Texas Instruments IC MCU 16B MSP430F2101TPW TSSOP-20 TID MSP430F2101TPW Datenbogen
Produktcode
MSP430F2101TPW
MSP430F21x1
SLAS439F
–
SEPTEMBER 2004
–
REVISED AUGUST 2011
Crystal Oscillator LFXT1, Low-Frequency Mode
(1)
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)
PARAMETER
TEST CONDITIONS
V
CC
MIN
TYP
MAX
UNIT
LFXT1 oscillator crystal
f
LFXT1,LF
XTS = 0, LFXT1Sx = 0 or 1
1.8 V to 3.6 V
32768
Hz
frequency, LF mode 0, 1
LFXT1 oscillator logic level
f
LFXT1,LF,logic
square wave input frequency, XTS = 0, LFXT1Sx = 3
1.8 V to 3.6 V
10000
32768
50000
Hz
LF mode
XTS = 0, LFXT1Sx = 0,
500
f
LFXT1,LF
= 32768 Hz, C
L,eff
= 6 pF
Oscillation allowance for
OA
LF
k
Ω
LF crystals
XTS = 0, LFXT1Sx = 0,
200
f
LFXT1,LF
= 32768 Hz, C
L,eff
= 12 pF
XTS = 0, XCAPx = 0
1
XTS = 0, XCAPx = 1
5.5
Integrated effective load
C
L,eff
pF
capacitance, LF mode
(2)
XTS = 0, XCAPx = 2
8.5
XTS = 0, XCAPx = 3
11
XTS = 0, Measured at P2.0/ACLK,
Duty cycle, LF mode
2.2 V/3 V
30
50
70
%
f
LFXT1,LF
= 32768 Hz
Oscillator fault frequency,
f
Fault,LF
XTS = 0, LFXT1Sx = 3
(4)
2.2 V/3 V
10
10000
Hz
LF mode
(3)
(1)
To improve EMI on the XT1 oscillator, the following guidelines should be observed.
(a) Keep the trace between the device and the crystal as short as possible.
(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
(a) Keep the trace between the device and the crystal as short as possible.
(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).
Because 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 crystal that is used.
Because 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 crystal that is used.
(3)
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.
Frequencies in between might set the flag.
(4)
Measured with logic-level input frequency but also applies to operation with crystals.
Copyright
©
2004
–
2011, Texas Instruments Incorporated
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