FM6124 Ramtron Corporation, FM6124 Datasheet - Page 24

• Manufacturer Part Number: FM6124
• Description: Event Data Recorder With F-ram
• Manufacturer: Ramtron Corporation

logic 0. When the CAL bit is 0, the ACS pin will
revert to the function according to Table 3.
Crystal Type
The crystal oscillator is designed to use a 12.5pF
crystal without the need for external components,
such as loading capacitors. The FM6124 device has
built-in loading capacitors that match the crystal.
If a 32.768kHz crystal is not used, an external
oscillator may be connected to the FM6124. Apply
the oscillator to the X1 pin. Its high and low voltage
levels can be driven rail-to-rail or amplitudes as low
as approximately 500mV p-p.
operation, a DC bias must be applied to the X2 pin.
It should be centered between the high and low levels
on the X1 pin. This can be accomplished with a
voltage divider.
In the example, R1 and R2 are chosen such that the
X2 voltage is centered around the oscillator drive
levels. If you wish to avoid the DC current, you may
choose to drive X1 with an external clock and X2
with an inverted clock using a CMOS inverter.
Rev. 4.0 (EOL)
July 2010
ACS/ALM
RESET
VSS
CNT
SDA
SCL
INT
IN4
IN5
IN6
IN7
1
2
3
4
5
6
7
8
9
10
11
F
44
12 13 14 15 16 17 18 19 20 21
IGURE
43
FM6124-QG
42
41
27. E
40
39
38
XTERNAL OSCILLATOR
37
36
35
34
22
33
32
31
30
29
28
27
26
25
24
23
X2
X1
IN0
IN1
IN2
IN3
NC
NC
VDD
NC
NC
To ensure proper
FM6124 Event Data Recorder
Page 24 of 53