5秒后页面跳转
IMP805LMJA PDF预览

IMP805LMJA

更新时间: 2024-10-27 22:31:11
品牌 Logo 应用领域
IMP 电池微处理器监控
页数 文件大小 规格书
10页 227K
描述
レP POWER SUPPLY SUPERVISOR WITH BATTERY BACKUP SWITCH

IMP805LMJA 数据手册

 浏览型号IMP805LMJA的Datasheet PDF文件第3页浏览型号IMP805LMJA的Datasheet PDF文件第4页浏览型号IMP805LMJA的Datasheet PDF文件第5页浏览型号IMP805LMJA的Datasheet PDF文件第7页浏览型号IMP805LMJA的Datasheet PDF文件第8页浏览型号IMP805LMJA的Datasheet PDF文件第9页 
IMP690A, 692A, 802L, 802M, 805L  
Application Information  
Watchdog Input  
Table 1. Pin Connections in Battery Backup Mode  
As discussed in the Reset section, the Watchdog Input is used to  
monitor microprocessor activity. It can be used to insure that the  
microprocessor is in a continually responsive state by requiring  
that the WDI pin be toggled every second. If the WDI pin is not  
toggled within the 1.6 second window (minimum tWD + tRS),  
a reset pulse will be asserted to return the microprocessor to the  
initial start-up state. Pulses as short as 50ns can be applied to the  
WDI pin. If this feature is not used, the WDI pin should be open-  
circuited or the logic placed into a high-impedance state to allow  
the pin to float.  
Pin  
VOUT  
VBATT  
PFI  
Connection  
Connected to VBATT through internal PMOS switch  
Connected to VOUT  
Disabled  
PFO  
Logic-LOW  
RESET Logic LOW (except on IMP805 where it is HIGH)  
WDI Watchdog timer disabled  
During the backup power mode, the internal circuitry of the  
supervisory circuit draws power from the battery supply. While  
CC is still alive, the comparator circuits remain alive and the cur-  
rent drawn by the device is typically 35µA. When VCC drops more  
than 1.1V below VBATT, the internal switchover comparator, the  
PFI comparator and WDI comparator will shut off, reducing the  
quiescent current drawn by the IC to less than 1µA.  
Backup-Battery Switchover  
A power loss can be made less severe if the system RAM contents  
are preserved. This is achieved in the IMP690/692/802/805 by  
switching from the failed VCC to an alternate power source con-  
V
nected at VBATT when V is less than the reset threshold voltage  
CC  
(V < V ), and V is less than VBATT. The VOUT pin is normally  
CC  
RT  
CC  
connected to V through a 2PMOS switch but a brown-out or  
CC  
Backup Power Sources - Batteries  
loss of V will cause a switchover to VBATT by means of a 20Ω  
CC  
Battery voltage selection is important to insure that the battery  
does not discharge through the parasitic device diode D1 (see  
PMOS switch. Although both conditions (V < V and V <  
CC  
RT  
CC  
V
BATT) must occur for the switchover to VBATT to occur, V  
will  
OUT  
Figure 4) when VCC is less than VBATT and VCC > V .  
be switched back to VCC when VCC exceeds VRT irrespective of the  
voltage at VBATT. It should be noted that an internal device diode  
RT  
Table 2. Maximum Battery Voltages  
(D1 in Figure 4) will be forward biased if VBATT exceeds V by  
CC  
Part No.  
IMP690A  
IMP802L  
IMP805L  
IMP692A  
IMP802M  
MAXIMUM Battery Voltage  
more than a diode drop when VCC is switched to VOUT. Because of  
this it is recommended that VBATT be no greater than VRT +0.6V.  
4.80  
4.80  
4.80  
4.55  
4.55  
VBATT  
VCC  
SW1  
SW2  
D1 D2  
SW3  
SW4  
Although most batteries that meet the requirements of Table 2 are  
acceptable, lithium batteries are very effective backup source due  
to their high-energy density and very low self-discharge rates.  
IMP690A IMP802L  
IMP692A IMP802M  
IMP805L  
D3  
Battery Replacement while Powered  
Batteries can be replaced even when the device is in a powered  
state as long as VCC remains above the reset threshold voltage VRT.  
In the IMP devices, a floating VBATT pin will not cause a power-  
supply switchover as can occur in some other supervisory  
circuits. If VBATT is not used, the pin should be grounded.  
VOUT  
CONDITION  
SW1/SW2 SW3/SW4  
VCC > Reset Threshold  
Open  
Open  
Closed  
Closed  
V
CC < Reset Threshold and  
VCC > VBATT  
VCC < Reset Threshold and  
VCC < VBATT  
Closed  
Open  
IMP690A/IMP802L/IMP805L Reset Threshold = 4.65V  
IMP692A/IMP802M Reset Threshold = 4.4V  
690A_06.eps  
Figure 4. Internal device configuration of battery  
switch-over function  
6

与IMP805LMJA相关器件

型号 品牌 获取价格 描述 数据表
IMP809 A1PROS

获取价格

3-Pin Microcontroller Power Supply Supervisor
IMP809 IMP

获取价格

3-Pin Microcontroller Power Supply Supervisor
IMP809JEUR-T A1PROS

获取价格

3-Pin Microcontroller Power Supply Supervisor
IMP809JEUR-T IMP

获取价格

3-Pin Microcontroller Power Supply Supervisor
IMP809LEUR-T A1PROS

获取价格

3-Pin Microcontroller Power Supply Supervisor
IMP809LEUR-T IMP

获取价格

3-Pin Microcontroller Power Supply Supervisor
IMP809MEUR-T IMP

获取价格

3-Pin Microcontroller Power Supply Supervisor
IMP809MEUR-T A1PROS

获取价格

3-Pin Microcontroller Power Supply Supervisor
IMP809REUR-T A1PROS

获取价格

3-Pin Microcontroller Power Supply Supervisor
IMP809REUR-T IMP

获取价格

3-Pin Microcontroller Power Supply Supervisor