3.3V, 16-Bit, 500Msps High Dynamic

Performance DAC with Differential LVDS Inputs

8

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Detailed Description

Architecture

The MAX5888 is a high-performance, 16-bit, current-

steering DAC (Figure 1) capable of operating with clock

speeds up to 500MHz. The converter consists of sepa-

rate input and DAC registers, followed by a current-

steering circuit. This circuit is capable of generating

differential full-scale currents in the range of 2mA to

20mA. An internal current-switching network in combi-

nation with external 50

Ω termination resistors convert

the differential output currents into a differential output

voltage with a peak-to-peak output voltage range of

0.1V to 1V. An integrated 1.2V bandgap reference, con-

trol amplifier, and user-selectable external resistor

determine the data converter’s full-scale output range.

Reference Architecture and Operation

The MAX5888 supports operation with the on-chip 1.2V

bandgap reference or an external reference voltage

source. REFIO serves as the input for an external, low-

impedance reference source, and as the output if the

DAC is operating with the internal reference. For stable

operation with the internal reference, REFIO should be

decoupled to AGND with a 0.1µF capacitor. Due to its

limited output drive capability REFIO must be buffered

with an external amplifier, if heavier loading is required.

The MAX5888’s reference circuit (Figure 2) employs a

control amplifier, designed to regulate the full-scale

DAC. Configured as a voltage-to-current amplifier, the

output current can be calculated as follows:

is the reference resistor, which determines the amplifi-

er’s output current for the DAC. See Table 1 for a matrix

PIN

NAME

FUNCTION

45

B14N

Complementary Data Bit 14

46

B13P

Data Bit 13

47

B13N

Complementary Data Bit 13

48

B12P

Data Bit 12

49

B12N

Complementary Data Bit 12

50

B11P

Data Bit 11

51

B11N

Complementary Data Bit 11

52

B10P

Data Bit 10

53

B10N

Complementary Data Bit 10

54

B9P

Data Bit 9

55

B9N

Complementary Data Bit 9

56

B8P

Data Bit 8

57

B8N

Complementary Data Bit 8

58

B7P

Data Bit 7

59

B7N

Complementary Data Bit 7

63

B6P

Data Bit 6

64

B6N

Complementary Data Bit 6

65

B5P

Data Bit 5

66

B5N

Complementary Data Bit 5

67

B4P

Data Bit 4

68

B4N

Complementary Data Bit 4

Pin Description (continued)