参数资料
型号: MAX17480EVKIT+
厂商: Maxim Integrated Products
文件页数: 40/48页
文件大小: 0K
描述: EVALUATION KIT FOR MAX17480
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 1
主要目的: DC/DC,步降
输出及类型: 3,非隔离
输入电压: 4 ~ 26 V
稳压器拓扑结构: 降压
板类型: 完全填充
已供物品:
已用 IC / 零件: MAX17480
AMD 2-/3-Output Mobile Serial
VID Controller
When using low-capacity ceramic filter capacitors,
capacitor size is usually determined by the capacity
needed to prevent V SOAR from causing problems during
load transients. Generally, once enough capacitance is
added to meet the overshoot requirement, undershoot at
the rising load edge is no longer a problem.
Core Input Capacitor Selection
The input capacitor must meet the ripple-current
requirement (I RMS ) imposed by the switching currents.
For a dual 180 ° interleaved controller, the out-of-phase
operation reduces the RMS input ripple current, effec-
tively lowering the input capacitance requirements.
Core Transient Droop and Stability
The inductor current ripple sensed across the current-
sense inputs (CSP_ - CSN_) generates a proportionate
current out of the FBAC pin. This AC current flowing
across the effective impedance at FBAC generates an
AC ripple voltage. Actual stability, however, depends
on the AC voltage at the FBDC pin, and not on the
FBAC pin. Based on the configuration shown in Figure
5, the ripple voltage at the FBDC pin can only be less
than, or equal to, the ripple at the FBAC pin.
With the requirement that R FBDC = R FBAC , and
(Z CFB //R FB ) < 10% of R FBAC , then:
When both outputs operate with a duty cycle less than
50% (V IN > 2V OUT ), the RMS input ripple current is
defined by the following equation:
R FBAC = R FBDC ≥
1
C OUT f SW R SENSE _ G m ( FBAC )
? ? I OUT 1 ( I OUT 1 ? I IN ) + ? ? V
? ? I OUT 2 ( I OUT 2 ? I IN )
? V OUT 1 ? ? V OUT 2 ?
? ? V
I IN = ? OUT 1 ? I OUT 1 + ? OUT 2 ? I OUT 2
I RMS OUT ? OUT ? ? ? OUT ?
? V ? ? 1 V ?
R DROOP _ AC ≈ FBDC FBAC SENSE G m ( FBA C )
C FB × ?? R FB FBAC + R FBDC ) ?? = 3 × t SW
I RMS =
IN I N
where I IN is the average input current:
? V ? ? V ?
? V IN ? ? V IN ?
In combined mode (GNDS1 = V DDIO or GNDS2 =
V DDIO ) with both phases active, the input RMS current
simplifies to:
= I
? V IN ? ? 2 V IN ?
For most applications, nontantalum chemistries (ceram-
ic, aluminum, or OS-CON) are preferred due
to their resistance to inrush surge currents typical of
systems with a mechanical switch or connector in
series with the input. If the MAX17480 is operated as
the second stage of a two-stage power-conversion sys-
tem, tantalum input capacitors are acceptable. In either
configuration, choose an input capacitor that exhibits
less than +10 ° C temperature rise at the RMS input cur-
rent for optimal circuit longevity.
Core Voltage Positioning and Loop Compensation
where G m(FBAC_) is typically 2mS as defined in the
Electrical Characteristics table, R SENSE_ is the effective
value of the current-sense element that is used to pro-
vide the (CSP_, CSN_) current-sense voltage, and f SW
is the selected switching frequency.
Based on the above requirement for R FBAC and R FBDC ,
and with the other requirement for R FBDC defined in the
Core Steady-State Voltage Positioning (DC Droop) sec-
tion, R FBAC and R FBDC can be chosen. The resultant
AC droop is:
R R R
R FBAC + R FBDC
Capacitor C FB is required when the R DROOP_DC is less
than R DROOP_AC . Choose C FB according to the following
equation:
/ /( R
Core Steady-State Voltage Positioning
With R DROOP_AC defined, the steady-state voltage-
positioning slope, R DROOP_DC , can only be less than,
or at most equal to, R DROOP_AC :
Voltage positioning dynamically lowers the output volt-
age in response to the load current, reducing the output
capacitance and processor’s power-dissipation require-
R DROOP _ DC =
R FBDC R FBAC R SENSE
R FBAC + R FBDC + R FB
G m ( FBAC )
ments. The controller uses a transconductance amplifier
to set the transient AC and DC output-voltage droop
(Figure 5). The FBAC and FBDC configuration adjusts
the steady-state regulation voltage as a function of the
load. This adjustability allows flexibility in the selected
current-sense resistor value or inductor DCR, and allows
smaller current-sense resistance to be used, reducing
the overall power dissipated.
Choose the R FBDC and R FBAC already previously cho-
sen, then select R FB to give the desired droop.
DC droop is typically used together with the +12.5mV
offset feature to keep within the DC tolerance window of
the application. See the Offset and Address Change for
Core SMPSs (OPTION) section.
40
______________________________________________________________________________________
相关PDF资料
PDF描述
LM4040A25IDCKRE4 IC VREF SHUNT PREC 2.5V SC-70-5
ECM25DCTN-S288 CONN EDGECARD 50POS .156 EXTEND
RCC05DRTI-S13 CONN EDGECARD 10POS .100 EXTEND
GBC31DCMH-S288 CONN EDGECARD 62POS .100 EXTEND
RBC07DREN-S13 CONN EDGECARD 14POS .100 EXTEND
相关代理商/技术参数
参数描述
MAX17480EVKIT+ 功能描述:电源管理IC开发工具 MAX17480 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
MAX17480GTL+ 功能描述:显示驱动器和控制器 2-/3-Output Mobile erial VID Ctlr RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel
MAX17480GTL+T 功能描述:显示驱动器和控制器 2-/3-Output Mobile erial VID Ctlr RoHS:否 制造商:Panasonic Electronic Components 工作电源电压:2.7 V to 5.5 V 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:QFN-44 封装:Reel
MAX17482GTL+ 功能描述:电压模式 PWM 控制器 NDA IC RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel
MAX17482GTL+T 功能描述:电压模式 PWM 控制器 NDA IC RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel