x40620 Intersil Corporation, x40620 Datasheet - Page 2

• Manufacturer Part Number: x40620
• Description: Dual Voltage Cpu Supervisor With 64k Serial Eeprom
• Manufacturer: Intersil Corporation

X40620
PACKAGE/PINOUTS
PIN NAMES
PIN DESCRIPTIONS
Serial Clock (SCL)
The SCL input is used to clock all data into and out of
the device.
Serial Data (SDA)
SDA is a bidirectional pin used to transfer data into
and out of the device. It is an open drain output and
may be wire-ORed with other open drain or open col-
lector outputs. An open drain requires the use of a
pull-up resistor.
Write Protect (WP)
The WP pin should be tied HIGH at all time. (This WP
pin is reserved for internal factory testing only).
Reset Output (RESET)
RESET is an active LOW, open drain output which
goes active whenever V
Vtrip sense level. It will remain active until V
above the minimum Vtrip sense level for 150ms.
RESET goes active if the Watchdog Timer is enabled
and there is no start bit before the end of the select-
able Watchdog time-out period. A serial start bit will
reset the Watchdog Timer. RESET also goes active on
power up at 1V and remains active for 150ms after the
power supply stabilizes.
V
SDA
V
SCL
WP
V2MON
RESET
V2FAIL
SS
CC
RESET
V
SDA
SS
WP
Ground
Serial Data
Power
Serial Clock
Write Protect
Voltage monitor input
Low Voltage Detect Output
V2 Voltage Fail Output
1
2
3
4
8L TSSOP
CC
falls below the minimum
8
7
6
5
V
V2MON
SCL
V2FAIL
CC
CC
rises
V2 Voltage Fail Output (V2FAIL)
V2FAIL is an active LOW, open drain output which
goes active whenever V2MON falls below the mini-
mum V2trip sense level. It will remain active until
V2MON rises above the minimum V2MON sense level.
DEVICE OPERATION
Power On Reset
Application of power to the X40620 activates a Power
On Reset Circuit. This circuit goes active at 1V and
pulls the RESET pin active. This signal prevents the
system microprocessor from starting to operate with
insufficient voltage or prior to stabilization of the oscil-
lator. When V
200ms (nominal) the circuit releases RESET allowing
the processor to begin executing code.
Low Voltage V
During operation, the X40620 monitors the V
and asserts RESET if supply voltage falls below a pre-
set minimum V
microprocessor from operating in a power fail or
brownout condition. The RESET signal remains active
until the voltage drops below 1V. It also remains active
until V
When the internal low voltage detect circuitry senses
that V
– The RESET pin goes active.
– Communication to the device is interrupted and any
The low V
to 3.7V operating range.
LOW VOLTAGE V2 MONITORING
The X40620 also monitors a second voltage level and
asserts V2FAIL if the voltage falls below a preset mini-
mum V2
RESET to prevent the microprocessor from operating
in a power fail or brownout condition or used to inter-
rupt the microprocessor with notification of an impend-
ing power failure. The V2FAIL signal remains active
until the V
until V2MON returns and exceeds V2
command is aborted. If a serial nonvolatile store is in
progress when power fails, the circuitry does not
stop the nonvolatile store operation, but attempts to
complete the operation.
CC
CC
TRIP
is low, the following happens:
returns and exceeds V
CC
CC
. The V2FAIL signal is either ORed with
threshold is typically set to 3.1V for a 2.5
CC
drops below 1V. It also remains active
CC
TRIP
Characteristics subject to change without notice.
exceeds the device V
(V1) Monitoring
. The RESET signal prevents the
TRIP
for 200ms.
TRIP
TRIP
by 0.2V
value for
CC
2 of 17
level