19-1301; Rev 1; 3/98
Low-Noise, Low-Dropout, 150mA Linear
Regulators with ‘2982 Pinout
__________________General Description
The MAX8877/MAX8878 low-noise, low-dropout linear
regulators operate from a 2.5V to 6.5V input and deliver
up to 150mA. These devices are pin-compatible with
the industry-standard ‘2982 and offer an improved
dropout voltage. Typical output noise is 30µV
RMS
, and
typical dropout is only 165mV at 150mA. The output
voltage is preset to voltages in the range of 2.5V to
5.0V, in 100mV increments.
Designed with an internal P-channel MOSFET pass
transistor, the MAX8877/MAX8878 maintain a low
100µA supply current, independent of the load current
and dropout voltage. Other features include a 10nA
logic-controlled shutdown mode, short-circuit and ther-
mal-shutdown protection, and reverse battery protec-
tion. The MAX8878 also includes an auto-discharge
function, which actively discharges the output voltage
to ground when the device is placed in shutdown. Both
devices come in a miniature 5-pin SOT23 package.
____________________________Features
o
Pin-Compatible with the Industry-Standard ‘2982
o
Low Output Noise: 30µV
RMS
o
Low 55mV Dropout at 50mA Output
(165mV at 150mA output)
o
Low 85µA No-Load Supply Current
o
Low 100µA Operating Supply Current
(even in dropout)
o
Thermal-Overload and Short-Circuit Protection
o
Reverse Battery Protection
o
Output Current Limit
o
Preset Output Voltages (±1.4% Accuracy)
o
10nA Logic-Controlled Shutdown
MAX8877/MAX8878
________________________Applications
Cellular Telephones
Cordless Telephones
PCS Telephones
PCMCIA Cards
Modems
Hand-Held Instruments
Palmtop Computers
Electronic Planners
_________________Ordering Information
PART**
MAX8877C/Dxy
MAX8877EUKxy-T
MAX8878C/Dxy
MAX8878EUKxy-T
TEMP. RANGE
0°C to +70°C
-40°C to +85°C
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
Dice*
5 SOT23-5
Dice*
5 SOT23-5
*Dice
are tested at T
A
= +25°C only.
**
xy is the output voltage code (see Expanded Ordering
Information table at end of data sheet).
____________Typical Operating Circuit
_____________________Pin Configuration
TOP VIEW
INPUT
2.5V TO 6.5V
IN
C
IN
1µF
ON
OFF
C
BP
0.01µF
OUT
C
OUT
1µF
OUTPUT
PRESET
2.5V TO 5.0V
150mA
IN
1
5
OUT
MAX8877
MAX8878
SHDN
BP
GND
GND
2
MAX8877
MAX8878
4
BP
SHDN
3
SOT23-5
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
Low-Noise, Low-Dropout, 150mA Linear
Regulators with ‘2982 Pinout
MAX8877/MAX8878
ABSOLUTE MAXIMUM RATINGS
IN to GND ....................................................................-7V to +7V
Output Short-Circuit Duration ............................................Infinite
SHDN
to GND..............................................................-7V to +7V
SHDN
to IN ...............................................................-7V to +0.3V
OUT, BP to GND ..........................................-0.3V to (V
IN
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
SOT23-5 (derate 7.1mW/°C above +70°C)..................571mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
θ
JB
..................................................................................140°C/W
Storage Temperature.........................................-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
(V
IN
= V
OUT(NOMINAL)
+ 0.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Input Voltage
Output Voltage Accuracy
Maximum Output Current
Current Limit
Ground Pin Current
I
LIM
I
Q
No load
I
OUT
= 150mA
I
OUT
= 1mA
Dropout Voltage (Note 2)
Line Regulation
Load Regulation
Output Voltage Noise
SHUTDOWN
SHDN
Input Threshold
SHDN
Input Bias Current
Shutdown Supply Current
Shutdown Exit Delay
(Note 3)
Resistance Shutdown Discharge
THERMAL PROTECTION
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
T
SHDN
∆T
SHDN
155
15
°C
°C
V
IH
V
IL
I
SHDN
I
Q(SHDN)
V
IN
= 2.5V to 5.5V
V
IN
= 2.5V to 5.5V
V
SHDN
= V
IN
V
OUT
= 0V
C
BP
= 0.1µF
C
OUT
= 1µF, no load
MAX8878 only
T
A
= +25°C
T
A
= +85°C
T
A
= +25°C
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
300
0.01
0.5
0.01
0.2
30
150
300
1
2.0
0.4
100
V
nA
µA
µs
Ω
∆V
LNR
∆V
LDR
e
n
I
OUT
= 50mA
I
OUT
= 150mA
V
IN
= (V
OUT
+ 0.1V) to 6.5V, I
OUT
= 1mA
I
OUT
= 0mA to 120mA, C
OUT
= 1µF
f = 10Hz to 100kHz,
C
BP
= 0.01µF
C
OUT
= 10µF
C
OUT
= 100µF
-0.15
SYMBOL
V
IN
I
OUT
= 0mA, T
A
= +25°C
I
OUT
= 0mA to 120mA, T
A
= -40°C to +85°C
CONDITIONS
MIN
2.5
-1.4
-3
150
160
390
85
100
1.1
55
165
0
0.01
30
20
0.15
0.04
%/V
%/mA
µV
RMS
120
mV
180
TYP
MAX
6.5
1.4
2
UNITS
V
%
mA
mA
µA
Note 1:
Limits are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed through
correlation using Statistical Quality Control (SQC) Methods.
