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19-1257; Rev 1; 3/98
Low-Dropout, 120mA Linear Regulators
_______________General Description
The MAX8873T/S/R and MAX8874T/S/R low-dropout lin-
ear regulators operate from a +2.5V to +6.5V input
range and deliver up to 120mA. A PMOS pass transis-
tor allows the low, 82µA supply current to remain inde-
pendent of load, making these devices ideal for
battery-operated portable equipment such as cellular
phones and cordless phones.
The devices feature Dual Mode™ operation: their out-
put voltage is preset (at 3.15V for the T versions, 2.84V
for the S versions, or 2.80V for the R versions) or can be
adjusted with an external resistor divider. Total error on
the output is ±3.5%. Output voltages are set on the low
side of popular ranges so that power drain is minimized
for longer battery life. Other features include low-power
shutdown, short-circuit protection, thermal shutdown
protection, and reverse battery protection. The
MAX8874 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.
For dual versions, refer to the MAX8865/MAX8866 data
sheet. For low-noise versions with 30µV
RMS
output
noise, refer to the MAX8877/MAX8878.
____________________________Features
o
LP2980 Pin-Compatible SOT23 Package
o
Low, 55mV Dropout Voltage at 50mA I
OUT
(130mV at 120mA)
o
Low, 73µA No-Load Supply Current
Low, 82µA Operating Supply Current (even in
dropout)
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
MAX8873T/S/R, MAX8874T/S/R
______________Ordering Information
PART
TEMP. RANGE
PIN-
PACKAGE
5 SOT23-5
5 SOT23-5
5 SOT23-5
5 SOT23-5
5 SOT23-5
5 SOT23-5
SOT TOP
MARK
ABZH
ABZI
ABZL
ABZJ
ABZK
ABZM
________________________Applications
Cordless Telephones
PCS Telephones
Cellular Telephones
PCMCIA Cards
Modems
Hand-Held Instruments
Palmtop Computers
Electronic Planners
MAX8873TEUK-T
-40°C to +85°C
MAX8873SEUK-T
-40°C to +85°C
MAX8873REUK-T -40°C to +85°C
MAX8874TEUK-T
-40°C to +85°C
MAX8874SEUK-T
-40°C to +85°C
MAX8874REUK-T -40°C to +85°C
__________Typical Operating Circuit
__________________Pin Configuration
TOP VIEW
IN
1
5
OUT
IN
OUT
OUTPUT
VOLTAGE
C
OUT
1µF
GND
2
BATTERY
C
IN
1µF
MAX8873
MAX8874
SHDN
GND
SET
MAX8873
MAX8874
SHDN
3
4
SET
SOT23-5
Dual Mode is a trademark of Maxim Integrated Products.
________________________________________________________________
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-Dropout, 120mA Linear Regulators
MAX8873T/S/R, MAX8874T/S/R
ABSOLUTE MAXIMUM RATINGS
V
IN
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 (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
JA
..................................................................................140°C/W
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
(V
IN
= +3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Input Voltage (Note 2)
Output Voltage
Adjustable Output Voltage
Range (Note 3)
Maximum Output Current
Current Limit (Note 4)
Ground Pin Current
Dropout Voltage (Note 5)
Line Regulation
Load Regulation
Output Voltage Noise
SHUTDOWN
SHDN Input Threshold
SHDN
Input Bias Current
Shutdown Supply Current
Shutdown Discharge
Resistance (MAX8874)
V
IH
V
IL
I
SHDN
I
Q
SHDN
V
SHDN
= V
IN
V
OUT
= 0V
T
A
= +25°C
T
A
= T
MAX
T
A
= +25°C
T
A
= T
MAX
0
0.05
0.0001
0.02
300
1
2.0
0.4
100
V
nA
µA
Ω
∆V
LNR
∆V
LDR
I
LIM
I
Q
SET = GND
I
OUT
= 1mA
I
OUT
= 50mA
V
IN
= 2.5V to 6.5V, SET tied to OUT,
I
OUT
= 1mA
I
OUT
= 0mA to 50mA
10Hz to 1MHz
SET = GND
SET tied to OUT
C
OUT
= 1µF
C
OUT
= 100µF
-0.15
I
OUT
= 0mA
I
OUT
= 50mA
SYMBOL
V
IN
V
OUT
0mA
≤
I
OUT
≤
50mA,
SET = GND
MAX887_T
MAX887_S
MAX887_R
V
OUT
CONDITIONS
MIN
2.5
3.05
2.75
2.70
V
SET
120
280
73
82
1.1
55
0
0.011
0.006
350
220
120
0.15
0.030
150
3.15
2.84
2.80
TYP
MAX
6.5
3.25
2.93
2.88
6.5
V
mA
mA
µA
mV
%/V
%/mA
µV
RMS
V
UNITS
V
2
_______________________________________________________________________________________
Low-Dropout, 120mA Linear Regulators
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
SET INPUT
SET Reference Voltage (Note 3)
SET Input Leakage Current
(Note 3)
THERMAL PROTECTION
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
T
SHDN
∆T
SHDN
170
20
°C
°C
V
SET
I
SET
V
IN
= 2.5V to 6.5V,
IOUT = 1mA
V
SET
= 1.3V
T
A
= +25°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= T
MAX
1.225
1.215
1.25
1.25
0.015
0.5
1.275
1.285
2.5
V
nA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX8873T/S/R, MAX8874T/S/R
Note 1:
Limits are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed through cor-
relation using Statistical Quality Control (SQC) methods.
Note 2:
Guaranteed by line-regulation test.
