MSP430F530x, MSP430F5310
www.ti.com
SLAS677B –SEPTEMBER 2010–REVISED MARCH 2011
Crystal Oscillator, XT2
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)
(1) (2)
PARAMETER
TEST CONDITIONS
VCC
MIN
TYP
MAX UNIT
fOSC = 4 MHz, XT2OFF = 0,
XT2BYPASS = 0, XT2DRIVEx = 0, TA = 25°C
200
fOSC = 12 MHz, XT2OFF = 0,
XT2BYPASS = 0, XT2DRIVEx = 1, TA = 25°C
260
325
450
XT2 oscillator crystal current
consumption
IDVCC.XT2
3 V
µA
fOSC = 20 MHz, XT2OFF = 0,
XT2BYPASS = 0, XT2DRIVEx = 2, TA = 25°C
fOSC = 32 MHz, XT2OFF = 0,
XT2BYPASS = 0, XT2DRIVEx = 3, TA = 25°C
XT2 oscillator crystal
frequency, mode 0
(3)
fXT2,HF0
fXT2,HF1
fXT2,HF2
fXT2,HF3
XT2DRIVEx = 0, XT2BYPASS = 0
4
8
8
MHz
XT2 oscillator crystal
frequency, mode 1
(3)
XT2DRIVEx = 1, XT2BYPASS = 0
16 MHz
24 MHz
32 MHz
XT2 oscillator crystal
frequency, mode 2
(3)
XT2DRIVEx = 2, XT2BYPASS = 0
16
24
XT2 oscillator crystal
frequency, mode 3
(3)
XT2DRIVEx = 3, XT2BYPASS = 0
XT2 oscillator logic-level
fXT2,HF,SW square-wave input frequency,
bypass mode
(4) (3)
XT2BYPASS = 1
0.7
32 MHz
XT2DRIVEx = 0, XT2BYPASS = 0,
fXT2,HF0 = 6 MHz, CL,eff = 15 pF
450
320
200
200
XT2DRIVEx = 1, XT2BYPASS = 0,
fXT2,HF1 = 12 MHz, CL,eff = 15 pF
Oscillation allowance for
HF crystals
OAHF
Ω
(5)
XT2DRIVEx = 2, XT2BYPASS = 0,
fXT2,HF2 = 20 MHz, CL,eff = 15 pF
XT2DRIVEx = 3, XT2BYPASS = 0,
fXT2,HF3 = 32 MHz, CL,eff = 15 pF
fOSC = 6 MHz,
XT2BYPASS = 0, XT2DRIVEx = 0,
TA = 25°C, CL,eff = 15 pF
0.5
0.3
tSTART,HF
Startup time
3 V
ms
pF
fOSC = 20 MHz
XT2BYPASS = 0, XT2DRIVEx = 2,
TA = 25°C, CL,eff = 15 pF
Integrated effective load
capacitance, HF mode
CL,eff
1
(6) (1)
Duty cycle
Measured at ACLK, fXT2,HF2 = 20 MHz
40
30
50
60
%
(7)
(8)
fFault,HF
Oscillator fault frequency
XT2BYPASS = 1
300 kHz
(1) Requires external capacitors at both terminals. Values are specified by crystal manufacturers.
(2) To improve EMI on the XT2 oscillator the following guidelines should be observed.
(a) Keep the traces 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 XT2IN and XT2OUT.
(d) Avoid running PCB traces underneath or adjacent to the XT2IN and XT2OUT pins.
(e) Use assembly materials and praxis to avoid any parasitic load on the oscillator XT2IN and XT2OUT pins.
(f) If conformal coating is used, ensure that it does not induce capacitive/resistive leakage between the oscillator pins.
(3) This represents the maximum frequency that can be input to the device externally. Maximum frequency achievable on the device
operation is based on the frequencies present on ACLK, MCLK, and SMCLK cannot be exceed for a given range of operation.
(4) When XT2BYPASS is set, the XT2 circuit is automatically powered down. Input signal is a digital square wave with parametrics defined
in the Schmitt-trigger Inputs section of this datasheet.
(5) Oscillation allowance is based on a safety factor of 5 for recommended crystals.
(6) 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.
(7) 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.
(8) Measured with logic-level input frequency but also applies to operation with crystals.
Copyright © 2010–2011, Texas Instruments Incorporated
Submit Documentation Feedback
47
TI [ TEXAS INSTRUMENTS ]
