TC51N2702ECBTR Datasheet, PDF (5/14 Pages) Microchip Technology – 1UA Voltage Detector with Output Delay

TC51
4.0 APPLICATIONS INFORMATION
4.1 Processor RESET Supervisor
Figure 4-1 shows the TC51 used as a processor reset
supervisor. Because the TC51 is available in threshold
settings of 1.6V to 6.0V, the user can choose the reset
single threshold setting best suited to the system power
supply voltage at hand. Also, the 1µA supply current is
significantly lower than its nearest competitor.
As shown in the timing diagram (Figure 3-1),V_OUT is
low for voltages between 0.7V and V_DET+. The TC51
activates its on-board delay timer once the power
supply voltage is within tolerance (i.e., greater than
V_DET+). V_OUT is released after delay time (T_DLY).
Should the power supply voltage momentarily dip
(“brown-out” condition), the TC51 immediately drives
and holds the processor RESET input low. RESET is
released after the power supply voltage is again within
tolerance, and after the delay timer expires. RESET is
driven and held low when power fails (power-off or
“blackout”), and is maintained down low to a supply
voltage of 0.7V.
FIGURE 4-1:
V_DD
PROCESSOR RESET
SUPERVISOR
V_DD
V_OUT
TC51
GND
Processor
R1
47K
RESET
FIGURE 4-2:
TC51 OPERATION DURING POWER-UP, BROWN-OUT AND POWER DOWN
Nominal
Power Supply
Voltage
Power-Up
Brown-Out
Steady
State
Operation
Power Down
Threshold
Voltage
(V_DET-, V_DET+)
0.7V
V_OH
TC51 Output
V_OL
Time
T_DLY
T_DLY
 2002 Microchip Technology Inc.
DS21429B-page 5