Maxim MAX882 5v/3.3v or adjustable, low-dropout, low iq, 200ma linear regulator Datasheet

19-0275; Rev 3; 9/08
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
The MAX882/MAX883/MAX884 linear regulators maximize battery life by combining ultra-low supply currents
and low dropout voltages. They feature 200mA output
current capability at up to +125°C junction temperature
and come in a 1.5W SOIC package. The 1.5W package
(compared to 0.47W for standard SOIC packages)
allows a wider operating range for the input voltage and
output current. The MAX882/MAX883/MAX884 use a Pchannel MOSFET pass transistor to maintain a low 11µA
(15µA max) supply current from no-load to the full
200mA output. Unlike earlier bipolar regulators, there are
no PNP base current losses that increase with output
current. In dropout, the MOSFET does not suffer from
excessive base currents that occur when PNP transistors
go into saturation. Typical dropout voltages are 220mV
at 5V and 200mA, or 320mV at 3.3V and 200mA.
The MAX882 features a 7µA standby mode that disables
the output but keeps the reference, low-battery comparator, and biasing circuitry alive. The MAX883/MAX884 feature a shutdown (OFF) mode that turns off all circuitry,
reducing supply current to less than 1µA. All three
devices include a low-battery-detection comparator, foldback current limiting, reverse-current protection, and
thermal-overload protection.
The output is preset at 3.3V for the MAX882/MAX884
and 5V for the MAX883. In addition, all 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.
For low-dropout linear regulators with output currents up
to 500mA, refer to the MAX603/MAX604 data sheet.
Applications
Pagers and Cellular Phones
3.3V and 5V Regulators
1.25V to 11V Adjustable Regulators
High-Efficiency Linear Regulators
Battery-Powered Devices
Portable Instruments
Solar-Powered Instruments
Features
♦ Foldback Current Limiting
♦ High-Power (1.5W) 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 1.1Ω P-Channel Pass Transistor
Draws No Base Current
♦ Low 220mV Dropout Voltage at 200mA
Output Current
♦ 11µA (typ) Quiescent Current
♦ 1µA (max) Shutdown Mode or 7µA (typ)
Standby Mode
♦ Low-Battery Detection Comparator
♦ Reverse-Current Protection
♦ Thermal-Overload Protection
Ordering Information
PART
TEMP RANGE
0°C to +70°C
MAX882CPA
PINPACKAGE
8 PDIP
MAX882CSA
0°C to +70°C
8 SO
MAX882C/D
0°C to +70°C
Dice*
MAX882EPA
-40°C to +85°C
8 PDIP
MAX882ESA
-40°C to +85°C
8 SO
Ordering Information continued at end of data sheet.
*Dice are tested at TJ = +25°C, DC parameters only.
**Contact factory for availability.
Typical Operating Circuit
ON/OFF
OFF (STBY)
Pin Configuration
TOP VIEW
( ) ARE FOR MAX882.
LBO
1
8 LBI
SET
2
7 OFF (STBY)
GND
3
OUT
4
MAX882
MAX883
MAX884
6 GND
5
IN
INPUT
VOLTAGE
LBI
CIN
O.1μF
BATTERY
SET
MAX882
MAX883
MAX884
GND
OUT
OUTPUT
VOLTAGE
COUT
2.2μF
IN
DIP/SO
( ) ARE FOR MAX882.
Dual Mode is a trademark of Maxim Integrated Products.
