參數(shù)資料
型號: ADM8694
廠商: Analog Devices, Inc.
英文描述: bqTINY(TM) Linear 1-cell Li-Ion Charger w/ 1-A FET, Charge Enable & Term Enable in QFN-10 10-SON -40 to 85
中文描述: 微處理器監(jiān)控電路
文件頁數(shù): 7/16頁
文件大小: 183K
代理商: ADM8694
ADM8690–ADM8695
REV. 0
–7–
T able I. ADM8691, ADM8693, ADM8695 Reset Pulse Width and Watchdog T imeout Selections
Watchdog T imeout Period
Reset Active Period
Immediately
After Reset
OSC SE L
OSC IN
Normal
ADM8691/ADM8693
ADM8695
Low
Low
Floating or High
Floating or High
External Clock Input
External Capacitor
Low
Floating or High
1024 CLK S
400 ms
×
C/47 pF
100 ms
1.6 s
4096 CLK S
1.6 s
×
C/47 pF
1.6 s
1.6 s
512 CLK S
200 ms
×
C/47 pF
50 ms
50 ms
2048 CLK S
520 ms
×
C/47 pF
200 ms
200 ms
NOT E
With the OSC SEL pin low, OSC IN can be driven by an external clock signal, or an external capacitor can be connected between OSC IN and GND. T he nominal
internal oscillator frequency is 10.24 kHz. T he nominal oscillator frequency with external capacitor is: F
OSC
(Hz) = 184,000/C (pF)
On the ADM8690/ADM8692 the watchdog timeout period is
fixed at 1.6 seconds and the reset pulse width is fixed at 50 ms.
On the ADM8694 the watchdog timeout period is also 1.6 sec-
onds but the reset pulse width is fixed at 200 ms. T he ADM8691/
ADM8693/ADM8695 allow these times to be adjusted as
shown in T able I. Figure 4 shows the various oscillator configu-
rations that can be used to adjust the reset pulse width and
watchdog timeout period.
T he internal oscillator is enabled when OSC SEL is high or
floating. In this mode, OSC IN selects between the 1.6 second
and 100 ms watchdog timeout periods. With OSC IN connected
high or floating, the 1.6 second timeout period is selected; while
with it connected low, the 100 ms timeout period is selected. In
either case, immediately after a reset the timeout period is 1.6
seconds. T his gives the microprocessor time to reinitialize the
system. If OSC IN is low, then the 100 ms watchdog period be-
comes effective after the first transition of WDI. T he software
should be written such that the I/O port driving WDI is left in
its power-up reset state until the initialization routines are com-
pleted and the microprocessor is able to toggle WDI at the mini-
mum watchdog timeout period of 70 ms.
Watchdog Output (WDO)
T he Watchdog Output
WDO
(ADM8691/ADM8693/
ADM8695) provides a status output which goes low if the
watchdog timer “times out” and remains low until set high by
the next transition on the Watchdog Input.
WDO
is also set
high when V
CC
goes below the reset threshold.
8
7
CLOCK
0 TO 500kHz
OSC SEL
OSC IN
ADM8691
ADM8693
ADM8695
Figure 4a. External Clock Source
8
7
OSC SEL
OSC IN
ADM8691
ADM8693
ADM8695
C
OSC
Figure 4b. External Capacitor
8
7
NC
NC
OSC SEL
OSC IN
ADM8691
ADM8693
ADM8695
Figure 4c. Internal Oscillator (1.6 Second Watchdog)
8
7
OSC SEL
OSC IN
ADM8691
ADM8693
ADM8695
NC
Figure 4d. Internal Oscillator (100 ms Watchdog)
相關(guān)PDF資料
PDF描述
ADM8694AN bqTINY(TM) Linear 1-cell Li-Ion Charger w/ 1-A FET, Temp Sense & Charge Enable in QFN-10 10-SON -40 to 85
ADM8694ARN Single Chip Li-Ion Charge Management IC for Handheld Applications (bqTINY) 10-SON -40 to 125
ADM8690-ADM8695 Microprocessor Supervisory Circuits
ADM8690 Microprocessor Supervisory Circuits(微處理器監(jiān)控電路)
ADM8690ADM8695 Microprocessor Supervisory Circuits
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參數(shù)描述
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ADM8694ARNZ 制造商:Analog Devices 功能描述:Processor Supervisor 4.65V 4.75V to 5.5V 8-Pin SOIC N 制造商:Analog Devices 功能描述:Microprocessor Supervisor