SI3232-G-FQ Silicon Laboratories Inc, SI3232-G-FQ Datasheet - Page 47

• Manufacturer Part Number: SI3232-G-FQ
• Description: IC SLIC PROG DUAL-CH 64TQFP
• Manufacturer: Silicon Laboratories Inc

Specifications of SI3232-G-FQ

• Function: Subscriber Line Interface Concept (SLIC)
• Interface: ISDN
• Number Of Circuits: 2
• Voltage - Supply: 3.13 V ~ 3.47 V
• Current - Supply: 28mA
• Power (watts): 280mW
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

where Full Scale V
The pulse metering oscillator has a volume envelope
(linear ramp) on the on/off transitions of the oscillator.
The ramp is controlled by the value entered into the
PMRAMP RAM address, and the sinusoidal generator
output is multiplied by this volume before being sent to
the pulse metering DAC. The volume value is
incremented by the value in PMRAMP at an 8 kHz rate.
The volume ramps from 0 to 7FFF in increments of
PMAMPL
Pulse-Metering Inactive Timer
Pulse-Metering Attack/Decay
Pulse-Metering Active Timer
Pulse-Metering Frequency
Pulse-Metering Amplitude
PM Inactive Timer Enable
PM Active Timer Enable
Pulse-Metering Enable
PM Waveform Present
Pulse-Metering AGC
Amplitude Threshold
Control Interrupt
Pulse-Metering,
Ramp Rate
Parameter
Coefficient
Coefficient
=
Table 28. Register and RAM Locations Used for Pulse Metering Generation
1
-- - 1 coeff
4
----------------------- -
1
+
–
PK
coeff
= 0.5 V.
×
(
2
15
–
1
)
×
----------------------------------------- -
Full Scale V
Desired V
PMTALO/PMTAHI
PMTILO/PMTIHI
Register/RAM
Mnemonic
PMAMPTH
IRQVEC1,
PMFREQ
PMRAMP
PMAMPL
IRQEN1
PMCON
PMCON
PMCON
PMCON
Preliminary Rev. 0.96
PK
PK
PMRAMP, thus allowing the value of PMRAMP to set
the slope of the ramp. The clip detector stops the ramp
once the signal seen at the transmit path exceeds the
amplitude threshold set by PMAMPTH, thus providing
an automatic gain control (AGC) function to prevent the
audio signal from clipping. When the pulse metering
signal is turned off, the volume ramps down to 0 by
decrementing according to the value of PMRAMP.
Figure 24 illustrates the functional blocks involved in
pulse-metering generation, and Table 28 presents the
register and RAM locations required that must be set to
generate pulse-metering signals.
PMAMPTH[15:0]
PMRAMP[15:0]
PULSETA[15:0]
PMFREQ[15:3]
PMAMPL[15:0]
PULSETI[15:0]
Register/RAM
PULSTAE,
PULSTAS,
PULSTIE,
PULSTIS
ENSYNC
PULSE1
TAEN1
TIEN1
Bits
Interrupt status and control
Sets oscillator frequency
Sets oscillator amplitude
Indicates Signal Present
Description / Range
0 to 8.19 s (125 µs)
0 to 8.19 s (125 µs)
(full amplitude)
Enable/disable
Enable/disable
Enable/disable
0 to PMAMPL
0 to 500 mV
(LSB Size)
registers
Si3232
47