m21315 Mindspeed Technologies, m21315 Datasheet - Page 11

• Manufacturer Part Number: m21315
• Description: M21315 Hd/sd-sdi Auto-rate Reclocker W/4 1 Selector
• Manufacturer: Mindspeed Technologies

1.2.2.1
The M21315 reclocker automatically resets after power up thus an external reset is not required. The M21315 is
fully operational 10 ms after the power supply has stabilized to within 10% of the final value.
1.2.2.2
The M21315 contains a 4:1 input selection multiplexer. The IN_SEL[1:0] pins select one of the four possible inputs
that will be retimed by the reclocker block and passed to the output. The mapping of the multiplexer pins is shown
in
1.2.2.3
The high-speed inputs are designed to be used in both AC coupled and DC coupled (PCML) modes. The high-
speed differential inputs contain on-chip 50Ω termination from DDI[n] to VDDI_TERM[n] as well as from DDI[n] to
VDDI_TERM[n]. With VDDI_TERM[n] tied to V
recommended for AC coupled inputs or with DC coupled PCML when the PCML is driven from the same supply
voltage. For use in other DC coupled situations, it is recommended that the termination voltage for the M21315 be
floated. For backwards compatibility with the GS1575B, VDDI_TERM[n] contains a weak internal bias near V
and the pin can be left floating for direct connection to the M21324 or the GS1524. In all cases, VDDI_TERM[n]
should be decoupled to V
alternative is shown in
Figure 1-2.
21315-DSH-001-B
Table
1-1. If the IN_SEL[1:0] pins are left floating, the 4:1 input multiplexer defaults to input DDI0/DDI0.
Input Circuit for GS1575B Drop-in
Reset
Input Selection Multiplexer
High-Speed I/O Pins
Figure 1-2
SS
to reduce input noise with a 10nF capacitor. The GS1575B compatible input and an
and
VDDI_TERMx
Mindspeed Technologies
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Figure
DDIx
DDIx
10nF
1-3.
DD
, the single-ended input impedance is 50Ω. This mode is
50 Ω
50 Ω
M21315
V
DD
®
8 kΩ
28 kΩ
Functional Description
DD
5