參數(shù)資料
型號(hào): MAX8875EUK27-T
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: 基準(zhǔn)電壓源/電流源
英文描述: 150mA, Low-Dropout Linear Regulator with Power-OK Output
中文描述: 2.7 V FIXED POSITIVE LDO REGULATOR, 0.22 V DROPOUT, PDSO5
封裝: MINIATURE, SOT-23, 5 PIN
文件頁數(shù): 6/8頁
文件大小: 435K
代理商: MAX8875EUK27-T
_______________Detailed Description
The MAX8875 is a low-dropout, low-quiescent-current
linear regulator designed primarily for battery-powered
applications. The device supplies loads up to 150mA
and is available with preset output voltages of 2.5V,
2.7V, 3.0V, 3.3V, or 5.0V. As illustrated in Figure 1, the
MAX8875 consists of a 1.25V reference, error amplifier,
P-channel pass transistor, power-OK comparator, and
internal feedback 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, which allows more current to pass to the output
and increases the output voltage. If the feedback volt-
age is too high, the pass-transistor gate is pulled up,
allowing less current to pass to the output. The output
voltage feeds back through an internal resistor voltage
divider connected to the OUT pin.
Additional blocks include a current limiter, reverse-
battery protection, thermal sensor, and shutdown logic.
Output Voltage
The MAX8875 is supplied with factory-set output volt-
ages of 2.5V, 2.7V, 3.0V, 3.3V, or 5.0V. The part number’s
two-digit suffix identifies the nominal output voltage. For
example, the MAX8875EUK33 has a preset output volt-
age of 3.3V (see
Output Voltage Selector Guide
).
Internal P-Channel Pass Transistor
The MAX8875 features a 1.1
(typ) P-channel MOSFET
pass transistor. This provides several advantages over
similar designs using PNP pass transistors, including
longer battery life. The P-channel MOSFET requires no
base drive, which reduces quiescent current signifi-
cantly. PNP-based regulators waste considerable
current in dropout when the pass transistor saturates.
They also use high base-drive currents under large
loads. The MAX8875 does not suffer from these prob-
lems and consumes only 100μA of quiescent current
whether in dropout, light-load, or heavy-load applica-
tions (see
Typical Operating Characteristics
).
Power-OK Output
When the output voltage goes out of regulation—as dur-
ing dropout, current limit, or thermal shutdown—POK
goes low. POK is an open-drain N-channel MOSFET. To
obtain a logic-level output, connect a pull-up resistor
from POK to OUT. To minimize current consumption,
make this resistor as large as practical. A 100k
resistor
works well for most applications. A capacitor to GND
may be added to generate a power-on-reset (POR)
delay. The POK function is not active during shutdown.
POK also provides a power-on-reset function that can
operate down to V
IN
1V. See POK Startup Response
in the
Typical Operating Characteristics
.
M
150mA, Low-Dropout Linear Regulator
with Power-OK Output
6
_______________________________________________________________________________________
SHUTDOWN
LOGIC
ERROR
AMP
1.25V
REF
95%
REF
P
GND
IN
SHDN
MAX8875
THERMAL
SENSOR
REVERSE-
BATTERY
PROTECTION
MOS DRIVER
WITH I
LIMIT
POK
OUT
POK
Figure 1. Functional Diagram
相關(guān)PDF資料
PDF描述
MAX8875EUK33 150mA, Low-Dropout Linear Regulator with Power-OK Output
MAX8875EUK33-T 150mA, Low-Dropout Linear Regulator with Power-OK Output
MAX8875EUK50 150mA, Low-Dropout Linear Regulator with Power-OK Output
MAX8875EUK50-T 150mA, Low-Dropout Linear Regulator with Power-OK Output
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX8875EUK29 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
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MAX8875EUK30+ 制造商:Maxim Integrated Products 功能描述:REG LDO LIN FIX POS 3V 0.15A 5PIN SOT-23 - Rail/Tube
MAX8875EUK30+T 功能描述:低壓差穩(wěn)壓器 - LDO 150mA Linear Regulator RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20
MAX8875EUK30-T 功能描述:低壓差穩(wěn)壓器 - LDO 150mA Linear Regulator RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動(dòng)電壓(最大值):307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20