MT88E43BSR1 Zarlink, MT88E43BSR1 Datasheet - Page 6

• Manufacturer Part Number: MT88E43BSR1
• Description: Caller ID CMOS 3.58MHz 3.3V/5V 24-Pin SOIC T/R
• Manufacturer: Zarlink

Specifications of MT88E43BSR1

• Package: 24SOIC
• Telecommunication Standards Supported: GR-30|SIN227|SIN242|SR-TSV-002476|TR-NWT-000030
• Fabrication Technology: CMOS
• Maximum Data Rate: 1212 Bd
• Typical Operating Supply Voltage: 3.3|5 V
• Typical Supply Current: 3 mA
• Minimum Operating Temperature: -40 °C
• Maximum Operating Temperature: 85 °C
• Operating Frequency: 3.58 MHz

Dual Tone Detection Guard Time
When the dual tone alert signal is detected by the MT88E43, ESt goes high. When the alerting signal ceases to be
detected, ESt goes low.
The ESt pin signals raw detection of CAS/Alerting Tones. Since both Bellcore and BT applications require a
minimum duration for valid signals, ESt detection must be guard time qualified. The StD pin provides guard time
qualified CAS/Alerting Tone detection. When the MT88E43 is used in a caller identity system, StD indicates correct
CAS/Alerting Tone detection.
Figure 4 shows the relationship between the St/GT, ESt and StD pins. It also shows the operation of a guard time
circuit.
The total recognition time is t
detect time (refer to timing between ESt, St/GT and StD in Figures 17 and 20).
The total tone absent time is t
detect time (refer to timing between ESt, St/GT and StD in Figures 17 and 20).
REC
1. In the future BT may specify the off-hook signal level as
2. The signal power is expressed in dBm referenced to 600 ohm
3. ASL = active speech level expressed in dBm referenced to
4. SIN227 suggests that the recognition time should be not less
ABS
Low tone
frequency
High tone
frequency
Received
signal level
Signal reject
level
Signal level
differential
(twist)
Unwanted
signals
Duration
Speech
present
Table 1 - Dual Tone Alert Signal Characteristics
at the CPE A/B (tip/ring) interface.
600 ohm at the CPE tip/ring interface. The level is measured
according to method B of Recommendation P.56 "Objective
Measurement of Active Speech Level" published in the CCITT
Blue Book, volume V "Telephone Transmission Quality" 1989.
EPL (Equivalent Peak Level) = ASL+11.7 dB
than 20 ms if both tones are detected.
-15 dBm to -34 dBm per tone for BT CIDCW.
= t
= t
Item
GP
GA
+ t
+ t
DP
DA
, where t
per tone on-hook
, where t
-2dBV to -40dBV
88ms to 110ms
Zarlink Semiconductor Inc.
2750Hz ± 1.1%
2130Hz ±1.1%
(300-3400Hz)
(0.22dBm
(-43.78dBm)
-37.78dBm)
MT88E43B
up to 7dB
<= -20dB
-46dBV
BT
No
GP
GA
6
is the tone present guard time and t
2
is the tone absent guard time and t
to
4
1
- 32dBm per tone
near end speech
<= -7dBm ASL
2750Hz ± 0.5%
2130Hz ±0.5%
75ms to 85ms
-14dBm
up to 6dB
Bellcore
off-hook
-45dBm
Yes
b
to
3
DP
DA
is the tone present
is the tone absent
Data Sheet