MSP430F2619S-HT Datasheet, PDF (47/90 Pages) Texas Instruments – MIXED SIGNAL MICROCONTROLLER

MSP430F2619S-HT
www.ti.com
SLAS697B – MARCH 2010 – REVISED JUNE 2011
Crystal Oscillator (LFXT1) High Frequency Modes – Electrical Characteristics⁽¹⁾
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)
f_LFXT1,HF0
PARAMETER
LFXT1 oscillator crystal frequency,
HF mode 0
TEST CONDITIONS
XTS = 1, LFXT1Sx = 0
V_CC
1.8 V to 3.6 V
MIN TYP MAX UNIT
0.4
1 MHz
f_LFXT1,HF1
LFXT1 oscillator lcrystal frequency,
HF mode 1
XTS = 1, LFXT1Sx = 1
1.8 V to 3.6 V
1
4 MHz
f_LFXT1,HF2
LFXT1 oscillator crystal frequency,
HF mode 2
XTS = 1, LFXT1Sx = 2
1.8 V to 3.6 V
2
2.2 V to 3.6 V
2
3 V to 3.6 V
2
10
12 MHz
16
f_{LFXT1,HF,logic}
LFXT1 oscillator logic-level
square-wave input frequency,
HF mode
XTS = 1, LFXT1Sx = 3
1.8 V to 3.6 V
0.4
2.2 V to 3.6 V
0.4
3 V to 3.6 V
0.4
10
12 MHz
16
OA_HF
C_L,eff
Oscillation allowance for HF crystals
(see Figure 24 and Figure 25)
Integrated effective load capacitance,
HF mode⁽²⁾
XTS = 0, LFXT1Sx = 0;
f_LFXT1,HF = 1 MHz,
C_L,eff = 15 pF
XTS = 0, LFXT1Sx = 1
f_LFXT1,HF = 4 MHz,
C_L,eff = 15 pF
XTS = 0, LFXT1Sx = 2
f_LFXT1,HF = 16 MHz,
C_L,eff = 15 pF
XTS = 1⁽³⁾
2700
800
Ω
300
1
pF
Duty Cycle
f_Fault,HF
HF mode
Oscillator fault frequency, HF mode⁽⁴⁾
XTS = 1, Measured at
P1.4/ACLK,
f_LFXT1,HF = 10 MHz
XTS = 1, Measured at
P1.4/ACLK,
f_LFXT1,HF = 16 MHz
XTS = 1, LFXT1Sx = 3⁽⁵⁾
3V
2.2 V/3 V
40
50
60
%
40
50
60
30
300 kHz
(1) To improve EMI on the LFXT1 oscillator the following guidelines should be observed:
(a) Keep as short of a trace as possible between the device and the crystal.
(b) Design a good ground plane around the oscillator pins.
(c) Prevent crosstalk from other clock or data lines into oscillator pins XIN and XOUT.
(d) Avoid running PCB traces underneath or adjacent to the XIN and XOUT pins.
(e) Use assembly materials and praxis to avoid any parasitic load on the oscillator XIN and XOUT pins.
(f) If conformal coating is used, ensure that it does not induce capacitive/resistive leakage between the oscillator pins.
(g) Do not route the XOUT line to the JTAG header to support the serial programming adapter as shown in other documentation. This
signal is no longer required for the serial programming adapter.
(2) Includes parasitic bond and package capacitance (approximately 2 pF per pin). Since the PCB adds additional capacitance it is
recommended to verify the correct load by measuring the ACLK frequency. For a correct setup the effective load capacitance should
always match the specification of the used crystal.
(3) Requires external capacitors at both terminals. Values are specified by crystal manufacturers.
(4) Frequencies below the MIN specification set the fault flag, frequencies above the MAX specification do not set the fault flag.
Frequencies in between might set the flag.
(5) Measured with logic-level input frequency, but also applies to operation with crystals
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