参数资料
型号: G690L293T91
厂商: Global Mixed-mode Technology Inc.
元件分类: 复位半导体
英文描述: Microprocessor Reset IC
中文描述: 微处理器复位IC
文件页数: 12/12页
文件大小: 219K
代理商: G690L293T91
Ver: 1.3
Oct 31, 2002
TEL: 886-3-5788833
http://www.gmt.com.tw
9
G690/G691
Global Mixed-mode Technology Inc.
Figure 3. Interfacing to Ps with Bidirectional Reset
I/O
Figure 4. G691L Open-Drain RESET Output Allows
Use with Multiple Supplies
Interfacing to Ps with Bidirectional Reset Pins
Since the RESET output on the G691L is open drain,
this device interfaces easily with Ps that have bidi-
rectional reset pins, such as the Motorola 68HC11.
Connecting the P supervisor’s RESET output di-
rectly to the microcontroller’s (C’s) RESET pin with
a single pull-up resistor allows either device to assert
reset (Figure 3).
G691L Open-Drain RESET Output Allows Use with
Multiple Supplies
Generally, the pull-up connected to the G691L will
connect to the supply voltage that is being monitored
at the IC’s VCC pin. However, some systems may use
the open-drain output to level-shift from the monitored
supply to reset circuitry powered by some other supply
(Figure 4). Note that as the G691L’s VCC decreases
below 1V, so does the IC’s ability to sink current at
RESET . Also, with any pull-up, RESET will be pulled
high as VCC decays toward 0. The voltage where this
occurs depends on the pull-up resistor value and the
voltage to which it is connected.
Benefits of Highly Accurate Reset Threshold
Most P supervisor ICs have reset threshold voltages
between 5% and 10% below the value of nominal
supply voltages. This ensures a reset will not occur
within 5% of the nominal supply, but will occur when
the supply is 10% below nominal.
When using ICs rated at only the nominal supply ±5%,
this leaves a zone of uncertainty where the supply is
between 5% and 10% low, and where the reset may or
may not be asserted.
The G69_ _463/G69_ _308 use highly accurate circuitry
to ensure that reset is asserted close to the 5% limit,
and long before the supply has declined to 10% below
nominal.
RESET
INPUT
GND
P
V
CC
RESET
GND
G691
V
CC
V
CC
MOTOROLA
68HCXX
RPULL-UP
RESET
INPUT
GND
P
V
CC
RESET
GND
G691
V
CC
V
CC
MOTOROLA
68HCXX
RPULL-UP
RESET
INPUT
GND
5V SYSTEM
V
CC
RESET
GND
G691
V
CC
RPULL-UP
+3.3V
+5.0V
RESET
INPUT
GND
5V SYSTEM
V
CC
RESET
GND
G691
V
CC
RPULL-UP
+3.3V
+5.0V
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G690L293T93 制造商:GMT 制造商全称:Global Mixed-mode Technology Inc 功能描述:Microprocessor Reset IC
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