ch2056tbr ETC-unknow, ch2056tbr Datasheet - Page 16

• Manufacturer Part Number: ch2056tbr
• Description: High Speed Modem Family
• Manufacturer: ETC-unknow

Cermetek Microelectronics, Inc.
1. Currently
2. Over Voltage and Lightning Protection.
2003 Cermetek Microelectronics, Inc.
Figure 6. PSTN Line Interface for all HS Modems.
Device. Currently limiting devices are mandatory
to meet UL safety standards.
conveyed FCC Part 68 approval, the current
limiting components identified as F1 and F2 in
dashed Box #1 must also survive FCC Part 68
surge testing. Refer to Cermetek Application Note
#126, Supplemental PSTN Line Protection, for
more details.
Summary of Recommend Suppliers, for a list of
suppliers and associated part numbers.
A. A Polyfuse (rated at 0.15 amps) is preferred
B. Resistors (10Ω carbon film or 1/8 watt
C. Although CSA CS-03 Part 1 (Canada) follows
A. Surge Protection is provided by internal
B. For CH1799LL, the required surge protection
because it resets automatically upon removal
of the current flow.
are also acceptable. Refer to Application Note
#130 for a complete list of recommended
vendors and associated part numbers.
minimum) may be used in Canada, as Canada
has no requirements that PSTN equipment be
operational after a Type B surge test.
the requirements of FCC Part 68 (USA),
Cermetek
(Canada) and/or a certified independent lab to
verify compliance.
10Ω resistors (carbon film or SMD parts 1/8
watt minimum) as described in paragraph B
above.
circuitry contained within all HS Modems
except the CH1799LL (see Figure 6).
additional external components are required to
maintain conveyed FCC Part 68 approval for
all HS Modems (excluding the CH1799LL).
(identified as D1 in dashed Box 2) must be
Limiting
Refer to Application Note # 130,
recommends
PSTN
For Canada, use either
Non-resettable devices
Protection
contacting
To maintain
DOT
Line
No
Page 16
3. EMI/RFI Suppression.
C. In most environments, 2 terminal surge
No external EMI/RFI noise suppression circuitry is
required to maintain conveyed FCC Part 68
approval.
required for other reasons, may be added as
described below in Sections 3A-3B without
adversely affecting FCC Part 68 approval.
A. To provide adequate EMI/RFI suppression,
B. Capacitors C1 and C2 should not exceed
supplied externally.
include some form of surge protection as
described herein to maintain conveyed FCC
Part 68 approval. Refer to Application Note #
130 for a list of recommended suppliers.
suppressors (300V sidactor or equivalent) are
adequate. For severe environments, use an
external 3 terminal device with an earth
ground.
this purpose.
the capacitor/inductor network contained in
dashed Box #3 should be located as close to
the RJ11 Jack as possible.
network should be provided with an excellent
ground path to the chassis.
0.005µf. They must have a rating of 1.5KV
and typically are 0.001µf ± 20%. Inductors L1
and L2 may be either individual inductors or a
dual inductor. Refer to Application Note #130
for a complete list of recommended vendors
and associated part numbers.
applications, choose capacitors and inductors
that are UL 1950 listed. The actual values of
the components used may vary depending on
the end product design.
However, additional suppression, if
DO NOT USE MOUs or transorbs
Document No. 607-0003 Revision K3 (09/03)
High Speed Modem and FAX Family
The purchaser must
Further, this
For UL