FM3164-STR Ramtron, FM3164-STR Datasheet - Page 3

• Manufacturer Part Number: FM3164-STR
• Description: case, leaded, supervisor, reflow, soic, supply, process, max, ram, Interface ICs, package, compatible, voltage, memor...
• Manufacturer: Ramtron

Pin Descriptions
Rev. 2.3
Oct. 2006
Pin Name
A0, A1
CNT1, CNT2
CAL/PFO
X1, X2
/RST
SDA
SCL
PFI
VBAK
VDD
VSS
CAL/PFO
A1, A0
VBAK
VDD
SDA
SCL
RST
PFI
2.5V
Output
Supply
Supply
Supply
Type
Input
Input
Input
Input
I/O
I/O
I/O
Interface
2-Wire
LockOut
+
-
Pin Description
Device select inputs are used to address multiple memories on a serial bus. To select
the device the address value on the two pins must match the corresponding bits
contained in the device address. The device select pins are pulled down internally.
Event Counter Inputs: These battery-backed inputs increment counters when an edge is
detected on the corresponding CNT pin. The polarity is programmable. These pins
should not be left floating. Tie to ground if pins are not used.
In calibration mode, this pin supplies a 512 Hz square-wave output for clock
calibration. In normal operation, this is the early power-fail output.
32.768 kHz crystal connection. When using an external oscillator, apply the clock to
X1 and leave X2 floating.
Active low reset output with weak pull-up. Also input for manual reset.
Serial Data & Address: This is a bi-directional line for the two-wire interface. It is
open-drain and is intended to be wire-OR’d with other devices on the two-wire bus.
The input buffer incorporates a Schmitt trigger for noise immunity and the output
driver includes slope control for falling edges. A pull-up resistor is required.
Serial Clock: The serial clock line for the two-wire interface. Data is clocked out of the
part on the falling edge, and in on the rising edge. The SCL input also incorporates a
Schmitt trigger input for noise immunity.
Early Power-fail Input: Typically connected to an unregulated power supply to detect
an early power failure. This pin should not be left floating.
Backup supply voltage: A 3V battery or a large value capacitor. If V
backup supply is used, this pin should be tied to V
supply is used, this pin should be left floating and the VBC bit should be set.
Supply Voltage.
Ground
+
-
1.2V
Watchdog
LV Detect
Figure 1. Block Diagram
512Hz
Switched Power
Registers
RTC Cal.
Function
Special
Nonvolatile
S/N
LockOut
RTC Registers
DD
Counters
Battery Backed
. If V
FRAM
Event
RTC
Array
DD
>3.6V and no backup
FM3104/16/64/256
DD
X1
X2
<3.6V and no
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CNT1
CNT2