LM3S2B93 Datasheet, PDF (1130/1194 Pages) Texas Instruments – Stellaris® LM3S2B93 Microcontroller

Electrical Characteristics
25.8.4
25.8.5
Hibernation Clock Source Specifications
Table 25-11. Hibernation Clock Characteristics
Parameter
Parameter Name
Min
Nom
Max
Unit
F_HIBOSC
Hibernation module oscillator frequency
-
4.194304
-
F_{HIBOSC_XTAL}
Crystal reference for hibernation oscillator
-
4.194304
-
T_{HIBOSC_START}
Hibernation oscillator startup time^a
-
-
10
F_{HIBOSC_EXT}
External clock reference for hibernation
-
32.768
-
module
MHz
MHz
ms
KHz
DC_{HIBOSC_EXT}
External clock reference duty cycle
45
-
55
%
a. This parameter is highly sensitive to PCB layout and trace lengths, which may make this parameter time longer. Care
must be taken in PCB design to minimize trace lengths and RLC (resistance, inductance, capacitance).
Table 25-12. HIB Oscillator Input Characteristics
Parameter
F_HIBOSC
TOL_HIBOSC
Parameter Name
Hibernation module oscillator
frequency
Hibernation oscillator frequency
tolerance
Min
Nom
Max
-
4.194304
-
-
Defined by customer
-
application requirements
Unit
MHz
PPM
Main Oscillator Specifications
Table 25-13. Main Oscillator Clock Characteristics
Parameter
Parameter Name
Min
Nom
Max
Unit
F_MOSC
Main oscillator frequency
1
-
T_{MOSC_PER}
T_{MOSC_SETTLE}
Main oscillator period
Main oscillator settling time^a
61
-
17.5
-
F_{REF_XTAL_BYPASS}
Crystal reference using the main oscillator
(PLL in BYPASS mode)^b
1
-
16.384
1000
20
16.384
MHz
ns
ms
MHz
F_{REF_EXT_BYPASS}
External clock reference (PLL in BYPASS
mode)^b
0
-
50
MHz
DC_{MOSC_EXT}
External clock reference duty cycle
45
-
55
%
a. This parameter is highly sensitive to PCB layout and trace lengths, which may make this parameter time longer. Care
must be taken in PCB design to minimize trace lengths and RLC (resistance, inductance, capacitance).
b. If the ADC is used, the crystal reference must be 16 MHz ± .03% when the PLL is bypassed.
Table 25-14. Supported MOSC Crystal Frequencies
Crystal Frequency (MHz) Not Using the PLL
Crystal Frequency (MHz) Using the PLL
1.000 MHz
reserved
1.8432 MHz
reserved
2.000 MHz
reserved
2.4576 MHz
reserved
3.579545 MHz
3.6864 MHz
4 MHz
4.096 MHz
1130
Texas Instruments-Production Data
January 20, 2012