參數(shù)資料
型號(hào): MAX822
廠商: Maxim Integrated Products, Inc.
英文描述: CMOS.High-Speed.8-Bit ADC with 4- or 8-Channel Multiplexer[MX7824/MX7828/MX7824BQ/MX7824CQ/MX7824KCWG/MX7824KCWG-T/MX7824KN/MX7824LCWG/MX7824LCWG-T/MX7824LN/MX7824TQ/MX7824TQ/883B/MX7824UQ/MX7824UQ/883B/5962-8876401LA/5962-8876402LA/MX7828BQ/MX7828CQ/MX7828KCWI/MX7828KCWI-T/MX7828KN/MX7828KP/MX7828KP-T/MX7828LCWI/MX7828LCWI-T/MX7828LN/MX7828LP/MX7828LP-T/MX7828TQ/MX7828TQ/883B/MX7828UQ/MX7828UQ/883B/5962-8876403XA/5962-8876404XA ]
中文描述: 4引腳、微處理器電壓監(jiān)測(cè)器,引腳可設(shè)置上電復(fù)位超時(shí)周期
文件頁數(shù): 14/16頁
文件大?。?/td> 272K
代理商: MAX822
M
Microprocessor and Nonvolatile
Memory Supervisory Circuits
14
______________________________________________________________________________________
Alternative Chip-Enable Gating
Using memory devices with both CE and
CE
inputs
allows the MAX792/MAX820 CE propagation delay
to be bypassed. To do this, connect
CE
IN to ground,
pull up
CE
OUT to V
CC
, and connect
CE
OUT to the
CE
input of each memory device (Figure 11). The CE input
of each memory device then connects directly to the
chip-select logic, which does not have to be gated by
the MAX792/MAX820.
Interfacing to μPs with Bidirectional
Reset Inputs
μPs with bidirectional reset pins, such as the Motorola
68HC11 series, can contend with the MAX792/MAX820
RESET
output. If, for example, the MAX792/MAX820
RESET
output is asserted high and the μP wants to pull it low,
indeterminate logic levels may result. To avoid this,
connect a 4.7k
resistor between the MAX792/MAX820
RESET
output and the μP reset I/O, as in Figure 12.
Buffer the MAX792/MAX820
RESET
output to other sys-
tem components.
Negative-Going V
CC
Transients
While issuing resets to the μP during power-up, power-
down, and brownout conditions, these supervisors are
relatively immune to short-duration negative-going V
CC
transients (glitches). It is usually undesirable to reset
the μP when V
CC
experiences only small glitches.
Figure 13 shows maximum transient duration vs. reset-
comparator overdrive, for which reset pulses are
not
generated. The graph was produced using negative-
going V
CC
pulses, starting at 5V and ending below the
reset threshold by the magnitude indicated (reset-
comparator overdrive). The graph shows the maximum
pulse width a negative-going V
CC
transient may typi-
cally have without causing a reset pulse to be issued.
As the amplitude of the transient increases (i.e., goes
farther below the reset threshold), the maximum allow-
able pulse width decreases. Typically, a V
CC
transient
that goes 100mV below the reset threshold and lasts for
30μs or less will not cause a reset pulse to be issued.
A 100nF bypass capacitor mounted close to the V
CC
pin provides additional transient immunity.
MAX792
MAX820
CE IN
13
14
12
+5V
GND
3
V
CC
CE OUT
CE
CE
CE
CE
CE
CE
CE
CE
RAM 1
RAM 2
RAM 3
RAM 4
ACTIVE-HIGH CE
LINES FROM LOGIC
MAXIMUM R
P
VALUE DEPENDS ON
THE NUMBER OF RAMS.
MINIMUM R
P
VALUE IS 1k
*
R
P
*
Figure 11. Alternate CE Gating
V
CC
V
CC
V
CC
μ
P
BUFFER
TO OTHER
SYSTEM RESET
INPUTS
4.7k
1
RESET
RESET
GND
GND
12
MAX792
MAX820
3
Figure 12. Interfacing to μPs with Bidirectional
RESET
Pins
Figure 13. Maximum Transient Duration Without Causing a
Reset Pulse vs. Reset-Comparator Overdrive
100
0
10
100
10,000
40
20
80
60
M
RESET COMPARATOR OVERDRIVE, (V
TH
- V
CC
) (mV)
M
1000
V
CC
= 5V
T
A
= +25°C
相關(guān)PDF資料
PDF描述
MAX823LEUK Power Supply Supervisor
MAX823LEUK-T Analog IC
MAX823LEXK-T Analog IC
MAX823MEUK Power Supply Supervisor
MAX823MEXK-T Analog IC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX82211CPA 制造商:Maxim Integrated Products 功能描述:
MAX822LUS 制造商:Maxim Integrated Products 功能描述:4-PIN UP VOLTAGE MONITORS WITH PIN- - Rail/Tube
MAX822LUS+ 制造商:Maxim Integrated Products 功能描述:PROCESSOR SUPERVISOR 4.63V 7UA 4PIN SOT-143 - Rail/Tube
MAX822LUS+T 功能描述:監(jiān)控電路 4-Pin uPower Voltage Monitor 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: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(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
MAX822LUS-T 功能描述:監(jiān)控電路 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: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復(fù)位:Resettable 監(jiān)視器:No Watchdog 電池備用開關(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