Note 2:
The dropout voltage is defined as V
IN
- V
OUT
, when V
OUT
is 100mV below the value of V
OUT
for V
IN
= V
OUT
+ 0.5V.
Note 3:
Time needed for V
OUT
to reach 95% of final value.
2
_______________________________________________________________________________________
Low-Noise, Low-Dropout, 150mA Linear
Regulators with ‘2982 Pinout
__________________________________________Typical Operating Characteristics
(V
IN
= V
OUT(NOMINAL)
+ 0.5V, C
IN
= 1µF, C
OUT
= 1µF, C
BP
= 0.01µF, T
A
= +25°C, unless otherwise noted.)
MAX8877/MAX8878
OUTPUT VOLTAGE vs. LOAD CURRENT
(MAX887_EUK25)
MAX8877-01
OUTPUT VOLTAGE vs. LOAD CURRENT
(MAX887_EUK50)
MAX8877-02
GROUND PIN CURRENT
vs. LOAD CURRENT
105
GROUND PIN CURRENT (µA)
100
95
90
85
80
75
70
65
MAX887_EUK25
MAX887_EUK50
MAX8877-03
2.60
5.2
110
OUTPUT VOLTAGE (V)
2.50
OUTPUT VOLTAGE (V)
2.55
5.1
5.0
2.45
4.9
2.40
0
50
100
150
LOAD CURRENT (mA)
4.8
0
50
100
150
LOAD CURRENT (mA)
60
0
50
100
150
LOAD CURRENT (mA)
GROUND PIN CURRENT vs. INPUT VOLTAGE
(MAX887_EUK25)
MAX8877-04
GROUND PIN CURRENT vs. INPUT VOLTAGE
(MAX887_EUK50)
MAX8877-05
OUTPUT VOLTAGE vs. INPUT VOLTAGE
NO LOAD
5
OUTPUT VOLTAGE (V)
MAX887_EUK50
4
3
2
1
0
MAX887_EUK25
MAX8877-06
120
I
LOAD
= 50mA
GROUND PIN CURRENT (µA)
100
80
NO LOAD
60
40
20
0
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
120
100
80
I
LOAD
= 50mA
6
GROUND PIN CURRENT (µA)
NO LOAD
60
40
20
0
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
OUTPUT VOLTAGE vs. TEMPERATURE
(MAX887_EUK25)
MAX8877-07
OUTPUT VOLTAGE vs. TEMPERATURE
(MAX887_EUK50)
MAX8877-08
GROUND PIN CURRENT
vs. TEMPERATURE
180
GROUND PIN CURRENT (µA)
160
140
120
100
80
60
40
20
MAX887_EUK25
MAX887_EUK50
I
LOAD
= 50mA
MAX8877-09
2.60
I
LOAD
= 50mA
2.55
5.2
I
LOAD
= 50mA
5.1
200
OUTPUT VOLTAGE (V)
2.50
OUTPUT VOLTAGE (V)
5.0
2.45
4.9
2.40
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
4.8
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
0
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
_______________________________________________________________________________________
3
Low-Noise, Low-Dropout, 150mA Linear
Regulators with ‘2982 Pinout
MAX8877/MAX8878
____________________________Typical Operating Characteristics (continued)
(V
IN
= V
OUT(NOMINAL)
+ 0.5V, C
IN
= 1µF, C
OUT
= 1µF, C
BP
= 0.01µF, T
A
= +25°C, unless otherwise noted.)
