dac1628d1g25 NXP Semiconductors, dac1628d1g25 Datasheet - Page 33

• Manufacturer Part Number: dac1628d1g25
• Description: Dual 16-bit Dac Jesd204b Interface Up To 1.25 Gsps; X2, X4 And X8 Interpolating
• Manufacturer: NXP Semiconductors

NXP Semiconductors
DAC1628D1G25
Objective data sheet
10.15.4 IQ-modulator - AC interface
10.16.1 Power and grounding
10.16 Design recommendations
The constraints to adjust the interface are:
Use the DAC1628D1G25 AC-coupled when the IQ-modulator common-mode voltage is
close to ground. The auxiliary DACs are required for local oscillator cancelation.
Figure 21
input level and auxiliary DACs.
Use a separate power supply regulator for the generation of the 1.8 V analog power
(pins 43, 48. 51. 56) and the 1.8 V digital power (pins 7, 10, 33, 36) to ensure optimal
performance.
High-speed input lanes are powered by a 1.8 V power supply that can require a dedicated
power supply. Pins 15, 16, 19, 22, 25, 28 can be connected to either the global 1.8 V
power supply or to a dedicated one.
Fig 21. IQ-modulator: AC interface with a 0.5 V common input level and auxiliary DACs
•
•
•
•
The output compliance range of the DAC
The output compliance range of the auxiliary DACs
The input common-mode level of the IQ-modulator
The range of offset correction
IOUTAN/IOUTBN
IOUTAP/IOUTBP
AUXAN/AUXBN
AUXAP/AUXBP
DAC1628D
shows an example of a connection to an IQ-modulator with a 0.5 V common
All information provided in this document is subject to legal disclaimers.
1.1 mA (typical)
Rev. 1.1 — 10 October 2011
0 mA to 20 mA
IOUTAP/IOUTAN
IOUTBP/IOUTBN
V
V
O(cm)
O(dif)
65.5 Ω
3.3 V
= 1.96 V
= 2.65 V
Dual 16-bit DAC: JESD204B interface; up to 1.25 Gsps
65.5 Ω
10 nF
10 nF
BBAP/BBAN
BBBP/BBBN
V
V
offset correction = up to 70 mV
I(cm)
I(dif)
174 Ω
34 Ω
2 kΩ
5 V
= 1.96 V
= 0.5 V
DAC1628D1G25
2 kΩ
174 Ω
34 Ω
IQ-modulator (V
BBAP/BBBP
BBAN/BBBN
© NXP B.V. 2011. All rights reserved.
aaa-000280
I(cm)
= 0.5 V)
33 of 133