參數(shù)資料
型號(hào): MAX1982-MAX1983
廠商: Maxim Integrated Products, Inc.
英文描述: EPS300 3/4 CR 48 IN 5700750CR
中文描述: 低電壓,低壓差線性與外部偏置電源穩(wěn)壓器
文件頁(yè)數(shù): 11/12頁(yè)
文件大?。?/td> 383K
代理商: MAX1982-MAX1983
The UVLO circuitry monitors V
BIAS
only. The UVLO
threshold is 4.2V, and V
BIAS
must remain above this
level for proper operation, regardless of the level of V
IN
.
Input Capacitor
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.
Output Capacitor
Bypass OUT to ground with a low-ESR ceramic capaci-
tor greater than 10μF. The ESR must be less than
35m
. 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
OUT
is the output capaci-
tance, and
t is the duration of the load step.
Noise, PSRR, and Transient Response
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.
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.
Input/Output (Dropout) Voltage
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
DS(ON)
= 1
max)
multiplied by the load current (see the
Typical
Operating Characteristics
):
PC Board Layout Guidelines
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
ground of the device, the input capacitor, and the
output capacitor together at one point.
2) To optimize performance, a ground plane is essen-
tial. Use all available copper layers in applications
where the device is located on a multilayer board.
3) Connect the input filter capacitor less than 10mm
from IN. The connecting copper trace carries large
currents and must be at least 2mm wide, preferably
5mm wide.
4) Use as much copper as necessary to increase the
thermal resistance of the device. In general, more
copper provides better heatsinking capabilities.
Chip Information
TRANSISTOR COUNT: 430
PROCESS: BiCMOS
V
V
V
R
I
DROPOUT
IN
OUT
DS ON
(
OUT
=
=
×
)
V
I ESR
t
C
OUT
=
+
M
Low-Voltage, Low-Dropout Linear Regulators
with External Bias Supply
______________________________________________________________________________________
11
INPUT-OUTPUT DIFFERENTIAL VOLTAGE (V)
M
5
4
3
2
1
50
100
150
200
250
300
350
0
0
T
MAXIMUM CONTINUOUS CURRENT
T
T
A
= +25
°
C
T
A
= +50
°
C
T
J
= +150
°
C
T
A
= +70
°
C
Figure 5. Power Operating Region—Maximum Output Current
vs. Supply Voltage
相關(guān)PDF資料
PDF描述
MAX1982EUT-T Low-Voltage, Low-Dropout Linear Regulators with External Bias Supply
MAX1983EUT-T Low-Voltage, Low-Dropout Linear Regulators with External Bias Supply
MAX1983 Low-Voltage, Low-Dropout Linear Regulators with External Bias Supply
MAX1984 Ultra-High-Efficiency White LED Drivers
MAX1984ETP Ultra-High-Efficiency White LED Drivers
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX1983EUT 制造商:Maxim Integrated Products 功能描述:LOW-VOLTAGE, LOW-DROPOUT LINEAR REGULATORS WI - Bulk 制造商:Rochester Electronics LLC 功能描述:
MAX1983EUT+ 制造商:Maxim Integrated Products 功能描述:LDO REG 0.8V TO 2V 0.3A 6PIN SOT-23 - Rail/Tube
MAX1983EUT+T 功能描述:低壓差穩(wěn)壓器 - LDO Low-Voltage w/ External Bias Supply 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
MAX1983EUT-T 功能描述:低壓差穩(wěn)壓器 - LDO 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
MAX1984ETP 功能描述:LED照明驅(qū)動(dòng)器 RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SO-16N