PRELIMINARY TECHNICAL DATA
®
MicroConverter , Dual 16-/24- Bit ADCs
a
with Embedded 62KB FLASH MCU
Preliminary Technical Data
ADuC834
FEATURES
FUNCT IONAL BLOCK DIAGRAM
High Resolution Sigm a-Delta ADCs
Tw o Independent ADCs (16- and 24-Bit Resolution)
24-Bit No Missing Codes, Prim ary ADC
13-Bit p-p Resolution @ 20 Hz, 20 m V Range
18-Bit p-p Resolution @ 20 Hz, 2.56 V Range
Me m o ry
AVDD
ADuC834
IEXC1
IEXC2
CURRENT
SOURCE
AVDD
AIN1
AIN2
12-BIT
DA C
BUF
DAC
PRIMARY
BUF
PGA
MUX
24-BIT Σ ∆ ADC
16-BIT
62Kbytes On-Chip Flash/ EE Program Mem ory
4 KBytes On-Chip Flash/ EE Data Mem ory
Flash/ EE, 100 Yr Retention, 100 Kcycles Endurance
In Circuit Serial Dow nload
High Speed User Bootload (5s Dow nload)
2304 Bytes On-Chip Data RAM
Σ ∆ DAC
AIN3
AIN4
AIN5
16-BIT
Σ ∆ DAC
AGND
PW M0
PW M1
AUXILIARY
16-BIT Σ ∆ ADC
MUX
MUX
16-BIT
P W M
16-BIT
P W M
TEMP
SENSOR
8051-BASED MCU W ITH ADDITIONAL
PERIPHERALS
8051 Based Core
62 KBYTES FLASH/EE PROGRAM MEMORY
4 KBYTES FLASH/EE DATA MEMORY
2304 BYTES USER RAM
INTERNAL
BANDGAP
VREF
PROG.
CLOCK
DIVIDER
8051-Com patible Instruction Set (12.58 MHz Max)
32 kHz External Crystal, On-Chip Program m able PLL
11 Interrupt Sources, Tw o Priority Levels
Dual Data Pointer
POW ER SUPPLY MON
WATCHDOG TIMER
3
×
16 BIT TIMERS
1
× REAL TIME CLOCK
OSC
&
EXTERNAL
VREF
UART AND SPI
SERIAL I/O
4
×
PARALLEL
PORTS
PLL
DETECT
Extended 11-bit Stack Pointer
On-Chip Peripherals
12-Bit Voltage Output DAC
REFIN› REFIN+ XTAL1
XTAL2
Dual 16-Bit Σ∆ DACs/ PWMs
On-Chip Tem perature Sensor
Dual Excitation Current Sources
62 Kbytes of nonvolatile Flash/EE program memory are provided
on-chip. 4 Kbytes ofnonvolatile Flash/EE data memory, 256 bytes
RAM and 2 KBytes of extended RAM are also integrated on-chip.
T he program memory can be configured as data memory in
datalogging applications.
Tim e Interval Counter (Real Tim e Clock/ WakeUp Cct)
UART and SPI® Serial I/ O
Tim er 3 for high speed UART baud rates (incl 115,200)
Watchdog Tim er (WDT), Pow er Supply Monitor (PSM)
Po w e r
Specified for 3 V and 5 V Operation
Norm al: 3 m A @ 3 V (Core CLK = 1.5 MHz)
Pow er-Dow n: 20µA m ax w ith w ake-up cct running
T he ADuC834 also incorporates additional analog functionality
with a 12-bit DAC, dual current sources, power supply monitor,
and a bandgap reference. On-chip digital peripherals include two
16-bit Σ∆ DACs/PWM, watchdog timer, real time clock (time
interval counter), four timers/counters, and two serial I/O ports
(UART and SPI).
GE NE RAL D E SC RIP TIO N
T he ADuC834 is a complete smart transducer front-end, inte-
grating two high-resolution sigma delta ADCs, an 8-bit MCU,
and program/data Flash/EE Memory on a single chip.
On-chip factory firmware supports in-circuit serial download (via
UART ), as well as single-pin emulation mode via the EA pin. A
functional block diagram of the ADuC834 is shown above with a
more detailed block diagram shown in figure 11 (page 18).
T he two independent ADCs (Primary and Auxiliary) include a
temperature sensor and a PGA (allowing direct measurement of
low-level signals). T he ADCs with on-chip digital filtering and
programmable output data rates are intended for the measure-
ment of wide dynamic range, low frequency signals, such as those
in weigh scale, strain-gauge, pressure transducer, or temperature
measurement applications.
T he part operates from a 3V or a 5V supply. When operating from
3V the power dissipation for the part is below 10mW. T he
ADuC834 is housed in a 52-lead MQFP package.
APPLICATIONS
Intelligent Sensors (IEEE1451.2-Com patible)
Weigh Scales
Portable Instrum entation
Pressure Transducers
4–20 m A Transm itters
T he device operates from a 32 kHz crystal with an on-chip PLL
generating a high-frequency clock of 12.58 MHz. T his clock is,
routed through a programmable clock divider from which the
MCU core clock operating frequency is generated. T he micro-
controller core is an 8052 and therefore 8051 instruction set
compatible with 12 core clock periods per machine cycle.
MicroConverter is a registered trademark of Analog Devices, Inc.
SPI is a registered trademark of Motorola Inc.
REV. PrC (12 March 2002)
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
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Tel: 781/329-4700
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© Analog Devices, Inc., 2002