Z02215
Single Chip Modem with Integrated Controller, Data Pump, and AFE
49
requirement for external components making the designs cost effective and space
efficient.
The 2-wire to 4-wire hybrid interfaces to telecom coupling transformers in the Data
Access Arrangement (DAA). The off-hook and shunt relay drivers provide a drive
capability of 30 mA to allow the use of commonly available mechanical telecom
relays.
Operating Notes
Dynamic Power Management
The Z02215 incorporates a low-power SLEEP mode. In this mode, the clock is
stopped.
The modem controller software automatically puts the modem's data pump into a
power-saving SLEEP mode when it is not in use. The modem controller software
also puts the modem controller to SLEEP when possible.
This SLEEP feature operates transparently to the modem's operation. Approxi-
mately 58 mA of power is saved when both the modem data pump and controller
are put in SLEEP mode.
When the Modem Controller is in SLEEP mode, it stays asleep until an interrupt is
issued for a condition, such as:
•
•
Start bit is received from the terminal
Telephone line ring is detected from the telephone line interface
The modem controller cannot be in SLEEP mode if dial blacklisting is enabled in
the country parameters and is being timed. The modem controller cannot be in
SLEEP mode if AT&D3is set because a DTR ON-to-OFF transition cannot change
the modem’s state out of SLEEP mode.
Clock Oscillator Description
The Z02215 on-chip oscillator has a high-gain, parallel-resonant amplifier, for con-
nection to a crystal (XTAL is Output, EXTAL is Input). The crystal is AT cut, 24.576
MHz, with a series resistance (RS) of less than or equal to 25 Ohms.
The crystal is connected across XTAL and EXTAL using the vendor's recom-
mended capacitor values from each pin directly to the device Ground pin to
reduce ground-noise injection into the oscillator.
For better noise immunity, the capacitors must be tied directly
to the device Ground pin (VSS).
Note:
PS001907-0904
Operating Notes
ZILOG [ ZILOG, INC. ]
