ADI AD5770R six-channel 14-bit low noise DAC optical control application scheme

The AD5770R is a 6-channel, 14-bit resolution, low noise, programmable current output, digital-to-analog converter (DAC) for photonics control applications. The device incorporates a 1.25 V, on-chip voltage reference, a 2.5 kΩ precision resistor for reference current generation, die temperature, output monitoring functions, fault alarm, and reset functions.

The AD5770R contains five 14-bit resolution current sourcing DAC channels and one 14-bit resolution current sourcing and sinking DAC channel.

Channel 0 can be configured to sink up to 60 mA and source up to 300 mA. Channel 1 to Channel 5 have multiple programmable output current sourcing ranges set by register access.

Each DAC operates with a wide power supply rail from 0.8 V to AVDD − 0.4 V for optimizing power efficiency and thermal power dissipation.

The AD5770R operates from a 2.9 V to 5.5 V AVDD supply and is specified over the −40℃ to +105℃ temperature range.

Main features of AD5770R

6-channel, current output DAC

14-bit resolution

Programmable output current ranges

Channel 0: 0 mA to 300 mA, −60 mA to +300 mA, −60 mA to 0 mA

Channel 1: 0 mA to 140 mA, 0 mA to 250 mA

Channel 2: 0 mA to 55 mA, 0 mA to 150 mA

Channel 3, Channel 4, Channel 5: 0 mA to 45 mA, 0 mA to 100 mA

All current sourcing output ranges scale back by up to 0.5×

1.25 V, on-chip voltage reference

Integrated precision reference resistor

SPI interface

Reset function

Output current monitor

Compliance voltage monitor

Die temperature monitor

Integrated thermal shutdown

49-ball,4 mm × 4 mm WLCSP package

Operating temperature: −40℃ to +105℃

The application of AD5770R

Photonics control

LED driver programmable current source

Current mode biasing

Evaluation board：EVAL-AD5770RSDZ

The EVAL-AD5770RSDZ is a fully featured evaluation board that is designed to help the user evaluate the AD5770R 6-channel, 14-bit, current output digital-to-analog converter (DAC).

The EVAL-AD5770RSDZ evaluation board is controlled by the following two methods: the on-board P11 connector and the EVAL-SDP-CB1Z (Connector P10). The system development (SDP-B) board uses the AD5770R evaluation software to control the EVAL-AD5770RSDZ evaluation board via a Windows® PC USB port.

The EVAL-AD5770RSDZ board contains a power solution that uses the ADP5073 switching regulator to generate −2 V from a +3.3 V supply and the ADP1741 linear regulator to generate +2 V from a +3.3 V supply. Alternatively, the AD5770R also uses a linear power supply connected through the nine on-board connectors (P0 to P8). The AD5770R incorporates an internal 1.25 V precision reference. The EVAL-AD5770RSDZ board contains an additional 1.25, V 0.5 ppm/°C voltage reference.

The AD5770R evaluation software provides an intuitive graphic user interface (GUI) that configures and controls the AD5770R over the serial peripheral interface (SPI).

The AD5770R is a 6-channel, 14-bit resolution, low noise, programmable current output DAC for photonics control applications. The output current ranges are software selectable, and channels are routed to the MUX_OUT pin for external monitoring.

See the AD5770R data sheet for full details and consult the AD5770R data sheet in conjunction with this user guide when using the EVAL-AD5770RSDZ board.

Evaluation board：Main features of EVAL-AD5770RSDZ

Fully featured evaluation board for the AD5770R

PC control in conjunction with Analog Devices® Inc., EVAL-SDP-CB1Z system development platform

PC software for control