MT9040AN Zarlink Semiconductor, MT9040AN Datasheet - Page 4

• Manufacturer Part Number: MT9040AN
• Description: Description = Single Reference Frequency Selectable, 3.3V Digital PLL With Multiple Clock Outputs For Stratum 4 Applications ;; Package Type = Ssop ;; No. Of Pins = 48
• Manufacturer: Zarlink Semiconductor

Functional Description
The MT9040 is a T1/E1 Trunk Synchronizer, providing timing (clock) and synchronization (frame) signals to
interface circuits for T1 and E1 Primary Rate Digital Transmission links. Figure 1 is a functional block diagram which
is described in the following sections.
Frequency Select MUX Circuit
The MT9040 operates on the falling edge of the reference. It operates with one of four possible input reference
frequencies (8kHz, 1.544MHz, 2.048MHz or 19.44MHz). The frequency select inputs (FS1 and FS2) determine
which of the four frequencies may be used at the reference input. A reset (RST) must be performed after every
frequency select input change. See Table 1.
Digital Phase Lock Loop (DPLL)
As shown in Figure 3, the DPLL of the MT9040 consists of a Phase Detector, Loop Filter, Digitally Controlled
Oscillator and a Control Circuit.
Phase Detector - the Phase Detector compares the reference signal with the feedback signal from the Frequency
Select MUX circuit, and provides an error signal corresponding to the phase difference between the two. This error
signal is passed to the Loop Filter. The Frequency Select MUX allows the proper feedback signal to be externally
selected (e.g., 8kHz, 1.544MHz, 2.048MHz or 19.44MHz).
Pin Description (continued)
Pin #
45
46
47
48
Name
TRST
TMS
TCK
TDI
Test Serial Data In (Input). JTAG serial test instructions and data are shifted in on this pin.
This pin is internally pulled up to V
Test Reset (Input). Asynchronously initializes the JTAG TAP controller by putting it in the
Test-Logic-Reset state. If not used, this pin should be held low.
Test Clock (Input). Provides the clock to the JTAG test logic.
Test Mode Select (Input). JTAG signal that controls the state transitions of the TAP controller.
0
1
FS2
0
1
Table 1 - Input Frequency Selection
FS1
0
1
0
1
Zarlink Semiconductor Inc.
MT9040
DD
4
.
Input Frequency
Description
19.44MHz
1.544MHz
2.048MHz
8kHz
Data Sheet