MA838 Datasheet, PDF (2/13 Pages) Zarlink Semiconductor Inc – SINGLE PHASE PULSE WIDTH MODULATION WAVEFORM GENERATOR

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DS3798-3.1
MA838 FAMILY
SINGLE PHASE PULSE WIDTH MODULATION
WAVEFORM GENERATOR
The MA838 PWM generator has been designed to provide
waveforms for the control of variable speed AC machines,
uninterruptible power supplies and other forms of power
electronic devices which require pulse width modulation as a
means of efficient power control.
Two TTL level PWM outputs control the upper and lower
switches in an inverter arm. This is usually via an external
isolation and amplification stage.
Information contained within the pulse width modulated
sequences controls the wave shape, power frequency and
amplitude of the output waveform. Parameters such as the
carrier frequency, minimum pulse width and pulse delay time
may be defined during initialisation of the device. The pulse
delay time (underlap) controls the delay between turning on
and off the two power switches in the inverter, in order to
accommodate variations in the turn-on and turn-off times of
families of power devices.
The MA838 is easily controlled by a microprocessor and
its fully digital generation of PWM waveforms gives
unprecedented accuracy and temperature stability. Precision
pulse shaping capability allows optimum efficiency with any
power circuitry. The device operates as a stand-alone
microprocessor peripheral reading the power waveform directly
from an internal ROM and requiring microprocessor intervention
only when operating parameters need to be changed.
An 8-bit multiplexed data bus is used to receive addresses
and data from the microprocessor/controller. This is a standard
MOTEL™ bus, compatible with most microprocessors/
controllers.
FEATURES
s Fully Digital Operation
s Interfaces with most Microprocessors
s Wide Power-Frequency Range
s 12-Bit Frequency Control accuracy
s Carrier Frequency Selectable up to 24kHz
s Waveform Stored in Internal ROM
s Double Edged Regular Sampling
s Selectable Minimum Pulse Width and Underlap Time
s DC Injection Braking
MOTEL is a registered trademark of Motorola corp. and Intel corp.
NOTE
* = Intel bus format
† = Motorola bus format
DP28
MP28/W
Fig.1 Pin connections (top view)
The power frequency is defined to 12 bits for high accuracy
and a zero setting is included in order to implement DC-injection
braking with no software overhead.
This family is functionally identical to the MA828 PWM
generator IC except that only one PWM channel is provided.
ORDERING INFORMATION
MA838-1 PLABA (Commercial, Plastic DIL)
MA838-2 PLABA (Commercial, Plastic DIL)
MA838-1 PLABD (Industrial, Plastic DIL)
MA838-2 PLABD (Industrial, Plastic DIL)
MA838-1 SLABA (Commercial, Plastic Small Outline)
MA838-2 SLABA (Commercial, Plastic Small Outline)
MA838-1 SLABD (Industrial, Plastic Small Outline)
MA838-2 SLABD (Industrial, Plastic Small Outline)
The MA838-1 and MA838-2 are the two standard waveform
options offered; refer to PRODUCT DESIGNATION section for
waveform specifications.
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