CSP1027 Datasheet, PDF (30/64 Pages) Agere Systems – CSP1027 Voice Band Codec for Cellular Handset and Modem Applications

CSP1027 Voice Band Codec for
Cellular Handset and Modem Applications
6 Signal Descriptions
Data Sheet
December 1999
CLOCK
INTERFACE
CLK
XOSCEN
XLO
XHI
CKO1
CKO2
RESET
INTERFACE
RSTB
PORCAP
PORB
SERIAL
INTERFACE
IOCK
SYNC
DI
DO
SADD
SMODE0
SMODE1
SMODE2
EXTERNAL
GAIN SELECT
INTERFACE
EIGS
CSP1027
MICIN
AUXIN
VREG
AOUTP
AOUTN
ANALOG
INTERFACE
REFC
Figure 27. CSP1027 Pinout by Interface
5-7606 (F)
Figure 27 shows the pinout by interface for the
CSP1027. The signals can be separated into five inter-
faces as shown. These interfaces and the signals that
comprise them are described below.
6.1 Clock Interface
The clock interface consists of the clock input, crystal
oscillator, and clock outputs for the codec.
6.1.1 CLK
Clock Input: The input clock for the CSP1027 when
the XOSCEN is a logic low. Codec operation restricts
CLK to integer frequencies from 1 MHz to 40 MHz or
specific multiples of 8 kHz. When XOSCEN is tied to
logic high, the CLK input is not selected but should be
tied low or high to minimize input buffer power.
6.1.2 XLO
Crystal Input: The crystal for CSP1027 voice band
codec is connected between XLO and XHI. When the
crystal is not being used, this pin is to be left floating
and the CMOS clock applied to CLK.
6.1.3 XHI
Crystal Output: The crystal for CSP1027 handset
codec is connected between XLO and XHI. When the
crystal is not being used, this pin is to be left floating
and the CMOS clock applied to CLK.
6.1.4 XOSCEN
Crystal Oscillator Enable: When a logic high, the
crystal oscillator is selected for XLO and XHI pins.
When a logic low, the input buffer is selected for CLK
pin and the crystal oscillator is powered down.
Note: The XOSCEN pin does not have a pull-up or
pull-down device. Make sure that it is tied to VDD,
tied to VSS, or driven by valid logic levels.
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Lucent Technologies Inc.