- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385531 > MAX4766 (Maxim Integrated Products, Inc.) Extended Common-mode RS-485 Transceiver 8-SOIC -40 to 85 PDF資料下載
參數(shù)資料
| 型號： | MAX4766 |
| 廠商： | Maxim Integrated Products, Inc. |
| 英文描述： | Extended Common-mode RS-485 Transceiver 8-SOIC -40 to 85 |
| 中文描述： | 0.075A至1.5A、可編程限流開關(guān) |
| 文件頁數(shù)： | 9/12頁 |
| 文件大?。?/td> | 326K |
| 代理商： | MAX4766 |
M
0.075A to 1.5A, Programmable
Current-Limit Switch
_______________________________________________________________________________________
9
Autoretry (MAX4766A)
When the forward current-limit threshold is exceeded,
the t
BLANK
timer begins counting (Figure 3). The timer
resets if the overcurrent condition disappears before
t
BLANK
has elapsed. A retry time delay (t
RETRY
) starts
immediately after t
BLANK
has elapsed and during that
time, the switch turns off. At the end of t
RETRY
, the
switch turns on again. If the fault still exists, the cycle
repeats. If the fault has been removed, the switch stays
on. The autoretry feature saves system power in the
case of an overcurrent or short-circuit condition. During
t
BLANK
, when the switch is on, the supply current is at
the current limit. During t
RETRY
, when the switch is off,
the current through the switch is zero. Instead of
observing the full load current, the switch sees the
equivalent load current times duty cycle or:
With a typical t
BLANK
= 15ms and typical t
RETRY
=
150ms, the duty cycle is 10%, which results in a 90%
power savings over the switch being on the entire time.
Continuous Current Limit
In the continuous current-limit version of the MAX4766,
the output stays at the current limit until the output load
reduces. In this case,
FLAG
asserts as soon as there is
current limit without waiting for blanking time and
deasserts as soon as a short-circuit condition is
removed. In this current mode, if the thermal power rat-
ing of the package is exceeded, the device will go into
thermal shutdown and will not operate until the die tem-
perature has cooled.
Latch-Off
When the forward current-limit threshold is exceeded,
t
BLANK
timer begins counting. The timer resets if the
overcurrent condition disappears before t
BLANK
has
elapsed. The switch turns off and
FLAG
asserts if the
overcurrent condition continues beyond the blanking
time. Reset the switch by either toggling ON (Figure 2a)
or cycling the input voltage (Figure 2b).
Reverse-Current Protection
The MAX4766 features a reverse-current protection cir-
cuitry to limit the current back flow to 1μA when the out-
put voltage exceeds the input voltage by a 100mV.
During this period, the switch turns off and
FLAG
asserts (MAX4766B/C) without waiting for t
BLANK
time to
elapse. If at this point the output voltage drops below
input +100mV, the switch turns on and
FLAG
deasserts
(MAX4766B/C).
Thermal Shutdown
A thermal-shutdown circuitry protects the devices from
overheating. The switch turns off and
FLAG
goes
(MAX4766B/C) low immediately (no fault blanking)
when the junction temperature exceeds +150°C. The
MAX4766B (latch-off) does not turn on again until ON is
cycled from high to low to high. The MAX4766A
(autoretry) and the MAX4766C (continuous) turn the
switch on again after the device temperature drops
approximately +15°C.
FLAG
Indicator
FLAG
is an open-drain fault indicator output and
requires an external pullup resistor to a DC supply
(usually IN).
FLAG
goes low when any of the following
conditions occur:
The device is in current limit for more than the fault-
blanking period in the case of MAX4766B.
The device is in current limit in the case of MAX4766C
(no blanking time).
The switch is in autoretry mode.
The OUT voltage is above the IN voltage by more
than 100mV.
The die temperature exceeds the thermal-shutdown
temperature limit of the +15°C.
I
I
SUPPLY
LOAD
t
t
t
BLANK
+
BLANK
RETRY
=
Figure 3. Autoretry Fault-Blanking Diagram
LOAD
CURRENT
SWITCH
STATUS
t
BLANK
OFF
ON
t
RETRY
CURRENT
LIMIT
SHORT
REMOVED
t
BLANK
t
BLANK
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MAX4766BETA | 0.075A to 1.5A, Programmable Current-Limit Switch |
| MAX476 | 325MHz High-Speed Op Amp(425MHz，高速，開環(huán)運(yùn)算放大器) |
| MAX477 | 300MHz High-Speed Op Amp(300MHz 高速運(yùn)算放大器) |
| MAX4789EUK | 200mA/250mA/300mA Current-Limit Switches |
| MAX4789EUS | 200mA/250mA/300mA Current-Limit Switches |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX4766AETA | 制造商:Maxim Integrated Products 功能描述:.075A TO 1.4A ADJUSTABLE CURRENT LI - Rail/Tube |
| MAX4766AETA+ | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX4766AETA+T | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX4766AETA-T | 制造商:Maxim Integrated Products 功能描述:.075A TO 1.4A ADJUSTABLE CURRENT LIMIT SWITCH - Tape and Reel |
| MAX4766BETA | 制造商:Maxim Integrated Products 功能描述:.075A TO 1.4A ADJUSTABLE CURRENT LI - Rail/Tube |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。