CH1786A-C Overview
In addition, certain applications can be supported by 22 pins.
CH1786A-C Features
22 pin count

CH1786A-C Applications
There are a lot of Cermetek MicroElectronics, Inc
CH1786A-C Modems ICs & Modules applications.

Desktop PC
Notebook
Pocket PC
Desktop radio
Clock radio
Tuner
Portable radio
Car radio
Satellite radio receiver
Shortwave receiver

ECCN (US)	EAR99
HTS	8471.80.40.00
Main Category	Module
Maximum Data Rate Range (Kbps)	2.4 to 20
Maximum Data Rate	2.4Kbps
Host Interface	V.24|EIA-232E
Transmission Media Type	Cable
Minimum Operating Supply Voltage	4.75V
Typical Operating Supply Voltage	5V
Maximum Operating Supply Voltage	5.25V
Typical Supply Current (mA)	58
Minimum Operating Temperature (°C)	0
Maximum Operating Temperature (°C)	70
Mounting	Through Hole
Package Height	13.21
Package Length	32.26
Package Width	25.65
PCB changed	22
Lead Shape	Through Hole
Manufacturer	Cermetek Microelectronics
Part Status	Active
Reach Compliance Code	unknown
Pin Count	22
Modulation Technique	FSK
RoHS Status	RoHS non-compliant