Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°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.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
SC70
Junction-to-Ambient Thermal Resistance (θ
JA
) .........324°C/W
Junction-to-Case Thermal Resistance (θ
JC
) ..............115°C/W
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to
www.maximintegrated.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(V
IN
= V
OUT
+ 0.5V, T
A
= -40°C to +85°C, unless otherwise noted. C
IN
= 1µF, C
OUT
= 1µF. Typical values are at T
A
= +25°C; the
MAX8892 is tested with 2.45V output, unless otherwise noted.) (Note 2)
PARAMETER
Input Voltage Range
Output Voltage Accuracy
Maximum Output Current
Current Limit
Dropout Voltage (Note 3)
Ground Current
Line Regulation
Load Regulation
Shutdown Supply Current
Ripple Rejection
Output Noise Voltage (RMS)
SHDN
Logic-Low Level
SHDN
Logic-High Level
SHDN
Input Bias Current
FB Input Bias Current
(MAX8892)
Thermal Shutdown
Thermal-Shutdown Hysteresis
I
Q
V
LNR
V
LDR
I
SHDN
PSRR
I
OUT
I
LIM
I
OUT
= 90% of nominal value
V
OUT
2.5V
2V
3V, I
OUT
= 120mA
V
OUT
< 3V, I
OUT
= 120mA
V
OUT
< 2.5V, I
OUT
= 120mA
SYMBOL
V
IN
I
OUT
= 100μA to 80mA
CONDITIONS
MIN
2
-3
150
200
120
135
180
40
0.001
0.003
0.003
0.05
65
230
0.4
1.5
T
A
= +25°C
T
A
= +85°C
T
A
= +25°C
T
A
= +85°C
0.01
0.006
0.01
160
10
0.1
1
μA
%/V
%/mA
μA
dB
μV
V
V
μA
μA
°C
°C
mV
TYP
MAX
6
+3
UNITS
V
%
mA
mA
I
OUT
= 0.05mA
V
IN
= (V
OUT
+ 0.5V) to 6V, I
OUT
= 0.1mA
I
OUT
= 1mA to 80mA
V
SHDN
= 0V
T
A
= +25°C
T
A
= +85°C
f = 10kHz, I
OUT
= 10mA
f = 100Hz to 100kHz, I
LOAD
= 80mA
V
IN
= 2V to 6V
V
IN
= 2V to 6V
V
IN
= 6V,
V
SHDN
= 0V or 6V
V
IN
= 6V,
V
FB
= 1.3V
Note 2:
Limits are 100% tested at T
A
= +25°C. Limits over operating temperature range are guaranteed by design.
Note 3:
Dropout 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.
2
Maxim Integrated
MAX8891/MAX8892
High PSRR, Low-Dropout, 150mA
Linear Regulators
Typical Operating Characteristics
(V
IN
= V
OUT
+ 0.5V, C
IN
= 1µF, C
OUT
= 1µF, T
A
= +25°C, unless otherwise noted.)
OUTPUT VOLTAGE ACCURACY
vs. LOAD CURRENT
MAX8891/2 toc01
MAX8891/2 toc02
OUTPUT VOLTAGE vs. INPUT VOLTAGE
3.0
2.5
OUTPUT VOLTAGE (V)
I
OUT
= 0mA
2.0
1.5
1.0
0.5
0.0
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
I
OUT
= 120mA
0.6
0.4
% DEVIATION (%)
0.2
0
-0.2
-0.4
-0.6
0
OUTPUT VOLTAGE ACCURACY
vs. TEMPERATURE
0.8
0.6
% DEVIATION (%)
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1.0
IOUT = 1mA
MAX8891/2 toc03
1.0
25
50
75
100
125
150
-40
-15
10
35
60
85
LOAD CURRENT (mA)
TEMPERATURE (°C)
DROPOUT VOLTAGE vs. LOAD CURRENT
MAX8891/2 toc04
DROPOUT VOLTAGE vs. OUTPUT VOLTAGE
MAX8891/2 toc05
GROUND PIN CURRENT vs. INPUT VOLTAGE
MAX8891/2 toc06
200
180
DROPOUT VOLTAGE (mV))
160
140
120
100
80
60
40
20
0
0
25
50
75
100
125
T
A
= -40°C
T
A
= +25°C
T
A
= +85°C
250
I
OUT
= 80mA
DROPOUT VOLTAGE (mV)
200
350
300
GROUND PIN CURRENT (μA)
250
200
150
100
50
I
OUT
= 0mA
150
100
50
0
150
2.0
2.2
2.4
2.6
2.8
3.0
3.2
LOAD CURRENT (mA)
OUTPUT (V)
0
0
1
2
3
4
5
INPUT VOLTAGE (V)
GROUND PIN CURRENT vs. LOAD CURRENT
MAX8891/2 toc07
GROUND PIN CURRENT vs. TEMPERATURE
MAX8891/2 toc08
PSRR vs. FREQUENCY
80
70
60
PSRR (dB)
50
40
30
MAX8891/2 toc09
350
300
GROUND PIN CURRENT (μA)
250
200
150
100
50
0
0
25
50
75
100
125
V
IN
= 3.8V
V
IN
= 5.5V
50
90
GROUND PIN CURRENT (μA)
45
40
35
20
10
I
LOAD
= 10mA
0.01
0.1
1
10
100
1000
30
150
-40
-15
10
35
60
85
LOAD CURRENT (mA)
TEMPERATURE (°C)
0
FREQUENCY (kHz)
Maxim Integrated
3
MAX8891/MAX8892
High PSRR, Low-Dropout, 150mA
Linear Regulators
Typical Operating Characteristics (continued)
(V
IN
= V
OUT
+ 0.5V, C
IN
= 1µF, C
OUT
= 1µF, T
A
= +25°C, unless otherwise noted.)