________________________________________________________________ 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
MAX882/MAX883/MAX884
General Description
MAX882/MAX883/MAX884
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (IN or OUT to GND).......................-0.3V to +12V
Output Short-Circuit Duration ...............................................1min
Continuous Output Current ...............................................300mA
LBO Output Current ............................................................50mA
LBO Output Voltage and LBI,
SET, STBY, OFF Input Voltages ............-0.3V to the greater of
(IN + 0.3V) or (OUT + 0.3V)
Continuous Power Dissipation (TJ = +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) ............727mW
High-Power SO (derate 18.75mW/°C above +70°C) .......1.5W
CERDIP (derate 8.00mW/°C above +70°C) .................640mW
Operating Temperature Ranges
MAX88_C_A ........................................................0°C to +70°C
MAX88_E_A .....................................................-40°C to +85°C
Junction Temperature .....................................................+150°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+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 (MAX883) or VIN = 4.3V (MAX882/MAX884), COUT = 2.2µF, STBY or OFF = VIN, SET = GND, LBI = VIN, TJ = -40°C to
+85°C, unless otherwise noted. Typical values are at TJ = +25°C.) (Note 1)
PARAMETER
Input Voltage Range
SYMBOL
VIN
CONDITIONS
SET = OUT, RL =
1kΩ
MAX883,
6.0V ≤ VIN ≤ 11.5V
Output Voltage (Note 2)
VOUT
MAX882/MAX884,
4.3V ≤ VIN ≤ 11.5V
Load Regulation
Line Regulation
ΔVLDR
ΔVLNR
IOUT = 1mA to
200mA
IOUT = 1mA to
150mA
ΔVDO
MAX882/MAX884
SET = OUT, VIN =
6V
Quiescent Current
IQ
VIN = 11.5V
2
TYP
MAX
MAX88_C_A
2.7
11.5
MAX88_E_A
2.9
11.5
MAX88_MJA
3.0
11.5
IOUT = 100µA - 250mA,
0°C ≤ TJ ≤ +85°C
4.75
IOUT = 100µA - 250mA,
-40°C ≤ TJ ≤ +85°C
4.65
IOUT = 100µA - 200mA,
0°C ≤ TJ ≤ +85°C
3.15
IOUT = 100µA - 200mA,
-40°C ≤ TJ ≤ +85°C
3.07
MAX883C_A/E_A
5.00
MAX882, MAX884
V
5.25
V
3.30
3.45
3.53
60
100
150
30
10
40
110
220
IOUT = 200mA
220
440
IOUT = 100mA
160
320
IOUT = 200mA
320
640
MAX88_C_A/E_A
11
MAX88_MJA
MAX88_MJA
_______________________________________________________________________________________
mV
mV
15
30
15
mV
100
IOUT = 100mA
MAX88_C_A/E_A
UNITS
5.35
MAX883MJA
(VOUT + 0.5V) < VIN < 11.5V, IOUT = 10mA
MAX883
Dropout Voltage (Note 3)
MIN
25
40
µA
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
(VIN = 6V (MAX883) or VIN = 4.3V (MAX882/MAX884), COUT = 2.2µF, STBY or OFF = VIN, SET = GND, LBI = VIN, TJ = -40°C to
+85°C, unless otherwise noted. Typical values are at TJ = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
STBY = 0, VIN =
6V, SET = OUT
STBY Quiescent Current (Note 4)
OFF Quiescent Current
Minimum Load Current
IQ STBY
IQ OFF
IOUT(MIN)
STBY = 0, VIN =
11.5V, SET = OUT
MIN
MAX882C_A/E_A
MAX
7
15
MAX882MJA
30
MAX882C_A/E_A
10
MAX882MJA
0.01
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
Reverse-Current-Protection
(Note 6)
ILIM
MAX88_C_A
1
MAX88_E_A
3
170
VOUT > 0.8V and VIN - VOUT > 0.7V
430
+160
10
20
VOUT = 3.0V
MAX882_A,
MAX884_A
6
20
MAX882: VIN = 0, STBY = 0, VOUT = 3.0V
7
0.01
Startup Overshoot
VOSH
RL = 1kΩ, COUT = 2.2µF
Dual Mode SET Threshold
VSET TH
VSET
SET = OUT, RL =
1kΩ
SET Input Leakage Current
ISET
VSET = 1.5V or 0
VLBI
LBI Hysteresis
ΔVLBI
LBI Input Leakage Current
LBO Output Low Voltage
ILBI
VLBOL
LBI signal falling
µA
200
For internal feedback
65
For external feedback
150
65
0°C ≤ TJ ≤ +85°C
1.16
1.20
-40°C ≤ TJ ≤ +85°C
1.12
0°C ≤ TJ ≤ +85°C
1.15
-40°C ≤ TJ ≤ +85°C
1.11
µs
30
1.24
1.28
±0.01
±50
1.20
1.25
1.29
7
VLBI = 1.5V
ILBO sink = 1.2mA, VLBI = 1V, 3V < VIN <
11.5V, SET = OUT
LBO Output Leakage Current
IBLO LKG
VLBI = VIN, VLBO = VIN
OUT Leakage Current
IOUT LKG
VIN = 11.5V, VOUT
= 2V, SET = OUT
MAX88_C_A
mV
% of
VOUT
VIN = 9V, RL = 33Ω, OFF from 0 to VIN, 0%
to 95% of VOUT
SET Reference Voltage
LBI Threshold Voltage
°C
6
MAX883/MAX884: VIN = 0, OFF = 0, VOUT
= 3.0V
TSTART
°C
MAX883_A
IRVL
µA
mA
VOUT = 4.5V
Reverse Leakage Current
µA
10
VOUT < 0.8V
TSD
Time Required to Exit OFF or
STBY Modes
1
5
ΔTSD
ΔVRTH
µA
10
MAX88_MJA
Foldback Current Limit (Note 5)
25
UNITS
40
