TPS65930 Datasheet, PDF (91/114 Pages) Texas Instruments – Integrated Power Management Audio Codec (TPS65930 Only)

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Figure 11-10 shows the 32-kHz square- or sine-wave input clock.
TPS65930/TPS65920
Integrated Power Management
\Audio Codec (TPS65930 Only)
SWCS037D – MAY 2008 – REVISED JUNE 2009
32KX
CK0
CK1
CK1
037-038
Figure 11-10. 32-kHz Square- or Sine-Wave Input Clock
11.3 Output Clock Specifications
The TPS65920/TPS65930 device provides two output clocks:
• 32KCLKOUT
• HFCLKOUT
11.3.1 32KCLKOUT Output Clock
Figure 11-11 is the block diagram for the 32.768-kHz clock output.
IO_1P8
OR
(1.8 V)
32KXIN
OR
32 kHz
32-kHz
OSC
32KXOUT
32KCLKOUT
RTC
037-037
Figure 11-11. 32.768-kHz Clock Output Block Diagram
The TPS65920/TPS65930 device has an internal 32.768-kHz oscillator connected to an external
32.768-kHz crystal through the 32KXIN/32KXOUT balls or an external digital 32.768-kHz clock through the
32KXIN input (see Figure 11-11). The TPS65920/TPS65930 device also generates a 32.768-kHz digital
clock through the 32KCLKOUT pin and can broadcast it externally to the application processor or any
other devices. The 32KCLKOUT clock is broadcast by default in TPS65920/TPS65930 active mode, but
can be disabled if it is not used.
The 32.768-kHz clock (or signal) is also used to clock the RTC embedded in the TPS65920/TPS65930
device. The RTC is not enabled by default. The host processor must set the correct date and time and
enable the RTC functionality.
The 32KCLKOUT output buffer can drive several devices (up to 40-pF load). At startup, 32KCLKOUT
must be stabilized (frequency/duty cycle) before the signal output. Depending on the startup conditions,
this can delay the startup sequence.
Table 11-9 lists the electrical characteristics of the 32KCLKOUT output clock.
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Clock Specifications
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