MicroConverter, Dual-Channel 16-Bit ADCs with Embedded Flash MCU

The ADuC816 is a complete smart transducer front-end, integrating two high-resolution sigma-delta ADCs, an 8-bit MCU, and program/data Flash/EE Memory on a single chip. This low power device accepts low-level signals directly from a transducer.

The two independent ADCs (Primary and Auxiliary) include a temperature sensor and a PGA (allowing direct measurement of low-level signals). The ADCs with on-chip digital filtering are intended for the measurement of wide dynamic range, low frequency signals, such as those in weigh scale, strain gauge, pressure transducer, or temperature measurement applications. The ADC output data rates are programmable and the ADC output resolution will vary with the programmed gain and output rate.

The device operates from a 32 kHz crystal with an on-chip PLL generating a high-frequency clock of 12.58 MHz. This clock is, in turn, routed through a programmable clock divider from which the MCU core clock operating frequency is generated. The microcontroller core is an 8052 and therefore 8051-instructionset-compatible. The microcontroller core machine cycle consists of 12 core clock periods of the selected core operating frequency. 8 Kbytes of nonvolatile Flash/EE program memory are provided on-chip. 640 bytes of nonvolatile Flash/EE data memory and 256 bytes RAM are also integrated on-chip.

The ADuC816 also incorporates additional analog functionality with a 12-bit DAC, current sources, power supply monitor, and a bandgap reference. On-chip digital peripherals include a watchdog timer, time interval counter, three timers/counters, and three serial I/O ports (SPI, UART, and I2C-compatible).

On-chip factory firmware supports in-circuit serial download and debug modes (via UART), as well as single-pin emulation mode via the EA pin.

The part operates from a single 3 V or 5 V supply. When operating from 3 V supplies, the power dissipation for the part is below 10 mW. The ADuC816 is housed in a 52-lead MQFP package. The part operates from a single 3 V or 5 V supply. When operating from 3 V supplies, the power dissipation for the part is below 10 mW. The ADuC816 is housed in 52-lead MQFP and 56-lead LFCSP packages.

Applications

* Intelligent Sensors (IEEE1451.2-Compatible)

* Weigh Scales

* Portable Instrumentation

* Pressure Transducers

* 4–20 mA Transmitters

* High-Resolution Sigma-Delta ADCs

* Dual 16-Bit Independent ADCs

* Programmable Gain Front End

* 16-Bit No Missing Codes, Primary ADC

* 13-Bit p-p Resolution @ 20 Hz, 20 mV Range

* 16-Bit p-p Resolution @ 20 Hz, 2.56 V Range

* Memory

* 8 Kbytes On-Chip Flash/EE Program Memory

* 640 Bytes On-Chip Flash/EE Data Memory

* Flash/EE, 100 Year Retention, 100 Kcycles Endurance

* 256 Bytes On-Chip Data RAM

* 8051-Based Core

* 8051-Compatible Instruction Set (12.58 MHz Max)

* 32 kHz External Crystal, On-Chip Programmable PLL

* Three 16-Bit Timer/Counters

* 26 Programmable I/O Lines

* 11 Interrupt Sources, Two Priority Levels

* Power

* Specified for 3 V and 5 V Operation

* Normal: 3 mA @ 3 V (Core CLK = 1.5 MHz)

* Power-Down: 20 μA (32 kHz Crystal Running)

* On-Chip Peripherals

* On-Chip Temperature Sensor

* 12-Bit Voltage Output DAC

* Dual Excitation Current Sources

* Reference Detect Circuit

* Time Interval Counter (TIC)

* UART Serial I/O

* I2C®-Compatible and SPI® Serial I/O

* Watchdog Timer (WDT), Power Supply Monitor (PSM)