OFF = 0, RL = 1kΩ, MAX88_C_A
VIN = 11.5V
MAX88_E_A
MAX883/MAX884
MAX88_MJA
VIN = 11.5V, SET =
OUT
TYP
mV
V
nA
V
mV
±0.01
±50
nA
90
250
mV
0.01
0.1
µA
0.01
1
MAX88_E_A
3
MAX88_MJA
10
µA
_______________________________________________________________________________________
3
MAX882/MAX883/MAX884
ELECTRICAL CHARACTERISTICS (continued)
MAX882/MAX883/MAX884
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
ELECTRICAL CHARACTERISTICS (continued)
(VIN = 6V (MAX883) or VIN = 4.3V (MAX882/MAX884), COUT = 2.2µF, STBY or OFF = VIN, SET = GND, LBI = VIN, TJ = -40°C to
+85°C, unless otherwise noted. Typical values are at TJ = +25°C.) (Note 1)
PARAMETER
STBY Threshold Voltage
STBY Hysteresis
STBY Input Leakage Current
SYMBOL
V STBY
ΔV STBY
ISTBY
VIL OFF
OFF Threshold Voltage
OFF Input Leakage Current
Output Noise
VIH OFF
IOFF
en
CONDITIONS
STBY signal falling, MAX882_A
MIN
TYP
MAX
UNITS
1.15
1.20
1.25
V
MAX882_A
7
V STBY = VIN or 0, MAX882_A
±0.01
In off mode, MAX883_A, MAX884_A
2.0
In on mode, SET = OUT, 6V < VIN < 11.5V,
MAX883_A, MAX884_A
3.0
10Hz to 10kHz, SET = OUT, RL = 1kΩ,
COUT = 2.2µF (Note 7)
nA
0.4
In on mode, SET = OUT, VIN < 6V,
MAX883_A, MAX884_A
V OFF = VIN or 0
mV
±50
V
±0.01
250
±50
nA
µVRMS
Note 1: Electrical specifications are measured by pulse testing and are guaranteed for a junction temperature (TJ) within the operating temperature range, unless otherwise noted. Specifications to -40°C are guaranteed by design and not production tested.
Note 2: (VIN - VOUT) is limited to keep the product (IOUT x (VIN - VOUT)) from exceeding the package power dissipation limits. See
Figure 5. Therefore, the combination of high output current and high supply voltage is not tested.
Note 3: Dropout Voltage is (VIN - VOUT) when VOUT falls to 100mV below its nominal value at VIN = (VOUT + 2V). For example, the
MAX883 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 ΔVDO.
Note 4: Since standby mode inhibits the output but keeps all biasing circuitry alive, the Standby Quiescent Current is similar to the
normal operating quiescent current.
Note 5: Foldback Current Limit was characterized by pulse testing to remain below the maximum junction temperature (not
production tested).
Note 6: 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. See the section Reverse-Current Protection in the Detailed
Description.
Note 7: Noise is tested using a bandpass amplifier with two poles at 10Hz and two poles at 10kHz.
4
_______________________________________________________________________________________
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
25
VOUT = 5V (MAX883)
VOUT = 3.3V (MAX882/MAX884)
20
15
98
10
97
IQ
OUTPUT VOLTAGE
NORMALIZED TO OUTPUT
VOLTAGE AT 1mA
5
101
100
99
98
97
0
95
0.01
0.1
1
10
100
96
250
-55 -35 -15
5
25
45 65
85 105 125
LOAD CURRENT (mA)
TEMPERATURE (°C)
OUTPUT VOLTAGE AND QUIESCENT
CURRENT vs. SUPPLY VOLTAGE
QUIESCENT CURRENT
vs. TEMPERATURE
16
5
14
VOUT = 5V (MAX883)
4
12
VOUT = 3.3V (MAX882/MAX884)
3
10
2
8
IQ (MAX882/MAX884)
1
15
MAX882/4-04
6
OUTPUT VOLTAGE (V)
102
QUIESCENT CURRENT (μA)
96
103
MAX882/4-03
99
MAX882/4-04a
100
104
NORMALIZED OUTPUT VOLTAGE (%)
30
QUIESCENT CURRENT (mA)
101
MAX882/4-01
OUTPUT VOLTAGE
vs. TEMPERATURE
QUIESCENT CURRENT (μA)
NORMALIZED OUTPUT VOLTAGE (%)
OUTPUT VOLTAGE AND QUIESCENT
CURRENT vs. LOAD CURRENT
12
6
9
6
3
IQ (MAX883)
0
0
4
2
3
4
5
6
7
8
9
-55 -35 -15
10 11 12
DROPOUT VOLTAGE
vs. LOAD CURRENT
25
45 65
0.3
0.2
VOUT = 5V (MAX883)
0.1
OUTPUT NOISE (1mV/div)
VOUT = 3.3V (MAX882/MAX884)
MAX882/4-06
MAX882/4-05
0.5
0.4
85 105 125
10Hz to 10kHz OUTPUT NOISE
0.6
DROPOUT VOLTAGE (V)
5
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
MAX883
VOUT = 5V
0
0
50
100
150
200
250
300
10ms/div
LOAD CURRENT (mA)
_______________________________________________________________________________________
5
MAX882/MAX883/MAX884
Typical Operating Characteristics
(VIN = 7V for MAX883, VIN = 5.3V for MAX882/MAX884, OFF or STBY = VIN, SET = GND, LBI = VIN, LBO = OPEN, CIN = COUT = 2.2µF,
RL = 1kΩ, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VIN = 7V for MAX883, VIN = 5.3V for MAX882/MAX884, OFF or STBY = VIN, SET = GND, LBI = VIN, LBO = OPEN, CIN = COUT = 2.2µF,
RL = 1kΩ, TA = +25°C, unless otherwise noted.)
