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20-pin SOP or DIP
Description
The FM573 and FM574 are innovative circuits that
store inputs like conventional logic families, and then
retain the stored state in the absence of power. These
products solve three basic problems in an elegant
fashion. First, they provide continuous access to
nonvolatile system settings without performing a
memory read operation or using dedicated processor
I/O pins. Second, they allow the storage of signals or
data that may change frequently and possibly without
notice. Third, they allow the nonvolatile storage of a
few bits of data or system settings without the system
overhead and extra pins of a serial memory. The
FM573 is a transparent latch. The inputs are passed
to the outputs when the clock is high; the state is
latched when the clock goes low. The FM574 is a D-
type register. Inputs are stored and passed to the
outputs on the rising edge of the clock. The
nonvolatile latch is a unique product that serves a
variety of applications. A few ideas as follows:
眉
Controls relays and valves with automatic setting
on power-up without processor intervention.
眉
Interface to soft/momentary front-panel switches
and indicator lamps. Capture switch settings and
light LED鈥檚 without processor intervention.
眉
Replaces jumpers & control signal routing
眉
Initialize state of I/O card signals.
眉
Save system errors or status codes when power
fails with a fast, no overhead write and automatic
restore on power up.
眉
Eliminate the overhead of serial memory for
systems needing only a few bits of data.
The FM573 and FM574 are provided in a 20-pin DIP
or SOP. They are rated from 鈥?0C to +85C.
This data sheet contains specifications for a product under development.
Characterization is not complete; specifications may change without notice.
Pin Configuration
OE
D0
D1
D2
D3
D4
D5
D6
D7
VSS
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
VDD
Q0
Q1
Q2
Q3
Q4
Q5
Q6
Q7
C
Pin Names
D0-D7
Q0-Q7
C
/OE
VSS
VDD
Function
Data in
Data Out
Clock/Latch Enable
Output enable
Ground
Supply Voltage
Ordering Information
FM573-P
FM573-S
FM574-P
FM574-S
Transparent latch, 20-pin plastic DIP
Transparent latch, 20-pin SOP
Register, 20-pin plastic DIP
Register, 20-pin SOP
Other package types may be available. Contact
the factory for more information.
Ramtron International Corporation
1850 Ramtron Drive, Colorado Springs, CO 80921
(800) 545-FRAM, (719) 481-7000, Fax (719) 481-7058
27 March 2001
www.ramtron.com
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