ADM6384 Analog Devices, ADM6384 Datasheet - Page 9

• Manufacturer Part Number: ADM6384
• Description: Microprocessor Supervisory Circuit in 4-Lead SC70
• Manufacturer: Analog Devices

Specifications of ADM6384

• # Of Monitored Voltages: 1
• Backup-battery Switch: No
• Manual Reset Capability: Yes
• Package: SC70
• Reset Threshold Summary: 31 Options--1.58 to 5.0V
• Reset Output-stage: Active-Low/Push-Pull
• Min Reset Timeout (ms): 1,1120,140,20
• Watchdog Timer: No

CIRCUIT DESCRIPTION
The ADM6384 provides microprocessor supply voltage supervi-
sion by controlling the microprocessor reset input. Code execution
errors are avoided during power-up, power-down, and brownout
conditions by asserting a reset signal when the supply voltage is
below a preset threshold. In addition, the ADM6384 allows
supply voltage stabilization with a fixed timeout before the reset
deasserts after the supply voltage rises above the threshold. If the
user detects a problem with the system operation, a manual reset
input is available to reset the microprocessor by means of an
external push-button, for example.
RESET OUTPUT
The ADM6384 features an active-low, push-pull reset output.
The reset signal is guaranteed to be logic low for V
The reset output is asserted when V
(V
duration of the reset active timeout period (t
above the reset threshold or after MR transitions from low to high.
Figure 12 illustrates the behavior of the reset outputs.
TH
) or when MR is driven low. Reset remains asserted for the
CC
is below the reset threshold
RP
) after V
CC
down to 1 V.
CC
rises
Rev. C | Page 9 of 12
MANUAL RESET INPUT
The ADM6384 features a manual reset input ( MR ) that, when
driven low, asserts the reset output. When MR transitions from
low to high, reset remains asserted for the duration of the reset
active timeout period before deasserting. The MR input has a
52 kΩ internal pull-up so that the input is always high when
unconnected. An external push-button switch can be connected
between MR and ground so that the user can generate a reset.
Debounce circuitry for this purpose is integrated on-chip. Noise
immunity is provided on the MR input, and fast, negative-going
transients of up to 100 ns (typical) are ignored. A 0.1 µF capacitor
between MR and ground provides additional noise immunity.
RESET
V
CC
V
V
1V
0V
0V
CC
CC
Figure 12. Reset Timing Diagram
V
TH
t
RP
V
TH
ADM6384
t
RD