LINE-TRANSIENT RESPONSE
LOAD-TRANSIENT RESPONSE
A
A
B
B
500μs/div
1ms/div
MAX883: VOUT = 5V, CIN = 0μF, tR = 15μs, tF = 13μs
A: VIN = 8V (HIGH) / VIN = 7V (LOW)
B: OUTPUT VOLTAGE (100mV/div)
MAX883: VOUT = 5V, tR = 24μs, tF = 44μs
A: OUTPUT VOLTAGE (100mV/div)
B: IOUT = 250mA (HIGH) / IOUT = 50mA (LOW)
LBO LOW VOLTAGE
vs. SINK CURRENT
OVERSHOOT AND TIME
EXITING SHUTDOWN MODE
MAX882/4-10
5
RL = 100Ω
B
5V
A
LBO LOW VOLTAGE (V)
MAX882/MAX883/MAX884
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
4
3
MAX882/MAX884
2
MAX883
1
0V
0
500μs/div
A: OFF PIN VOLTAGE (1V/div):
RISE TIME = 9μs
B: MAX883 OUTPUT VOLTAGE (1V/div):
DELAY = 135μs, RISE TIME = 67μs,
OVERSHOOT = 0%
6
0.1
1
10
SINK CURRENT (mA)
_______________________________________________________________________________________
50
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
PIN
MAX882
MAX883/
MAX884
NAME
DESCRIPTION
1
1
LBO
Low-Battery Output is an open-drain output that goes low when LBI is less than 1.2V. Connect
to IN or OUT through a pull-up resistor. LBO is undefined during shutdown mode
(MAX883/MAX884).
2
2
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.
3, 6
3, 6
GND
Ground pins—also function as heatsinks in the SO package. All GND pins must be soldered to
the PC board for proper power dissipation. Connect to large copper pads or planes to channel
heat from the IC.
4
4
OUT
Regulator Output. Fixed or adjustable from 1.25V to 11.0V. Sources up to 200mA. Bypass with a
2.2µF capacitor.
5
5
IN
7
—
STBY
Standby. Active-low comparator input. Connect to GND to disable the output or to IN for normal
operation. A resistor network (from IN) can be used to set a standby mode threshold.
—
7
OFF
Shutdown. Active-low logic input. In OFF mode, supply current is reduced below 1µA and
VOUT = 0.
8
8
LBI
Low-Battery comparator Input. Tie to IN when not used.
Regulator Input. Supply voltage can range from 2.7V to 11.5V.
_______________Detailed Description
The MAX882/MAX883/MAX884 are micropower, lowdropout linear regulators designed primarily for batterypowered applications. They feature Dual Mode operation,
allowing a fixed output of 5V for the MAX883 and 3.3V for
the MAX882/MAX884, or an adjustable output from 1.25V
to 11V. These devices supply up to 200mA while requiring
less than 15µA quiescent current. As illustrated in Figure
1, they consist of a 1.20V reference, error amplifier, MOSFET driver, P-channel pass transistor, dual-mode comparator, and feedback voltage-divider.
The 1.20V 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’s 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 pin
voltage and selects the feedback path used. If the SET
pin is below 65mV, internal feedback is used and the
output voltage is regulated to 5V for the MAX883 or
3.3V for the MAX882/MAX884. Additional blocks
include a foldback current limiter, reverse-current protection, a thermal sensor, shutdown or standby logic,
and a low-battery-detection comparator.
Internal P-Channel Pass Transistor
The MAX882/MAX883/MAX884 feature a 200mA Pchannel 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 large amounts of current in dropout when
the pass transistor saturates. They also use high basedrive currents under large loads. The MAX882/MAX883/
MAX884 do not suffer from these problems and consume
only 11µA of quiescent current during light loads, heavy
loads, and dropout.
Output Voltage Selection
The MAX882/MAX883/MAX884 feature Dual Mode
operation. In preset voltage mode, the MAX883’s output is set to 5V and the MAX882/MAX884’s output is set
to 3.3V, using internal trimmed feedback resistors.
