参数资料
型号: MAX17480EVKIT+
厂商: Maxim Integrated Products
文件页数: 42/48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
select the boost capacitors to avoid discharging the
capacitor more than 200mV while charging the high-
side MOSFETs’ gates:
NB Peak Inductor Current Limit (ILIM3)
The MAX17480 NB regulator overcurrent protection
employs a peak current-sensing algorithm that uses the
C BST =
N × Q GATE
200 mV
high-side MOSFET R ON(NH3) as the current-sense ele-
ment. Since the controller limits the peak inductor cur-
rent, the maximum average load current is less than the
where N is the number of high-side MOSFETs used for
one SMPS, and Q GATE is the gate charge specified in the
MOSFET ’s data sheet. For example, assume two
IRF7811W n-channel MOSFETs are used on the high
side. According to the manufacturer’s data sheet, a single
IRF7811W has a maximum gate charge of 24nC (V GS =
5V). Using the above equation, the required boost
peak current-limit threshold by an amount equal to half
the inductor ripple current. Therefore, the maximum
load capability is a function of the current-limit setting,
inductor value, switching frequency, and input-to-out-
put voltage difference. When combined with the output
undervoltage-protection circuit, the system is effectively
protected against excessive overload conditions.
C BST =
capacitance would be:
:
2 × 24nC
200 mV
= 0 . 24μ F
The peak current-limit threshold is set by the ILIM3 pin
setting (see the Offset and Current-Limit Setting for NB
SMPS (ILIM3) section).
V IN 3 ? V OUT 3
L 3 = ??
: ? ? OUT 3 ?
? f SW 3 I LOAD 3 ( MAX ) LIR ? ? V IN 3 ?
( R ESR PCB ) ≤
+ R
? I LOAD ( MAX )
V ( V IN 3 ? V OUT 3 )
? I INDUCTOR = OUT 3
V IN 3 f SW 3 3
? ?
V IN 3 f SW 3 3
R ESR ≤ ?
? V RI P PLE3
? ? ( V IN 3 ? V OUT 3 ) V OUT 3 ? ?
I PEAK 3 = I LOAD 3 ( MAX ) + ? INDUCTOR ?
Selecting  the  closest  standard  value,  this  example
requires a 0.22μF ceramic capacitor.
NB SMPS Design Procedure
NB Inductor Selection
The switching frequency and operating point (% ripple
current or LIR) determine the inductor value as follows:
? ? ? V ?
?
where I LOAD3(MAX) is the maximum current and f SW3 is
the switching frequency of the NB regulator.
Find a low-loss inductor having the lowest possible DC
resistance that fits in the allotted dimensions. If using
a swinging inductor (where the inductance decreases
linearly with increasing current), evaluate the LIR with
properly scaled inductance values. For the selected
inductance value, the actual peak-to-peak inductor rip-
ple current ( ? I INDUCTOR ) is defined by:
:
L
Ferrite cores are often the best choice, although pow-
dered iron is inexpensive and can work well at 200kHz.
The core must be large enough not to saturate at the
peak inductor current (I PEAK3 ):
? ? I ?
? 2 ?
NB Output Capacitor Selection
The output filter capacitor must have low enough ESR to
meet output ripple and load-transient requirements. In
CPU V CORE converters and other applications where the
output is subject to large load transients, the output
capacitor’s size 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:
V STEP
:
The output capacitor ’s size often depends on how
much ESR is needed to maintain an acceptable level of
output ripple voltage. The output ripple voltage of a
step-down controller equals the total inductor ripple
current multiplied by the output capacitor’s ESR. For
single-phase operation, the maximum ESR to meet the
output-ripple-voltage requirement is:
L
:
where f SW3 is the switching frequency. The actual
capacitance value required relates to the physical size
needed to achieve low ESR, as well as to the chemistry
of the capacitor technology. Thus, capacitor selection
is usually limited by ESR and voltage rating rather than
by capacitance value (this is true of polymer types).
42
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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