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| 型号： | MAX17014ETM+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 26/33页 |
| 文件大小： | 0K |
| 描述： | IC PWR SUPPLY MULT-OUTPUT 48TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 应用： | LCD 电视机/监控器 |
| 电流 - 电源： | 8mA |
| 电源电压： | 8 V ~ 16.5 V |
| 工作温度： | -40°C ~ 85°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（7x7） |
| 包装： | 带卷 (TR) |
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Low-Cost Multiple-Output
Power Supply for LCD TVs
V OUT × ( V VIN ? V OUT )
I OUT _ RIPPLE =
Fault Protection
During steady-state operation, if any output of the four
regulators (step-down regulator, step-up regulator,
positive charge-pump regulator, and negative charge-
pump regulator) does not exceed its respective fault-
detection threshold, the MAX17014 activates an inter-
nal fault timer. If any condition or the combination of
conditions indicates a continuous fault for the fault timer
duration (50ms, typ), the MAX17014 triggers a non-
latching output undervoltage fault. After triggering, the
MAX17014 turns off for 160ms (typ) and then restarts
according to the EN1 and EN2 logic states. If, after
restarting, another 50ms fault timeout occurs, the
MAX17014 shuts down for 160ms again, and then
restarts. The restart sequence is repeated 3 times and
after the 50ms fault timeout, the MAX17014 shuts down
connected to VL or 0.6MHz when FSEL is connected to
GND. The exact inductor value is not critical and can
be adjusted to make trade-offs among size, cost, and
efficiency. Lower inductor values minimize size and
cost, but they also increase the output ripple and
reduce the efficiency due to higher peak currents. On
the other hand, higher inductor values increase effi-
ciency, but at some point resistive losses due to extra
turns of wire exceed the benefit gained from lower AC
current levels.
The inductor’s saturation current must exceed the peak
inductor current. The peak current can be calculated by:
f SW × L OUT × V VIN
and latches off. Once the fault condition is removed,
toggle either EN1 or EN2, or cycle the input voltage to
clear the fault latch and restart the supplies.
I OUT _ PEAK = I OUT ( MAX ) +
I OUT _ RIPPLE
2
3 . 3 V × ( 12 V ? 3 . 3 V )
L OUT = ≈ 2 . 6 μ H
Thermal-Overload Protection
The thermal-overload protection prevents excessive
power dissipation from overheating the MAX17014.
When the junction temperature exceeds T J = +160°C, a
thermal sensor immediately activates the fault protec-
tion, which shuts down all the outputs except the refer-
ence and latches off, allowing the device to cool down.
Once the device cools down by at least approximately
15°C, cycle the input voltage to clear the fault latch and
restart the MAX17014.
The thermal-overload protection protects the controller
in the event of fault conditions. For continuous opera-
tion, do not exceed the absolute maximum junction
temperature rating of T J = +150°C.
The inductor’s DC resistance should be low for good
efficiency. Find a low-loss inductor having the lowest
possible DC resistance that fits in the allotted dimen-
sions. Ferrite cores are often the best choice. Shielded-
core geometries help keep noise, EMI, and switching
waveform jitter low.
Considering the typical operating circuit in Figure 1, the
maximum load current (I OUT(MAX) ) is 2A with a 3.3V
output and a typical 12V input voltage. Choosing an
LIR of 0.4 at this operating point:
12 V × 1 . 2 MHz × 2 A × 0 . 4
At that operating point, the ripple current and the peak
Design Procedure
Step-Down Regulator
current are:
I OUT _ RIPPLE =
3.3V × ( 12V ? 3.3V )
1 . 2 MHz × 2 . 6 μ H × 12
≈ 0 . 77 A
Inductor Selection
Three key inductor parameters must be specified:
inductance value (L), peak current (I PEAK ), and DC
I OUT _ PEAK = 2 A +
0.77A
2
= 2 . 39 A
resistance (R DC ). The following equation includes a
V OUT × ( V IN ? V OUT )
L OUT =
V OUT × ( V VIN ? V OUT )
constant, LIR, which is the ratio of peak-to-peak induc-
tor ripple current to DC load current. A higher LIR value
allows smaller inductance, but results in higher losses
and higher ripple. A good compromise between size
and losses is typically found at about 20% to 50% rip-
ple-current to load-current ratio (LIR):
V IN × f SW × I OUT ( MAX ) × LIR
where I OUT(MAX) is the maximum DC load current, and
the switching frequency f SW is 1.2MHz when FSEL is
Input Capacitors
The input filter capacitors reduce peak currents drawn
from the power source and reduce noise and voltage
ripple on the input caused by the regulator’s switching.
They are usually selected according to input ripple cur-
rent requirements and voltage rating, rather than
capacitance value. The input voltage and load current
determine the RMS input ripple current (I RMS ):
I RMS = I OUT ×
V VIN
26
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相关代理商/技术参数 |
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| MAX17014EVKIT+ | 功能描述:电源管理IC开发工具 MAX17014 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 |
| MAX17015AETP+ | 功能描述:电池管理 1.2MHz High-Perf Charger RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
| MAX17015AETP+T | 功能描述:电池管理 1.2MHz High-Perf Charger RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
| MAX17015BETP+ | 功能描述:电池管理 1.2MHz High-Perf Charger RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
| MAX17015BETP+T | 功能描述:电池管理 1.2MHz High-Perf Charger RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
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