73M1903-IM/F Maxim Integrated Products, 73M1903-IM/F Datasheet - Page 13

• Manufacturer Part Number: 73M1903-IM/F
• Description: IC MODEM AFE V.22BIS 32-QFN
• Manufacturer: Maxim Integrated Products

Specifications of 73M1903-IM/F

• Number Of Channels: 2
• Voltage - Supply, Analog: 3 V ~ 3.6 V
• Voltage - Supply, Digital: 3 V ~ 3.6 V
• Package / Case: 32-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power (watts): -
• Number Of Bits: -

3.1
scaler is to convert the crystal oscillator frequency, Fxtal, to a convenient frequency to be used as a
reference frequency, Fref, for the PLL. The NCO pre-scaler requires a set of three numbers to be
entered through the serial port (Pseq[7:0], Prst[2:0] and Pdvsr[2:0]. The PLL also requires 3 numbers as
for programming; Ndvsr[6:0], Nseq[7:0], and Nrst[2:0]. The following is a brief description of the registers
Pdvsr[4:0] represents the divisor.
DS_1903_032
3 Clock Generation
The crystal oscillator operates over wide choice of crystals (from 9 MHz to 27 MHz) and it is first input to
an NCO based pre-scaler (divider) prior to being passed onto an on-chip PLL
that control the NCOs, PLLs, and sample rates for the 73M1903 IC. The tables show some examples of
the register settings for different clock and sample rates. A more detailed discussion on how these values
are derived can be found in
3.1.1 Control Register (CTRL 8): Address 08h
Reset State 00h
This corresponds to the sequence of divisor. If Prst{2:0] =0 this register is ignored.
3.1.2 Control Register (CTRL 9): Address 09h
Reset State 0Ah
Prst[2:0] represents the rate at which the sequence register is reset.
3.1.3 Control Register (CTRL 10): Address 0Ah
Reset State 22h
Kvco2:0 represents the magnitude of Kvco associated with the VCO within PLL. This indicates the center
frequency of the VCO when the control voltage is 1.6 Volts and the slope of the VCO freq versus control
voltage (i.e., Kvco.). FL represents the PLL loop filter settings.
Rev. 2.1
Bit 7
Pseq7
Bit 7
Prst2
Bit 7
Ichp3
Crystal Oscillator and Pre-scaler NCO
Bit 6
Pseq6
Bit 6
Prst1
Bit 6
Ichp2
Kvco2
0
0
0
0
1
1
1
1
Bit 5
Pseq5
Bit 5
Prst0
Bit 5
Ichp1
Table 4: Kvco versus Settings at Vc=1.6 V, 25 °C
Appendix B
Kvco1
0
0
1
1
0
0
1
1
Bit 4
Pseq4
Bit 4
Pdvsr4
Bit 4
Ichp0
.
Kvco0
Bit 3
Pseq3
Bit 3
Pdvsr3
Bit 3
0
1
0
1
0
1
0
1
FL
Bit 2
Pseq2
Bit 2
Pdvsr2
Bit 2
Kvco2
33 MHz
36 MHz
44 MHz
48 MHz
57 MHz
61 MHz
69 MHz
73 MHz
Fvco
Bit 1
Pseq1
Bit 1
Pdvsr1
Bit 1
Kvco1
. The intent of the pre-
38 MHz/v
38 MHz/v
40 MHz/v
40 MHz/v
63 MHz/v
63 MHz/v
69 MHz/v
69 MHz/v
Kvco
Bit 0
Pseq0
Bit 0
Pdvsr0
Bit 0
Kvco0
73M1903 Data Sheet
13