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| 型号： | MAX15035ETL+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 20/27页 |
| 文件大小： | 0K |
| 描述： | IC REG BOOST SYNC 15A 40TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 类型： | 升压（升压） |
| 输出类型： | 固定 |
| 输出数： | 1 |
| 输出电压： | 1.05V，1.5V |
| 输入电压： | 4.5 V ~ 26 V |
| PWM 型： | 电流模式 |
| 电流 - 输出： | 15A |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 40-WFQFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 40-TQFN-EP（6x6） |
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15A Step-Down Regulator with Internal Switches
?
Switching frequency: This choice determines the
basic trade-off between size and efficiency. The
optimal frequency is largely a function of maximum
which can be calculated from the on-time and minimum
off-time. The worst-case output sag voltage can be
determined by:
(
) 2
? ? + t OFF (M IN ) ?
? ? V OUT t SW ? ?
L Δ I LOAD(MAX) ? ? M
?
?
? ? ( V IN ? V OUT ) t SW ? ?
2 C OUT OUT ? ? ? ? t OFF ( MIN ) ?
? ? ?
? ?
?
input voltage due to MOSFET switching losses that
are proportional to frequency and V IN 2 . The opti-
mum frequency is also a moving target, due to
rapid improvements in MOSFET technology that are
making higher frequencies more practical.
Inductor operating point: This choice provides
V SAG =
V
? V IN
V IN
≈ ( Δ I LOAD ( MAX ) ) 2 L
2 C OUT OUT
OUT ?
? V
? ? ? V
L = ?
? ?
? f SW I LOAD ( MAX ) LIR ? ? V IN ?
Δ I L
I LIMIT ( LOW ) > I LOAD ( MAX ) ?
trade-offs between size vs. efficiency and transient
response vs. output noise. Low inductor values pro-
vide better transient response and smaller physical
size, but also result in lower efficiency and higher
output noise due to increased ripple current. The
minimum practical inductor value is one that causes
the circuit to operate at the edge of critical conduc-
tion (where the inductor current just touches zero
with every cycle at maximum load). Inductor values
lower than this grant no further size-reduction bene-
fit. The optimum operating point is usually found
between 20% and 50% ripple current.
Inductor Selection
The switching frequency and operating point (% ripple
current or LIR) determine the inductor value as follows:
V IN OUT
?
Find a low-loss inductor having the lowest possible DC
resistance that fits in the allotted dimensions. Ferrite
cores are often the best choice, although powdered
iron is inexpensive and can work well at 200kHz. The
core must be large enough not to saturate at the peak
inductor current (I PEAK ):
where t OFF(MIN) is the minimum off-time (see the Electrical
Characteristics table).
The amount of overshoot due to stored inductor energy
when the load is removed can be calculated as:
V SOAR
V
Setting the Valley Current Limit
The minimum current-limit threshold must be high
enough to support the maximum load current when the
current limit is at the minimum tolerance value. The val-
ley of the inductor current occurs at I LOAD(MAX) minus
half the inductor ripple current ( Δ I L ); therefore:
2
where I LIMIT(LOW) equals the minimum current-limit
threshold voltage divided by 0.006.
The valley current-limit threshold is precisely 1/20 the
voltage seen at ILIM. Connect a resistive divider from
REF to ILIM to analog ground (AGND) to set a fixed val-
ley current-limit threshold. The external 400mV to 2V
adjustment range corresponds to a 20mV to 100mV val-
ley current-limit threshold. When adjusting the current-
I PEAK = I LOAD ( MAX ) +
Δ I L
2
limit threshold, use 1% tolerance resistors and a divider
current of approximately 5μA to 10μA to prevent signifi-
cant inaccuracy in the valley current-limit tolerance.
Transient Response
The inductor ripple current impacts transient-response
performance, especially at low V IN - V OUT differentials.
Low inductor values allow the inductor current to slew
faster, replenishing charge removed from the output fil-
ter capacitors by a sudden load step. The amount of
output sag is also a function of the maximum duty factor,
The MAX15035 uses the low-side MOSFET’s on-resis-
tance as the current-sense element (R SENSE =
R DS(ON) ). A good general rule is to allow 0.5% addi-
tional resistance for each degree celsius of tempera-
ture rise, which must be included in the design margin
unless the design includes an NTC thermistor in the
ILIM resistive voltage-divider to thermally compensate
the current-limit threshold.
20
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX15035EVKIT+ | 功能描述:电源管理IC开发工具 MAX15035 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 |
| MAX15036ATE/V+ | 功能描述:直流/直流开关转换器 2.2MHz 3A Buck wInt High-Side Switch 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 |
| MAX15036ATE/V+T | 功能描述:直流/直流开关转换器 2.2MHz 3A Buck wInt High-Side Switch 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 |
| MAX15036ATE+ | 功能描述:直流/直流开关转换器 2.2MHz 3A Buck wInt High-Side Switch 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 |
| MAX15036ATE+T | 功能描述:直流/直流开关转换器 2.2MHz 3A Buck wInt High-Side Switch 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 |
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