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参数资料
| 型号： | MAX5067ETH+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 27/32页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 44-TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 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： | 44-WFQFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
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Dual-Phase, +0.6V to +3.3V Output Parallelable,
Average-Current-Mode Controllers
?
? 2 × C
× V 2 × f
?? + 1 . 4 R DS ( ON ) × I RMS ? LO
??
?
?
( I
)
2 2 ( 1 ? D ) (16)
I RMS ? LO = DC + I PK + I DC × I PK ×
PD MOS ? LO = ( Q G × V DD × f SW ) +
(15)
OSS IN SW 2
3
where C OSS is the MOSFET drain-to-source capacitance.
3
For example, from the typical specifications in the
Applications Information section with V OUT = +1.8V, the
high-side and low-side MOSFET RMS currents are 9.9A
and 24.1A, respectively. Ensure that the thermal imped-
ance of the MOSFET package keeps the junction tem-
perature at least 25 ° C below the absolute maximum
rating. Use the following equation to calculate maxi-
Input Capacitors
The discontinuous input-current waveform of the buck
converter causes large ripple currents in the input
capacitor. The switching frequency, peak inductor cur-
rent, and the allowable peak-to-peak voltage ripple
reflected back to the source dictate the capacitance
requirement. Increasing the number of phases increas-
es the effective switching frequency and lowers the
peak-to-average current ratio, yielding a lower input
capacitance requirement.
The input ripple is comprised of ? V Q (caused by the
capacitor discharge) and ? V ESR (caused by the ESR of
the capacitor). Use low-ESR ceramic capacitors with
high-ripple-current capability at the input. Assume the
contributions from the ESR and capacitor discharge are
equal to 30% and 70%, respectively. Calculate the
input capacitance and ESR required for a specified rip-
ple using the following equation:
? I OUT ? I L ?
? N
2 ?
mum junction temperature:
T J = PD MOS x θ J-A + T A
(17)
ESR IN =
( ? V ESR )
? + ?
(18)
× D ( 1 ? D )
Table 3. Peak-to-Peak Output Ripple
Current Calculations
C IN =
I OUT
N
? V Q × f SW
(19)
? I = O
( V IN ? V O ) ( 2 D ? 1 )
L × f SW
? I = O
? I = O
NUMBER OF
PHASES (N)
2
2
4
4
DUTY
CYCLE (D)
< 50%
> 50%
0 to 25%
25% to 50%
EQUATION FOR ? I P-P
V (1 ? 2D)
L × f SW
? I =
V (1 ? 4D)
L × f SW
V (1 ? 2D)(4D ? 1)
2 × D × L × f SW
where I OUT is the total output current of the multiphase
converter and N is the number of phases.
For example, at V OUT = +1.8V, the ESR and input
capacitance are calculated for the input peak-to-peak
ripple of 100mV or less yielding an ESR and capaci-
tance value of 1m ? and 200μF.
Output Capacitors
The worst-case peak-to-peak and capacitor RMS ripple
current, the allowable peak-to-peak output ripple volt-
age, and the maximum deviation of the output voltage
during step loads determine the capacitance and the
ESR requirements for the output capacitors.
In multiphase converter design, the ripple currents from
the individual phases cancel each other and lower the
ripple current. The degree of ripple cancellation
depends on the operating duty cycle and the number of
? I = O
4
> 50%
V (2D ? 1)(3 ? 4D)
D × L × f SW
phases. Choose the right equation from Table 3 to calcu-
late the peak-to-peak output ripple ( ? I P-P ) for a given
duty cycle of two-, four-, and six-phase converters. The
maximum ripple cancellation occurs when N PH = K / D.
? I = O
6
< 17%
V (1 ? 6D)
L × f SW
______________________________________________________________________________________
27
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相关代理商/技术参数 |
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|---|---|
| MAX5068 | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:High-Frequency, Current-Mode PWM Controller with Accurate Programmable Oscillator |
| MAX5068AAUE | 功能描述:电流型 PWM 控制器 High-Frequency Current-Mode PWM 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 |
| MAX5068AAUE+ | 功能描述:电流型 PWM 控制器 High-Frequency Current-Mode PWM 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 |
| MAX5068AAUE+T | 功能描述:电流型 PWM 控制器 High-Frequency Current-Mode PWM 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 |
| MAX5068AAUE-T | 功能描述:电流型 PWM 控制器 High-Frequency Current-Mode PWM 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 |
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