ADUC7121:  Precision Analog Microcontroller, 12-Bit Analog I/O, ARM7TDMI MCU

The ADuC7121 is a fully integrated, 1 MSPS, 12-bit data acquisi-tion system incorporating a high performance multichannel ADC, 16-bit/32-bit MCU, and Flash®/EE memory on a single chip.

The ADC consists of up to seven single-ended inputs and two extra differential input pairs. The two differential pair inputs can be routed through a programmable gain amplifier (PGA). The ADC can operate in single-ended or differential input mode. The ADC input voltage is 0 V to V_REF. A low drift band gap ref-erence, temperature sensor, and voltage comparator complete the ADC peripheral set.

The ADuC7121 provides five current output digital-to-analog converters (DACs). The current sources (five current DACs) feature low noise and low drift high-side current output at 11-bit resolution. The five IDACs are as follows: IDAC0 with 250 mA full-scale (FS) output, IDAC1 with 200 mA FS output, IDAC2 with 80 mA FS output, IDAC3 with 45 mA FS output, and IDAC4 with 20 mA FS output.

The ADuC7121 also contains four voltage output digital-to-analog converters (DACs). The DAC output range is programmable to one of three voltage ranges.

The devices operate from an on-chip oscillator and a PLL generating an internal high frequency clock of 41.78 MHz (UCLK). This clock is routed through a programmable clock divider from which the MCU core clock operating frequency is generated. The microcontroller core is an ARM7TDMI®, 16-bit/32-bit RISC machine, which offers up to 41 MIPS peak performance. Eight kB of SRAM and 126 kB of nonvolatile Flash/EE memory are provided on chip. The ARM7TDMI core views all memory and registers as a single linear array.

On-chip factory firmware supports in-circuit serial download via the I²C serial interface port; nonintrusive emulation is also supported via the JTAG interface. These features are incorporated into a low cost QuickStart™ development system supporting this MicroConverter® family.

The device operates from 3.0 V to 3.6 V, and it is specified over an industrial temperature range of −10°C to +95°C. The IDACs are powered from a separate 2 V input power supply. When operating at 41.78 MHz, the power dissipation is typically 120 mW. The ADuC7121 is available in a 108-ball chip scale package ball grid array [CSP_BGA].