LM97593VH/NOPB National Semiconductor, LM97593VH/NOPB Datasheet - Page 44

• Manufacturer Part Number: LM97593VH/NOPB
• Description: IC DDC ADC/TUNER/AGC 128-PQFP
• Manufacturer: National Semiconductor

Specifications of LM97593VH/NOPB

• Number Of Bits: 12
• Sampling Rate (per Second): 65M
• Data Interface: Serial
• Number Of Converters: 2
• Power Dissipation (max): 560mW
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 128-BFQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM97593VH

General Applications Information
10.0 OUTPUTS
Be very careful when driving a high capacitance bus. The
more capacitance the output drivers must charge for each
conversion, the more instantaneous digital current flows
through V
and DRGND. These large charging current
DR
spikes can cause on-chip ground noise and couple into the
analog circuitry, degrading dynamic performance. Adequate
bypassing, limiting output capacitance and careful attention
to the ground plane will reduce this problem.
To minimize noise due to output switching, minimize the load
currents at the digital outputs. Only one driven input should
be connected to each output pin. Additionally, inserting series
resistors of about 100Ω at the digital outputs, close to the ADC
pins, will isolate the outputs from trace and other circuit ca-
pacitances and limit the output currents, which could other-
wise result in performance degradation. See Figure 45.
30008741
FIGURE 44. AGC integrator output limits
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