Z86L972 Datasheet, PDF (34/91 Pages) Zilog, Inc. – Low-Voltage Microcontrollers

Z86L972/Z86L973/Z86L974
Z86L972/Z86L973/Z86L974
Low-Voltage Microcontrollers
27
Figure 13. Active Glitch/Power Filter
When the internal power/glitch filter is not used, both V_{DD_padring} and V_DD must be
connected together externally to the power supply.
When the internal circuitry is used, the V_{DD_padring} has to be connected to the
power supply and the V_DD has to be connected to an external energy storage
capacitor (1−10 µF range). The core is connected only to this capacitor during
power supply glitches.
Table 8 describes the active glitch/filter specifications.
Table 8. Active Glitch/Filter Specifications (Preliminary)
Parameter
Max
Diff. stage gain
Diff. stage bandwidth
Rise time
255 ns
Fall time
214 ns
R_dson
10 Ω
Min
75 dB
15 MHz
Condition
50 mV pulse
50 mV pulse
On the wafer level, all three power buses are available. Depending on the number
of pins of the package, one or more power buses are connected together.
The active glitch/power filter effectively increases the noise immunity for battery-
operated designs where the controller is driving high current loads (IR LED, key-
board scanning).
PS010504-1002
PRELIMINARY