Select this mode by connecting SET to ground.
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 65mV dual-mode threshold.
_______________________________________________________________________________________
7
MAX882/MAX883/MAX884
Pin Description
MAX882/MAX883/MAX884
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
IN
LBI
LOW-BATTERY
COMPARATOR
LBO
MOSFET DRIVER
WITH FOLDBACK
CURRENT LIMIT
N
REVERSECURRENT
PROTECTION
P
ERROR AMP
SHUTDOWN
LOGIC
OFF
(STBY)
OUT
1.20V
REFERENCE
SET
DUAL-MODE
COMPARATOR
THERMAL
SENSOR
R1
R2
65mV
GND
( ) ARE FOR MAX882.
Figure 1. MAX882/MAX883/MAX884 Functional Diagram
In adjustable mode, the user selects an output voltage
in the 1.25V to 11V range by connecting two external
resistors, used as a voltage-divider, to the SET pin
(Figure 2).
The output voltage is set by the following equation:
⎛
R1 ⎞
VOUT = VSET ⎜1 +
⎟
R2 ⎠
⎝
where VSET = 1.20V.
To simplify resistor selection:
⎛V
⎞
R1 = R2 ⎜ OUT − 1⎟
⎝ VSET
⎠
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.
8
Standby Mode (MAX882)
The MAX882 has a standby feature that disconnects
the input from the output when STBY is brought low, but
keeps all other circuitry awake. In this mode, VOUT
drops to 0, and the internal biasing circuitry (including
the low-battery comparator) remains on. The maximum
quiescent current during standby is 15µA. STBY is a
comparator input with the other input internally tied to
the reference voltage. Use a resistor network as shown
in Figure 3 to set a standby-mode threshold voltage for
undervoltage lockout. Connect STBY to IN for normal
operation.
OFF Mode (MAX883/MAX884)
A low-logic input on the OFF pin shuts down the
MAX883/MAX884. In this mode, the pass transistor,
control circuit, reference, and all biases are turned off,
and the supply current is reduced to less than 1µA.
LBO is undefined in OFF mode. Connect OFF to IN for
normal operation.
_______________________________________________________________________________________
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
IN
OUTPUT
VOLTAGE
OUT
R1
MAX882
OFF
(STBY) MAX883
MAX884
CIN
O.1μF
GND
IN
LBI
INPUT
VOLTAGE
LBI
R1
LOAD
SET
R2
COUT
2.2μF
CIN
O.1μF
R2
VSTBY TRIP = VSTBY
R1 + R2
, VSET = 1.20V
R2
Figure 2. Adjustable Output Using External Feedback
Resistors
MAX882
STBY
( ) ARE FOR MAX882.
VOUT = VSET
OUTPUT
VOLTAGE
OUT
GND
SET
COUT
2.2μF
R1+ R2
, VSTBY = 1.20V
R2
Figure 3. Setting an Undervoltage Lockout Threshold Using
STBY
Foldback Current Limiting
Power Dissipation and Operating Region
The MAX882/MAX883/MAX884 also include a foldback
current limiter. It monitors and controls the pass transistor’s gate voltage, estimating the output current and
limiting it to 430mA for output voltages above 0.8V and
(VIN - VOUT) > 0.7V. If the output voltage drops below
0.8V, implying a short-circuit condition, the output current is limited to 170mA. The output can be shorted to
ground for 1min without damaging the device if the
package can dissipate (VIN x 170mA) without exceeding TJ = +150°C. When the output is greater than 0.8V
and (VIN - VOUT) < 0.7V (dropout operation), no current
limiting is allowed, to provide maximum load drive.
Maximum power dissipation of the MAX882/MAX883/
MAX884 depends on the thermal resistance of the case
and PC 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 power dissipation
is as follows:
(TJ − TA )
P=
(θ JB + θ BA )
Thermal Overload Protection
Thermal overload protection limits total power dissipation in the MAX882/MAX883/MAX884. 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 turns 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
MAX882/MAX883/MAX884 if fault conditions occur. It is
not intended to be used as an operating mode.
Prolonged operation in thermal-shutdown mode may
reduce the IC’s reliability. For continual operation, do
not exceed the absolute maximum junction temperature
rating of TJ = +150°C.
where (TJ - TA) is the temperature difference between
the MAX882/MAX883/MAX884 die junction and the surrounding air, θJB (or θJC) is the thermal resistance of
the package chosen, and θBA is the thermal resistance
through the PC board, copper traces, and other materials to the surrounding air.
The 8-pin small-outline package for the MAX882/
MAX883/MAX884 features a special lead frame with a
lower thermal resistance and higher allowable power
dissipation. This package’s thermal resistance package
is θJB = 53°C/W, compared with θJB = 110°C/W for an
8-pin plastic DIP package and θJB = 125°C/W for an 8pin ceramic DIP package.
