G696 GMT [Global Mixed-mode Technology Inc], G696 Datasheet - Page 7

• Manufacturer Part Number: G696
• Description: Microprocessor Reset IC
• Manufacturer: GMT [Global Mixed-mode Technology Inc]

Interfacing to µPs with Bidirectional Reset Pins
Since the RESET output on the G697L is open drain,
this device interfaces easily with µPs that have bidi-
rectional reset pins, such as the Motorola 68HC11.
Connecting the µP supervisor’s RESET output di-
rectly to the microcontroller’s (µC’s) RESET pin with
a single pull-up resistor allows either device to assert
reset (Figure 5).
G697L Open-Drain
Multiple Supplies
Generally, the pull-up connected to the G697L will
connect to the supply voltage that is being monitored
at the IC’s V
the open-drain output to level-shift from the monitored
supply to reset circuitry powered by some other supply
(Figure 6). Note that as the G697L’s V
below 1V, so does the IC’s ability to sink current at
Ver: 1.1
Jul 26, 2002
RESET . Also, with any pull-up, RESET will be pulled
CC
Global Mixed-mode Technology Inc.
pin. However, some systems may use
RESET
Output Allows Use with
CC
decreases
7
high as
occurs depends on the pull-up resistor value and the
voltage to which it is connected.
Benefits of Highly Accurate Reset Threshold
Most µP 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.
VCC
decays toward 0. The voltage where this
G696/G697
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