Precision analog MCUs feature on-chip data conversion to simplify optical module design

NORWOOD, USA: Analog Devices Inc. (ADI) has introduced a pair of highly integrated precision analog microcontrollers featuring on-chip memory, data converters, and other analog peripherals that combine to deliver the highest level of programmability and smallest package size.

Effective for digital diagnostics in optical transceivers and modules based on both fixed and tunable frequency lasers, the ADuC7023 and ADuC7122 precision analog microcontrollers use an ARM7 processor with up to 126 KB of flash memory to ensure the accurate control of optical drivers and diagnostics.

The new microcontrollers feature on-chip 12-bit ADCs (analog-to-digital converters) and DACs (digital-to-analog converters), which reduce the size of the overall solution by up to 75 percent compared to competing discrete solutions.

The devices support interrupt nesting and up to 16 levels of interrupt priority, and retain DAC and GPIO outputs during a software or watchdog reset, which are of particular benefit to optical module designers.

ADuC7122 analog MCU boosts control functions in tunable optical modules
The ADuC7122 includes a 32-bit ARM7TDMI processor core operating at 41.78 MHz with 8 KB (kilobytes) of on-chip SRAM and 128 KB of on-chip EEPROM memory with software-triggered in-circuit re-programmability.

While competing devices use PWMs (pulse-width modulators) and lower performance ADCs to perform monitoring and control functions, the ADuC7122 microcontroller features a 14-channel, 12-bit, 1-MSPS SAR (successive-approximation register) ADC, 12 buffered 12-bit DACs, a programmable gain amplifier and an on-chip temperature sensor.

This high level of precision component integration allows for the robust monitoring and control of key parameters in tunable optical modules, resulting in higher overall system performance. The integration and precision of the ADuC7122 eases the task for the system engineer, while versatile programmability allows multiple systems to use the same component.

The ADuC7122 also features five timers, including a wake-up timer and watchdog timer, as well as two I²C interfaces, one SPI, one UART and 32 GPIO signal pins that can be independently configured as inputs, outputs or open drain. All of this functionality is provided in a tiny 7 mm × 7 mm 108-ball BGA (ball grid array) package.

ADuC7023 analog MCU for fixed frequency laser apps
For fixed frequency optical transceivers in SFP, SFP+, XFP and GPON, the ADuC7023 offers 8 KB of SRAM, 62 KB of flash/EEPROM memory, 19 general-purpose I/O (input/output) pins, three general-purpose timers and 16 programmable-logic elements.

Analog peripherals include a 12-channel, 12-bit, 1-MSPS ADC, a 16-bit, 6-channel PWM and four buffered 12-bit DACs. All of this functionality is provided in a tiny 5 mm × 5 mm 32-lead LFCSP (lead frame chip scale package).