Member of the Pin-Compatible

CommsDAC Product Family

125 MSPS Update Rate

12-Bit Resolution

Spurious Free Dynamic Range (SFDR) to

Nyquist at 40 MHz Output: 60 dBc

1 ns Setup/Hold Time

Differential Scalable Current Outputs: 2 mA

to 20 mA

On-Chip 1.2 V Reference

3 V and 5 V CMOS-Compatible Digital

Interface

Straight Binary or Twos Complement Input

Power Dissipation: 175 mW at 5 V, Sleep

Mode: 25 mW at 5 V

Package: 28-Pin SOIC and TSSOP

description

The THS5661A is a 12-bit resolution digital-to-analog converter (DAC) specifically optimized for digital data

transmission in wired and wireless communication systems. The 12-bit DAC is a member of the CommsDAC

series of high-speed, low-power CMOS digital-to-analog converters. The CommsDAC family consists of pin

compatible 14-, 12-, 10-, and 8-bit DACs. All devices offer identical interface options, small outline package, and

pinout. The THS5661A offers superior ac and dc performance while supporting update rates up to 125 MSPS.

The THS5661A operates from an analog and digital supply of 3 V to 5.5 V. Its inherent low power dissipation

of 175 mW ensures that the device is well-suited for portable and low-power applications. Lowering the full-scale

current output reduces the power dissipation without significantly degrading performance. The device features

a SLEEP mode, which reduces the standby power to approximately 25 mW, thereby optimizing the power

consumption for system needs.

The THS5661A is manufactured in Texas Instruments advanced high-speed mixed-signal CMOS process. A

current-source-array architecture combined with simultaneous switching shows excellent dynamic

performance. On-chip edge-triggered input latches and a 1.2 V temperature-compensated bandgap reference

provide a complete monolithic DAC solution. The digital supply range of 3 V to 5.5 V supports 3 V and 5 V CMOS

logic families. Minimum data input setup and hold times allow for easy interfacing with external logic. The

THS5661A supports both a straight binary and twos complement input word format, enabling flexible interfacing

with digital signal processors.

The THS5661A provides a nominal full-scale differential output current of 20 mA and >300 kΩ output

impedance, supporting both single-ended and differential applications. The output current can be directly fed

to the load (e.g., external resistor load or transformer), with no additional external output buffer required. An

accurate on-chip reference and control amplifier allows the user to adjust this output current from 20 mA down

to 2 mA, with no significant degradation of performance. This reduces power consumption and provides 20 dB

gain range control capabilities. Alternatively, an external reference voltage and control amplifier may be applied

in applications using a multiplying DAC. The output voltage compliance range is 1.25 V.