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参数资料
| 型号： | MAX8715EUA+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 12/14页 |
| 文件大小： | 0K |
| 描述： | IC REG BOOST ADJ 0.8A 8UMAX |
| 标准包装： | 50 |
| 类型： | 升压（升压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 2.6 V ~ 12 V |
| 输入电压： | 2.6 V ~ 5.5 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 640kHz, 1.22MHz |
| 电流 - 输出： | 1.8A |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-TSSOP，8-MSOP（0.118"，3.00mm 宽） |
| 包装： | 管件 |
| 供应商设备封装： | 8-uMAX |
Low-Noise Step-Up DC-DC Converters
R2 can have a value up to 100k Ω without sacrificing
accuracy. Connect the resistor-divider as close to the IC
as possible.
Loop Compensation
V IN
2.6V TO 5.5V
C1
10 μ F
The voltage feedback loop needs proper compensation
to prevent excessive output ripple and poor efficiency
caused by instability. This is done by connecting a resis-
tor (R COMP ) and capacitor (C COMP ) in series from
COMP to GND, and another capacitor (C COMP2 ) from
SHDN
IN
LX
L1A
5.3 μ H
C2
10 μ F
10V
D1
V OUT
3.3V
COMP to GND. R COMP is chosen to set the high-fre-
quency integrator gain for fast transient response, while
C COMP is chosen to set the integrator zero to maintain
loop stability. The second capacitor, C COMP2 , is chosen
to cancel the zero introduced by output-capacitance
MAX1790
FREQ
GND
L1B
5.3 μ H
C OUT
22 μ F
20V
ESR. For optimal performance, choose the components
using the following equations:
SS
FB
R COMP ? (200 Ω / A 2 ) x V OUT2 x C OUT / L (MAX1790)
0.027 μ F
CC
R2
R1
1M Ω
R COMP ? (274 Ω / A) x V IN x V OUT x C OUT / (L x I OUT )
605k Ω
(MAX8715)
C COMP ? (0.4 x 10 -3 A/ Ω ) x L / V IN
(MAX1790)
C COMP2
56pF
R COMP
22k Ω
C COMP ? (0.36 x 10 -3 A/ Ω ) x L / V IN (MAX8715)
C COMP2 ? (0.005 A 2 / Ω ) x R ESR x L / V OUT2
(MAX1790)
C COMP
330pF
L1 = CTX8-1P
C OUT = TPSD226025R0200
C SS > 21 × 10 ? 6 × C OUT ?
× I
? I
×
? V IN INRUSH OUT OUT ?
?
C COMP2 ? (0.0036 A/ Ω ) x R ESR x L x I OUT / (VIN x VOUT)
(MAX8715)
For the ceramic output capacitor, where ESR is small,
C COMP2 is optional. Table 1 shows experimentally verified
external component values for several applications.
The best gauge of correct loop compensation is by
inspecting the transient response of the MAX1790/
MAX8715. Adjust R COMP and C COMP as necessary to
obtain optimal transient performance.
Soft-Start Capacitor
The soft-start capacitor should be large enough that it
does not reach final value before the output has
reached regulation. Calculate C SS to be:
? V OUT 2 ? V IN × V OUT ?
V
where:
C OUT = total output capacitance including any bypass
capacitor on the output bus
V OUT = maximum output voltage
I INRUSH = peak inrush current allowed
Figure 3. MAX1790 in a SEPIC Configuration
I OUT = maximum output current during power-up stage
V IN = minimum input voltage
The load must wait for the soft-start cycle to finish
before drawing a significant amount of load current.
The duration after which the load can begin to draw
maximum load current is:
t MAX = 6.77 x 10 5 C SS
Application Circuits
1-Cell to 3.3V SEPIC Power Supply
Figure 3 shows the MAX1790 in a single-ended primary
inductance converter (SEPIC) topology. This topology is
useful when the input voltage can be either higher or
lower than the output voltage, such as when converting
a single lithium-ion (Li+) cell to a 3.3V output. L1A and
L1B are two windings on a single inductor. The coupling
capacitor between these two windings must be a low-
ESR type to achieve maximum efficiency, and must also
be able to handle high ripple currents. Ceramic capaci-
tors are best for this application. The circuit in Figure 3
provides 400mA output current at 3.3V output when
operating with an input voltage from +2.6V to +5.5V.
12
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX8715EUA+ | 功能描述:直流/直流开关转换器 Low-Noise Step-Up DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX8715EUA+T | 功能描述:直流/直流开关转换器 Low-Noise Step-Up DC/DC Converter RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX8715EUA-T | 功能描述:直流/直流开关转换器 RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX8716ETG | 功能描述:接口 - 专用 RoHS:否 制造商:Texas Instruments 产品类型:1080p60 Image Sensor Receiver 工作电源电压:1.8 V 电源电流:89 mA 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:BGA-59 |
| MAX8716ETG+ | 功能描述:接口 - 专用 RoHS:否 制造商:Texas Instruments 产品类型:1080p60 Image Sensor Receiver 工作电源电压:1.8 V 电源电流:89 mA 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:BGA-59 |
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