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参数资料
| 型号： | MAX5065EAI+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 26/32页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 28-SSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 46 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 1MHz |
| 占空比： | 90% |
| 电源电压： | 4.75 V ~ 28 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 28-SSOP（0.209"，5.30mm 宽） |
| 包装： | 管件 |
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Dual-Phase, +0.6V to +3.3V Output Parallelable,
Average-Current-Mode Controllers
all these issues when determining the number of phases
necessary for the voltage regulator application.
Inductor Selection
The switching frequency per phase, peak-to-peak rip-
ple current in each phase, and allowable ripple at the
output determine the inductance value.
MAX5065/MAX5067 limits the maximum peak inductor
current and prevents the inductor from saturating.
Choose an inductor with a saturating current greater
than the worst-case peak inductor current. Use the fol-
lowing equation to determine the worst-case inductor
current for each phase:
Selecting higher switching frequencies reduces the
inductance requirement, but at the cost of lower efficien-
cy. The charge/discharge cycle of the gate and drain
I L _ PEAK =
0 . 051 V
R SENSE
+
? I L
2
(12)
capacitances in the switching MOSFETs create switching
losses. The situation worsens at higher input voltages,
since switching losses are proportional to the square of
input voltage. Use 500kHz per phase for V IN = +5V and
250kHz or less per phase for V IN > +12V.
Although lower switching frequencies per phase increase
the peak-to-peak inductor ripple current ( ? I L ), the ripple
cancellation in the multiphase topology reduces the input
and output capacitor RMS ripple current.
Use the following equation to determine the minimum
inductance value:
where R SENSE is the sense resistor in each phase.
Switching MOSFETs
When choosing a MOSFET for voltage regulators,
consider the total gate charge, R DS(ON) , power dissipa-
tion, and package thermal impedance. The product of
the MOSFET gate charge and on-resistance is a figure of
merit, with a lower number signifying better performance.
Choose MOSFETs optimized for high-frequency switch-
ing applications.
The average gate-drive current from the MAX5065/
L MIN =
( V INMAX ? V OUT ) × V OUT
V IN × f SW × ? I L
(10)
MAX5067 output is proportional to the total capacitance it
drives from DH1, DH2, DL1, and DL2. The power dissi-
pated in the MAX5065/MAX5067 is proportional to the
input voltage and the average drive current. See the V IN,
PD MOS ? HI = ( Q G × V DD × f SW ) +
? V IN × I OUT × ( t R + t F ) × f SW ? 2
? ? + 1 . 4 R DS ( ON ) × I RMS ? HI
?
?
( 13 . 2 ? 1 . 8 ) × 1 . 8 = 0 . 6 μ H
=
L MIN
( I )
(14)
I RMS ? HI =
DC + I PK + I DC PK ×
× I
Choose ? I L equal to about 40% of the output current
per phase. Since ? I L affects the output-ripple voltage,
the inductance value may need minor adjustment after
choosing the output capacitors for full-rated efficiency.
Choose inductors from the standard high-current,
surface-mount inductor series available from various
manufacturers. Particular applications may require cus-
tom-made inductors. Use high-frequency core material
for custom inductors. High ? I L causes large peak-to-peak
flux excursion increasing the core losses at higher fre-
quencies. The high-frequency operation coupled with
high ? I L , reduces the required minimum inductance
and even makes the use of planar inductors possible.
The advantages of using planar magnetics include low-
profile design, excellent current-sharing between phas-
es due to the tight control of parasitics, and low cost.
For example, calculate the minimum inductance at
V IN(MAX) = +13.2V, V OUT = +1.8V, ? I L = 10A, and f SW =
250kHz:
(11)
13 . 2 × 250 k × 10
The average-current-mode control feature of the
V CC , V DD section to determine the maximum total gate
charge allowed from all the driver outputs combined.
The gate charge and drain capacitance (CV 2) loss, the
cross-conduction loss in the upper MOSFET due to
finite rise/fall time, and the I 2 R loss due to RMS current
in the MOSFET R DS(ON) account for the total losses in
the MOSFET. Estimate the power loss (PD MOS _) in the
high-side and low-side MOSFETs using the following
equations:
(13)
4
where Q G , R DS(ON) , t R , and t F are the upper-switching
MOSFET ’ s total gate charge, on-resistance at +25 ° C,
rise time, and fall time, respectively.
2 2 D
3
where D = V OUT /V IN , I DC = (I OUT - ? I L )/2 and I PK =
(I OUT + ? I L )/2
26
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX5065EAI+ | 功能描述:电流型 PWM 控制器 Dual-Phase .6-3.3V Parallelable Average 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 |
| MAX5065EAI+T | 功能描述:电流型 PWM 控制器 Dual-Phase .6-3.3V Parallelable Average 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 |
| MAX5065EAI-T | 功能描述:电流型 PWM 控制器 Dual-Phase .6-3.3V Parallelable Average 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 |
| MAX5065EVKIT | 功能描述:电源管理IC开发工具 MAX5065 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 |
| MAX5066 | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:Configurable, Single-/Dual-Output, Synchronous Buck Controller for High-Current Applications |
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