a FEATURES 12-Bit CMOS DAC with Output Amplifier and Reference Improved AD7245/AD7248: 12 V to 15 V Operation ؎1/2 LSB Linearity Grade Faster Interface–30 ns typ Data Setup Time Extended Plastic Temperature Range (–40؇C to +85؇C) Single or Dual Supply Operation Low Power–65 mW typ in Single Supply Parallel Loading Structure: AD7245A (8+4) Loading Structure: AD7248A
LC2MOS 12-Bit DACPORTs AD7245A/AD7248A AD7245A FUNCTIONAL BLOCK DIAGRAM
The AD7245A/AD7248A is an enhanced version of the industry standard AD7245/AD7248. Improvements include operation from 12 V to 15 V supplies, a ± 1/2 LSB linearity grade, faster interface times and better full scale and reference variations with VDD. Additional features include extended temperature range operation for commercial and industrial grades.
AD7248A FUNCTIONAL BLOCK DIAGRAM
The AD7245A/AD7248A is a complete, 12-bit, voltage output, digital-to-analog converter with output amplifier and Zener voltage reference on a monolithic CMOS chip. No external user trims are required to achieve full specified performance. Both parts are microprocessor compatible, with high speed data latches and double-buffered interface logic. The AD7245A accepts 12-bit parallel data which is loaded into the input latch on the rising edge of CS or WR. The AD7248A has an 8-bit wide data bus with data loaded to the input latch in two write operations. For both parts, an asynchronous LDAC signal transfers data from the input latch to the DAC latch and updates the analog output. The AD7245A also has a CLR signal on the DAC latch which allows features such as power-on reset to be implemented. The on-chip 5 V buried Zener diode provides a low noise, temperature compensated reference for the DAC. 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 available with dual supplies. The output amplifiers are capable of developing +10 V across a 2 kΩ load to GND. The AD7245A/AD7248A is fabricated in linear compatible CMOS (LC2MOS), an advanced, mixed technology process that combines precision bipolar circuits with low power CMOS logic. The AD7245A is available in a small, 0.3" wide, 24-pin DIP and
DACPORT is a registered trademark of Analog Devices, Inc.
SOIC and in 28-terminal surface mount packages. The AD7248A is packaged in a small, 0.3" wide, 20-pin DIP and SOIC and in 20-terminal surface mount packages. PRODUCT HIGHLIGHTS
1. The AD7245A/AD7248A is a 12-bit DACPORT® on a single chip. This single chip design and small package size offer considerable space saving and increased reliability over multichip designs. 2. The improved interface times on the part allows easy, direct interfacing to most modern microprocessors. 3. The AD7245A/AD7248A features a wide power supply range allowing operation from 12 V supplies.
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