Datasheet

LM809, LM810
www.ti.com SNVS052D –SEPTEMBER 1999–REVISED MAY 2013
Figure 10. Maximum Transient Duration without Causing a Reset Pulse vs. Reset Comparator Overdrive
Interfacing to µPs with Bidirectional Reset Pins
Microprocessors with bidirectional reset pins, such as the Motorola 68HC11 series, can be connected to the
LM809 RESET output. To ensure a correct output on the LM809 even when the microprocessor reset pin is in
the opposite state, connect a 4.7kΩ resistor between the LM809 RESET output and the µP reset pin, as shown
in Figure 11. Buffer the LM809 RESET output to other system components.
Figure 11. Interfacing to Microprocessors with Bidirectional Reset I/O
SON Mounting
The SON package requires special mounting techniques which are detailed in Texas Instruments Application
Note AN-1187. Referring to the section PCB Design Recommendations, it should be noted that the pad style
which should be used with the SON package is the NSMD (non-solder mask defined) type.
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