Operating Temperature Range .........................-40°C to +125°C
Junction Temperature Range ............................-40°C to +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.
ELECTRICAL CHARACTERISTICS
(V
IN
= V
EN
= 5V, OUTS = OUT, circuit of Figure 2 (MAX8902A) and Figure 3 (MAX8902B), T
A
= -40°C to +125°C, unless otherwise
noted.) (Note 1)
PARAMETER
IN
Input Voltage Range
Input Undervoltage Lockout
OUT
Output Voltage Range
Output Voltage Accuracy
Load Regulation
Line Regulation
V
IN
V
OUT
+ 0.1V
0.6
-1.5
0.02
0.04
+85°C
+125°C
600
50
150
700
16
92
85
62
0.5
0.591
-0.1
0.600
0.02
0.03
1
50
100
7.0
0.609
+0.1
μA
V
μA
dB
800
mA
μV
RMS
100
120
5.3
+1.5
V
%
%
%
V
IN
rising, 100mV typical hysteresis
1.7
1.5
1.6
5.5
1.7
V
V
CONDITIONS
MIN
TYP
MAX
UNITS
V
IN
= 1.7V to 5.5V for V
OUT
1.4V,
V
IN
= (V
OUT
+ 0.3V) to 5.5V for V
OUT
> 1.4V,
I
OUT
= 0.1mA to 500mA
I
OUT
= 0.1mA to 500mA
V
IN
= 1.7V to 5.5V for V
OUT
1.4V,
V
IN
= (V
OUT
+ 0.3V) to 5.5V for V
OUT
> 1.4V,
I
OUT
= 200mA
I
OUT
= 500mA
V
IN
3.6V, T
A
V
IN
3.6V, T
A
V
IN
= 1.7V
Dropout Voltage
(Note 2)
Current Limit
Output Noise
Power-Supply Rejection Ratio
OUTS
(MAX8902A
only)
OUTS Input Bias Current
FB
(MAX8902B
only)
FB Threshold Accuracy
FB Input Bias Current
BYP
BYP Capacitor Range
BYP Startup Current
mV
V
OUT
= 95% of regulation, V
IN
= V
OUT
+ 0.5V
I
OUT
= 100mA, f = 10Hz to 100kHz, C
BYP
= 0.01μF
f = 5kHz
I
OUT
= 10mA
f = 10kHz
f = 100kHz
In regulation
V
IN
= 1.7V to 5.5V, I
OUT
= 0.1mA to 500mA
T
A
= +25°C
V
FB
= 0.6V
T
A
= -40°C
Regulator remains stable
From BYP to GND during startup
nF
μA
2
Maxim Integrated
MAX8902A/MAX8902B
Low-Noise 500mA LDO Regulators
in a 2mm x 2mm TDFN Package
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
EN
= 5V, OUTS = OUT, circuit of Figure 2 (MAX8902A) and Figure 3 (MAX8902B), T
A
= -40°C to +125°C, unless otherwise
noted.) (Note 1)
PARAMETER
GND
GND Supply Current
GND Shutdown Current
SELA/SELB
(MAX8902A
only)
Select Input Resistance
Select Input Capacitance
EN
Enable Input Threshold
V
IN
= 1.7V to 5.5V
EN rising
EN falling, T
A
< +85°C
EN falling, T
A
< +125°C
Enable Input Bias Current
POK
(MAX8902B only)
POK
Threshold
POK
Voltage, Low
POK
Leakage Current
THERMAL SHUTDOWN
Thermal Shutdown Threshold
OUTPUT TRANSIENT
Load Transient
Line Transient
IN-to-OUT Reverse Voltage
Turnoff Threshold
I
OUT
= 50mA to 500mA to 50mA, t
RISE
= t
FALL
= 1μs
V
IN
= 4V to 5V to 4V, t
RISE
= t
FALL
= 5μs, I
OUT
= 500mA
IN falling below OUT
25
3
10
mV/
P-P
mV/
P-P
mV
T
J
rising
T
J
falling
165
150
°C
OUT voltage when
POK
switches
I
POK
= 1mA
POK
= 5.5V, V
EN
= 0V
T
A
= +25°C
T
A
= +85°C
-1
OUT rising
OUT falling
88
91
88
10
0.001
0.01
100
+1
94
%
%
mV
μA
V
EN
= 0V to 5.5V
T
A
= +25°C
T
A
= +85°C
0.4
0.38
-1
0.8
0.7
0.7
0.001
0.01
+1
μA
1.2
V
When shorted to GND or V
IN
When open
When open
1
10
500
M
pF
I
OUT
= 0mA
V
IN
= 5.5V, EN = 0V
T
A
< +85°C
T
A
< +125°C
T
A
= +25°C
T
A
= +85°C
80
0.001
0.01
120
160
+1
μA
μA
CONDITIONS
MIN
TYP
MAX
UNITS
Note 1:
All devices are production tested at T
A
= +25°C. Specifications over the operating temperature range are guaranteed by
design and characterization.
Note 2:
The dropout voltage is defined V
IN
- V
OUT
, when V
OUT
is 5% lower than the value of V
OUT
when V
IN
= V
OUT
+ 0.5V.
Maxim Integrated
3
MAX8902A/MAX8902B
Low-Noise 500mA LDO Regulators
in a 2mm x 2mm TDFN Package
Typical Operating Characteristics
(MAX8902A, V
IN
= 3.6V, V
OUT
= 2.5V, T
A
= +25°C, unless otherwise noted.)
