MAX1793EUE50 Maxim Integrated Products, MAX1793EUE50 Datasheet - Page 7

• Manufacturer Part Number: MAX1793EUE50
• Description: Low Dropout (LDO) Regulators Low-IQ 1A
• Manufacturer: Maxim Integrated Products

Specifications of MAX1793EUE50

• Number Of Outputs: 1
• Polarity: Positive
• Input Voltage Max: 5.5 V
• Output Voltage: 1.25 V to 5 V, 5 V
• Output Type: Adjustable, Fixed
• Dropout Voltage (max): 0.35 V at 1 A
• Output Current: 1 A
• Line Regulation: 0 % / V
• Load Regulation: 0.70%
• Voltage Regulation Accuracy: 3%
• Maximum Power Dissipation: 1.5 W
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: TSSOP-16 EP
• Minimum Operating Temperature: - 40 C
• Reference Voltage: 1.25 V

Figure 1. Functional Diagram
The MAX1793 features Dual Mode™ operation, allow-
ing a fixed output or an adjustable output from +1.25V
to +5V. The regulators are guaranteed to supply 1A of
output current.
As Figure 1 shows, the device consists of a +1.25V ref-
erence, error amplifier, MOSFET driver, p-channel pass
transistor, internal feedback voltage-divider, Dual Mode
comparator, and 4ms reset output.
The +1.25V reference is connected to the inverting
input of the error amplifier. The error amplifier com-
pares this reference with the selected feedback voltage
and amplifies the difference. The MOSFET driver reads
the error signal and applies the appropriate drive to the
p-channel transistor. If the feedback voltage is lower
than the reference, the pass transistor’s gate is pulled
SHDN
GND
IN
Low-Dropout, Low I
_______________________________________________________________________________________
MAX1793
SHUTDOWN
REFERENCE
LOGIC
1.25V
Detailed Description
1175mV
DUAL MODE
COMPARATOR
ERROR AMP
SHUTDOWN
94% V
DETECTOR
OUT
lower, allowing more current to pass and increase the
output voltage. If the feedback voltage is high, the pass
transistor’s gate is pulled up, allowing less current to
pass to the output. The low V
when the feedback voltage has dropped 6% below its
expected level, causing RST to go low.
The output voltage is fed back through either an inter-
nal resistor-divider connected to OUT or an external
resistor network connected to SET. The Dual Mode
comparator examines V
path. If V
is used and the output is regulated to the factory-preset
voltage.
Dual Mode is a trademark of Maxim Integrated Products, Inc.
Q
, 1A Linear Regulator
100mV
IN
4ms DELAY TIMER
4ms
WITH FOLDBACK
MOSFET DRIVER
CURRENT LIMIT
SET
is below 50mV, the internal feedback path
OUT
THERMAL
SENSOR
SET
and selects the feedback
NMOS
OUT
comparator senses
PMOS
R1
R2
OUT
RST
SET
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