48
SLAS826F – MARCH 2015 – REVISED MARCH 2017
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Specifications
Copyright © 2015–2017, Texas Instruments Incorporated
lists the characteristics of the high-frequency crystal oscillator, HFXT.
(1)
Maximum frequency of operation of the entire device cannot be exceeded.
(2)
When HFXTBYPASS is set, HFXT circuits are automatically powered down. Input signal is a digital square wave with parametrics
defined in the Schmitt-trigger Inputs section of this data sheet. Duty cycle requirements are defined by DC
HFXT, SW
.
Table 5-10. High-Frequency Crystal Oscillator, HFXT
over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted)
PARAMETER
TEST CONDITIONS
V
CC
MIN
TYP
MAX
UNIT
I
DVCC,HFXT
HFXT oscillator crystal current
HF mode at typical ESR
f
OSC
= 1 MHz,
HFXTBYPASS = 0, HFXTDRIVE = 0,
HFFREQ = 0, C
L,eff
= 16 pF,
Typical ESR and C
SHUNT
3.0 V
40
µA
f
OSC
= 4 MHz,
HFXTBYPASS = 0, HFXTDRIVE = 1,
HFFREQ = 0, C
L,eff
= 16 pF,
Typical ESR and C
SHUNT
60
f
OSC
= 8 MHz,
HFXTBYPASS = 0, HFXTDRIVE = 1,
HFFREQ = 1, C
L,eff
= 16 pF,
Typical ESR and C
SHUNT
100
f
OSC
= 16 MHz,
HFXTBYPASS = 0, HFXTDRIVE = 1,
HFFREQ = 2, C
L,eff
= 16 pF,
Typical ESR and C
SHUNT
180
f
OSC
= 24 MHz,
HFXTBYPASS = 0, HFXTDRIVE = 1,
HFFREQ = 3, C
L,eff
= 16 pF,
Typical ESR and C
SHUNT
260
f
OSC
= 32 MHz,
HFXTBYPASS = 0, HFXTDRIVE = 1,
HFFREQ = 4, C
L,eff
= 16 pF,
Typical ESR and C
SHUNT
320
f
OSC
= 40 MHz,
HFXTBYPASS = 0, HFXTDRIVE = 1,
HFFREQ = 5, C
L,eff
= 16 pF,
Typical ESR and C
SHUNT
480
f
OSC
= 48 MHz,
HFXTBYPASS = 0, HFXTDRIVE = 1,
HFFREQ = 6, C
L,eff
= 16 pF,
Typical ESR and C
SHUNT
550
f
HFXT
HFXT oscillator crystal
frequency, crystal mode
HFXTBYPASS = 0, HFFREQ = 0
(1)
1
4
MHz
HFXTBYPASS = 0, HFFREQ = 1
(1)
4.01
8
HFXTBYPASS = 0, HFFREQ = 2
(1)
8.01
16
HFXTBYPASS = 0, HFFREQ = 3
(1)
16.01
24
HFXTBYPASS = 0, HFFREQ = 4
(1)
24.01
32
HFXTBYPASS = 0, HFFREQ = 5
(1)
32.01
40
HFXTBYPASS = 0, HFFREQ = 6
(1)
40.01
48
DC
HFXT
HFXT oscillator duty cycle
Measured at MCLK or HSMCLK,
f
HFXT
= 1 MHz to 48 MHz
40%
50%
60%
f
HFXT,SW
HFXT oscillator logic-level
square-wave input frequency,
bypass mode
HFXTBYPASS = 1
(1) (2)
0.8
48
MHz
DC
HFXT, SW
HFXT oscillator logic-level
square-wave input duty cycle
HFXTBYPASS = 1,
External clock used as a direct source to
MCLK or HSMCLK with no divider
(DIVM = 0 or DIVHS = 0).
45%
55%
HFXTBYPASS = 1,
External clock used as a direct source to
MCLK or HSMCLK with divider (DIVM > 0
or DIVHS > 0) or not used as a direct
source to MCLK or HSMCLK.
40%
60%