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參數(shù)資料
| 型號： | ADM690 |
| 廠商： | Analog Devices, Inc. |
| 英文描述： | Microprocessor Supervisory Circuits(微處理器監(jiān)控電路) |
| 中文描述： | 微處理器監(jiān)控電路（微處理器監(jiān)控電路） |
| 文件頁數(shù)： | 5/16頁 |
| 文件大小： | 207K |
| 代理商： | ADM690 |
ADM690–ADM695
REV. A
–5–
PIN CONFIGURAT IONS
PRODUCT SE LE CT ION GUIDE
Part
Number
Nominal Reset
T ime
Nominal V
CC
Reset T hreshold
Nominal Watchdog
T imeout Period
Battery Backup
Switching
Base Drive
E xt PNP
Chip E nable
Signals
ADM690
ADM691
ADM692
ADM693
ADM694
ADM695
50 ms
50 ms or ADJ
50 ms
50 ms or ADJ
200 ms
200 ms or ADJ
4.65 V
4.65 V
4.4 V
4.4 V
4.65 V
4.65 V
1.6 s
100 ms, 1.6 s, ADJ
1.6 s
100 ms, 1.6 s, ADJ
1.6 s
100 ms, 1.6 s, ADJ
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
CIRCUIT INFORMAT ION
Battery Switchover Section
T he battery switchover circuit compares V
CC
to the V
BAT T
input, and connects V
OUT
to whichever is higher. Switchover
occurs when V
CC
is 50 mV higher than V
BAT T
as V
CC
falls, and
when V
CC
is 70 mV greater than V
BAT T
as V
CC
rises. T his
20 mV of hysteresis prevents repeated rapid switching if V
CC
falls very slowly or remains nearly equal to the battery voltage.
Figure 1. Battery Switchover Schematic
During normal operation with V
CC
higher than V
BAT T
, V
CC
is in-
ternally switched to V
OUT
via an internal PMOS transistor
switch. T his switch has a typical on-resistance of 1.5
and can
supply up to 100 mA at the V
OUT
terminal. V
OUT
is normally
used to drive a RAM memory bank which may require instanta-
neous currents of greater than 100 mA. If this is the case then a
bypass capacitor should be connected to V
OUT
. T he capacitor
will provide the peak current transients to the RAM. A capaci-
tance value of 0.1
μ
F or greater may be used.
If the continuous output current requirement at V
OUT
exceeds
100 mA or if a lower V
CC
–V
OUT
voltage differential is desired,
an external PNP pass transistor may be connected in parallel
with the internal transistor. T he BAT T ON output (ADM691/
ADM693/ADM695) can directly drive the base of the external
transistor.
A 20
MOSFET switch connects the V
BAT T
input to V
OUT
during battery backup. T his MOSFET has very low input-to-
output differential (dropout voltage) at the low current levels
required for battery back up of CMOS RAM or other low
power CMOS circuitry. T he supply current in battery back up
is typically 0.6
μ
A.
T he ADM690/ADM691/ADM694/ADM695 operates with
battery voltages from 2.0 V to 4.25 V and the ADM692/ADM693
operates with battery voltages from 2.0 V to 4.0 V. High value
capacitors, either standard electrolytic or the farad size double
layer capacitors, can also be used for short-term memory back
up. A small charging current of typically 10 nA (0.1
μ
A max)
flows out of the V
BAT T
terminal. T his current is useful for
maintaining rechargeable batteries in a fully charged condition.
T his extends the life of the back up battery by compensating
for its self discharge current. Also note that this current poses
no problem when lithium batteries are used for back up since
the maximum charging current (0.1
μ
A) is safe for even the
smallest lithium cells.
If the battery-switchover section is not used, V
BAT T
should be
connected to GND and V
OUT
should be connected to V
CC
.
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
TOP VIEW
(Not to Scale)
ADM691
ADM693
ADM695
GND
V
BATT
V
OUT
PFI
PFO
WDO
V
CC
RESET
BATT ON
LOW LINE
OSC IN
OSC SEL
RESET
CE
IN
CE
OUT
WDI
GND
V
BATT
V
OUT
PFI
PFO
WDI
RESET
V
CC
1
2
3
4
8
7
6
5
TOP VIEW
(Not to Scale)
ADM690
ADM692
ADM694
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ADM690A | 制造商:AD 制造商全稱:Analog Devices 功能描述:Microprocessor Supervisory Circuits |
| ADM690AAN | 功能描述:IC SUPERVISOR MPU 4.65V WD 8DIP RoHS:否 類別:集成電路 (IC) >> PMIC - 監(jiān)控器 系列:- 標準包裝:1 系列:- 類型:簡單復(fù)位/加電復(fù)位 監(jiān)視電壓數(shù)目:1 輸出:開路漏極或開路集電極 復(fù)位:高有效 復(fù)位超時:- 電壓 - 閥值:1.8V 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:6-TSOP（0.059"，1.50mm 寬）5 引線 供應(yīng)商設(shè)備封裝:5-TSOP 包裝:剪切帶 (CT) 其它名稱:NCP301HSN18T1GOSCT |
| ADM690AANZ | 功能描述:IC SUPERVISOR MPU 4.65V WD 8DIP RoHS:是 類別:集成電路 (IC) >> PMIC - 監(jiān)控器 系列:- 其它有關(guān)文件:STM6717 View All Specifications 標準包裝:1 系列:- 類型:多壓監(jiān)控器 監(jiān)視電壓數(shù)目:2 輸出:開路漏極或開路集電極 復(fù)位:低有效 復(fù)位超時:最小為 600 ms 電壓 - 閥值:1.11V，3.075V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SC-74A，SOT-753 供應(yīng)商設(shè)備封裝:SOT-23-5 包裝:Digi-Reel® 產(chǎn)品目錄頁面:1194 (CN2011-ZH PDF) 其它名稱:497-7019-6 |
| ADM690AARM | 功能描述:IC SUPERVISOR MPU 4.65V WD 8MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 監(jiān)控器 系列:- 標準包裝:1 系列:- 類型:簡單復(fù)位/加電復(fù)位 監(jiān)視電壓數(shù)目:1 輸出:開路漏極或開路集電極 復(fù)位:高有效 復(fù)位超時:- 電壓 - 閥值:1.8V 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:6-TSOP（0.059"，1.50mm 寬）5 引線 供應(yīng)商設(shè)備封裝:5-TSOP 包裝:剪切帶 (CT) 其它名稱:NCP301HSN18T1GOSCT |
| ADM690AARM-REEL | 制造商:Analog Devices 功能描述:Processor Supervisor 4.65V 4.65V 8-Pin MSOP T/R |
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