adc12d800rfrb National Semiconductor Corporation, adc12d800rfrb Datasheet - Page 11

• Manufacturer Part Number: adc12d800rfrb
• Description: 12-bit, 1.6/1.0 Gsps Rf Sampling Adc
• Manufacturer: National Semiconductor Corporation

Ball No.
W4
U3
V3
A4
A5
Y3
DDRPh
Name
NDM
PDQ
TPM
FSR
PDI
Equivalent Circuit
11
Description
Power Down I- and Q-channel. Setting either
input to logic-high powers down the respective I-
or Q-channel. Setting either input to logic-low
brings the respective I- or Q-channel to a
operational state after a finite time delay. This pin
is active in both ECM and Non-ECM. In ECM,
each Pin is logically OR'd with its respective Bit.
Therefore, either this pin or the PDI and PDQ Bit
in the Control Register can be used to power-
down the I- and Q-channel (Addr: 0h, Bit 11 and
Bit 10), respectively.
Test Pattern Mode select. With this input at logic-
high, the device continuously outputs a fixed,
repetitive test pattern at the digital outputs. In the
ECM, this input is ignored and the Test Pattern
Mode can only be activated through the Control
Register by the TPM Bit (Addr: 0h, Bit 12).
Non-Demuxed Mode select. Setting this input to
logic-high causes the digital output bus to be in
the 1:1 Non-Demuxed Mode. Setting this input to
logic-low causes the digital output bus to be in the
1:2 Demuxed Mode. This feature is pin-controlled
only and remains active during ECM and Non-
ECM.
Full-Scale input Range select. In Non-ECM,
when this input is set to logic-low or logic-high,
the full-scale differential input range for both I-
and Q-channel inputs is set to the lower or higher
FSR value, respectively. In the ECM, this input is
ignored and the full-scale range of the I- and Q-
channel inputs is independently determined by
the setting of Addr: 3h and Addr: Bh, respective-
ly. Note that the high (lower) FSR value in Non-
ECM corresponds to the mid (min) available
selection in ECM; the FSR range in ECM is
greater.
DDR Phase select. This input, when logic-low,
selects the 0° Data-to-DCLK phase relationship.
When logic-high, it selects the 90° Data-to-DCLK
phase relationship, i.e. the DCLK transition
indicates the middle of the valid data outputs.
This pin only has an effect when the chip is in 1:2
Demuxed Mode, i.e. the NDM pin is set to logic-
low. In ECM, this input is ignored and the DDR
phase is selected through the Control Register by
the DPS Bit (Addr: 0h, Bit 14); the default is 0°
Mode.
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