X45620 Datasheet, PDF (1/20 Pages) Intersil Corporation – Dual Voltage Monitor with Integrated System Battery Switch and EEPROM

®
Data Sheet
July 29, 2005
X45620
FN8250.0
Dual Voltage Monitor with Integrated
System Battery Switch and EEPROM
FEATURES
• Dual voltage monitoring
• Active low reset outputs
• Two standard reset threshold voltages
—Factory programmable threshold
• Lowline Output — zero delayed POR
• Reset signal valid to V_CC = 1V
• System battery switch-over circuitry
• Selectable watchdog timer
—(0.15s, 0.4s, 0.8s, off)
• 256Kbits of EEPROM
• Built-in inadvertent write protection
—Power-up/power-down protection circuitry
—Protect 0, 1/4, 1/2 or all of EEPROM array with
programmable Block Lock^™ protection
—In circuit programmable ROM mode
• Minimize EEPROM programming time
—64 byte page write mode
—Self-timed write cycle
—5ms write cycle time (typical)
• 400kHz 2-wire Interface
BLOCK DIAGRAM
• 2.7V to 5.5V power supply operation
• Available package — 20-lead TSSOP
• Dual supervisor
• Battery switch and output
DESCRIPTION
The Intersil X45620 combines power-on reset control,
battery switch circuit, watchdog timer, supply voltage
supervision, secondary voltage supervision, block lock
protect and serial EEPROM in one package. This
combination lowers system cost, reduces board space
requirements, and increases reliability.
Applying power to the device activates the power-on
reset circuit which holds RESET active for a period of
time. This allows the power supply and oscillator to
stabilize before the processor can execute code.
A system battery switch circuit compares V_CC (V1MON)
with V_BATT input and connects V_OUT to whichever is
higher. This provides voltage to external SRAM or other
circuits in the event of main power failure. The X45620
can drive 50mA from V_CC and 250µA from V_BATT. The
device switches to V_BATT when V_CC drops below the
low V_CC voltage threshold and V_{BATT >} V_CC.
V2MON
WP
SDA
SCL
S0
S1
V_CC
(V1MON)
V_OUT
V_BATT
V2 Monitor
Logic
V_OUT
+
V_TRIP2
-
Watchdog Transition
Detector
Data
Register
Command
Decode, Test
& Control
Logic
Device
Select
Logic
System
Battery
Switch
V_CC Monitor
Logic
Protect Logic
Status
Register
EEPROM
Array
512 X 512
(32K X 8 Bit)
V_OUT
+
V_TRIP1
-
Watchdog
Timer Reset
Reset &
Watchdog
Timebase
Power-on,
Low Voltage
Reset
Generation
V2FAIL
WDO
BATT-ON
RESET/MR
LOWLINE
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Copyright Intersil Americas Inc. 2005. All Rights Reserved
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