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90 page 
Signalswing limitingcircuit Biasgenerator andstartup circuit XI XO Signal shaping Squarewave: Vpp=VIO_1P8V Y Currentcontrol circuitandmode selection Floating VBATOK (1) Internal GND Internal GND VBATOK (1) 037-040 TPS65930/TPS65920 Integrated Power Management \Audio Codec (TPS65930 Only) SWCS037D – MAY 2008 – REVISED JUNE 2009 www.ti.com (1) Switches close by default and open only if register access enables very-low-power mode when VBAT < 2.7 V. Figure 11-9. 32-kHz Oscillator in Bypass Mode Block Diagram Without Crystal Option 3 Table 11-7 lists the electrical constraints required by the 32-kHz input square- or sine-wave clock. Table 11-7. 32-kHz Input Square- or Sine-Wave Clock Source Electrical Characteristics Name Parameter Description Min Typ Max Unit f Frequency 32.768 kHz CI Input capacitance 35 pF CFI On-chip foot capacitance to GND on each input (see Figure 11-7, Figure 11-8, and 10 pF VPP Square-/sine-wave amplitude in bypass mode or not 1.8(1) V VIH Voltage input high, square wave in bypass mode 0.8 V VIL Voltage input low, square wave in bypass mode 0.6 V (1) Bypass input maximum voltage is the same as the maximum voltage provided for the I/O interface. Table 11-8 lists the timing requirements of the 32-kHz square-wave input clock. Table 11-8. 32-kHz Square-Wave Input Clock Source Timing Requirements Name Parameter Description Min Typ Max Unit CK0 1/tC(32KHZ) Frequency, 32 kHz 32.768 MHz CK1 tW(32KHZ) Pulse duration, 32 kHz low or high 0.45*tC(32KHZ) 0.55*tC(32KHZ) µs CK3 tR(32KHZ) Rise time, 32 kHz(1) 0.1*tC(32KHZ) µs CK4 tF(32KHZ) Fall time, 32 kHz(1) 0.1*tC(32KHZ) µs (1) The capacitive load is 30 pF. Clock Specifications 90 |
