您的位置：维库电子市场网 > Datasheet > MAX793T
MAX793T数据手册封面

MAX793T Datasheet

  • MAX793T

  • 3.0V/3.3V可调、微处理器监控电路, 微处理器监控电路, 提供备用...

  • 604.40KB

  • 20页

  • MAXIM

阅览下载 纠错 0

扫码查看芯片数据手册

上传产品规格书

PDF预览

3.0V/3.3V Adjustable Microprocessor
Supervisory Circuits
MAX793/MAX794/MAX795
3.0V OR 3.3V
R1
PFI
R2
V
CC
R1
PFO
PFI
R2
MR
GND
V
IN
V
CC
PFO
V
L
V
TRIP
= R2 (V
PFT
+ V
PFH
)
V
L
= R2 (V
PFT
)
1
V
TRIP
V
CC
R1
0V
V
IN
R1
+
R2
R2
V
CC
PFO
V
TRIP
V
TRIP
= V
PFT
WHERE V
PFT
= 1.237V
V
PFH
= 10mV
NOTE: V
TRIP,
V
L
ARE NEGATIVE
V
H
V
IN
GND
V
IN
V
CC
3.0V OR 3.3V
MAX793
MAX794
MAX793
MAX794
PFO
(
R1 + R2
)
鈥?/div>
1
V
CC
R1
1
1
(
)
)
(
R1 + R2
)
鈥?/div>
V
H
= (V
PFT
+ V
PFH
)
(
R1
+
R2
R2
(a)
(b)
Figure 12. Using the Power-Fail Comparator to Monitor an Additional Power Supply: (a) V
IN
Is Negative, (b) V
IN
Is Positive
The power-fail comparator turns off and PFO goes low
when V
CC
falls below V
SW
on power-down. During the
first half of the reset timeout period (t
RP
), PFO is forced
high, irrespective of V
PFI
. At the beginning of the sec-
ond half of t
RP
, the power-fail comparator is enabled
and PFO follows PFI. If the comparator is unused, con-
nect PFI to V
CC
and leave PFO unconnected. PFO may
be connected to MR so that a low voltage on PFI will
generate a reset (Figure 12b). In this configuration,
when the monitored voltage causes PFI to fall below
V
PFT
, PFO pulls MR low, causing a reset to be assert-
ed. Reset remains asserted as long as PFO holds MR
low, and for 200ms after PFO pulls MR high when the
monitored supply is above the programmed threshold.
Backup-Battery Switchover
In the event of a brownout or power failure, it may be
necessary to preserve the contents of RAM. With a
backup battery installed at BATT, the devices automati-
cally switch RAM to backup power when V
CC
falls. In
order to allow the backup battery (e.g., a 3.6V lithium
cell) to have a higher voltage than V
CC
, this family of 碌P
supervisors (designed for 3.3V and 3V systems) does
not always connect BATT to OUT when V
BATT
is
greater than V
CC
. BATT connects to OUT (through a
140鈩?switch) either when V
CC
falls below V
SW
and
V
BATT
is greater than V
CC
,
or
when V
CC
falls below
1.75V (typ) regardless of the BATT voltage.
Switchover at V
SW
ensures that battery-backup mode is
entered before V
OUT
gets too close to the 2.0V mini-
mum required to reliably retain data in most CMOS
RAM, (switchover at higher V
CC
voltages would
decrease backup-battery life). When V
CC
recovers,
switchover is deferred either until V
CC
crosses V
BATT
if
V
BATT
is below V
RST
, or when V
CC
rises above the
reset threshold (V
RST
) if V
BATT
is above V
RST
. This
power-up switchover technique prevents V
CC
from
charging the backup battery through OUT when using
an external transistor driven by BATT ON. OUT con-
nects to V
CC
through a 4鈩?(max) PMOS power switch
when V
CC
crosses the reset threshold (Figure 13).
BATT ON (MAX793/MAX794)
BATT ON is high when OUT is connected to BATT.
Although BATT ON can be used as a logic output to
indicate the battery switchover status, it is most often
used as a gate or base drive for an external pass tran-
sistor for high-current applications (see
Driving an
External Switch with BATT ON
in the
Applications
Information
section). When V
CC
exceeds V
RST
on
power-up, BATT ON sinks 3.2mA at 0.4V. In battery-
backup mode, this terminal sources 100碌A from BATT.
14
______________________________________________________________________________________