_______________________________________________________________________________________
9
MAX882/MAX883/MAX884
INPUT
VOLTAGE
1.0
0.9
0.1cm2
0.0155in2
1cm2
0.155in2
10cm2
1.55in2
100cm2
15.5in2
150
100
50
HIGHPOWER
SOIC
PLASTIC DIP
CERAMIC DIP
OPERATING
REGION AT
TA = +25°C
TJ = +125°C
0
2
3
4
5 6
IOUT(MAX) =
250
MAXIMUM CURRENT
MAXIMUM POWER
DISSIPATION LIMIT
TYPICAL DROPOUT VOLTAGE LIMIT
200
150
100
50
HIGHPOWER
SOIC
PLASTIC DIP
CERAMIC DIP
OPERATING
REGION AT
TA = +25°C
TJ = +125°C
0
4
5
6
7
8
9
10 11 12
13
SUPPLY VOLTAGE (V)
Figure 5b. Safe Operating Regions: MAX883 Maximum Output
Current vs. Supply Voltage
P(TJ − TA )
(VIN − VOUT )100°C
where P is derived from Figure 4.
10
MAX882/4-05a
9 10 11 12 13
Figure 5a. Safe Operating Regions: MAX882/MAX884 Maximum
Output Current vs. Supply Voltage
MAXIMUM OUTPUT CURRENT (mA)
The GND pins of the MAX882/MAX883/MAX884 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. For a given power dissipation, the pad
should exceed the associated dimensions in Figure 4.
Figure 4 assumes the IC is in an 8-pin small-outline package that has a maximum junction temperature of +125°C
and is soldered directly to the pad; it also has a +25°C
ambient air temperature and 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. When operating C- and E-grade parts up to a
TJ of +125°C, expect performance similar to M-grade
specifications. For TJ between +125°C and +150°C, the
output voltage may drift more.
The MAX882/MAX883/MAX884 can regulate currents up
to 250mA 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 small, as
shown in Figure 5. Maximum power dissipation depends
on packaging, temperature, and air flow. The maximum
output current is as follows:
8
SUPPLY VOLTAGE (V)
COPPER GROUND PAD AREA
Figure 4. Typical Maximum Power Dissipation vs. Ground Pad
Area
7
MAXIMUM SUPPLY VOLTAGE LIMIT
1.1
200
MAXIMUM POWER
DISSIPATION LIMIT
MAX882/4-05b
1.2
MAXIMUM CURRENT
MAXIMUM SUPPLY VOLTAGE LIMIT
1.3
250
TYPICAL DROPOUT VOLTAGE LIMIT
1.4
MAX883, VOUT = 5V
8-PIN SO PACKAGE
77.4cm2,
SINGLE-SIDED BOARD
1oz COPPER
GLASS EPOXY,
TJ = +125°C,
TA = +25°C, STILL AIR
MAXIMUM OUTPUT CURRENT (mA)
1.5
MAX882/4-fig04
1.6
POWER DISSIPATION (W)
MAX882/MAX883/MAX884
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
______________________________________________________________________________________
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
R1
CIN R2
O.1μF
GND
R3
MAX882
MAX883
MAX884
SET
INPUT
VOLTAGE
OUT
IN
POWERCOUT
FAIL
INDICATION 2.2μF
R1 + R2
, VLBI = 1.20V
R2
Figure 6. Using the Low-Battery Comparator to Monitor Battery
Voltage
Reverse-Current Protection
The MAX882/MAX883/MAX884 have a unique protection
scheme that limits reverse currents when the input voltage falls below the output. It monitors the voltages on IN
and OUT and switches the IC’s substrate and power bus
to the more positive of the two. The control circuitry is
then able to remain functioning and turn the pass transistor off, limiting reverse currents back through to the input
of the device. In this mode, typical current into OUT to
GND is 15µA at VOUT = 3.3V and 50µA at VOUT = 5V.
Reverse-current protection activates when the voltage
on IN falls 6mV (or 20mV max) below the voltage on
OUT. Before this happens, currents as high as several
milliamperes can flow back through the device.
Low-Battery-Detection Comparator
The MAX882/MAX883/MAX884 provide a low-battery comparator that compares the voltage on the LBI pin to the
1.20V internal reference. LBO, an open-drain output, goes
low when LBI is below 1.20V. Hysteresis of 7mV has been
added to the low-battery comparator to provide noise
immunity during switching. LBO remains functional in standby mode for the MAX882, but is undefined in OFF mode for
the MAX883 and MAX884. Tie LBI to IN when not used.
Use a resistor-divider network as shown in Figure 6 to set
the low-battery trip voltage. Current into the LBI input is
±50nA (max), so R2 can be as large as 1MΩ. Add extra
noise immunity by connecting a small capacitor from LBI
to GND. Additional hysteresis can be added by connecting a high-value resistor from LBI to LBO.
