MAX8532EBTG MAXIM [Maxim Integrated Products], MAX8532EBTG Datasheet - Page 5

• Manufacturer Part Number: MAX8532EBTG
• Description: Low-Noise, Low-Dropout, 200mA Linear Regulator in UCSP
• Manufacturer: MAXIM [Maxim Integrated Products]

The MAX8532 is a low-power, low-dropout, low-quies-
cent current linear regulator designed primarily for bat-
tery-powered applications. For preset output voltages,
see the Output Voltage Selector Guide. The device
supplies up to 200mA for OUT. The MAX8532 consists
of a 1.25V reference, error amplifier, P-channel pass
transistor, reference bypass block, and internal feed-
back voltage divider.
The 1.25V bandgap reference is connected to the error
amplifier’s inverting input. The error amplifier compares
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
lower, allowing more current to pass to the output and
increasing the output voltage. If the feedback voltage is
high, the pass-transistor gate is pulled up, allowing less
current to pass to the output. The output voltage is fed
back through an internal resistor voltage-divider con-
nected to the OUT pin.
SHDN
GND
IN
_______________________________________________________________________________________
Detailed Description
SHUTDOWN
POWER-ON
CONTROL
THERMAL
SENSOR
AND
200mA Linear Regulator in UCSP
1.25V
REF
Low-Noise, Low-Dropout,
ERROR
AMP
The MAX8532 has a single shutdown control input
(SHDN). Drive SHDN low to shut down the output,
reducing supply current to 10nA. Connect SHDN to a
logic-high, or IN, for normal operation.
The MAX8532 features a 1Ω P-channel MOSFET pass
transistor. A P-channel MOSFET provides several advan-
tages over similar designs using PNP pass transistors,
including longer battery life. It requires no base drive,
reducing quiescent current. PNP-based regulators waste
considerable current in dropout when the pass transistor
saturates and also use high base-drive currents under
heavy loads. The MAX8532 does not suffer these prob-
lems and consumes only 90µA quiecent current whether
in dropout, light-load, or heavy-load applications (see the
Typical Operating Characteristics). Whereas a PNP-
based regulator has dropout voltage independent of the
load, a P-channel MOSFET’s dropout voltage is propor-
tional to load current, providing for low dropout voltage
at heavy loads and extremely low dropout voltage at
lighter loads.
MAX8532
WITH I
Internal P-Channel Pass Transistor
DRIVER
MOS
LIMIT
Functional Diagram
OUT
BP
Shutdown
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