to large copper pads or planes to channel heat from the IC.
4
OFF
Shutdown, active low. Switch logic levels in less than 1µs with the high level above the OFF threshold.
5
SET
Feedback for Setting the Output Voltage. Connect to GND to set the output voltage to the preselected 3.3V
or 5V. Connect to an external resistor network for adjustable output operation.
8
OUT
Regulator Output. Fixed or adjustable from 1.25V to 11.0V. Sources up to 500mA for input voltages above 4V.
Regulator Input. Supply voltage can range from 2.7V to 11.5V.
1
2
VIN
3
CIN
10µF
4
IN
MAX603
8
MAX604 OUT
GND
GND
GND
GND
OFF
SET
VOUT
7
6
R1
5
COUT
10µF
RL
R2
Figure 1. Test Circuit
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Maxim Integrated │ 5
MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
IN
SHUTDOWN
ERROR AMP
OFF
MOSFET DRIVER
WITH FOLDBACK
CURRENT LIMIT
REVERSE
CURRENT
PROTECTION
P
SHUTDOWN
LOGIC
OUT
SET
R1
THERMAL
SENSOR
1.20V
REFERENCE
DUAL-MODE
COMPARATOR
GND
80mV
R2
MAX603
MAX604
Figure 2. Functional Diagram
Detailed Description
The MAX603/MAX604 are low-dropout, low-quiescentcurrent linear regulators designed primarily for batterypowered applications. They supply an adjustable 1.25V
to 11V output or a preselected 5V (MAX603) or 3.3V
(MAX604) output for load currents up to P-channel. As
illustrated in Figure 2, they consist of a 1.20V reference,
error amplifier, MOSFET driver, P-channel pass transistor, dual-mode comparator, and internal feedback voltage
divider.
The 1.20V 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 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.
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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 used. If SET is below
80mV, internal feedback is used and the output voltage is
regulated to 5V for the MAX603 or 3.3V for the MAX604.
Additional blocks include a foldback current limiter, reverse
current protection, thermal sensor, and shutdown logic.
Internal P-Channel Pass Transistor
The MAX603/MAX604 feature a 500mA 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 considerably. PNP based regulators waste considerable amounts of current in dropout
when the pass transistor saturates. They also use high
base-drive currents under large loads. The MAX603/
MAX604 do not suffer from these problems and consume
only 15μA of quiescent current under light and heavy
loads, as well as in dropout.
Maxim Integrated │ 6
MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
Output Voltage Selection
The MAX603/MAX604 feature dual-mode operation. In
preset voltage mode, the output of the MAX603 is set
to 5V and the output of the MAX604 is set to 3.3V using
internal, trimmed feedback resistors. Select this mode by
connecting SET to ground.
In adjustable mode, an output between 1.25V and 11V is
selected using two external resistors connected as a voltage divider to SET (Figure 3). The output voltage is set by
the following equation:
MAX603
MAX604
CIN
BATTERY 0.1µF to
10µF
OUTPUT
VOLTAGE
OUT
IN
OFF
R1
SET
GND
COUT
10µF
R2
RL
R1
=
VOUT VSET 1 +
R2
where VSET = 1.20V. To simplify resistor selection:
V
=
R1 R2 OUT − 1
V
SET
Since the input bias current at SET is nominally zero,
large resistance values can be used for R1 and R2 to
minimize power consumption without losing accuracy. Up
to 1.5MΩ is acceptable for R2. Since the VSET tolerance
is less than ±40mV, the output can be set using fixed
resistors instead of trim pots.
In preset voltage mode, impedances between SET and
ground should be less than 10kΩ. Otherwise, spurious
conditions could cause the voltage at SET to exceed the
80mV dual-mode threshold.
Shutdown
A low input on the OFF pin shuts down the MAX603/
MAX604. In the off mode, the pass transistor, control circuit, reference, and all biases are turned off, reducing the
supply current below 2μA. OFF should be connected to IN
for normal operation.
Use a fast comparator, Schmitt trigger, or CMOS or TTL
logic to drive the OFF pin in and out of shutdown. Rise
times should be shorter than 1μs. Do not use slow RC circuits, leave OFF open, or allow the input to linger between
thresholds; these measures will prevent the output from
jumping to the positive supply rail in response to an indeterminate input state.
Since the OFF threshold varies with input supply voltage
(see Electrical Characteristics), do not derive the drive
voltage from 3.3V logic. With VIN at 11.5V, the high OFF
logic level needs to be above 4V.
Foldback Current Limiting
The MAX603/MAX604 also include a foldback current
limiter. It monitors and controls the pass transistor’s gate
voltage, estimating the output current and limiting it to 1.2A
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Figure 3. Adjustable Output Using External Feedback Resistors
for output voltages above 0.8V and VIN - VOUT > 0.7V.
For VIN - VOUT < 0.7V (dropout operation), there is no
current limit. If the output voltage drops below 0.8V, implying a short-circuit condition, the output current is limited
to 350mA. The output can be shorted to ground for one
minute without damaging the device if the package can
dissipate VIN x 350mA without exceeding TJ = +150°C.
