LM3S6938 Datasheet, PDF (481/516 Pages) List of Unclassifed Manufacturers – Microcontroller

LM3S6938 Microcontroller
21.2.3
Parameter Parameter Name
Min
f_MOSC
Main oscillator frequency
1
t_{MOSC_per}
Main oscillator period
125
f_{ref_crystal_bypass}
Crystal reference using the main oscillator (PLL in BYPASS mode)
a
1
Nom
-
-
-
Max Unit
8 MHz
1000 ns
8 MHz
f_{ref_ext_bypass} External clock reference (PLL in BYPASS mode)^a
0
-
50 MHz
f_{system_clock}
System clock
0
-
50 MHz
a. The ADC must be clocked from the PLL or directly from a 14-MHz to 18-MHz clock source to operate properly.
Table 21-8. Crystal Characteristics
Parameter Name
Value
Units
Frequency
8
6
4
3.5 MHz
Frequency tolerance
±50 ±50 ±50 ±50 ppm
Aging
±5
±5
±5
±5 ppm/yr
Oscillation mode
Parallel Parallel Parallel Parallel
Temperature stability (0 - 85 °C) ±25 ±25 ±25 ±25 ppm
Motional capacitance (typ)
27.8 37.0 55.6 63.5 pF
Motional inductance (typ)
14.3 19.1 28.6 32.7 mH
Equivalent series resistance (max) 120 160 200 220 Ω
Shunt capacitance (max)
10
10
10
10
pF
Load capacitance (typ)
16
16
16
16
pF
Drive level (typ)
100 100 100 100 µW
Analog-to-Digital Converter
Table 21-9. ADC Characteristics
Parameter Parameter Name
Min Nom Max Unit
V_ADCIN
Maximum single-ended, full-scale analog input voltage -
Minimum single-ended, full-scale analog input voltage -
- 3.0 V
- 0V
Maximum differential, full-scale analog input voltage - - 1.5 V
Minimum differential, full-scale analog input voltage
- - -1.5 V
C_ADCIN
N
Equivalent input capacitance
Resolution
-1
- 10
- pF
- bits
f_ADC
t_ADCCONV
f _ADCCONV
INL
ADC internal clock frequency
Conversion time
Conversion rate
Integral nonlinearity
14 16 18 MHz
-
-
16 t_ADCcycles^a
875 1000 1125 k samples/s
- - ±1 LSB
DNL
Differential nonlinearity
- - ±1 LSB
OFF
Offset
- - ±1 LSB
GAIN
Gain
- - ±1 LSB
a. t_ADC= 1/f_{ADC clock}
October 08, 2007
481
Preliminary