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參數(shù)資料
| 型號(hào)： | 2557 |
| 廠商： | Allegro MicroSystems, Inc. |
| 英文描述： | PROTECTED QUAD LOW-SIDE DRIVER WITH FAULT DETECTION & SLEEP MODE |
| 中文描述： | 保護(hù)四低側(cè)驅(qū)動(dòng)與故障檢測(cè) |
| 文件頁(yè)數(shù)： | 6/12頁(yè) |
| 文件大小： | 176K |
| 代理商： | 2557 |
2557
PROTECTED QUAD DRIVER
WITH FAULT DETECTION
& SLEEP MODE
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
6
CIRCUIT DESCRIPTION AND APPLICATION (continued)
Fault diagnostics
A pull-up resistor or current source is required on the
FAULT output. This can be connected to whatever supply level
the following circuitry requires (within the specification
constraints). For a 5 V supply (i.e., Vcc) 150 k
or greater
should be used. As the fault diagnostic function is to indicate
when the output state is different from the input state for any
channel, the FAULT output waveform will obviously produce a
pulse waveform following the combined duty-cycle of all
channels showing a fault condition. There are therefore two
basic approaches to using the function in an application:
has a microcontroller then a FAULT low causes an interrupt,
which then initiates a diagnostic sequence to find the culprit
channel. This sequence usually consists of cycling through
each channel one at a time, while monitoring the FAULT
output. It is then easy to determine which channel has the
faulty output and how it is failing (i.e., short to supply, open-
circuit or short to ground). The system may then take whatever
action is required, but could continue with operation of the
remaining ‘good’ channels while disabling signals to the faulty
channel.
As an interrupt in a controller-based system. If the system
controller in the system then the FAULT output can be set to
give an indication (via a lamp or LED, etc.) of a fault condition
which might be anywhere on the four channels. Because the
FAULT output is dependent on the states of the input and
output (four possibilities) but will only indicate on two of them,
the duty cycle at the FAULT output will reflect the duty cycle at
the faulty channel’s input (or its inverse, depending upon fault
type).
As a simple ‘common’ fault indication. If there is no
In typical applications (50% duty cycles) a simple solution
is to make the pull-up current on the FAULT output much less
than the pull-down current (60
μ
A), and add a capacitor to give
a time constant longer than the period of operation. For typical
values, the device will produce a continuous dc output level.
Component values will need to be adjusted to cope with
different conditions.
Inductive load driver
Bifilar (unipolar) stepper motors (and other inductive
loads) can be driven directly. The internal diodes prevent
damage to the output transistors by suppressing the high-voltage
spikes that occur when turning off an inductive load. For rapid
current decay (fast turn-off speeds), the use of Zener diodes will
raise the flyback voltage and improve performance. However,
the peak voltage must not exceed the specified minimum
sustaining voltage (V
SUPPLY
+ V
Z
+ V
F
< V
O(SUS)
).
Over-current conditions
In the event of a shorted load, or stalled motor, the load
current will attempt to increase. As described above, the drive
current to the affected output stage is linearly reduced, causing
the output to go linear (limiting the load current to about 500
mA). As the junction temperature of the output stage increases,
the thermal-shutdown circuit will shut off the affected output.
If the fault condition is corrected, the output driver will return
to its normal saturated condition.
NORMAL LAMP IN-RUSH CURRENT
TIME
THERMAL GRADIENT SENSING
CURRENT LIMIT
Dwg. WP-008
NOT TO SCALE
I
TRIP
0
L
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PDF描述 |
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| 2559 | PROTECTED QUAD POWER DRIVER |
| 256-FBGA | 32-bit ARM7TDMI RISC static CMOS CPU core |
| 256FBGA | 32-bit ARM7TDMI RISC static CMOS CPU core |
| 2560A | Pulse Dialer |
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 2557.000.00 | 功能描述:ID NET.24V-B POWER SUPPLY UNIT RoHS:是 類別:RF/IF 和 RFID >> RFID配件 系列:- 標(biāo)準(zhǔn)包裝:1 系列:- 附件類型:WLAN-A 無(wú)線適配器 適用于相關(guān)產(chǎn)品:629-1002-ND、629-1045-ND、629-1046-ND、LRU2000 讀取器 其它名稱:2421.000.01.00629-1048DCF-660W |
| 2557_06 | 制造商:ALLEGRO 制造商全稱:Allegro MicroSystems 功能描述:PROTECTED QUAD LOW-SIDE DRIVER WITH FAULT DETECTION and SLEEP MODE |
| 255-700 | 制造商:WAGO 功能描述:LT GREEN END PLATE |
| 25-5702-10SW | 功能描述:SUPPLIED AIR RESPIRATORY PROTECT 制造商:3m 系列:* 零件狀態(tài):在售 標(biāo)準(zhǔn)包裝:1 |
| 25-5702-20SW | 功能描述:SUPPLIED AIR RESPIRATORY PROTECT 制造商:3m 系列:* 零件狀態(tài):在售 標(biāo)準(zhǔn)包裝:1 |
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