Thermal Overload Protection
Thermal overload protection limits total power dissipation
in the MAX603/MAX604. When the junction temperature
exceeds TJ = +160°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 cools by 10°C, resulting in a pulsed output during
thermal overload conditions.
Thermal overload protection is designed to protect the
MAX603/MAX604 in the event of fault conditions. For
continual operation, the absolute maximum junction temperature rating of TJ = +150°C should not be exceeded.
Operating Region and Power Dissipation
Maximum power dissipation of the MAX603/MAX604
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:
(TJ − T A )
PMAX =
(θ + θ )
BA
JB
where (TJ - TA) is the temperature difference between the
MAX603/MAX604 die junction and the surrounding air, θJB
Maxim Integrated │ 7
MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
POWER DISSIPATION vs.
GROUND PAD AREA
MAX603, VOUT = 5V
8-PIN SO PACKAGE
PAPER EPOXY BOARD
SINGLE SIDED
1oz. COPPER
TJ = +125°C
TA = +25°C STILL AIR
1.3
1.2
1.1
1.0
0.2
1.3
1
6.5
10
65
500
400
300
200
100
0
20 (in2)
130 (cm2)
4
PLASTIC DIP
OPERATING
REGION AT
TA = +25°C
TJ = +125°C
5
6
COPPER GROUND PAD AREA
The GND pins of the MAX603/MAX604 SOIC package
perform the dual function of providing an electrical connection to ground and channeling heat away. Connect all
GND pins to ground using a large pad or ground plane.
Where this is impossible, place a copper plane on an
adjacent layer. The pad should exceed the dimensions
in Figure 4.
Figure 4 assumes the IC is an 8-pin SOIC package, is soldered directly to the pad, has a +125°C maximum junction
temperature and a +25°C ambient air temperature, and
has no other heat sources. Use larger pad sizes for other
packages, lower junction temperatures, higher ambient
temperatures, or conditions where the IC is not soldered
directly to the heat-sinking ground pad.
The MAX603/MAX604 can regulate currents up to 500mA
and operate with input voltages up to 11.5V, but not simultaneously. High output currents can only be sustained
when input-output differential voltages are low, as shown
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600
500
400
300
200
100
0
8 9 10 11
7
SUPPLY VOLTAGE (V)
12
MAX603/4-FIG-04A
13
MAXIMUM CONTINUOUS CURRENT LIMIT
TYPICAL DROPOUT VOLTAGE LIMIT
(or θJC) is the thermal resistance of the package chosen,
and θBA is the thermal resistance through the printed circuit board, copper traces and other materials to the surrounding air. The 8-pin SOIC package for the MAX603/
MAX604 features a special lead frame with a lower thermal
resistance and higher allowable power dissipation. The
thermal resistance of this package is θJB = 42°C/W, compared with θJB = 110°C/W for an 8-pin plastic DIP package
and θJB = 125°C/W for an 8-pin ceramic DIP package.
CERAMIC DIP
MAX604
700
MAXIMUM OUTPUT CURRENT (mA)
Figure 4. Typical Maximum Power Dissipation vs. Ground Pad
Size.
MAXIMUM SUPPLY VOLTAGE LIMIT
1.4
HIGH-POWER
SOIC
2
3
HIGH-POWER SOIC
PLASTIC DIP
OPERATING
REGION AT
TA = +25°C
TJ = +125°C CERAMIC DIP
4
MAX603/4-FIG-04B
1.5
600
MAXIMUM SUPPLY VOLTAGE LIMIT
1.6
MAXIMUM CONTINUOUS CURRENT LIMIT
TYPICAL DROPOUT VOLTAGE LIMIT
POWER DISSIPATION (W)
1.7
MAX603
700
MAXIMUM OUTPUT CURRENT (mA)
MAX603/4 FIG 4
1.8
MAXIMUM OUTPUT CURRENT vs. SUPPLY VOLTAGE
5 6 7 8 9 10 11 12 13
SUPPLY VOLTAGE (V)
Figure 5. Power Operating Regions: Maximum Output Current
vs. Differential Supply Voltage
in Figure 5. Maximum power dissipation depends on
packaging, board layout, temperature, and air flow. The
maximum output current is:
I OUT(max) =
PMAX × (TJ − T A )
(VIN − VOUT ) × 100°C
where PMAX is derived from Figure 4.
Reverse-Current Protection
The MAX603/MAX604 has a unique protection scheme
that limits reverse currents when the input voltage falls
below the output. It monitors the voltages on IN and OUT
Maxim Integrated │ 8
MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
IN
MAX603
MAX604
COUT
10µF
OFF
CIN
BATTERY
OUTPUT
VOLTAGE
OUT
GND
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
IOUT = 1mA
70
PSRR (dB)
60
50
40
30
20
10
0
VIN = 1Vp-p
FOR f < 400kHz
CIN = 0µF
COUT = 10µF
100
101
102
104
105
106
FREQUENCY (Hz)
Figure 7. Power-Supply Rejection Ratio vs. Ripple Frequency
and switches the IC’s substrate and power bus to the
more positive of the two. The control circuitry can then
remain functioning and turn the pass transistor off, limiting reverse currents back through the device. This feature
allows a backup regulator or battery pack to maintain
VOUT when the supply at IN fails.
