MAX6850 Datasheet, PDF (1/34 Pages) Maxim Integrated Products – 4-Wire Interfaced, 7-, 14-, and 16-Segment Alphanumeric Vacuum-Fluorescent Display Controller

19-2635; Rev 1; 1/03
4-Wire Interfaced, 7-, 14-, and 16-Segment Alpha-
numeric Vacuum-Fluorescent Display Controller
General Description
The MAX6850 compact vacuum-fluorescent display
(VFD) controller provides microprocessors with the mul-
tiplex timing for 7-segment, 14-segment, or 16-segment
alphanumeric VFD displays up to 96 characters and
controls industry-standard, shift-register, high-voltage
grid/anode VFD tube drivers. The device supports dis-
play tubes using either one or two digits per grid, as
well as universal displays. Hardware is included to sim-
plify the generation of cathode bias and filament sup-
plies and to provide up to five logic outputs, including a
buzzer driver. The MAX6850 provides an internal cross-
point switch to match any tube-driver shift-register
grid/anode order, and is compatible with both chip-in-
glass and external tube drivers.
The MAX6850 includes an ASCII 104-character font,
multiplex scan circuitry, and static RAM that stores
digit, cursor, and annunciator data, as well as font data
for 24 user-definable characters. The display intensity
can be adjusted by an internal 16-step digital bright-
ness control. The device also includes separate annun-
ciator and cursor control with automatic blinking, as
well as a low-power shutdown mode.
The MAX6850 provides timing to generate the PWM
waveforms to drive the tube filament from a DC supply.
The filament drive is synchronized to the display multi-
plexing to eliminate beat artifacts. The MAX6850 is
compatible with SPI™ and QSPI™.
For a 2-wire interfaced version, refer to the MAX6851*
data sheet.
*Future product—contact factory for availability.
Display Modules
Retail POS Displays
Weight and Tare
Displays
Bar Graph Displays
Applications
Industrial Controllers
White Goods
Professional Audio
Equipment
Pin Configuration and Functional Diagram appear at end of
data sheet.
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
Features
o High-Speed 26MHz SPI-/QSPI-/MICROWIRE™-
Compatible Serial Interface
o 2.7V to 3.6V Operation
o Controls Up to 48 Grids of 7-Segment, 14-Segment,
or 16-Segment Alphanumeric Digits
o One Digit and Two Digits per Grid and Universal
Displays Supported
o 16-Step Digital Brightness Control
o Built-In ASCII 104-Character Font
o 24 User-Definable Characters
o Up to Four Annunciators per Grid with Automatic
Blinking Control
o Separate Cursor Control with Automatic Blinking
o Filament Drive Full-Bridge Waveform Synthesis
o Buzzer Tone Generator with Single-Ended or
Push-Pull Driver
o Up to Five General-Purpose Logic Outputs
o 9µA Low-Power Shutdown (Data Retained)
o 16-Pin QSOP Package
PART
MAX6850AEE
Ordering Information
TEMP RANGE
-40°C to +125°C
PIN-PACKAGE
16 QSOP
Typical Application Circuit
CHIP-ON-GLASS VFD
0.1µF
VFD SUPPLY VOLTAGE
MICROCONTROLLER
DOUT
SCLK
CS
VFCLK
MAX6850
VFDOUT
DIN
VFLOAD
SCLK
VFBLANK
CS
OSC2
OSC1
GND
56pF
10kΩ
________________________________________________________________ Maxim Integrated Products 1
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