X40430 Datasheet, PDF (1/24 Pages) Intersil Corporation – Triple Voltage Monitor with Integrated CPU Supervisor

Preliminary Information
4kbit EEPROM
X40430/X40431
Triple Voltage Monitor with Integrated CPU Supervisor
FEATURES
• Triple voltage detection and reset assertion
—Three standard reset threshold settings
(4.6V/2.9V/1.7V, 4.4V/2.6V/1.7V,
2.9V/1.7V/2.4V)
—Adjust low voltage reset threshold voltages
using special programming sequence
—Reset signal valid to V_CC = 1V
—Monitor three voltages or detect power fail
• Fault detection register
• Selectable power on reset timeout
• Selectable watchdog timer interval
• Debounced manual reset input
• Low power CMOS
—30µA typical standby current, watchdog on
—10µA typical standby current, watchdog off
• 4Kbits of EEPROM
—16 byte page write mode
—Self-timed write cycle
—5ms write cycle time (typical)
• Built-in inadvertent write protection
—Power-up/power-down protection circuitry
—Block lock protect 0, 1/4, 1/2, all of EEPROM
• 400kHz I²C interface
• 2.4V to 5.5V power supply operation
• Available packages
—14-lead SOIC, TSSOP
BLOCK DIAGRAM
DESCRIPTION
The X40430/31 combines power-on reset control,
watchdog timer, supply voltage supervision, secondary
and third voltage supervision, manual reset, and Block
Lock^™ protect serial EEPROM in one package. This
combination lowers system cost, reduces board space
requirements, and increases reliability.
Applying voltage to V_CC activates the power on reset
circuit which holds RESET/RESET active for a period of
time. This allows the power supply and system oscillator
to stabilize before the processor can execute code.
Low V_CC detection circuitry protects the user’s system
from low voltage conditions, resetting the system when
V_CC falls below the minimum V_TRIP1 point. RESET/
RESET is active until V_CC returns to proper operating
level and stabilizes. A second and third voltage monitor
circuit tracks the unregulated supply to provide a
power fail warning or monitors different power supply
voltage. Three common low voltage combinations are
available, however, Xicor’s unique circuits allows the
threshold for either voltage monitor to be repro-
grammed to meet special needs or to fine-tune the
threshold for applications requiring higher precision.
V3MON
V2MON
V3 Monitor
Logic
+
V_TRIP3
-
V2 Monitor
Logic
+
V_TRIP2
-
V3FAIL
V2FAIL
SDA
WP
SCL
V_CC
(V1MON)
Data
Register
Command
Decode Test
& Control
Logic
REV 1.2.3 11/28/00
Fault Detection
Register
Status
Register
EEPROM
Array
V_{CCLoMgoicnitor}
+
V_TRIP1
-
www.xicor.com
Watchdog
and
Reset Logic
WDO
MR
Power on,
Manual Reset
Low Voltage
Reset
Generation
RESET
X40430
RESET
X40431
LOWLINE
Characteristics subject to change without notice. 1 of 24