- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄379178 > DS1236A MicroManager Chip PDF資料下載
參數(shù)資料
| 型號： | DS1236A |
| 英文描述： | MicroManager Chip |
| 中文描述： | 微管理器芯片 |
| 文件頁數(shù)： | 4/20頁 |
| 文件大小： | 320K |
| 代理商： | DS1236A |
DS1236A
4 of 20
NON-MASKABLE INTERRUPT
The DS1236A generates a non-maskable interrupt
NMI
for early warning of power failure to a
microprocessor. A precision comparator monitors the voltage level at the IN pin relative to a reference
generated by the internal band gap. The IN pin is a high-impedance input allowing for a user-defined
sense point. An external resistor voltage divider network (NO TAG) is used to interface with high voltage
signals. This sense point may be derived from the regulated 5-volt supply or from a higher DC voltage
level closer to the main system power input. Since the IN trip point V
TP
is 2.54 volts, the proper values
for R1 and R2 can be determined by the equation as shown in NO TAG. Proper operation of the
DS1236A requires that the voltage at the IN pin be limited to V
IN
. Therefore, the maximum allowable
voltage at the supply being monitored (V
MAX
) can also be derived as shown in NO TAG. A simple
approach to solving this equation is to select a value for R2 high enough to keep power consumption low,
and solve for R1. The flexibility of the IN input pin allows for detection of power loss at the earliest point
NMI
and RST or
RST
.
When the supply being monitored decays to the voltage sense point, the DS1236A pulses the
NMI
output
to the active state for a minimum of 200
μ
s. The
NMI
power-fail detection circuitry also has built-in time
domain hysteresis. That is, the monitored supply is sampled periodically at a rate determined by an
internal ring oscillator running at approximately 30 kHz (33
μ
s/cycle). Three consecutive samplings of
out-of-tolerance supply (below V
SENSE
) must occur at the IN pin to activate
NMI
. Therefore, the supply
must be below the voltage sense point for approximately 100
μ
s or the comparator will reset. In this way,
power supply noise is removed from the monitoring function, preventing false trips. During a power-up,
any detected IN pin levels be low V
TP
by the comparator are disabled from reaching the
NMI
pin until
V
CC
rises to V
CCTP
. As a result, any potential
NMI
pulse will not be initiated until V
CC
reaches V
CCTP
.
Removal of an active low level on the
NMI
pin is controlled by either an internal timeout (when IN pin is
less than V
TP
) or by the subsequent rise of the IN pin above V
TP
. The initiation and removal of the
NMI
signal during power-up results in an
NMI
pulse of from 0
μ
s minimum to 500
μ
s maximum, depending
on the relative voltage relationship between V
CC
and the IN pin voltage. As an example, when the IN pin
is tied to ground during power-up, the internal timeout will result in a pulse of 200
μ
s minimum to 500
μ
s
maximum. In contrast, if the IN pin is tied to V
CCO
during power-up,
NMI
will not produce a pulse on
power-up. Note that a fast-slewing power supply may cause the
NMI
to be virtually nonexistent on
power-up. This is of no consequence, however, since an RST will be active.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| DS1238A | CAP 3.0UF 250VAC METALLIZED POLY |
| DS1245ABP-70-IND | GT 31C 1#4,2#8,14#12,14#16 SKT |
| DS1245ABP-85-IND | GT 24C 24#16 PIN PLUG |
| DS1245YP-100-IND | CAT5E PATCH CORD 10 FOOT BEIGE |
| DS1245YP-120-IND | CAT5E PATCH CORD 15 FOOT BEIGE |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| DS1236A-10 | 功能描述:監(jiān)控電路 RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(guān):No Backup 上電復(fù)位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
| DS1236A-10+ | 功能描述:監(jiān)控電路 RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(guān):No Backup 上電復(fù)位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
| DS1236A-10N | 功能描述:監(jiān)控電路 RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(guān):No Backup 上電復(fù)位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
| DS1236A-10N+ | 功能描述:監(jiān)控電路 RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(guān):No Backup 上電復(fù)位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
| DS1236A-5 | 功能描述:監(jiān)控電路 RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數(shù): 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(guān):No Backup 上電復(fù)位延遲（典型值）:10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。