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参数资料
| 型号： | MAX17019ATM+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 22/25页 |
| 文件大小： | 0K |
| 描述： | IC VOLT CTRL QUAD OUT 48-TQFN-EP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 应用： | 嵌入式系统，控制台/机顶盒 |
| 电源电压： | 5.5 V ~ 38 V |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 48-WFQFN 裸露焊盘 |
| 供应商设备封装： | 48-TQFN-EP（6x6） |
| 包装： | 带卷 (TR) |
High-Input-Voltage Quad-Output Controller
I RMS = ? LOAD ? V OUT IN OUT )
( V - V
Internal SMPS Transient Response
The load-transient response depends on the overall
output impedance over frequency, and the overall
amplitude and slew rate of the load step. In applica-
tions with large, fast load transients (load step > 80% of
full load and slew rate > 10A/μs), the output capacitor’s
high-frequency response—ESL and ESR—needs to be
considered. To prevent the output voltage from spiking
too low under a load-transient event, the ESR is limited
by the following equation (ignoring the sag due to finite
capacitance):
Input Capacitor Selection
The input capacitor must meet the ripple current
requirement (I RMS ) imposed by the switching currents.
The I RMS requirements of an individual regulator can be
determined by the following equation:
? I ?
? V IN ?
The worst-case RMS current requirement occurs when
operating with V IN = 2V OUT . At this point, the above
?
R ESR ≤ ?
V STEP
? Δ I LOAD ( MAX )
?
- R PCB ?
?
equation simplifies to I RMS = 0.5 x I LOAD. However, the
MAX17019 uses an interleaved fixed-frequency archi-
tecture, which helps reduce the overall input RMS cur-
rent on the INBC input supply.
L ( Δ I LOAD ( MAX ) ) 2 Δ I L OAD ( MAX ) ( T - Δ T )
2 C OUT ( V IN × D MAX - V OUT )
≈ ( Δ I LOAD ( MAX ) ) 2 L
2 C OUT OUT
where V STEP is the allowed voltage drop, ΔI LOAD(MAX) is
the maximum load step, and R PCB is the parasitic board
resistance between the load and output capacitor.
The capacitance value dominates the midfrequency
output impedance and dominates the load-transient
response as long as the load transient’s slew rate is
less than two switching cycles. Under these conditions,
the sag and soar voltages depend on the output
capacitance, inductance value, and delays in the tran-
sient response. Low inductor values allow the inductor
current to slew faster, replenishing charge removed
from or added to the output filter capacitors by a sud-
den load step, especially with low differential voltages
across the inductor. The sag voltage (V SAG ) that occurs
after applying the load current can be estimated by the
following:
V SAG = +
C OUT
where D MAX is the maximum duty factor (see the
Electrical Characteristics table), T is the switching peri-
od (1/f OSC ), and Δ T equals V OUT /V IN x T when in PWM
mode, or L x I IDLE /(V IN - V OUT ) when in pulse-skipping
mode. The amount of overshoot voltage (V SOAR ) that
occurs after load removal (due to stored inductor ener-
gy) can be calculated as:
V SOAR
V
When using low-capacity ceramic filter capacitors,
capacitor size is usually determined by the capacity
needed to prevent V SOAR from causing problems during
load transients. Generally, once enough capacitance is
added to meet the overshoot requirement, undershoot at
the rising load edge is no longer a problem.
For the MAX17019 system (INA) supply, nontantalum
chemistries (ceramic, aluminum, or OS-CON) are pre-
ferred due to their resistance to inrush surge currents
typical of systems with a mechanical switch or connector
in series with the input. For the MAX17019 INBC input
supply, ceramic capacitors are preferred on input due to
their low parasitic inductance, which helps reduce the
high-frequency ringing on the INBC supply when the
internal MOSFETs are turned off. Choose an input
capacitor that exhibits less than +10°C temperature rise
at the RMS input current for optimal circuit longevity.
BST Capacitors
The boost capacitors (C BST ) must be selected large
enough to handle the gate charging requirements of
the high-side MOSFETs. For these low-power applica-
tions, 0.1μF ceramic capacitors work well.
Regulator A Power-MOSFET Selection
Most of the following MOSFET guidelines focus on the
challenge of obtaining high load-current capability
when using high-voltage (> 20V) AC adapters. Low-
current applications usually require less attention.
The high-side MOSFET (N H ) must be able to dissipate
the resistive losses plus the switching losses at both
V IN(MIN) and V IN(MAX) . Ideally, the losses at V IN(MIN)
should be roughly equal to the losses at V IN(MAX) , with
lower losses in between. If the losses at V IN(MIN) are
significantly higher, consider increasing the size of N H .
Conversely, if the losses at V IN(MAX) are significantly
higher, consider reducing the size of N H . If V IN does
not vary over a wide range, maximum efficiency is
achieved by selecting a high-side MOSFET (N H ) that
has conduction losses equal to the switching losses.
Choose a low-side MOSFET (N L ) that has the lowest
possible on-resistance (R DS(ON) ), comes in a moder-
ate-sized package (i.e., 8-pin SO, DPAK, or D 2 PAK),
22
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX17019EVKIT+ | 功能描述:电源管理IC开发工具 Maxim Evaluation 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 |
| MAX17019NEVKIT+ | 功能描述:电源管理IC开发工具 Maxim Evaluation 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 |
| MAX1701EEE | 功能描述:直流/直流开关转换器 1-3 Cell 1A Step-Up DC/DC Converters 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 |
| MAX1701EEE+ | 功能描述:直流/直流开关转换器 1-3 Cell 1A Step-Up DC/DC Converters 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 |
| MAX1701EEE+T | 功能描述:直流/直流开关转换器 1-3 Cell 1A Step-Up DC/DC Converters 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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