参数资料
型号: MAX17497AATE+T
厂商: Maxim Integrated
文件页数: 16/30页
文件大小: 0K
描述: IC OFF-LINE CONVERTER 16TQFN
产品培训模块: Obsolescence Mitigation Program
标准包装: 2,500
输出隔离: 隔离
频率范围: 235kHz ~ 265kHz
输入电压: 4.5 V ~ 29 V
工作温度: -40°C ~ 125°C
封装/外壳: 16-WFQFN 裸露焊盘
供应商设备封装: 16-TQFN-EP(3x3)
包装: 带卷 (TR)
MAX17497A/MAX17497B
AC-DC and DC-DC Peak Current-Mode Converters
with Integrated Step-Down Regulator
The startup capacitor (C START ) can be calculated as
follows:
V DC
? Q GATE sw SSF
C START = 6 ? ? ×
?
? ?
?
? × f ? ? t
10 10
μF
R IN1
where I IN is the supply current drawn at the IN pin in mA,
Q GATE is the gate charge of the external MOSFET used
in nC, f SW is the switching frequency of the converter in
Hz, and t SSF is the soft-start time programmed for the
flyback converter in ms.
R START
R IN2
R IN3
V DC
D1
V OUTF
C OUTF
Resistors R START and R ISRC can be calculated as:
M 1
IN
V START
V BEQ1
R START
=
R ISRC
=
10
70
M ?
M ?
V OUTF
D2
Q1
R ISRC
IN
MAX17497A
LDO
LXF
The IN UVLO rising threshold of the MAX17497B is
set to 3.9V with hysteresis of 200mV, optimized for
low-voltage DC-DC applications down to 4.5V. For
C START
C VCC
V CC
PGNDF
applications where the input DC voltage is low enough
(e.g., 4.5V to 5.5V DC) so the power loss incurred to
supply the operating current of the MAX17497B can be
tolerated, the IN pin is directly connected to the DC input
( Figure 6 ). For higher DC input voltages (e.g., 16V to 32V
DC), a startup circuit ( Figure 7 ) can be used to minimize
Figure 5. MAX17497A Current-Source-Based Startup Circuit
power dissipation in the startup circuit. In this start-
up scheme, the transistor (Q1) supplies the switching
current until a bias winding NB comes up. The resistor
(R Z ) can be calculated as:
V DC
D1
V OUTF
9 ×
R Z = (V INMIN ? 6.3) k ?
where V INMIN is the minimum input DC voltage.
IN
C IN
IN
LDO
MAX17497B
V CC
C VCC
C OUTF
Programming the Soft-Start of the
Flyback/Boost Converter (SSF)
The devices’ soft-start period of the flyback/boost con-
LXF
Np
Ns
verter can be programmed by selecting the value of
the capacitor connected from the SSF pin to GND. The
capacitor (C SSF ) can be calculated as:
SSF
C = 8.13 × t SSF nF
where t SSF is expressed in ms.
Maxim Integrated
Figure 6. MAX17497B Typical Startup Circuit with IN
Connected Directly to DC Input
16
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相关代理商/技术参数
参数描述
MAX17497AEVKIT# 功能描述:电源管理IC开发工具 MAX17497 Eval Kit RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V
MAX17497BATE+ 功能描述:电流型 PWM 控制器 Univ AC/DC-Iso DC/DC Flyback controller 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
MAX17497BATE+T 功能描述:电流型 PWM 控制器 Univ AC/DC-Iso DC/DC Flyback controller 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
MAX17498AATE+ 功能描述:电流型 PWM 控制器 Uvrsl AC/DC & Iso DC/DC Flyback ctlr 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
MAX17498AATE+T 功能描述:电流型 PWM 控制器 Uvrsl AC/DC & Iso DC/DC Flyback ctlr 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