Note 3:
Adjustable mode only.
Note 4:
For design purposes, the current limit should be considered 120mA minimum to 420mA maximum.
Note 5:
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
+ 2V.
__________________________________________Typical Operating Characteristics
(V
IN
= +3.6V, C
IN
= 1µF, C
OUT
= 1µF, MAX887_T, T
A
= +25°C, unless otherwise noted.)
OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX8873/74-01
SUPPLY CURRENT
vs. LOAD CURRENT
MAX8873/74-02
OUTPUT VOLTAGE
vs. INPUT VOLTAGE
MAX8873/74-03
3.30
3.25
OUTPUT VOLTAGE (V)
3.20
3.15
3.10
3.05
3.00
0
20
40
60
80
100
100
95
90
SUPPLY CURRENT (µA)
85
80
75
70
65
60
55
50
3.5
3.0
OUTPUT VOLTAGE (V)
2.5
2.0
NO LOAD
1.5
1.0
0.5
0
120
0
20
40
60
80
100
120
0
1
2
3
4
5
6
7
LOAD CURRENT (mA)
LOAD CURRENT (mA)
INPUT VOLTAGE (V)
_______________________________________________________________________________________
3
Low-Dropout, 120mA Linear Regulators
MAX8873T/S/R, MAX8874T/S/R
____________________________Typical Operating Characteristics (continued)
(V
IN
= +3.6V, C
IN
= 1µF, C
OUT
= 1µF, MAX887_T, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX8873/74-04
OUTPUT VOLTAGE
vs. TEMPERATURE
MAX8873/74-05
SUPPLY CURRENT
vs. TEMPERATURE
90
80
SUPPLY CURRENT (µA)
70
60
50
40
30
20
10
I
LOAD
= 50mA
MAX8863/4-06
100
90
80
SUPPLY CURRENT (µA)
70
60
50
40
30
20
10
0
0
1
2
3
4
5
6
7
INPUT VOLTAGE (V)
I
LOAD
= 0mA
I
LOAD
= 50mA
3.30
I
LOAD
= 50mA
3.25
OUTPUT VOLTAGE (V)
3.20
3.15
3.10
3.05
3.00
-40
-20
0
20
40
60
80
100
0
100
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
TEMPERATURE (°C)
DROPOUT VOLTAGE
vs. LOAD CURRENT
MAX8873/74-07
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX8873/74-08
OUTPUT SPECTRAL NOISE DENSITY
vs. FREQUENCY
OUTPUT SPECTRAL NOISE DENSITY (µV/√Hz)
R
L
= 50Ω
C
OUT
= 1µF
1
MAX8873/74-8A
160
140
DROPOUT VOLTAGE (mV)
120
T
A
= +85°C
70
60
50
PSRR (dB)
40
30
20
10
0
V
OUT
= 3.15V
R
L
= 100Ω
10
100
80
60
40
20
0
0
20
40
T
A
= +25°C
C
OUT
= 10µF
C
OUT
= 100µF
0.10
T
A
= -40°C
C
OUT
= 1µF
0.01
0.01
0.1
1
10
FREQUENCY (kHz)
100
1000
0.1
1
10
FREQUENCY (kHz)
100
1000
60
80
100
120
LOAD CURRENT (mA)
REGION OF STABLE C
OUT
ESR
vs. LOAD CURRENT
C
OUT
= 1µF
100
C
OUT
ESR (Ω)
INTERNAL FEEDBACK
MAX8873/74-8B
OUTPUT NOISE DC TO 1MHz
1000
10
V
OUT
EXTERNAL FEEDBACK
STABLE REGION
1
0.1
0.01
0
20
40
60
80
100
120
LOAD CURRENT (mA)
1ms/div
I
LOAD
= 50mA, V
OUT
IS AC COUPLED
4
_______________________________________________________________________________________
Low-Dropout, 120mA Linear Regulators
____________________________Typical Operating Characteristics (continued)
(V
IN
= +3.6V, C
IN
= 1µF, C
OUT
= 1µF, MAX887_T, T
A
= +25°C, unless otherwise noted.)
LINE-TRANSIENT RESPONSE
3.16V
V
OUT
3.15V
3.14V
3.16V
V
OUT
3.15V
3.14V
MAX8873T/S/R, MAX8874T/S/R
LOAD-TRANSIENT RESPONSE
V
IN
4.6V
3.6V
50µs/div
I
LOAD
= 50mA, V
OUT
IS AC COUPLED
50mA
I
LOAD
0mA
10µs/div
I
LOAD
= 0mA to 50mA, C
IN
= 10µF, V
OUT
IS AC COUPLED
LOAD-TRANSIENT RESPONSE
3.16V
V
OUT
3.15V
3.14V
3.16V
V
OUT
3.15V
3.14V
LOAD-TRANSIENT RESPONSE
50mA
I
LOAD
0mA
10µs/div
V
IN
= V
OUT
+ 0.2V, I
LOAD
= 0mA to 50mA, C
IN
= 10µF,
V
OUT
IS AC COUPLED
50mA
I
LOAD
0mA
10µs/div
V
IN
= V
OUT
+ 0.1V, I
LOAD
= 0mA to 50mA, C
IN
= 10µF,
V
OUT
IS AC COUPLED
MAX8874 SHUTDOWN (NO LOAD)
4V
V
OUT
2V
0V
V
OUT
MAX8874 SHUTDOWN
4V
2V
0V
V
SHDN
2V
V
SHDN
0V
2V
0V
500µs/div
NO LOAD
I
LOAD
= 50mA
200µs/div
_______________________________________________________________________________________
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