Reverse-current protection activates when the voltage on
IN falls 6mV (20mV maximum) below the voltage on OUT.
Before this happens, currents as high as several milliamperes can flow back through the device. After switchover,
typical reverse currents are limited to 0.01μA for as long
as the condition exists.
www.maximintegrated.com
The MAX603/MAX604 exhibit 3mVP-P to 4mVP-P of
noise during normal operation. This is negligible in most
applications. When using the MAX603/MAX604 in applications that include analog-to-digital converters of greater
than 12 bits, consider the ADC’s power-supply rejection
specifications. Refer to the output noise plot in the Typical
Operating Characteristics.
PSRR and Operation from Sources
Other than Batteries
IOUT = 100mA
103
Capacitor Selection and
Regulator Stability
Noise
MAX603/4-FIG-06
80
Figure 6 illustrates the typical application for the MAX603/
MAX604.
Normally, use 0.1μF to 10μF capacitors on the input and
10μF on the output of the MAX603/MAX604. The larger
input capacitor values provide better supply-noise rejection and line-transient response. Improve load-transient
response, stability, and power-supply rejection by using
large output capacitors. For stable operation over the full
temperature range and with load currents up to 500mA,
10μF is recommended. Using capacitors smaller than
3.3μF can result in oscillation.
SET
Figure 6. 3.3V or 5V Linear-Regulator Application
90
Applications Information
The MAX603/MAX604 are designed to deliver low dropout
voltages and low quiescent currents in battery-powered
systems. Achieving these objectives requires trading off
power-supply noise rejection and swift response to supply variations and load transients. Power-supply rejection
is 80dB at low frequencies and rolls off above 10Hz. As
the frequency increases above 10kHz, the output capacitor is the major contributor to the rejection of powersupply noise (Figure 7). Do not use power supplies with
ripple above 100kHz, especially when the ripple exceeds
100mVP-P. When operating from sources other than
batteries, improved supply-noise rejection and transient
response can be achieved by increasing the values of the
input and output capacitors, and through passive filtering
techniques. The Typical Operating Characteristics show the
MAX603/MAX604 supply and load-transient responses.
Transient Considerations
The Typical Operating Characteristics show the MAX603/
MAX604 load-transient response. Two components of the
output response can be observed on the load-transient
graphs—a DC shift from the output impedance due to the
different load currents, and the transient response. Typical
transients for step changes in the load current from 5mA
to 500mA are 0.2V. Increasing the output capacitor’s value
attenuates transient spikes.
Maxim Integrated │ 9
MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
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 MAX603/
MAX604 use a P-channel MOSFET pass transistor, their
dropout voltage is a function of rDS(ON) multiplied by the
load current (see Electrical Characteristics).
Quickly stepping up the input voltage from the dropout
voltage can result in overshoot. This occurs when the
pass transistor is fully on at dropout and the IC is not
given time to respond to the supply voltage change.
Prevent this by slowing the input voltage rise time.
Chip Topography
IN
Package Information
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.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 OUTLINE
CODE
NO.
LAND PATTERN
NO.
8 PDIP
P8+3
21-0043
—
8 SOIC
S8-7F
21-0041
90-0096
8 CDIP
J8-3
—
–
Ordering Information
PART
OUT
0.100"
(2.54mm)
TEMP. RANGE
PIN-PACKAGE
MAX603CPA
0°C to +70°C
8 Plastic DIP
MAX603CSA
0°C to +70°C
8 SO
MAX603C/D
0°C to +70°C
Dice*
MAX603EPA
-40°C to +85°C
8 Plastic DIP
MAX603ESA
-40°C to +85°C
8 SO
MAX603MSA/PR+T
-55°C to +125°C
8 SO
MAX604CPA
0°C to +70°C
8 Plastic DIP
MAX604CSA
0°C to +70°C
8 SO
MAX604C/D
0°C to +70°C
Dice*
MAX604EPA
-40°C to +85°C
8 Plastic DIP
MAX604ESA
-40°C to +85°C
8 SO
* Dice are tested at TA = +25°C, DC parameters only.
** Contact factory for availability.
OFF GND
SET
0.104"
(2.64mm)
TRANSISTOR COUNT: 111
NO DIRECT SUBSTRATE CONNECTION. THE N-SUBSTRATE
IS INTERNALLY SWITCHED BETWEEN THE MORE POSITIVE
OF IN OR OUT.
www.maximintegrated.com
Maxim Integrated │ 10
MAX603/MAX604
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 500mA Linear Regulators
Revision History
REVISION
NUMBER
REVISION
DATE
0
9/94
Initial Release
—
1
4/17
Updated Ordering Information table
10
DESCRIPTION
PAGES
CHANGED
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated 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.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
© 2017 Maxim Integrated Products, Inc. │ 11
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