TC1232COE Microchip Technology, TC1232COE Datasheet - Page 5

• Manufacturer Part Number: TC1232COE
• Description: IC MPU MONITOR 4.5V 16-SOIC
• Manufacturer: Microchip Technology
• Type: Simple Reset/Power-On Resetr

Specifications of TC1232COE

• Number Of Voltages Monitored: 1
• Output: Open Drain or Open Collector
• Reset: Active High/Active Low
• Reset Timeout: 250 ms Minimum
• Voltage - Threshold: 4.37V, 4.62V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Threshold Voltage: 4.37V
• No. Of Supervisors / Monitors: 1
• Supply Voltage Range: 4V To 5.5V
• Reset Type: Active-High / Active-Low
• Supply Current: 50µA
• Delay Time: 1200ms
• Digital Ic Case Style: SOIC
• Monitored Voltage: 4.5 V to 4.75 V
• Undervoltage Threshold: 4.5 V, 4.25 V
• Output Type: Active High, Active Low, Open Drain, Push-Pull
• Manual Reset: Resettable
• Watchdog: Watchdog
• Battery Backup Switching: No Backup
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4 V
• Supply Current (typ): 200 uA
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Power Fail Detection: Yes
• Overvoltage Threshold: 4.74 V or 4.49 V
• Power-up Reset Delay (typ): 1000 ms
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

3.0
3.1
The TC1232 provides the function of warning the pro-
cessor of a power failure. When V
being below the voltage levels defined by the TOL pin,
the TC1232’s comparator outputs the RST and RST
signals to a logic level that warns the system of an out-
of-tolerance power supply. The RST and RST signals
switch at a threshold value of 4.5V if TOL is tied to V
and at a value of 4.75 volts if TOL is grounded. The
RST and RST signals are held active for a minimum of
250 msec to ensure that the power supply voltage has
been stabilized.
3.2
The debounced manual reset input (PB RST) manually
forces the reset outputs into their active states. Once
PB RST has been low for a time t
delay time) the reset outputs go active. The reset
outputs remain in their active states for a minimum of
250 msec after PB RST rises above V
A mechanical push-button or active logic signal can
drive the PB RST input. The debounced input ignores
input pulses less than 1 msec and ecognizes pulses of
20 msec or greater. No external pull-up resistor is
required because the PB RST input has an internal
pull-up to V
3.3
When the ST input is not stimulated for a preset time
period, the watchdog timer function forces RST and
RST signals to the active state. The preset time period
is determined by the TD inputs to be 150 msec with TD
connected to ground, 600 msec with TD floating, or
1200 msec with TD connected to V
watchdog timer starts timing-out from the set time
period as soon as RST and RST are inactive. If a high-
to-low transition occurs on the ST input pin prior to
time-out, the watchdog timer is reset and begins to
time-out again. If the watchdog timer is allowed to time-
out, then the RST and RST signals are driven to the
active state for 250 msec minimum (Figure 3-2).
The software routine that strobes ST is critical. The
code must be in a section of software that is executed
frequently enough so the time between toggles is less
than the watchdog time-out period. One common
technique controls the µP I/O line from two sections of
the program. The software might set the I/O line high
while operating in the foreground mode and set it low
while in the background or interrupt mode. If both
modes do not execute correctly, the watchdog timer
issues reset pulses.
2003 Microchip Technology Inc.
DETAILED DESCRIPTION
Power Monitor
Push-Button Reset Input
Watchdog Timer
CC
of approximately 100 µA.
PBD
CC
CC
(the push-button
IH
is detected as
(Figure 3-3).
(typical). The
CC
3.4
The TC1232 is optimized for fast response to negative-
going changes in V
amount of electrical noise on V
using relays) may require a 0.01 µF or 0.1 µF bypass
capacitor to reduce detection sensitivity. This capacitor
should be installed as close to the TC1232 as possible
to keep the capacitor lead length short.
FIGURE 3-1:
FIGURE 3-2:
3-Terminal
Regulator
Supply Monitor Noise Sensitivity
PB RST
+5V
0.1
µF
V
+5V
CC
TC1232
GND
DD
V
TD
Push-Button Reset.
Watchdog Timer.
CC
TC1232
. Systems with an inordinate
TOL
TD
RST
TOL GND
ST
RST
DD
ST
TC1232
+5V
(such as systems
I/O
Reset
10 k
DS21370B-page 5
processor
processor
RESET
I/O
Micro-
Micro-