MB201A2V/MB201A20V
Single Board Precision DVM with direct PC Interface
The ALD MB201 is a precision +/-5½-digit Digital Voltmeter (DVM) printed circuit board that
contains the ALD500R/ALD521D A/D Converter chipset that directly plugs into the parallel printer port
of a PC computer. It features calibrated analog input (w/scalable input ranges), and digital circuitry to
communicate with PC or other microprocessors. It is designed to be used as a stand-alone, embedded
system component in a variety of applications including digital panel meters, customized instrumentation
displays, temperature monitoring, high resolution DVM’s, weigh scales and others. Direct Full-scale
analog input range is +/-2.00000V DC with a linearity of 0.005%. ALD's 18-bit plus sign integrating
dual-slope analog processor (ALD500) functions as the input device and the ALD521D microprocessor
IC implements the digital conversion, control mode and I/O functions.
The MB201 supports two optional versions, each populated with different components and
configurations:
Mode A – calibrated reference used primarily for measurements against a calibrated reference
voltage typically required in precision voltmeter applications. Mode A is the default version of
MB201A.
Mode B – ratio-metric intended for measurements against a ratio-metric reference voltage, such
as those required in weigh scale applications. Mode B is a simple application specific adaptation
of the standard MB201A.
The MB201 board has a provision for PC interface (DB25), BASIC interface modules, and input resistor
divider network for input scaling. Optional MS-DOS Software (P/N - MBCDROM) is also available for
user setup and calibration. Only one copy of the software is necessary, regardless of the number of
boards in use. DC Inputs are single ended or optionally fully differential, and features automatic zero and
automatic input polarity detection. A DB25 connector is provided on-board, to conveniently interconnect
the MB201 to a personal computer (PC) via the parallel printer port for operation, initial setup, and
calibration.
Hardware and Software Features
Directly plug into a PC parallel printer port and displays readings on the monitor.
Measurement Range: +/-2.00000V DC direct input.
(Other ranges are user configurable and scalable, using both hardware and software scaling)
All solid-state construction.
User selectable +/-3½ to +/-6½ digits.
Differential analog inputs with auto-polarity and auto-zero.
Calibration for positive and/or negative inputs.
Smart Input Filtering (Sample Averaging) selection for noise reduction and accurate displays.
Optional MS-DOS software for user operation, setup, and calibration is sold separately.
Rev 2.0 © 2012 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, CA 94089-1706 Tel: (408) 747-1155 Fax: (408) 747-1286
MB201
www.aldinc.com
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Key Specifications
MB201A2V
Direct Full Scale Analog Input Range: +/- 2.00000V DC
Input Impedance: 1GΩ min, 100GΩ typical.
Optional on-board input resistor divider/preamplifier network for wide input voltage ranges
Resolution: +/-1 digit, (+/-10µV) @ Vin = 1.00000V (16x input averaging)
Overvoltage Protection: Not available
Conversion Sample Rate: 3-samples/sec (from 1 sample/min. to 10 samples/sec.)
No external power source necessary, draws power directly from the PC printer port
Optional external Power Supply: +4.5 to +5.5V max @ 6mA max.
Accuracy +/-0.02% (After 2 hour warm-up)
Linearity +/-0.01% full-scale (23º C, +/-1º C).
Logic Compatibility: CMOS inputs and outputs.
MB201A20V
Direct Full Scale Analog Input Range: +/-20.000V DC
Input Impedance: 10MEGΩ nominal
Optional on-board input resistor divider for wide input voltage ranges
Resolution: +/-1 digit, (+/-100µV) @ Vin = 10.0000V (16x input averaging)
Overvoltage Protection: 200V DC
Conversion Sample Rate: 3-samples/sec (from 1 sample/min. to 10 samples/sec)
No external power source necessary, draws power directly from the PC printer port
Optional external Power Supply: +4.5 to +5.5V max @ 6mA max.
Accuracy +/-0.02% (After 2 hour warm-up)
Linearity +/-0.01% full-scale (23º C, +/-1º C).
Logic Compatibility: CMOS inputs and outputs.
Applications
Applications for the M201 Board include embedded digital panel meters, customized
instrumentation displays, temperature monitoring, high resolution DVM’s, weigh scales, signal
conditioners, laboratory data-logging, process monitors, portable/field troubleshooting and calibration.
Configuration & Outline Drawing
All MB201 boards include a DB25 pin connector that plugs directly into the parallel printer port of a
desktop or laptop PC computer for operation, initial setup & calibration. The board outputs 24 bit serial
data to the PC or other digital processors for further data processing.
Rev 2.0 © 2012 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, CA 94089-1706 Tel: (408) 747-1155 Fax: (408) 747-1286
MB201
www.aldinc.com
2 of 3
ALD500/ALD521D Chipset
For complete technical information and operating specifications for the ALD chipset as well as other
ALD products, you can download complete datasheets on-line.
Environmental
Operating Temperature range: 0 to 50º C.
Storage Temperature range: -40 to +85 ºC.
Humidity: to 90% (no condensation).
Protection: no shielding - open board construction.
Mechanical
Outline Dimensions: 3.20 in. x 2.45 in. x 0.5 in.
Mounting Holes: 0.125 in. diameter @ 0.125 in from 4 corners
Weight: 1 ounce (28 grams) Nominal
Ordering Information
MB201 or MB201A2V (MODE A, DVM Mode)
MB201Tyyyy
where Tyyyy is a Custom Part Number designator
MB201AxxV (Custom Option)
where xx specifies the input voltage range,
e.g. xx=20 for +/- 20V input voltage range
MBCDROM (optional MS-DOS software for user operation, setup, and calibration,
and user design documentation.)
Rev 2.0 © 2012 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, CA 94089-1706 Tel: (408) 747-1155 Fax: (408) 747-1286
MB201
www.aldinc.com
3 of 3