參數(shù)資料
型號(hào): TPS3620-50DGK
廠商: Texas Instruments, Inc.
英文描述: BACKUP-BATTERY SUPERVISORS FOR RAM RETENTION
中文描述: 備用電池RAM保持監(jiān)督員
文件頁(yè)數(shù): 10/14頁(yè)
文件大?。?/td> 309K
代理商: TPS3620-50DGK
www.ti.com
DETAILED DESCRIPTION
Battery Freshness Seal (TPS3619)
The battery freshness seal of the TPS3619 family disconnects the backup-battery from internal circuitry until it is
needed. This function prevents the backup-battery from being discharged unitl the final product is put to use. The
following steps explain how to enable the freshness seal mode.
1. Connect V
BAT
(V
BAT
> V
BAT
min)
2. Ground PFO
3. Connect PFI to V
DD
(PFI = V
DD
)
4. Connect V
DD
to power supply (V
DD
> V
IT
) and keep connected for 5 ms < t < 35 ms
The battery freshness seal mode is automatically removed by the positive-going edge of RESET when V
DD
is
applied.
Power-Fail Comparator (PFI and PFO)
An additional comparator is provided to monitor voltages other than the nominal supply voltage. The
power-fail-input (PFI) is compared with an internal voltage reference of 1.15 V. If the input voltage falls below the
power-fail threshold V
of typical 1.15 V, the power-fail output (PFO) goes low. If V
goes above V
,
plus about 12-mV hysteresis, the output returns to high. By connecting two external resistors, it is possible to
supervise any voltages above V
(PFI)
. The sum of both resistors should be about 1 M
, to minimize power
consumption and also to assure that the current in the PFI pin can be ignored compared with the current through
the resistor network. The tolerance of the external resistors should be not more than 1% to ensure minimal
variation of sensed voltage. If the power-fail comparator is unused, PFI should be connected to ground and PFO
left unconnected.
Backup-Battery Switchover
In case of a brownout or power failure, it may be necessary to preserve the contents of RAM. If a backup battery
is installed at V
, the device automatically switches the connected RAM to backup power when V
fails. In
order to allow the backup battery (e.g., a 3.6-V lithium cell) to have a higher voltage than V
DD
, these supervisors
do not connect V
BAT
to V
OUT
when V
BAT
is greater than V
DD
. V
BAT
only connects to V
OUT
(through a 15-
switch)
when V
falls below V
and V
is greater than V
. When V
DD
recovers, switchover is deferred either until
V
DD
crosses V
BAT
, or until V
DD
rises above the reset threshold V
IT
. V
OUT
connects to V
DD
through a 1-
(max)
PMOS switch when V
DD
crosses the reset threshold.
TPS3619-33, TPS3619-50
TPS3620-33, TPS3620-50
SLVS387E–APRIL 2001–REVISED SEPTEMBER 2004
FUNCTION TABLE
V
DD
> V
IT
V
DD
> V
BAT
1
1
0
0
V
OUT
V
DD
V
DD
V
DD
V
BAT
1
0
1
0
10
相關(guān)PDF資料
PDF描述
TPS3620-33DGK BACKUP-BATTERY SUPERVISORS FOR RAM RETENTION
TPS3705-30Y PROCESSOR SUPERVISORY CIRCUITS WITH POWER-FAIL
TPS3705-33Y PROCESSOR SUPERVISORY CIRCUITS WITH POWER-FAIL
TPS3705-50Y PROCESSOR SUPERVISORY CIRCUITS WITH POWER-FAIL
TPS3707-25Y PROCESSOR SUPERVISORY CIRCUITS WITH POWER-FAIL
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參數(shù)描述
TPS3620-50DGKR 功能描述:監(jiān)控電路 5-V Battery-Backup for RAM Retention RoHS:否 制造商:STMicroelectronics 監(jiān)測(cè)電壓數(shù): 監(jiān)測(cè)電壓: 欠電壓閾值: 過(guò)電壓閾值: 輸出類(lèi)型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開(kāi)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(fēng)格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel
TPS3620-50DGKRG4 功能描述:監(jiān)控電路 5-V Battery-Backup for RAM Retention RoHS:否 制造商:STMicroelectronics 監(jiān)測(cè)電壓數(shù): 監(jiān)測(cè)電壓: 欠電壓閾值: 過(guò)電壓閾值: 輸出類(lèi)型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開(kāi)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(fēng)格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel
TPS3620-50DGKT 功能描述:監(jiān)控電路 5-V Battery-Backup for RAM Retention RoHS:否 制造商:STMicroelectronics 監(jiān)測(cè)電壓數(shù): 監(jiān)測(cè)電壓: 欠電壓閾值: 過(guò)電壓閾值: 輸出類(lèi)型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開(kāi)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(fēng)格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel
TPS3620-50DGKTG4 功能描述:監(jiān)控電路 5-V Battery-Backup for RAM Retention RoHS:否 制造商:STMicroelectronics 監(jiān)測(cè)電壓數(shù): 監(jiān)測(cè)電壓: 欠電壓閾值: 過(guò)電壓閾值: 輸出類(lèi)型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開(kāi)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(fēng)格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel
TPS3700 制造商:TI 制造商全稱(chēng):Texas Instruments 功能描述:Window Comparator for Over- and Undervoltage Detection