MT88E46AS1 Zarlink, MT88E46AS1 Datasheet - Page 4

• Manufacturer Part Number: MT88E46AS1
• Description: Caller ID CMOS 3.58MHz 3.3V/5V 20-Pin SOIC Tube
• Manufacturer: Zarlink

Specifications of MT88E46AS1

• Package: 20SOIC
• Telecommunication Standards Supported: Bellcore GR-30-CORE|SR-TSV-002476|TIA/EIA-716|TIA/EIA-777
• Fabrication Technology: CMOS
• Maximum Data Rate: 1.212 KBd
• Typical Operating Supply Voltage: 3.3|5 V
• Typical Supply Current: 4.3 mA
• Minimum Operating Temperature: -40 °C
• Maximum Operating Temperature: 85 °C
• Operating Frequency: 3.58 MHz

MT88E46
Control Bit (CB0/1/2) Functionality
The number of control bits (CB) required to interface the MT88E46 to the microcontroller depends on the functionality of
the application.
4
CB0 CB1 CB2
0/1
0/1
0/1
FSK,
Off Hook mode CAS
(Non MEI compatible)
FSK,
Off Hook mode CAS,
On Hook mode CAS
FSK (Interface mode 1),
Off Hook mode CAS,
On Hook mode CAS,
Power Down
FSK (Interface mode 0),
Off Hook mode CAS,
On Hook mode CAS,
Power Down
1
0
Functionality Group
1
1
0
0
0
1
0
1
0
0
Set by CB0
Set by CB0
Set by CB0
Interface
Mode 1
Mode 0
FSK
Op-Amp
Input
GS1
GS2
GS1
-
-
Controls
Table 2 -Control Bit Functionality Groups
CB2
CB1
CB2
CB1
CB2
CB0
CB1
CB2
Table 1 - CB0/1/2 Function Table
FSK Demodulation. DR/DET pin is the DR signal.
‘Off hook mode’ CAS Detection. DR/DET pin is the DET signal.
The off hook mode algorithm is Bellcore talkoff and talkdown compliant when
near end speech level is attenuated 8 dB or better. It should be used for the off
hook state CPE.
‘On hook mode’ CAS Detection. DR/DET pin is the DET signal.
When the line is in use, a TIA Multiple Extension Interworking (MEI)
compatible Type 2 CPE must be able to detect CAS even though the CPE itself is
on hook. Since in most telephone designs the hybrid or speech IC is not
operational when the CPE itself is on hook, this mode provides Tip Ring CAS
detection for the on hook state MEI CPE.
The on hook mode algorithm is optimized for talkdown only and typically meets
talkdown condition 1 (the average case) without near end speech attenuation. It
must not be used when the CPE itself is off hook. See ‘On Hook Mode CAS
Detection’ section in ‘Functional Description’.
Power Down. DR/DET pin is logic high.
The MT88E46 is disabled and draws virtually no power supply current. Note that
the DCLK pin becomes an input pin because FSK interface mode 1 is selected by
CB0=1.
Reserved for factory testing.
CB0 is connected to Vdd or Vss to select the FSK interface mode.
CB1 connected to Vdd.
The microcontroller uses CB2 to select between the 2 functions.
CB0 is connected to Vdd or Vss to select the FSK interface mode.
The microcontroller uses CB1 and CB2 to select between the 3 functions.
CB0 is connected to Vdd to select FSK interface mode 1.
The microcontroller uses CB1 and CB2 to select between the 4 functions.
All 3 pins are required.
Function
Description
Data Sheet