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参数资料
| 型号： | MAX5040EUB+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 14/21页 |
| 文件大小： | 0K |
| 描述： | IC CNTRLR VOLT TRACK 10-UMAX |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 应用： | 处理器 |
| 电流 - 电源： | 1.3mA |
| 电源电压： | 2.5 V ~ 5.5 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 供应商设备封装： | 10-µMAX |
| 包装： | 带卷 (TR) |
Voltage-Tracking Controllers for
PowerPC, DSPs, and ASICs
of the maximum output current rating of the CORE or
I/O power supplies is adequate. However, care should
be taken when selecting this MOSFET to make sure it is
capable of sustaining all of the worst-case conditions,
as well as riding through all of the fault conditions. The
following are guidelines for selecting the external N-
channel MOSFET:
1) MOSFET drain-to-source maximum voltage rating:
well as the charging of the CORE output
capacitor. For most practical cases, the
power charging the CORE output capacitor
can be ignored. The power dissipation in the
MOSFET for this case is (V I/O - V CORE ) x
I CORE , where V I/O is the regulated I/O volt-
age, V CORE is the regulated CORE voltage,
and I CORE is the CORE full-load current.
V DS rating > V I/O maximum voltage.
2) MOSFET gate-to-source maximum voltage rating:
V GS rating > V CC maximum.
3) MOSFET gate turn-on threshold voltage: V GS(th) <
minimum operating voltage of (V CC - V CORE ). For
example, if V CC minimum operating voltage is 4.5V,
CORE voltage is 1.8V, then V GS(th) < (4.5V - 1.8V) =
2.7V. A MOSFET with logic-level gate turn-on
threshold voltage is appropriate for this application.
?
During power-up, the CORE voltage comes
up first, and the I/O power supply fails to turn
on. The MOSFET turns on hard, keeping the
I/O voltage close to the CORE voltage. The
MOSFET in this case supports the I/O load
current, as well as the charging of the I/O
output capacitor. For most practical cases,
the power charging the I/O output capacitor
can be ignored. Since the I/O voltage never
reaches its final value, the I/O load current
4)
Determine the maximum current that can go
might be off and the power dissipation in the
through the MOSFET during power-up, power-
down/brownout, or output short-circuit conditions.
In most cases, this maximum current is the current
limit of the CORE or the I/O power supplies,
whichever is larger. Choose the MOSFET with
pulse current rating sufficiently higher than this cur-
rent. Note that typical MOSFET pulse current rating
is much larger than its continuous current rating.
5) Determine the MOSFET maximum R DSON such that
under worst-case current, the voltage drop across
its drain-to-source is within the tracking limit
(approximately 400mV for most PowerPCs, ASICs,
and DSPs).
6) Determine the maximum single-shot power dissipa-
tion in the MOSFET during power-up, or during an
output short-circuit condition. Considering the fol-
lowing cases:
? When either the I/O or CORE is shorted to
GND, NDRV is driven high to V CC , turning the
MOSFET on. The current through the MOSFET
is the maximum current that the supply not
shorted can produce (the CORE supply maxi-
mum current if I/O is shorted or vice versa).
Depending on which supply is shorted, take
the maximum short-circuit current that either
the I/O or CORE supplies produce. Call this
current I PSLIM . In this case, the power dissi-
pation in the MOSFET is I PSLIM2 x R DS(ON) .
MOSFET is minimal. However, assuming the
worst-case condition that the I/O load draws
its full-load current, the power dissipation in
the MOSFET would be I I/O 2 x R DS(ON) , where
I I/O is the I/O full-load current.
The worst-case single-shot power dissipation in
the MOSFET is the maximum value from the steps
above and for a maximum duration of t FAULT .
7) Next, select the MOSFET that can take this single
pulse energy without going over its maximum junc-
tion temperature rating. The maximum MOSFET
junction temperature can be calculated as follows:
T J = T AMB + P PULSE x Z θ JA
where T J is the junction temperature, T AMB is the
ambient temperature, P PULSE is the single-shot
power dissipation calculated in step 6 above, and
Z θ JA is the junction-to-ambient thermal impedance
of the selected MOSFET for a single pulse of
t FAULT duration. Z θ JA is specified in all typical
MOSFET data sheets.
Example: I/O = 3.3V, I/O power supply has a current
limit (I I/O(LIM )) of 6A, I/O full-load current is 3A. CORE is
1.8V, CORE power supply has a current limit
(I CORE(LIM) ) of 6A, CORE full-load current is 4A. V CC =
5V + 0.5V. CORE and I/O voltages must track to within
400mV.
Choose a Si9428DY (N-channel MOSFET, V DS max =
?
During power-up, the I/O voltage comes up
first, and the CORE power supply fails to turn
on. The MOSFET is in linear regulator mode,
supporting the CORE full-load current, as
20V, R DS(ON) at +25°C = 0.04 ? at V GS = 2.5V, R DS(ON)
at +125°C = 1.5 x R DS(ON) at 25°C, from the MOSFET
data sheet, V GS max = 8V).
14
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX5040EVKIT | 制造商:Maxim Integrated Products 功能描述:VOLTAGE-TRACKING CONTROLLER FOR POWERPC, DSPS - Bulk |
| MAX5041 | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:Dual-Phase.Parallelable.Average Current-Mode Controllers |
| MAX-504-1205 | 制造商:SLPOWER 制造商全称:SL Power Electronics 功能描述:400, 500 WATTS MULTIPLE OUTPUT |
| MAX-504-1205AP | 功能描述:PWR SPY QD OP +5VLT +-12VLT +5.2 RoHS:否 类别:电源 - 外部/内部（非板载） >> AC DC 转换器 系列:MAX-500 产品培训模块:MP Modular-Configurable AC-DC Power Supply 特色产品:Configurable Power Supplies 标准包装:1 系列:MP |
| MAX-504-1205F | 制造商:SL Power Electronics 功能描述:Power Supply-Multiple Output |
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