BATTERY
CIN
O.1μF
OUTPUT
VOLTAGE
MAX882
MAX883
MAX884
LBI
LBO
( ) ARE FOR MAX882.
VLBI TRIP = VLBI
OFF (STBY)
*
OFF (STBY)
LBI
ON/OFF
SET
GND
COUT
2.2μF
( ) ARE FOR MAX882.
* OPTIONAL REVERSE BATTERY PROTECTION
Figure 7. Typical 3.3V or 5V Linear Regulator Circuit
Applications Information
The MAX882/MAX883/MAX884 are series linear regulators designed primarily for battery-powered systems.
Figure 7 shows a typical application.
Standby Mode vs. OFF Mode
STBY is a comparator input that allows the user to set
the standby-mode threshold voltage, while OFF is a
logic-level input. When in standby mode, the output is
disconnected from the input, but the biasing circuitry
(including the low-battery comparator) is kept alive,
causing the device to draw approximately 7µA.
Standby mode is useful in applications where a lowbattery comparator function is still needed in shutdown.
A logic low at the OFF pin turns off all biasing circuitry,
including the LBI/LBO comparator, and reduces supply
current to less than 1µA. OFF mode is useful for maximizing battery life. There is little difference in the time it
takes to exit standby mode or OFF mode.
Output Capacitor Selection
and Regulator Stability
An output filter capacitor is required at the MAX882/
MAX883/MAX884 OUT pin. The minimum output
capacitance required for stability is 2.2µF.
______________________________________________________________________________________
11
MAX882/MAX883/MAX884
IN
BATTERY
OUTPUT
VOLTAGE
OUT
70
A: COUT = 1μF
B: COUT = 10μF
C: COUT = 100μF
50
60
IOUT = 1mA
MAX882/4-8b
60
MAX882/4-8a
80
40
50
PSRR (dB)
PSRR (dB)
MAX882/MAX883/MAX884
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
40
30
30
C
20
MAX884
ΔVIN = 1VP-P
CIN = 0μF
COUT = 2.2μF
20
10
IOUT = 100mA
0
A
0
100
101
102
103
104
105
106
FREQUENCY (Hz)
Figure 8a. Power-Supply Rejection Ratio vs. Ripple Frequency
for Light and Heavy Loads
The filter capacitor’s size depends primarily on the
desired power-up time and load-transient responses.
Load-transient response is improved by using larger
output capacitors.
The output capacitor’s equivalent series resistance
(ESR) will not affect stability as long as the minimum
capacitance requirement is observed. The type of
capacitor selected is not critical, but it must remain
above the minimum value over the full operating temperature range.
Input Bypass Capacitor
Normally, use 0.1µF to 10µF capacitors on the MAX882/
MAX883/MAX884 input. The best value depends primarily on the power-up slew rate of VIN, and on load
and line transients. Larger input capacitor values provide better supply-noise rejection and line-transient
response, as well as improved performance, when the
supply has a high AC impedance. The type of input
bypass capacitor used is not critical.
12
B
MAX883
ΔVIN = 1VP-P
CIN = 0μF
IOUT = 100mA
10
101
102
103
104
105
106
FREQUENCY (Hz)
Figure 8b. Power-Supply Rejection Ratio vs. Ripple Frequency
for Various Output Capacitances
Noise
The MAX882/MAX883/MAX884 exhibit up to 4mVp-p of
noise during normal operation. This is negligible in
most applications. When using the MAX882/MAX883/
MAX884 for applications that include analog-to-digital
converters (ADCs) with resolutions greater than 12 bits,
consider the ADC’s power-supply rejection specifications. See the output noise plot in the Typical Operating
Characteristics section.
PSRR and Operation from
Sources Other than Batteries
The MAX882/MAX883/MAX884 are designed to
achieve low dropout voltages and low quiescent currents in battery-powered systems. However, to gain
these benefits, the devices must trade away powersupply noise rejection, as well as swift response to supply variations and load transients. For a 1mA load
current, power-supply rejection ranges from 60dB
down to 20dB at 2kHz. At higher frequencies, the circuit depends primarily on the characteristics of the output capacitor, and the PSRR increases (Figure 8).
______________________________________________________________________________________
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
INPUT
VOLTAGE
OUTPUT
VOLTAGE
IN
OUT
LBI
R1
COUT
2.2μF
MAX882
D2
STBY
CIN
O.1μF
R2
GND
SET
BACKUP
BATTERY
Figure 9. Short-Term Battery Backup Using the MAX882
When operating from sources other than batteries, supply-noise rejection and transient response can be
improved by increasing the values of the input and output capacitors and employing passive filtering techniques. Do not use power supplies with ripple voltage
exceeding 200mV at 100kHz.
