Table of Contents Section 1 – New and Featured Products

®
CPU Supervisors, System Management, RTC and Timing Solution Products
X45620 Dual Voltage Monitor Battery Switch and 256K EE Memory
Product Highlights
• CPU Supervisor with Dual Voltage Monitor
• System Battery Switch-Over Circuitry
• Lowline Output with Zero Delayed POR
Key Features
• Integrated System Battery Switch-Over Circuitry
• Electronically-Programmable V TRIP
Setting
• Standard V TRIP
Offerings
Device V TRIP1
V TRIP2
X45620 4.62V 2.62V
X45620-2.7 2.62V 1.75V
• Independent Watchdog Timer with User-Selectable Protection
• Manual Reset Capability
• 256K EEPROM with Block-Lock Write Protection
Benefits
• Circuitry provides protection from main power failure
• Asserts a reset when either V TRIP
voltage is triggered
• Prevents system lock up and improved system accuracy
• WDT provides independent protection mechanism
for microcontrollers
• User programmable levels to meet special system requirements
Block Diagram
V2MON
WP
SDA
SCL
S0
S1
V CC
(V1MON)
V OUT
V BATT
Watchdog Transition
Detector
Data
Register
Command
Decode, Test
& Control
Logic
Device
Select
Logic
System
Battery
Switch
V2 Monitor
Logic
Address-Decoder
V CC Monitor
Logic
Protect Logic
Status
Register
EEPROM
Array
V OUT
+
V TRIP2
-
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
Description
The Xicor 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 Watchdog Timer provides an independent protection
mechanism for microcontrollers. When the micro-controller
fails to restart a timer within a selectable time out interval, the
device activates the WDO signal.
The device’s low V CC detection circuitry protects the user’s
system from low voltage conditions, resetting the system when
V CC (V1MON) falls below the minimum V CC trip point (V TRIP1 ).
RESET is asserted until V CC returns to proper operating level
and stabilizes. A second voltage monitor circuit tracks the
unregulated supply or monitors a second power supply voltage
to provide a power fail warning.
Pin Configuration
S0
S1
NC
LOWLINE
NC
V2FAIL
V2MON
RESET/MR
WDO
V SS
1
2
3
4
5
6
7
8
9
10
20-Pin TSSOP
20
19
18
17
16
15
14
13
12
11
V CC (V1MON)
WP
NC
BATT-ON
V OUT
V BATT
SCL
NC
NC
SDA
Ordering Information
Operating Temperature
Part Number RESET
V CC Range V TRIP Range V TRIP2 Range Package Range (Active LOW)
4.75–5.5V 4.5–4.75V 2.55–2.7V 20L TSSOP 0°C–70°C X45620V20
-40°C–85°C
X45620V20I
2.7–5.5V 2.55–2.7V 1.7–1.80V 20L TSSOP 0°C–70°C X45620V20-2.7
-40°C–85°C
X45620V20I-2.7
1–12 www.xicor.com