MAX1983EUT+T Maxim Integrated Products, MAX1983EUT+T Datasheet - Page 11

• Manufacturer Part Number: MAX1983EUT+T
• Description: IC REG LDO ADJ 0.3A SOT23-6
• Manufacturer: Maxim Integrated Products

Specifications of MAX1983EUT+T

• Regulator Topology: Positive Adjustable
• Voltage - Output: 0.8 ~ 2 V
• Voltage - Input: 1.25 ~ 5.5 V
• Number Of Regulators: 1
• Current - Output: 300mA
• Current - Limit (min): 330mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-6
• Number Of Outputs: 1
• Polarity: Positive
• Input Voltage Max: 5.5 V
• Output Voltage: 0.8 V to 2 V
• Output Type: Adjustable
• Dropout Voltage (max): 0.35 V at 300 mA
• Output Current: 300 mA
• Line Regulation: 0.15 % / V
• Voltage Regulation Accuracy: 1 %
• Maximum Power Dissipation: 0.696 W
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Dropout (typical): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: MAX1983EUT+T; MAX1983EUT+TTR

Figure 5. Power Operating Region—Maximum Output Current
vs. Supply Voltage
only. The UVLO threshold is 4.2V, and V
remain above this level for proper operation, regardless
of the level of V
Bypass IN to ground with a 10µF or greater ceramic
capacitor. Bypass BIAS to ground with a 0.1µF ceramic
capacitor for normal operation in most applications.
Bypass OUT to ground with a low-ESR ceramic capaci-
tor greater than 10µF. The ESR must be less than
35mΩ. Choose an output capacitor to maintain the
required output voltage tolerance during a load step.
The change in output voltage is,
where I is the load current, C
tance, and Δt is the duration of the load step.
The MAX1982/MAX1983 operate with low-dropout volt-
age and low quiescent current in notebook computers
while maintaining good noise, transient response, and
AC rejection specifications. See the Typical Operating
Characteristics for a graph of Power-Supply Rejection
Ratio (PSRR) vs. Frequency. Improved supply-noise
rejection and transient response can be achieved by
increasing the values of the input and output capacitors
and use passive filtering techniques when operating
from noisy sources.
Noise, PSRR, and Transient Response
Low-Voltage, Low-Dropout Linear Regulators
350
300
250
200
150
100
50
0
0
IN
INPUT-OUTPUT DIFFERENTIAL VOLTAGE (V)
Δ
.
V
______________________________________________________________________________________
MAXIMUM CONTINUOUS CURRENT
=
1
T
I ESR
A
T
⎡
⎢
⎢
⎣
J
= +25°C
T
= +150°C
A
2
= +50°C
T
A
= +70°C
+
OUT
C
3
OUT
Δ
Output Capacitor
t
is the output capaci-
Input Capacitor
4
⎤
⎥
⎥
⎦
5
BIAS
must
with External Bias Supply
The MAX1982/MAX1983 load-transient response graphs
(see the Typical Operating Characteristics ) show two
components of the output response: a DC shift from the
output impedance due to the load current change and
the transient response. A typical transient response for a
step change in the load current from 1mA to 300mA is
20mV. Increasing the output capacitor’s value and
decreasing the ESR attenuate the overshoot.
A regulator’s minimum input-to-output voltage differen-
tial (dropout voltage) determines the lowest usable sup-
ply voltage. In battery-powered systems, the dropout
voltage determines the useful end-of-life battery volt-
age. Because the MAX1982/MAX1983 use an N-chan-
nel pass transistor, the dropout voltage is a function of
the drain-to-source on-resistance (R
multiplied by the load current (see the Typical
Operating Characteristics ):
The MAX1982/MAX1983 require proper layout to
achieve the intended output power level, high efficiency,
and low noise. Proper layout involves the use of a
ground plane, appropriate component placement, and
correct routing of traces using appropriate trace widths.
1) Minimize high-current ground loops. Connect the
2) To optimize performance, a ground plane is essen-
3) Connect the input filter capacitor less than 10mm
4) Use as much copper as necessary to increase the
ground of the device, the input capacitor, and the
output capacitor together at one point.
tial. Use all available copper layers in applications
where the device is located on a multilayer board.
from IN. The connecting copper trace carries large
currents and must be at least 2mm wide, preferably
5mm wide.
thermal resistance of the device. In general, more
copper provides better heatsinking capabilities.
V
DROPOUT
Input/Output (Dropout) Voltage
=
PC Board Layout Guidelines
V
IN
−
V
OUT
=
R
DS ON
DS(ON)
(
)
×
= 1Ω max)
I
OUT
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