参数资料
型号: MAX1897ETP+
厂商: Maxim Integrated Products
文件页数: 22/33页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM 20-TQFN
标准包装: 60
系列: Quick-PWM™
PWM 型: 控制器
输出数: 1
频率 - 最大: 550kHz
电源电压: 4.5 V ~ 5.5 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: 0°C ~ 85°C
封装/外壳: 20-WQFN 裸露焊盘
包装: 管件
Quick-PWM Slave Controllers for
Multiphase, Step-Down Supplies
SLAVE CURRENT-LIMIT VOLTAGES
vs. AVERAGE INDUCTOR CURRENT
160
I ADJ(MIN) = I PEAK = ITHS
140
V ITHM(HIGH)
V
R CM
120
MASTER
100
80
V ITHM(LOW)
CONTROLLER
60
40
R CM I LM(PEAK) = R CS I LS(PEAK)
R CM I LM(VALLEY) = R CS I LS(VALLEY)
V ITHS
SLAVE
CONTROLLER
]
20
0
? I ADJ - ? I INDUCTOR =
[
V OUT (V IN - V OUT )
V IN f SW L
0
10
20
30
40
50
AVERAGE INDUCTOR CURRENT (A)
MASTER CURRENT-LIMIT VOLTAGES
vs. AVERAGE INDUCTOR CURRENT
160
( )
140
120
100
80
60
40
20
0
UNADJUSTED ? I LIMIT ≤ ? I LIMIT = V ITHM(HIGH)
V ITHM(HIGH)
ADJUSTED ? I LIMIT ≤ ? I INDUCTOR
V ITHM(LOW)
R DS(ON)(MIN) = L LM(VALLEY)
R DS(ON)(MIN) = L LM(VALLEY)
A RDS - 1
R DS(ON)(MAX)
0
10
20
30
40
50
AVERAGE INDUCTOR CURRENT (A)
Figure 6. Master/Slave Current-Limit Thresholds
? ?
Unadjusted ? I LIMIT ITHM ( HIGH ) ?
= V
?
When unadjusted, the on-resistance variation of the
low-side MOSFETs results in a maximum current-limit
variation ( ? I LIMIT ) determined by the following equation:
A RDS ? 1
? R DS ( ON )( MAX ) ?
where A RDS = R DS(ON)(MAX) /R DS(ON)(MIN) . Using the
MAX1887/MAX1897 to adjust the master ’ s current-limit
threshold results in a maximum current-limit variation
less than the peak-to-peak inductor current:
Adjusted ? I LIMIT ≤ ? I INDUCTOR
rent-limit variation from 21.7A (unadjusted) to less than
6.4A (adjusted).
Output Capacitor Selection
The output filter capacitor must have low enough effec-
tive series resistance (ESR) to meet output ripple and
load-transient requirements, yet have high enough ESR
to satisfy stability requirements.
In CPU V CORE converters and other applications where
the output is subject to large load transients, the output
capacitor selection typically depends on how much
ESR is needed to prevent the output from dipping too
low under a load transient. Ignoring the sag due to
finite capacitance:
As shown in Figure 6, the resulting current-limit varia-
tion of the master is dramatically reduced. For the
above example, this control scheme reduces the cur-
R ESR ≤
V STEP
? I LOAD ( MAX )
22
______________________________________________________________________________________
相关PDF资料
PDF描述
MAX1844ETP+ IC REG CTRLR BUCK PWM CM 20-TQFN
VE-2TY-EX-F4 CONVERTER MOD DC/DC 3.3V 49.5W
MAX1844EEP+ IC REG CTRLR BUCK PWM CM 20-QSOP
UPM1J122MHD CAP ALUM 1200UF 63V 20% RADIAL
MAX771EPA+ IC REG CTRLR BST PWM 8-DIP
相关代理商/技术参数
参数描述
MAX1897ETP+ 功能描述:电流型 PWM 控制器 Integrated Circuits (ICs) RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14
MAX1897ETP+T 功能描述:电流型 PWM 控制器 Integrated Circuits (ICs) RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14
MAX1897ETP-T 功能描述:电流型 PWM 控制器 RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14
MAX1898EUB41 功能描述:电池管理 Linear Charger for 1-Cell Li+ Battery RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel
MAX1898EUB41+ 功能描述:电池管理 Linear Charger for 1-Cell Li+ Battery RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel