Si3035
Table 21. Si3021 Pin Descriptions (Continued)
Pin Name Description
SOIC TSSOP
Pin #
Pin #
10
6
M1
Mode Select 1 Input.
The second of two mode select pins that is used to select the operation of the
serial port/DSP interface.
11
7
C1A
Isolation Capacitor 1A.
Connects to one side of the isolation capacitor C1. Used to communicated
with the line-side device.
12
13
8
9
GND
VA
Ground.
Connects to the system digital ground.
Analog Supply Voltage.
Provides the analog supply voltage for the Si3021, nominally 5 V. This supply
is typically generated internally with an on-chip charge pump set through a
control register.
14
15
10
11
M0
Mode Select 0 Input.
The first of two mode select pins that is used to select the operation of the
serial port/DSP interface.
RGDT/FSD
Ring Detect/Delayed Frame Sync Output.
Output signal that indicates the status of a ring signal. Produces an active
low rectified version of the ring signal. When daisy chain is enabled, this sig-
nal becomes a delayed frame sync to drive a slave device.
16
12
OFHK
Off-Hook Input.
An active low input control signal that provides a termination across TIP and
RING for line seizing and pulse dialing.
Rev. 1.2
47
ETC [ ETC ]