DROPOUT VOLTAGE vs. LOAD CURRENT
(MAX887_EUK25)
MAX8877-10
DROPOUT VOLTAGE vs. LOAD CURRENT
(MAX887_EUK50)
MAX8877-11
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX8877-12
250
T
A
= +85°C
T
A
= +25°C
T
A
= -40°C
100
200
70
60
50
PSRR (dB)
40
30
20
10
I
LOAD
= 50mA
C
BP
= 0.1µF
0.01
0.1
1
10
100
C
OUT
= 1µF
DROPOUT VOLTAGE (mV)
DROPOUT VOLTAGE (mV)
200
150
T
A
= +85°C
T
A
= +25°C
C
OUT
= 10µF
150
100
T
A
= -40°C
50
50
0
0
20
40
60
80
100 120 140 160
LOAD CURRENT (mA)
0
0
20
40
60
80
100 120 140 160
LOAD CURRENT (mA)
0
1000
FREQUENCY (kHz)
OUTPUT NOISE SPECTRAL DENSITY
vs. FREQUENCY
MAX8877-13
OUTPUT NOISE vs. BP CAPACITANCE
70
OUTPUT NOISE (µV
RMS
)
60
50
MAX887_EUK50
40
30
20
MAX887_EUK25
10
0
10
0
0.001
0.01
BP CAPACITANCE (µF)
0.1
1
MAX887_EUK30
C
OUT
= 10µF
I
LOAD
= 10mA
f = 10Hz to 100kHz
MAX8877-14
OUTPUT NOISE vs. LOAD CURRENT
MAX8877-15
OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz)
10
C
BP
= 0.01µF
I
LOAD
= 10mA
80
60
50
OUTPUT NOISE (µV
RMS
)
40
MAX887_EUK30
30
20
C
OUT
= 10µF
C
BP
= 0.01µF
f = 10Hz to 100kHz
10
100
MAX887_EUK25
MAX887_EUK50
1
C
OUT
= 1µF
0.1
C
OUT
= 10µF
0.01
0
1
10
FREQUENCY (kHz)
100
1000
1000
LOAD CURRENT (mA)
OUTPUT NOISE 10Hz TO 100kHz
MAX8877-16
REGION OF STABLE C
OUT
ESR
vs. LOAD CURRENT
MAX8877-17
100
10
C
OUT
ESR (Ω)
C
OUT
= 10µF
V
OUT
50µV/div
1
STABLE REGION
0.1
C
OUT
= 1µF
0.01
1ms/div
MAX887_EUK25, C
OUT
= 10µF, I
LOAD
= 10mA, C
BP
= 0.1µF
0
100
LOAD CURRENT (mA)
150
4
_______________________________________________________________________________________
Low-Noise, Low-Dropout, 150mA Linear
Regulators with ‘2982 Pinout
____________________________Typical Operating Characteristics (continued)
(V
IN
= V
OUT(NOMINAL)
+ 0.5V, C
IN
= 1µF, C
OUT
= 1µF, C
BP
= 0.01µF, T
A
= +25°C, unless otherwise noted.)
LINE-TRANSIENT RESPONSE
MAX8877-18
MAX8877/MAX8878
LOAD-TRANSIENT RESPONSE
MAX8877-19
LOAD-TRANSIENT RESPONSE
NEAR DROPOUT
MAX8877-20
4V
3V
V
IN
3.01V
3.00V
2.99V
V
OUT
3.01V
3.00V
2.99V
V
OUT
3.001V
3.000V
2.999V
V
OUT
50mA
I
LOAD
50mA
I
LOAD
100µs/div
MAX887_EUK30, I
LOAD
= 50mA
10µs/div
MAX887_EUK30, V
IN
= V
OUT
+ 0.5V,
C
IN
= 10µF, I
LOAD
= 0mA TO 50mA
10µs/div
MAX887_EUK30, V
IN
= V
OUT
+ 0.1V,
C
IN
= 10µF, I
LOAD
= 0mA TO 50mA
MAX887_EUK25
SHUTDOWN EXIT DELAY
MAX8877-21
MAX887_EUK50
SHUTDOWN EXIT DELAY
MAX8877-22
ENTERING SHUTDOWN
MAX8877-23
2V
0V
C
BP
= 0.01µF
V
SHDN
2V
0V
C
BP
= 0.01µF
V
SHDN
2V
0V
5V
V
SHDN
2V
C
BP
= 0.1µF
V
OUT
4V
C
BP
= 0.1µF
V
OUT
V
OUT
1V
2V
0V
0V
5µs/div
MAX887_EUK50, I
LOAD
= 50mA
500µs/div
MAX8878, NO LOAD
0V
5µs/div
MAX887_EUK25, I
LOAD
= 50mA
______________________________________________________________Pin Description
PIN
1
2
3
4
5
NAME
IN
GND
SHDN
BP
OUT
FUNCTION
Regulator Input. Supply voltage can range from 2.5V to 6.5V. Bypass with a 1µF capacitor to GND (see
Capacitor Selection and Regulator Stability
section).
Ground. This pin also functions as a heatsink. Solder to a large pad or the circuit-board ground plane to
maximize power dissipation.
Active-Low Shutdown Input. A logic low reduces the supply current to 10nA. On the MAX8878, a logic low
also causes the output voltage to discharge to GND. Connect to IN for normal operation.
Reference-Noise Bypass. Bypass with a low-leakage, 0.01µF ceramic capacitor for reduced noise at the
output.
Regulator Output. Sources up to 150mA. Bypass with a 1µF (<0.2Ω typical ESR) capacitor to GND.
_______________________________________________________________________________________
5
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