NS32FX100-15 Datasheet, PDF (53/94 Pages) National Semiconductor (TI) – System Controller

3 0 System Interface
3 1 POWER AND GROUNDING
The NS32FX100 requires a 5V g10% supply to nine digital
pins and a 5V g5% supply to two analog pins Two pins
provide analog ground nine pins provide digital ground
3 2 CLOCKS AND TRAPS CONNECTIVITY
TL EE 11331 – 33
TL EE 11331 – 34
FIGURE 3-2 Oscillator Circuits
TABLE 3-1 R C and L Values
Frequency
R1
R2 ^{C1 C2 C3 L}
(pF) (pF) (pF) mH
32 768 kHz
10 MX 1 MX 27 27
455 kHz (ceramic) 1 MX 4 7 kX 22 100
29 49 – 31 95 MHz 180 kX 51X 22 22
39 32 – 41 79 MHz 150 kX 51X 22 22 1000 1 8
49 15 MHz
150 kX 51X 22 22 1000 1 1
3 3 CONTROL OF POWER CONSUMPTION
An NS32FX100-based FAX-system controller is always in
one of three modes
1 Normal mode during a FAX transaction
2 Power Save mode between FAX transactions Power
can be saved by running at a lower frequency and dis-
abling unused modules
In order to run at a lower frequency (the Normal mode
frequency divided by 16) bit 4 of the CSCL register
should be set to ‘‘1’’ Due to clock synchronization de-
lays up to 80 ms may elapse between setting this bit and
the actual change in running frequency
3 Freeze mode when the main power supply is turned off
A back-up battery is used to operate the NS32FX100
time keeper and optionally to maintain critical portions
of the memory
The following table summarizes the operation modes and
their power consumption
TABLE 3-2 System Chip Operation
Modes and Power Consumption
Operation Mode
Current
DRAM
ETC
Consumption
Refresh
Normal Mode
k_{200 mA} a
a
Power Save Mode E1 MHz ^k16 mA a
a
Freeze Mode
(5V)
k_{1 mA} a
a
Freeze Mode (32 kHz) (3V) ^k0 1 mA a
b
NS32FX200 NS32FV100 only
FIGURE 3-1 Power and Ground Connections
TL EE 11331 – 32
53