LOAD TRANSIENT RESPONSE
dl/dt = 0.5mA/μs
MAX8891/2 toc10
LOAD TRANSIENT RESPONSE
dl/dt = 5mA/μs
MAX8891/2 toc11
LOAD TRANSIENT RESPONSE
dl/dt = 20mA/μs
MAX8891/2 toc12
50mA
V
IN
= 3.5V
10mA
I
LOAD
25mA/div
10mA
50mA
V
IN
= 3.5V
10mA
I
LOAD
25mA/div
10mA
50mA
V
IN
= 3.5V
10mA
I
LOAD
25mA/div
10mA
dl/dt = 0.5mA/μs
dl/dt = 0.5mA/μs
dl/dt = 20mA/μs
V
IN
10mV/div
V
IN
10mV/div
V
IN
10mV/div
V
OUT
10mV/div
200μs/div
20μs/div
V
OUT
10mV/div
4μs/div
V
OUT
10mV/div
STARTUP WAVEFORM
MAX8891/2 toc13
SHUTDOWN WAVEFORM
MAX8891/2 toc14
LINE TRANSIENT RESPONSE
dv/dt = 500mV/μs
MAX8891/2 toc15
V
IN
= 3.5V
R
LOAD
= 30Ω
ON
V
SHDN
2V/div
ON
V
IN
= 3.5V
R
LOAD
= 30Ω
OFF
V
SHDN
2V/div
4V
R
LOAD
= 30Ω
dv/dt = 500mV/μs
4V
V
IN
500mV/div
3.5V
OFF
V
OUT
500mV/div
V
OUT
500mV/div
V
OUT
10mV/div
10μs/div
40μs/div
40μs/div
LINE TRANSIENT RESPONSE
dv/dt = 200mV/μs
MAX8891/2 toc16
REGION OF STABLE C
OUT
ESR
vs. LOAD CURRENT
MAX8891/2 to17
100
R
LOAD
= 30Ω
5V
dv/dt = 200mV/μs
5V
V
IN
1V/div
3.5V
V
OUT
10mV/div
C
OUT
ESR (Ω)
10
1
0.1
STABLE REGION
0.01
40μs/div
0
25
50
75
100
125
150
LOAD CURRENT (mA)
4
Maxim Integrated
MAX8891/MAX8892
High PSRR, Low-Dropout, 150mA
Linear Regulators
Pin Description
PIN
MAX8891
1
2
3
—
4
5
MAX8892
1
2
3
4
—
5
NAME
IN
GND
SHDN
FB
N.C.
OUT
Unregulated Input Supply
Ground
Shutdown. Pull low to disable the regulator.
Adjustable Output Feedback Point
Not Internally Connected
Regulated Output Voltage. Bypass with a capacitor to GND. See the
Capacitor Selection
and Regulator Stability
section for more details.
FUNCTION
Detailed Description
The MAX8891/MAX8892 are low-dropout, low-quies-
cent current linear regulators designed for space-
restricted applications. The parts are available with
preset output voltages ranging from 1.5V to 4.5V in
100mV increments. These devices can supply loads up
to 150mA. As shown in the
Functional Diagram,
the
MAX8891 consists of an innovative bandgap core, error
amplifier, p-channel pass transistor, and internal feed-
back voltage-divider. The MAX8892 allows for
adjustable output with an external feedback network.
Additional blocks include a current limiter, thermal sen-
sor, and shutdown logic.
The 1.225V bandgap reference is connected to the
error amplifier’s inverting input. The error amplifier com-
pares this reference with the feedback voltage and
amplifies the difference. If the feedback voltage is lower
than the reference voltage, the pass-transistor gate is
pulled low. This allows more current to pass to the out-
put and increases the output voltage. If the feedback
voltage is too high, the pass transistor gate is pulled
high, allowing less current to pass to the output. The
output voltage is fed back through an internal (external
for the MAX8892) resistor voltage-divider connected to
the OUT pin.
heavy loads. The MAX8891/MAX8892 do not suffer from
these problems and consume only 40µA of quiescent
current in light load and 220µA in dropout (see the
Typical Operating Characteristics).
Output Voltage Selection
The MAX8891 is supplied with factory-set output volt-
ages from 1.5V to 4.5V, in 100mV increments (see the
Ordering Information).
The MAX8892 features a user-
adjustable output through an external feedback net-
work (see the
Typical Operating Circuits).
To set the output of the MAX8892, use the following
equation:
⎛
V
OUT
⎞
R1
=
R2
× ⎜
-1
⎝
V
REF
⎟
⎠
where R2 is chosen to be less than 240kΩ and V
REF
=
1.225V. Use 1% or better resistors.
Shutdown
The MAX8891/MAX8892 feature a low-power shutdown
mode that reduces quiescent current less than 1µA.
Driving
SHDN
low disables the voltage reference, error
amplifier, gate-drive circuitry, and pass transistor (see
the
Functional Diagram),
and the device output enters a
high-impedance state. Connect
SHDN
to IN for normal
operation.
Internal P-Channel Pass Transistor
The MAX8891/MAX8892 feature a 1Ω (typ) p-channel
MOSFET pass transistor. This provides several advan-
tages over similar designs using a PNP pass transistor,
including longer battery life. The p-channel MOSFET
requires no base drive, which considerably reduces qui-
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