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| 型号： | MAX17003ETJ+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 28/36页 |
| 文件大小： | 0K |
| 描述： | IC PS CTRLR FOR NOTEBOOKS 32TQFN |
| 标准包装： | 2,500 |
| 应用： | 控制器，笔记本电脑电源系统 |
| 输入电压： | 6 V ~ 26 V |
| 输出数： | 4 |
| 输出电压： | 3.3V，5V，2 V ~ 5.5 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-WFQFN 裸露焊盘 |
| 供应商设备封装： | 32-TQFN-EP（5x5） |
| 包装： | 带卷 (TR) |
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High-Efficiency, Quad-Output, Main Power-
Supply Controllers for Notebook Computers
Setting the Current Limit
The minimum current-limit threshold must be great
enough to support the maximum load current when the
current limit is at the minimum tolerance value. The
C EQ R 1 =
L ESL
R SENSE
I LIMIT > I LOAD ( MAX ) + ? ? Δ I INDUCTOR ? ?
R CS = ?
? R 1 + R 2 ?
peak inductor current occurs at I LOAD(MAX) plus half
the ripple current; therefore:
? 2 ?
where I LIMIT_ equals the minimum current-limit thresh-
old voltage divided by the current-sense resistance
(R SENSE_ ). For the default setting, the minimum current-
Alternatively, high-power applications that do not
require highly accurate current-limit protection may
reduce the overall power dissipation by connecting a
series RC circuit across the inductor (Figure 7B) with
an equivalent time constant:
? R 2 ?
? R DCR
? R 1 + R 2 ?
limit threshold is 45mV.
Connect ILIM to LDO5 for a default 50mV current-limit
threshold. In adjustable mode, the current-limit thresh-
old is precisely 1/10th the voltage seen at ILIM. For an
adjustable threshold, connect a resistive divider from
and:
R DCR =
L
C EQ
? 1 1 ?
? ?
REF to analog ground (GND) with ILIM connected to
the center tap. The external 0.5V to 2V adjustment
range corresponds to a 50mV to 200mV current-limit
threshold. When adjusting the current limit, use 1% tol-
erance resistors and a divider current of approximately
10mA to prevent significant inaccuracy in the current-
limit tolerance.
The current-sense method (Figure 7) and magnitude
determines the achievable current-limit accuracy and
power loss. Typically, higher current-sense limits pro-
vide tighter accuracy, but also dissipate more power.
Most applications employ a current-limit threshold
(V LIMIT ) of 50mV to 100mV, so the sense resistor may
be determined by:
where R CS is the required current-sense resistance,
and R DCR is the inductor’s series DC resistance. Use
the typical inductance and R DCR values provided by
the inductor manufacturer.
Output Capacitor Selection
The output filter capacitor must have low enough equiva-
lent series resistance (ESR) to meet output ripple and
load-transient requirements, yet have high enough ESR to
satisfy stability requirements. The output capacitance
must be high enough to absorb the inductor energy while
transitioning from full-load to no-load conditions without
tripping the overvoltage fault protection. When using high
capacitance, low-ESR capacitors (see stability require-
R CS = =
V LIMIT
I LIMIT
V ILIM
10 x I LIMIT
ments), the filter capacitor’s ESR dominates the output
voltage ripple. So the output capacitor’s size depends on
the maximum ESR required to meet the output voltage
ripple (V RIPPLE(P-P) ) specifications:
V RIPPLE ( P – P ) = IDLE ESR
For the best current-sense accuracy and overcurrent
protection, use a 1% tolerance current-sense resistor
between the inductor and output as shown in Figure
7A. This configuration constantly monitors the inductor
current, allowing accurate current-limit protection.
However, the parasitic inductance of the current-sense
resistor can cause current-limit inaccuracies, especially
when using low-value inductors and current-sense
resistors. This parasitic inductance (L ESL ) can be can-
celed by adding an RC circuit across the sense resistor
with an equivalent time constant:
V RIPPLE(P-P) = R ESR I LOAD(MAX) LIR
In idle mode, the inductor current becomes discontinu-
ous, with peak currents set by the idle mode current-
sense threshold (V IDLE = 0.2V LIMIT ). In idle mode, the
no-load output ripple may be determined as follows:
V R
R SENSE
28
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相关代理商/技术参数 |
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|---|---|
| MAX17004AETJ+ | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX17004ETJ+ | 功能描述:电压模式 PWM 控制器 Quad Out Main Power Supply Controller 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 |
| MAX17004ETJ+T | 功能描述:电压模式 PWM 控制器 Quad Out Main Power Supply Controller 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 |
| MAX17005AETP+ | 功能描述:电池管理 1.2MHz High-Perf Charger 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 |
| MAX17005AETP+T | 功能描述:电池管理 1.2MHz High-Perf Charger 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 |
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