参数资料
型号: MAX632ACJA
厂商: Maxim Integrated Products, Inc.
元件分类: 数字电源管理
英文描述: Voltage-Mode SMPS Controller
中文描述: 电压模式开关电源控制器
文件页数: 2/14页
文件大小: 205K
代理商: MAX632ACJA
MAX6316–MAX6322
5-Pin P Supervisory Circuits with
Watchdog and Manual Reset
10
______________________________________________________________________________________
Applications Information
Watchdog Input Current
The WDI input is internally driven through a buffer and
series resistor from the watchdog counter. For minimum
watchdog input current (minimum overall power con-
sumption), leave WDI low for the majority of the watch-
dog timeout period. When high, WDI can draw as much
as 160A. Pulsing WDI high at a low duty cycle will
reduce the effect of the large input current. When WDI
is left unconnected, the watchdog timer is serviced
within the watchdog timeout period by a low-high-low
pulse from the counter chain.
Negative-Going VCC Transients
These supervisors are immune to short-duration, nega-
tive-going VCC transients (glitches), which usually do
not require the entire system to shut down. Typically,
200ns large-amplitude pulses (from ground to VCC) on
the supply will not cause a reset. Lower amplitude puls-
es result in greater immunity. Typically, a VCC transient
that goes 100mV under the reset threshold and lasts
less than 4s will not trigger a reset. An optional 0.1F
bypass capacitor mounted close to VCC provides addi-
tional transient immunity.
Ensuring Valid Reset Outputs
Down to VCC = 0
The MAX6316_/MAX6317H/MAX6318_H/MAX6319_H/
MAX6321HP/MAX6322HP are guaranteed to operate
properly down to VCC = 1V. In applications that require
valid reset levels down to VCC = 0, a pulldown resistor
to active-low outputs (push/pull and bidirectional only,
Figure 8) and a pullup resistor to active-high outputs
(push/pull only, Figure 9) will ensure that the reset line
is valid while the reset output can no longer sink or
source current. This scheme does not work with the
open-drain outputs of the MAX6320/MAX6321/MAX6322.
The resistor value used is not critical, but it must be
large enough not to load the reset output when VCC is
above the reset threshold. For most applications,
100k
is adequate.
Watchdog Software Considerations
(MAX6316/MAX6317/MAX6318/
MAX6320/MAX6321)
One way to help the watchdog timer monitor software
execution more closely is to set and reset the watchdog
input at different points in the program, rather than
pulsing the watchdog input high-low-high or low-high-
low. This technique avoids a stuck loop, in which the
watchdog timer would continue to be reset inside the
loop, keeping the watchdog from timing out.
VCC
tWD
tRP
tRST
WDI
RESET
MAX6316/MAX6317
MAX6318/MAX6320
MAX6321
Figure 7. Watchdog Timing Relationship
GND
*THIS SCHEMATIC DOES NOT WORK ON THE OPEN-DRAIN
OUTPUTS OF THE MAX6321/MAX6322.
100k
VCC
RESET
MAX6317
MAX6318
MAX6319
MAX6321*
MAX6322*
Figure 9. Ensuring RESET Valid to VCC = 0 on Active-High
Push/Pull Outputs
GND
100k
VCC
RESET
MAX6316
MAX6318
MAX6319
Figure 8. Ensuring RESET Valid to VCC = 0 on Active-Low
Push/Pull and Bidirectional Outputs
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MAX632ACPA 功能描述:直流/直流开关调节器 5V Fixed/Adjustable Step-Up Reg RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MAX632ACPA+ 功能描述:直流/直流开关调节器 5V Fixed/Adjustable Step-Up Reg RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MAX632ACSA 功能描述:直流/直流开关调节器 5V Fixed/Adjustable Step-Up Reg RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MAX632ACSA+ 功能描述:直流/直流开关调节器 5V Fixed/Adjustable Step-Up Reg RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MAX632ACSA+T 功能描述:直流/直流开关调节器 5V Fixed/Adjustable Step-Up Reg RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5