Datasheet

DAC1405D750 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
Product data sheet Rev. 5 — 31 January 2012 35 of 43
NXP Semiconductors
DAC1405D750
Dual 14-bit DAC, up to 750 Msps; 4 and 8 interpolating
Figure 18 provides an example of a DC interface with the auxiliary DACs to an AQM with
a 3.3 V
I(cm)
common-mode input level.
The constraints to adjust the interface are the output compliance range of the DAC and
the auxiliary DACs, the input common-mode level of the AQM, and the range of offset
correction.
10.14.3 AC interface to an Analog Quadrature Modulator (AQM)
When the AQM common-mode voltage is close to ground, the DAC1405D750 must be
AC-coupled and the auxiliary DACs are needed for offset correction.
Figure 19
provides an example of a connection to an AQM with a 0.5 V
I(cm)
common-mode input level using auxiliary DACs.
Fig 18. An example of a DC interface to a 3.3 V
I(cm)
AQM using auxiliary DACs
001aaj544
54.9 Ω
54.9 Ω
237 Ω
237 Ω
3.3 V
IOUTnP
IOUTnN
AUXnP
AUXnN
BBP
BBN
AQM (V
i(cm)
= 3.3 V)
750 Ω 750 Ω
5 V
634 Ω 634 Ω
442 Ω 442 Ω
(1)
IOUTnP/IOUTnN; V
o(cm)
= 2.75 V; V
o(dif)(p-p)
= 1.96 V
(2)
BBP/BBN; V
i(cm)
= 3.3 V; V
i(dif)(p-p)
= 1.5 V; offset correction up to 36 mV
(1) (2)