Features: Complete Dual 12-Bit DAC Comprising
-Two 12-Bit CMOS DACs
-On-Chip Voltage Reference
-Output Amplifiers
-Reference Buffer Amplifiers
Improved AD7237/AD7247:
-12 V to 15 V Operation
-Faster Interface 30 ns typ Data Setup Time
Parallel Loading Structure: AD7247A
(8+4) Loading Structure: AD7237A
Single or Dual Supply Operation
Low Power-165 mW typ in Single SupplyPinout
Specifications(TA= +25°C unless otherwise noted)
VDD to GND (AD7247A) . . . . . . . . . . . . ... . . .0.3 V to +17 V
VDD to AGND, DGND (AD7237A) . . . . . ...... . .0.3 V to +17 V
VDD to VSS . . . . . . . . . . . . . . . . . . . . . . . . . .0.3 V to +34 V
AGND to DGND (AD7237A) . . . . . . . ....... .0.3 V, VDD +0.3 V
VOUTA,2 VOUTB2 to AGND (GND) . .VSS 0.3 V to VDD +0.3 V
REF OUT to AGND (GND) . . . . . . . . .......... . . . . . . . .0 V to VDD
REF IN to AGND (GND) . . . . . . . . . ..........0.3 V to VDD +0.3 V
Digital Inputs to DGND (GND) . . . ....... . .0.3 V to VDD +0.3 V
Operating Temperature Range
Industrial (A, B Versions) . . . . . . . . . . ...... . .40°C to +85°C
Extended (T Version) . . . . . . . . . . . . . . ......55°C to +125°C
Storage Temperature Range . . . . . . . . . . . .65°C to +150°C
Lead Temperature (Soldering, 10 secs) . . . . . . . .. . . . .+300°C
Power Dissipation (Any Package) to +75°C . . . . . ... .1000 mW
Derates above +75°C by . . . . . . . . . . . . . . . . . . . . .10 mW/°CDescriptionThe AD7237A/AD7247A is an enhanced version of the industry standard AD7237/AD7247. Improvements include operation from 12 V to 15 V supplies, faster interface times and better reference variations with VDD. Additional features include faster settling times.
The AD7237A/AD7247A is a complete, dual, 12-bit, voltage output digital-to-analog converter with output amplifiers and Zener voltage reference on a monolithic CMOS chip. No exter-nal user trims are required to achieve full specified performance.
Both parts are microprocessor compatible, with high speed data latches and interface logic. The AD7247A accepts 12-bit paral-lel data which is loaded into the respective DAC latch using the WR</a> input and a separate Chip Select input for each DAC. The AD7237A has a double buffered interface structure and an 8-bit wide data bus with data loaded to the respective input latch in two write operations. An asynchronous LDAC</a> signal on the AD7237A updates the DAC latches and analog outputs.
A REF OUT/REF IN function is provided which allows either the on-chip 5 V reference or an external reference to be used as a reference voltage for the part. For single supply operation, two output ranges of 0 V to +5 V and 0 V to +10 V are available, while these two ranges plus an additional ±5 V range are avail-able with dual supplies. The output amplifiers are capable of de-veloping +10 V across a 2 kΩ load to GND.
The AD7237A/AD7247A is fabricated in Linear Compatible CMOS (LC2MOS), an advanced, mixed technology process that combines precision bipolar circuits with low power CMOS logic. Both parts are available in a 24-pin, 0.3" wide plastic and hermetic dual-in-line package (DIP) and are also packaged in a 24-lead small outline (SOIC) package.
AD7237A Data Sheet