QUIESCENT CURRENT
EN = HIGH, NO LOAD
MAX8902A/02B toc01
LOAD REGULATION
MAX8902A/02B toc02
LINE REGULATION
2.508
2.506
OUTPUT VOLTAGE (V)
2.504
2.502
2.500
2.498
2.496
2.494
2.492
200mA LOAD
MAX8902A/02B toc03
140
120
INPUT CURRENT (μA)
100
80
60
40
20
0
0
1
2
3
4
5
INPUT VOLTAGE (V)
2.506
2.505
OUTPUT VOLTAGE (V)
2.504
2.503
2.502
2.501
2.500
0
100
200
300
2.510
3.6V INPUT
2.490
400
500
1.5
2.5
3.5
INPUT VOLTAGE (V)
4.5
5.5
LOAD CURRENT (mA)
LOAD TRANSIENT RESPONSE
50mA TO 500mA TO 50mA
MAX8902A/02B toc04
LINE TRANSIENT RESPONSE
MAX8902A/02B toc05
STARTUP WAVEFORM
MAX8902A/02B toc06
2V/div
5V
V
OUT
100mV/div
V
IN
5V
2V/div
4V
V
EN
500mV/div
200mA/div
V
OUT
2mV/div
V
OUT
I
OUT
t
RISE
= t
FALL
= 1μs
40ms/div
10μs/div
200mA/div
2.5V OUTPUT
5Ω LOAD
I
IN
5Ω LOAD
C
BYP
= 0.01μF
100μs/div
DROPOUT VOLTAGE vs. LOAD CURRENT
MAX8902A/02B toc07
PSRR vs. FREQUENCY
MAX8902A/02B toc08
MAX8902A LDO OUTPUT-NOISE SPECTRAL
DENSITY vs. FREQUENCY
MAX8902A/02B toc09
80
70
DROPOUT VOLTAGE (mV)
60
50
40
30
20
10
0
0
0
-10
-20
-30
PSRR (dB)
-40
-50
-60
-70
-80
-90
-100
NOISE DENSITY (nV
√
Hz)
3.6V INPUT, 4.6V OUTPUT PRESET
THE SLOPE OF THE LINE INDICATES
A 129mΩ ON-RESISTANCE IN
DROPOUT
10E+3
1E+3
100E+0
10E+0
10
100
1k
FREQUENCY (Hz)
10k
100k
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
100
200
300
400
500
LOAD CURRENT (mA)
4
Maxim Integrated
MAX8902A/MAX8902B
Low-Noise 500mA LDO Regulators
in a 2mm x 2mm TDFN Package
Pin Description
PIN
1
2
3
NAME
MAX8902A
IN
GND
EN
MAX8902B
IN
GND
EN
FUNCTION
Regulator Power Input. Connect IN to a supply from 1.7V to 5.5V. Bypass IN with a 10μF
ceramic capacitor to GND.
Ground
Enable Input. A logic-low drives the output low through a 3k resistor and reduces the supply
current to less than 1μA. Drive logic-high or connect to IN for normal operation.
Output Voltage Select Input. Connect SELA to GND, IN, or leave unconnected. The states of
SELA and SELB are sampled when the regulator turns on and the output voltage is set as
shown in Table 2.
Internally Used. Connect GS to GND.
Output Voltage Select Input. Connect SELB to GND, IN, or leave unconnected. The states of
SELA and SELB are sampled when the regulator turns on and the output voltage is set as
shown in Table 2.
Power-OK Output. Open-drain output that goes low when the output is above 91% of the
nominal regulation voltage.
POK
is high impedance in shutdown or when the output is below
the regulation voltage.
Output Sense Input. Connect OUTS to the load at a point where accurate regulation is
required, or connect OUTS directly to OUT.
Feedback Input. Connect FB to the center of a resistor voltage-divider connected between
OUT and GND to set the output voltage. V
FB
regulates to 0.6V.
Bypass Input. Connect a 0.01μF ceramic capacitor from BYP to OUT to achieve 16μV
RMS
output noise. Adjust the value of this capacitor to control the output slew rate during startup.
Slew Rate = (5V / ms) x (0.01μF / C
BYP
)
8
—
OUT
EP
OUT
EP
Regulator Output. Sources up to 500mA at the output regulation voltage. Bypass with a 10μF
(< 0.03 ESR) capacitor to GND.
Exposed Paddle. Connect the exposed paddle to a ground plane to provide heat sinking.
4
SELA
—
SELB
—
GS
—
5
—
POK
OUTS
6
—
—
FB
7
BYP
BYP
Detailed Description
The MAX8902A/MAX8902B low-noise, low-dropout lin-
ear regulators deliver up to 500mA of output current
with only 16µV
RMS
of output noise in a 100kHz band-
width. These regulators maintain their output voltage
over a wide input range, requiring only 100mV of input-
to-output headroom at full load.
The MAX8902 maintains a low 80µA typical supply cur-
rent, independent of the load current and dropout volt-
age. The regulator control circuitry includes a
programmable soft-start circuit and short circuit,
reverse current, and thermal-overload protection. Other
features include an enable input and a power-OK
(POK) output (MAX8902B only). A simplified functional
diagram is shown in Figure 1.
The MAX8902A output voltage can be set to 1.5V, 1.8V,
2.0V, 2.5V, 3.0V, 3.1V, 3.3V, 4.6V, or 4.7V using the
SELA and SELB inputs. The MAX8902B output voltage
can be set between 0.6V and 5.3V with an external
resistor voltage-divider.
Enable (EN)
The MAX8902A/MAX8902B include an enable input,
EN. Pull EN low to shut down the output, or drive EN
high to enable the output. If shutdown is not needed,
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