The AD5668 device is a low power, octal, 16-bit, buffered voltage-output DAC. All devices operate from a single 2.7 V to 5.5 V supply and are guaranteed monotonic by design. The AD5668 and AD5628 are available in both a 4 mm × 4 mm LFCSP and a 16-lead TSSOP, while the AD5648 is available in both a 14-lead and 16-lead TSSOP.
The AD5628/AD5648/AD5668 have an on-chip reference with an internal gain of 2. The AD5628-1/AD5648-1/AD5668-1 have a 1.25 V 5 ppm/°C reference, giving a full-scale output range of 2.5 V; the AD5628-2/AD5648-2/AD5668-2 and AD5668-3 have a 2.5 V 5 ppm/°C reference, giving a full-scale output range of 5 V. The on-board reference is off at power-up, allowing the use of an external reference. The internal reference is enabled via a software write.
The part incorporates a power-on reset circuit that ensures that the DAC output powers up to 0 V (AD5628-1/AD5648-1/AD5668-1, AD5628-2/AD5648-2/AD5668-2) or midscale (AD5668-3) and remains powered up at this level until a valid write takes place. The part contains a power-down feature that reduces the current consumption of the device to 400 nA at 5 V and provides software-selectable output loads while in power-down mode for any or all DAC channels. The outputs of all DACs can be updated simultaneously using the LDAC function, with the added functionality of user-selectable DAC channels to simultaneously update. There is also an asynchronous CLR that updates all DACs to a userprogrammable code—zero scale, midscale, or full scale.
The AD5628/AD5648/AD5668 utilize a versatile 3-wire serial interface that operates at clock rates of up to 50 MHz and is compatible with standard SPI®, QSPI™, MICROWIRE™, and DSP interface standards. The on-chip precision output amplifier enables rail-to-rail output swing.
**Product Highlights**
1. Octal, 12-/14-/16-bit DAC.
2. On-chip 1.25 V/2.5 V, 5 ppm/°C reference.
3. Available in 14-lead/16-lead TSSOP, 16-lead LFCSP, and 16-ball WLCSP.
4. Power-on reset to 0 V or midscale.
5. Power-down capability. When powered down, the DAC typically consumes 200 nA at 3 V and 400 nA at 5 V.
**Applications**
Process control
Data acquisition systems
Portable battery-powered instruments
Digital gain and offset adjustment
Programmable voltage and current sources
Programmable attenuators
### Features and Benefits
Low power, small footprint, pin-compatible octal DACs: 16 bits
14-lead/16-lead TSSOP, 16-lead LFCSP, and 16-ball WLCSP
On-chip 1.25 V/2.5 V, 5 ppm/°C reference
Power down to 400 nA at 5 V, 200 nA at 3 V
2.7 V to 5.5 V power supply
Guaranteed monotonic by design
Power-on reset to zero scale or midscale
3 power-down functions
Hardware LDAC and LDAC override function
CLR function to programmable code
Rail-to-rail operation
AD5668-EP supports defense and aerospace applications (AQEC standard)
