The AD7656-1/AD7657-1/AD7658-1 are reduced decoupling pin- and software-compatible versions of AD7656/AD7657/AD7658. The AD7656-1/AD7657-1/AD7658-1 devices contain six 16-/14-/12-bit, fast, low power successive approximation ADCs in a package designed on the iCMOS^® process (industrial CMOS). iCMOS is a process combining high voltage silicon with submicron CMOS  and complementary bipolar technologies. It enables the development of a wide range of high performance analog ICs capable of 33 V operation in a footprint that no previous generation of high voltage parts could achieve. Unlike analog ICs using conventional CMOS processes, iCMOS components can accept bipolar input signals while providing increased performance, which dramatically reduces power consumption and package size.

The AD7656-1/AD7657-1/AD7658-1 feature throughput rates of up to 250 kSPS. The parts contain low noise, wide bandwidth track-and-hold amplifiers that can handle input frequencies up to 4.5 MHz.

The conversion process and data acquisition are controlled using the CONVST signals and an internal oscillator. Three CONVST pins (CONVST A, CONVST B, and CONVST C) allow independent, simultaneous sampling of the three ADC pairs. The AD7656-1/AD7657-1/AD7658-1 have a high speed parallel and serial interface, allowing the devices to interface with microprocessors or DSPs. When the serial interface is selected, each part has a daisy-chain feature that allows multiple ADCs to connect to a single serial interface. The AD7656-1/AD7657-1/AD7658-1 can accommodate true bipolar input signals in the ±4 × V_REF and ±2 × V_REF ranges. Each AD7656-1/AD7657-1/AD7658-1 also contains an on-chip 2.5 V reference.

Product Highlights

1. Six 16-/14-/12-bit, 250 kSPS ADCs on board.
2. Six true bipolar, high impedance analog inputs.
3. High speed parallel and serial interfaces.
4. Reduced decoupling requirements and reduced bill of materials cost compared with the AD7656/AD7657/ AD7658 devices.

Applications

• Power line monitoring and measuring systems
• Instrumentation and control systems
• Multiaxis positioning systems

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.