Short-Term Battery Backup
Using the MAX882
Figure 9 illustrates a scheme for implementing battery
backup for 3.3V circuits using the MAX882. When the
supply voltage drops below some user-specified value
based on resistors R1 and R2, the standby function
activates, turning off the MAX882’s output. Under
these conditions, the backup battery supplies power to
the load. Reverse current protection prevents the battery from draining back through the regulator to the
input.
Overshoot and Transient Considerations
This application is limited to short-term battery backup
for 3.3V circuits. The current drawn by the MAX882’s
OUT pin at 3.3V during reverse-current protection is
typically 8µA. It should not be used with the MAX883
and MAX884, since the OFF pin is a logic input, and
indeterminate inputs can cause the regulator to turn on
intermittently, draining the battery.
The Typical Operating Characteristics section shows
power-up, supply, and load-transient response graphs.
On the load-transient graphs, two components of the
output response can be observed: 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 50mA to 250mA are
200mV. Increasing the output capacitor’s value attenuates transient spikes.
Reverse battery protection can be added by including
an inexpensive Schottky diode between the battery
input and the regulator circuit, as shown in Figure 7.
However, the dropout voltage of the regulator will be
increased by the forward voltage drop of the diode. For
example, the forward voltage of a standard 1N5817
Schottky diode is typically 0.29V at 200mA.
Reverse Battery Protection
During recovery from shutdown, overshoot is negligible
if the output voltage has been given time to decay adequately. During power-up from VIN = 0, overshoot is
typically less than 1% of VOUT.
______________________________________________________________________________________
13
MAX882/MAX883/MAX884
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 determines the useful end-of-life battery voltage. Because
the MAX882/MAX883/MAX884 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.
MAX882/MAX883/MAX884
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
Ordering Information (continued)
PART
TEMP RANGE
___________________Chip Topography
PINPACKAGE
MAX883CPA
0°C to +70°C
MAX883CSA
0°C to +70°C
8 SO
MAX883C/D
0°C to +70°C
Dice*
MAX883EPA
-40°C to +85°C
8 PDIP
MAX883ESA
-40°C to +85°C
8 SO
MAX883MSA/PR
-55°C to +125°C
8 SO**
MAX883MSA/PR-T
LB0
GND
8 PDIP
-55°C to +125°C
8 SO**
MAX884CPA
0°C to +70°C
8 PDIP
MAX884CSA
0°C to +70°C
8 SO
MAX884C/D
0°C to +70°C
MAX884EPA
-40°C to +85°C
8 PDIP
MAX884ESA
-40°C to +85°C
8 SO
LBI
SET
OFF (MAX883/4)
STBY (MAX882)
0.085"
(2.159mm)
OUT
Dice*
*Dice are tested at TJ = +25°C, DC parameters only.
**Contact factory for availability.
OUT
IN
0.080"
(2.032mm)
NO DIRECT SUBSTRATE CONNECTION. THE N-SUBSTRATE IS INTERNALLY SWITCHED BETWEEN THE
MORE POSITIVE OF IN OR OUT.
14
______________________________________________________________________________________
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
PACKAGE CODE
DOCUMENT NO.
8 PDIP
P8-T
21-0043
8 SO
S8-6F
21-0041
PDIPN.EPS
PACKAGE TYPE
______________________________________________________________________________________
15
MAX882/MAX883/MAX884
Package Information
(For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.)
Package Information (continued)
(For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.)
DIM
A
A1
B
C
e
E
H
L
N
E
H
INCHES
MILLIMETERS
MAX
MIN
0.069
0.053
0.010
0.004
0.014
0.019
0.007
0.010
0.050 BSC
0.150
0.157
0.228
0.244
0.016
0.050
MAX
MIN
1.35
1.75
0.10
0.25
0.35
0.49
0.19
0.25
1.27 BSC
3.80
4.00
5.80
6.20
0.40
SOICN .EPS
MAX882/MAX883/MAX884
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
1.27
VARIATIONS:
1
INCHES
TOP VIEW
DIM
D
D
D
MIN
0.189
0.337
0.386
MAX
0.197
0.344
0.394
MILLIMETERS
MIN
4.80
8.55
9.80
MAX
5.00
8.75
10.00
N MS012
8
AA
14
AB
16
AC
D
A
B
e
C
0∞-8∞
A1
L
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .150" SOIC
APPROVAL
DOCUMENT CONTROL NO.
21-0041
16
______________________________________________________________________________________
REV.
B
1
1
5V/3.3V or Adjustable, Low-Dropout,
Low IQ, 200mA Linear Regulators
REVISION
NUMBER
REVISION
DATE
3
9/08
DESCRIPTION
Added information for rugged plastic product
PAGES
CHANGED
14
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 17
© 2008 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.
MAX882/MAX883/MAX884
Revision History