MAX793T相关型号PDF文件下载

  • 型号
    版本
    描述
    厂商
    下载
  • MAX700
    英文版
    Power-Supply Monitor with Reset
    MAXIM
    MAX700
  • MAX700
    英文版
    Power-Supply Monitor with Reset
    MAXIM [Max...
    MAX700
  • MAX701
    英文版
    Power-Supply Monitor with Reset
    MAXIM
    MAX701
  • MAX701
    英文版
    Power-Supply Monitor with Reset
    MAXIM [Max...
    MAX701
  • MAX702
    英文版
    Power-Supply Monitor with Reset
    MAXIM
    MAX702
  • MAX702
    英文版
    Power-Supply Monitor with Reset
    MAXIM [Max...
    MAX702
  • MAX703
    英文版
    Low-Cost レP Supervisory Circuits with Battery Backup
    MAXIM
    MAX703
  • MAX703
    英文版
    Low-Cost レP Supervisory Circuits with Battery Backup
    MAXIM [Max...
    MAX703
  • MAX704
    英文版
    Low-Cost レP Supervisory Circuits with Battery Backup
    MAXIM
    MAX704
  • MAX704
    英文版
    Low-Cost レP Supervisory Circuits with Battery Backup
    MAXIM [Max...
    MAX704
  • MAX705
    英文版
    Low-Cost, uP Supervisory Circuits
    MAXIM
    MAX705
  • MAX705
    英文版
    Low-Cost, uP Supervisory Circuits
    MAXIM [Max...
    MAX705
  • MAX706
    英文版
    +3V Voltage Monitoring, Low-Cost, レP Supervisory Circuits
    MAXIM
    MAX706
  • MAX706
    英文版
    Low-Cost, uP Supervisory Circuits
    MAXIM [Max...
    MAX706
  • MAX706
    英文版
    +3V Voltage Monitoring, Low-Cost, レP Supervisory Circuits
    MAXIM [Max...
    MAX706
  • MAX707
    英文版
    Low-Cost, uP Supervisory Circuits
    MAXIM
    MAX707
  • MAX707
    英文版
    Low-Cost, uP Supervisory Circuits
    MAXIM [Max...
    MAX707
  • MAX708
    英文版
    Low-Cost, uP Supervisory Circuits
    MAXIM
    MAX708
  • MAX708
    英文版
    Low-Cost, uP Supervisory Circuits
    MAXIM [Max...
    MAX708
  • MAX709
    英文版
    Power-Supply Monitor with Reset
    MAXIM
    MAX709

您可能感兴趣的PDF文件资料

热门IC型号推荐

©2024 维库电子市场网（www.dzsc.com）　备案号：浙B2-20050339-1 经营许可证：浙B2-20210386版权声明
买家服务热线：0571-85317607 | 买家服务部QQ： QQ:1609526468
卖家服务热线：0571-85317607 | 卖家服务部QQ： QQ:331652727

扫码下载APP，
一键连接广大的电子世界。

在线人工客服

买家服务：
卖家服务：

0571-85317607

客服在线时间周一至周五
9:00-17:30

关注官方微信号，
第一时间获取资讯。

建议反馈
返回顶部

建议反馈

联系人：

联系方式：

按住滑块，拖拽到最右边
>>
感谢您向阿库提出的宝贵意见，您的参与是维库提升服务的动力！意见一经采纳，将有感恩红包奉上哦！

PDF纠错X

投诉电话：0571-85317607 投诉QQ：

如选匿名将无法为您反馈投诉结果，建议实名投诉！