m21408 Mindspeed Technologies, m21408 Datasheet - Page 6

• Manufacturer Part Number: m21408
• Description: M21408/m21418/m21428 Sd, Hd/sd And 2xhd-sdi Cable Drivers
• Manufacturer: Mindspeed Technologies

1.1
1.1.1
The output slew rate of the M21418 and M21428 are selectable to conform with the different SD-SDI and HD-SDI
specifications, in the case of the M21428 this includes 2xHD-SDI. With SD/HD = Low, rise/fall time is typically 100
ps. The slew rate will vary depending on the output matching network and connector used.
With SD/HD = High, for standard definition (143 to 540 Mbps) applications, the rise/fall time is typically 600 ps,
which is compliant with SMPE 259M and SMPTE 344M. The M21408 has no control over the slew rate, this is set
at the SD requirement.
1.1.2
For SMPTE compliance, an external 750Ω ±1% resistor at RSET to A
800mV within a tolerance that is less than ±10% which meets SMPTE requirements. The output amplitude can
also be adjusted to range from 500 to 1600 mVpp single ended using the following formula:
The actual swing is set as a function of the IC supply voltage, the external termination voltage and the limitations
are shown in
voltages. In applications where a lossy matching or splitting networks are used, the M21408/M21418/M21428
offers additional gain of up to 1600 mVpp swings, so the output after the lossy network can be SMPTE compliant.
Table 1-1.
214x8-DSH-001-D
Output Swing = (600/RSET) [RSET in kΩ] (in mVpp, Single Ended)
AV
2.5–3.3V
2.5–3.3V
DD
Table
Output Swing vs. Supply and Termination Voltage
(V)
Features
HD-SDI and SD-SDI Slew-rate Selection
Output Amplitude Adjustment
1-1. For a 2.5V minimum termination voltage, the IC can be SMPTE compliant for all supply
1.0 Functional Description
AV
Mindspeed Proprietary and Confidential
Mindspeed Technologies
DDTERM
3.3V
5.0V
(V)
(Single-ended mVp–p)
Maximum Swing
®
1200 mV
1600 mV
VDD
is recommended for a swing level of
(Single-ended mVp–p)
Minimum Swing
500 mV
500 mV
1