参数资料
| 型号： | MAX8704EUB+ |
| 厂商： | Maxim Integrated |
| 文件页数： | 11/13页 |
| 文件大小： | 0K |
| 描述： | IC REG LDO 1.5V/1.2V/ADJ 10-UMAX |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 50 |
| 稳压器拓扑结构： | 正，固定式或可调式 |
| 输出电压： | 1.5V，1.2V，可调式 |
| 输入电压： | 1 V ~ 5.5 V |
| 稳压器数量： | 1 |
| 电流 - 输出： | 5A |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 供应商设备封装： | 10-µMAX |
| 包装： | 管件 |
High-Current, Low-Voltage Linear Regulator
with Power-Limited, External MOSFET
that provide on-resistance specifications with a 1.8V
gate-to-source voltage.
MOSFET Power Dissipation
The maximum power dissipation of the MAX8704
depends on the thermal resistance of the external n-
channel MOSFET package, the board layout, the tem-
perature difference between the die and ambient air,
and the rate of airflow. The power dissipated in the
MOSFET is:
P DIS = I OUT x (V IN - V CSP )
The maximum power dissipation allowed is determined
50
40
30
20
OUTPUT CAPACITANCE
vs. LOAD CURRENT
V IN > V OUT + 0.2V
by the following formula:
10
R DIS ( MAX ) =
T J(MAX ) ? T A
θ JC + θ CA
0
1
2
3
4
5
where T J(MAX) is the maximum junction temperature
(+150°C), T A is the ambient temperature, θ JC is the ther-
mal resistance from the die junction to the package
case, and θ CA is the thermal resistance from the case
through the PC board, copper traces, and other materi-
als to the surrounding air. Standard SO-8 MOSFETs are
typically rated for 2W, while new power packages
(PowerPAK, DirectFET, etc.) can achieve power dissipa-
tion ratings as high as 5W. For optimum power dissipa-
tion, use a large ground plane with good thermal contact
to ground and use wide input and output traces. Extra
copper on the PC board increases thermal mass and
reduces the thermal resistance of the board.
Setting the Current Limit
The current-sense voltage threshold is preset to 50mV
(typ), so the achievable peak source current (I PEAK ) is
determined by the current-sense resistor. The current-
sense resistor can be determined by:
R SENSE = V CSLIMIT / I PEAK
For the best current-sense accuracy, use a 1% current-
sense resistor between the source of the MOSFET and
the output.
Setting the Power Limit
The MAX8704 includes a unique power-limit protection
circuit that limits the maximum power dissipation in the
external MOSFET. An external resistor (R PLIM ) adjusts the
actual power limit as defined by the following equation:
LOAD CURRENT (A)
Figure 4. Output Capacitance vs. Load Current
conversion gain (K PLIM ) equals 200μA/V 2 , and the
power-limit threshold (V PWRLIMIT ) equals 1.0V. An exter-
nal capacitor (C PLIM ) adjusts the power-limit time con-
stant ( τ PLIM = R PLIM x C PLIM ), allowing short high-power
transients while protecting against thermal stress.
Short PLIM to ground to disable the power-limit protection.
Input Capacitor Selection (C IN )
Typically, the linear regulator is powered from the out-
put of a step-down regulator, effectively providing a
low-impedance source for the MAX8704. Under these
conditions, a local 10μF or greater ceramic capacitor is
sufficient for most applications. If the linear regulator is
connected to a high-impedance input, low-ESR poly-
mer capacitors are recommended on the input.
Output Capacitor Selection (C OUT )
The MAX8704 requires 10μF/A or greater ceramic
capacitor for stable operation and optimized load-tran-
sient response. For higher capacitance values, the reg-
ulator remains stable with low-ESR, polymer output
capacitors as shown in the Output Capacitance vs.
Load Current graph (see Figure 4). When selecting the
output capacitor to provide good transient response,
the capacitor’s ESR should be minimized:
R PLIM =
V PWRLIMIT
P LIMIT × K PLIM × R SENSE
? V OUT = ? I OUT x ESR
where ? I OUT is the maximum peak-to-peak load current
where R SENSE is the current-sense resistor, P LIMIT is the
maximum MOSFET power dissipation, the power-limit
step, and ? V OUT is the transient output-voltage tolerance.
______________________________________________________________________________________
11
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相关代理商/技术参数 |
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|---|---|
| MAX8704EUB+ | 功能描述:线性稳压器 - 标准 High current Low Voltage LDO RoHS:否 制造商:STMicroelectronics 输出类型: 极性: 输出电压:1.8 V 输出电流:150 mA 负载调节: 最大输入电压:5.5 V 线路调整率: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SOT-323-5L |
| MAX8704EUB+T | 功能描述:线性稳压器 - 标准 High current Low Voltage LDO RoHS:否 制造商:STMicroelectronics 输出类型: 极性: 输出电压:1.8 V 输出电流:150 mA 负载调节: 最大输入电压:5.5 V 线路调整率: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SOT-323-5L |
| MAX8704EUB-T | 功能描述:低压差稳压器 - LDO RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| MAX8704EVKIT | 功能描述:低压差稳压器 - LDO Evaluation Kit for the MAX8704 RoHS:否 制造商:Texas Instruments 最大输入电压:36 V 输出电压:1.4 V to 20.5 V 回动电压（最大值）:307 mV 输出电流:1 A 负载调节:0.3 % 输出端数量: 输出类型:Fixed 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-20 |
| MAX8705ETL | 制造商:Maxim Integrated Products 功能描述:IMVP-5 CPU CORE SUPPLY - Rail/Tube 制造商:Rochester Electronics LLC 功能描述: |
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