DESCRIPTION
The 73K222BL is a highly integrated single-chip modem IC which provides the functions needed to construct a CCITT V.22, V.21, Bell 212A and Bell 103, compatible modem, capable of 1200 bit/s full duplex operation over dial-up lines. The 73K222BL is an enhancement of the 73K222AL single-chip modem which adds the hybrid hook switch control, and driver to the 73K222AL. In Bell 212A mode, the 73K222BL provides the normal Bell 212A and Bell 103 functions and employs a 2225 Hz answer tone. The 73K222BL in V.22 mode produces either 550 or 1800 Hz guard tone, recognizes and generates a 2100 Hz answer tone, and allows 600 bit/s V.22 or 0-300 bit/s V.21 operation.

FEATURES
• Includes features of 73K222AL single-chip modem
• One-chip CCITT V.22, V.21, Bell 212A and Bell 103 standard compatible modem data pump
• Full-duplex operation at 0-300 bit/s (FSK) or 600 and 1200 bit/s (DPSK)
• On chip 2-wire/4-wire hybrid driver and off hook relay buffer driver
• Serial or parallel microcontroller control interface
• Interfaces directly with standard microcontroller (8048, 80C51 typical)
• Serial port for data transfer
• Both synchronous and asynchronous modes of operation including V.22 extended overspeed
• Call progress, carrier, precise answer tone (2100 or 2225 Hz), and long loop detectors
• DTMF, and 550 or 1800 Hz guard tone generators
• Test modes available: ALB, DL, RDL, Mark, Space, Alternating bit patterns
• Precise automatic gain control allows 45 dB dynamic range
• CMOS technology for low power consumption using 60 mW @ 5 V
• Single +5 V supply