The ADuC7120/ADuC7121 are fully integrated, 12-bit, 1 MSPS, data acquisition systems incorporating a high performance multichannel ADC, 16-bit/32-bit microcontroller unit (MCU), and Flash®/EE memory on a single chip.
The analog-to-digital converter (ADC) consists of eleven single-ended inputs for the ADuC7120 (seven single-ended inputs for the ADuC7121) and two extra differential input pairs. The two differential input pairs 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 VREF. A low drift band gap reference, temperature sensor, and voltage comparator complete the ADC peripheral set.
The ADuC7120/ADuC7121 provide 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 an 11-bit resolution. The five current digital-to-analog converters (IDACs) are as follows: IDAC0 with 250 mA full-scale (FS) output, IDAC1 with 200 mA FS output, IDAC2 with 45 mA FS output, IDAC3 with 80 mA FS output, and IDAC4 with 20 mA FS output.
The ADuC7120/ADuC7121 also contain up to 12 voltage output DACs. The DAC output range is programmable to one of three voltage ranges.
The devices operate from an on-chip oscillator and a phase-locked loop (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 reduced instruction set computer (RISC) machine, which offers up to 41 MIPS peak performance. 8 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 devices operate from 3.0 V to 3.6 V, and they are specified over the −40°C to +105°C industrial temperature range. The IDACs are powered from a separate input power supply, PVDD. When operating at 41.78 MHz, the power dissipation is typically 120 mW. The ADuC7120/ADuC7121 are available in a 108-ball chip-scale package ball grid array [CSP_BGA].
**Applications**
Optical modules—tunable laser
### Features and Benefits
Analog input/output
Multiple channel, 12-bit, 1 MSPS ADC
2 differential pairs with input PGA
General-purpose inputs (differential or single-ended)
ADuC7121: 7 channels
Fully differential and single-ended modes
0 V to VREF analog input voltage range (single-ended mode)
5 low noise IDACs
250 mA, 200 mA, 45 mA, 80 mA, 20 mA
12-bit voltage output DACs
ADuC7121: 4 channels
4× 12-bit voltage output DACs
On-chip voltage reference
On-chip temperature sensor
Microcontroller
ARM7TDMI core, 16-bit/32-bit RISC architecture
JTAG port supports code download and debug
Clocking options
Trimmed on-chip oscillator (±3%)
External watch crystal
External clock source up to 41.78 MHz
41.78 MHz PLL with programmable divider
Memory
126 kB Flash/EE memory, 8 kB SRAM
In-circuit download, JTAG-based debug
Software triggered in-circuit reprogrammability
On-chip peripherals
UART, 2 × I2C and SPI serial I/O
32-pin GPIO port
4× general-purpose timers
Wake-up timers and WDT
Power supply monitor
IDAC monitor
Temperature monitor
Vectored interrupt controller for FIQ and IRQ
8 priority levels for each interrupt type
Interrupt on edge or level external pin inputs
Power
Specified for 3 V operation
Normal mode: 11 mA at 5.22 MHz, 30 mA at 41.78 MHz
