参数资料
型号: LT8582IDKD#TRPBF
厂商: Linear Technology
文件页数: 10/36页
文件大小: 0K
描述: IC REG MULTI CONFIG ADJ 3A 24DFN
标准包装: 2,500
类型: 升压(升压),反相,回扫,Sepic
输出类型: 可调式
输出数: 2
输出电压: 最高 42V
输入电压: 2.5 V ~ 22 V
PWM 型: 电流模式
频率 - 开关: 200kHz ~ 2.5MHz
电流 - 输出: 3A
同步整流器:
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 24-WFDFN 裸露焊盘
包装: 带卷 (TR)
供应商设备封装: 24-DFN(7x4)

LT8582
OPERATION
OPERATION – OVERVIEW
The LT8582 uses a constant frequency, current mode control
scheme to provide excellent line and load regulation. Each
channel’s undervoltage lockout (UVLO) function, together
with soft-start and frequency foldback, offer a controlled
means of starting up. Fault features are incorporated into
each channel of the LT8582 to facilitate the detection of
output shorts, overvoltage and overtemperature condi-
V IN
R UVLO1
R UVLO2
(OPTIONAL)
V IN
SHDN
GND
1.31V
12.3μA
AT 1.31V
ACTIVE/
LOCKOUT
tions. Please refer to the Block Diagram (Figure 1) and
the State Diagram (Figure 2) for the following description
of the part’s operation.
OPERATION – START-UP
Several functions are provided to enable a very clean
start-up of both channels of the LT8582.
Precise Turn-On Voltage
The SHDN pin on each channel is compared to an internal
voltage reference to give a precise turn on voltage level. Tak-
ing each SHDN pin above 1.31V enables the corresponding
channel. Taking each SHDN pin below 300mV shuts down
the channel, resulting in extremely low quiescent current
for that channel. The SHDN pin has 35mV of hysteresis
to protect against glitches and slow ramping.
Configurable Undervoltage Lockout (UVLO)
The SHDN pin can also be used to create a configurable
UVLO for each channel. This function sets the turn on/
off of each of LT8582’s channels at a desired voltage
(VIN UVLO ). Figure 3 shows how a resistor divider (or a
single resistor) from V IN to the SHDN pin can be used to
program VIN UVLO . R UVLO2 is optional. If left out, set it to
infinite in the equation below. For increased accuracy, set
R UVLO2 ≤ 10k. Pick R UVLO1 as follows:
8582 F03
Figure 3. Configurable UVLO
Internal Undervoltage Lockout (UVLO)
Regardless of where external circuitry sets VIN UVLO , the
LT8582 also has internal UVLO circuitry that disables the
chip when V IN < 2.3V (typical).
Soft-Start of Switch Current
The soft-start circuitry provides for a gradual ramp-up of
the switch current in each channel (refer to Commanded
Current Limit vs SS Voltage in Typical Performance
Characteristics). When the channel is taken out of shut-
down, the external SS capacitor is first discharged. This
resets the state of the logic circuits in the channel. Then
an integrated 250k resistor pulls the channel’s SS pin to
~1.84V. The ramp rate of the SS pin voltage is set by this
250k resistor and the external capacitor connected to this
pin. Once SS gets to ~1.84V, the CLKOUT pin is enabled
and an internal regulator pulls the pin up quickly to ~2.1V.
Typical values for the external soft-start capacitor range
from 100nF to 1μF.
Soft-Start of External PMOS (if used)
The soft-start circuitry also gradually ramps up the GATE
pin pull-down current for the corresponding channel. This
? + 12.3μA
? ?
R UVLO1 =
VIN UVLO – 1.31V
? 1.31V ?
R UVLO2 ?
allows an external PMOS to slowly turn on (M1 in Block
Diagram). The GATE pin current increases linearly with
SS voltage, with a maximum current of 1mA when the
SS voltage gets above 550mV. Note that if the GATE pin
voltage is less than 2V for SS voltages exceeding 550mV,
then the GATE pin impedance to ground is 2kΩ. The soft
turn on of the external PMOS helps limit inrush current at
start up, making hot plugs of LT8582s feasible.
8582f
10
相关PDF资料
PDF描述
LTC1043CSW#TRPBF IC BUILDNG BLK SW-CAP DUAL18SOIC
LTC1044CS8#TRPBF IC REG MULTI CONFIG 20MA 8SOIC
LTC1046IS8#TRPBF IC REG SWITCHD CAP DIV INV 8SOIC
LTC1142LCG-ADJ#TRPBF IC REG CTRLR BUCK PWM CM 28-SSOP
LTC1143LCS#PBF IC REG CTRLR BUCK PWM CM 16-SOIC
相关代理商/技术参数
参数描述
LT8584IFE#PBF 制造商:Linear Technology 功能描述:IC BATT CELL BALANCE 16TSSOP 制造商:Linear Technology 功能描述:BATTERY BALANCER, 2.5V-5.3V, TSSOP-16, Supply Voltage Min:2.5V, Supply Voltage M
LT8610 制造商:LINER 制造商全称:Linear Technology 功能描述:42V, 2.5A Synchronous Step-Down Regulator
LT8610ABEMSE#PBF 制造商:Linear Technology 功能描述:SWITCHING REG, BUCK, ADJ, 2.2MHZ, MSOP16, Primary Input Voltage:42V, No. of Outp
LT8610AEMSE#PBF 制造商:Linear Technology 功能描述:IC REG BUCK SYNC ADJ 2.5A 16MSOP 制造商:Linear Technology 功能描述:SWITCHING REG, BUCK, ADJ, 2.2MHZ, MSOP16, Primary Input Voltage:42V, No. of Outp
LT8610AHMSE#PBF 制造商:Linear Technology 功能描述:IC REG BUCK SYNC ADJ 2.5A 16MSOP 制造商:Linear Technology 功能描述:SWITCHING REG, BUCK, ADJ, 2.2MHZ, MSOP16 制造商:Linear Technology 功能描述:SWITCHING REG, BUCK, ADJ, 2.2MHZ, MSOP16, Primary Input Voltage:42V, No. of Outp