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参数资料
| 型号： | MAX6750KA18-T |
| 厂商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分类： | 电源管理 |
| 英文描述： | µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay |
| 中文描述： | 1-CHANNEL POWER SUPPLY MANAGEMENT CKT, PDSO8 |
| 封装： | SOT-23, 8 PIN |
| 文件页数： | 13/14页 |
| 文件大小： | 170K |
| 代理商： | MAX6750KA18-T |
MAX6746–MAX6753
where VMON_TH is the desired reset threshold voltage
and VTH is the reset input threshold (1.235V). Resistors
R1 and R2 can have very high values to minimize cur-
rent consumption due to low leakage currents. Set R2
to some conveniently high value (500k
Ω, for example)
and calculate R1 based on the desired reset threshold
voltage, using the following formula:
R1 = R2 x (VMON_TH/VRESET IN - 1) (
Ω)
The MAX6748 and MAX6749 do not monitor VCC sup-
ply voltage, therefore, VCC must be greater than 1.5V to
guarantee RESET IN threshold accuracy and timing
performance. The MAX6748 and MAX6749 can be con-
figured to monitor VCC voltage by connecting VCC to
VMON_TH.
Dual-Voltage Monitoring
(MAX6750/MAX6751)
The MAX6750 and MAX6751 contain both factory-
trimmed threshold voltages and an adjustable reset
threshold input, allowing the monitoring of two voltages,
VCC and VMON_TH (see Figure 2). RESET is asserted
when either of the voltages falls below it respective
threshold voltages.
Manual Reset (MAX6746/MAX6747)
Many P-based products require manual reset capabil-
ity, to allow an operator or external logic circuitry to initi-
ate a reset. The manual reset input (MR) can connect
directly to a switch without an external pullup resistor or
debouncing network. MR is internally pulled up to VCC
and, therefore, can be left unconnected if unused.
MR is designed to reject fast, falling transients (typically
100ns pulses) and it must be held low for a minimum of
1s to assert the reset output. A 0.1F capacitor from
MR to ground provides additional noise immunity. After
MR transitions from low to high, reset remains asserted
for the duration of the reset timeout period.
A manual reset option can easily be implemented
with the MAX6748–MAX6751 by connecting a normally
open momentary switch in parallel with R2 (Figure 3).
When the switch is closed, the voltage on RESET IN
goes to zero, initiating a reset. Similar to the MAX6746/
MAX6747 manual reset, reset remains asserted while
the voltage at RESET IN is zero and for the reset time-
out period after the switch is opened.
P Reset Circuits with Capacitor-Adjustable
Reset/Watchdog Timeout Delay
8
_______________________________________________________________________________________
VCC
WDI
tWD
tRP
RESET
NORMAL MODE (WDS = GND)
VCC
OV
Figure 4a. Watchdog Timing Diagram, WDS = GND
MAX6748
MAX6749
MAX6750
MAX6751
RESET IN
GND
VCC
VMON_TH
R1
R2
Figure 3. Adding an External Manual Reset Function to the
MAX6748–MAX6751
相关PDF资料 |
PDF描述 |
|---|---|
| MAX6750KA19-T | µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay |
| MAX6750KA20-T | µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay |
| MAX6750KA21-T | µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay |
| MAX6750KA22-T | µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay |
| MAX6750KA24-T | µP Reset Circuits with Capacitor-Adjustable Reset/Watchdog Timeout Delay |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX6750KA19 | 制造商:Maxim Integrated Products 功能描述:SINGLE/DUAL-VOLT MICROPROC. RESET C - Rail/Tube |
| MAX6750KA19+T | 功能描述:监控电路 RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟（典型值）:10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel |
| MAX6750KA19-T | 功能描述:监控电路 RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟（典型值）:10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel |
| MAX6750KA20 | 制造商:Maxim Integrated Products 功能描述:SINGLE/DUAL-VOLT MICROPROC. RESET C - Rail/Tube |
| MAX6750KA20+T | 功能描述:监控电路 RoHS:否 制造商:STMicroelectronics 监测电压数: 监测电压: 欠电压阈值: 过电压阈值: 输出类型:Active Low, Open Drain 人工复位:Resettable 监视器:No Watchdog 电池备用开关:No Backup 上电复位延迟（典型值）:10 s 电源电压-最大:5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:UDFN-6 封装:Reel |
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