MAX6852AEE+ Maxim Integrated Products, MAX6852AEE+ Datasheet - Page 7

• Manufacturer Part Number: MAX6852AEE+
• Description: IC VFD CTRLR MATRIX 16QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX6852AEE+

• Display Type: Vacuum Fluorescent (VF)
• Configuration: 5 x 7 (Matrix)
• Interface: Serial
• Current - Supply: 3.5mA
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Digits Or Characters: -

Figure 2. Example of a Two-Digits-per-Grid Display (8 Grids, 16 Digits)
Figure 3. Digit Structure with 5
Segment, Cursor Segment, Four Annunciators
The cursor segment is controlled differently. A single
register selects one digit’s cursor from the entire dis-
play, and that can be lit either continuously or blinking.
All the other digits’ cursors are off.
The designations of DP, cursor, and annunciator are
interchangeable. For example, consider an application
requiring only one DP lit at a time, but the DP needs to
blink. The DP function does not have blink capability.
Instead, the DP segments on the display are routed
(using the output map) to the cursor function. In this
case, the DP segments are controlled using the cursor
register.
The output of the controller is a 4-wire serial stream that
interfaces to industry-standard, shift-register, high-volt-
age grid/anode VFD tube drivers (Figure 4). This inter-
face uses three outputs to transfer and latch grid and
anode data into the tube drivers, and a fourth output
that enables/disables the tube driver outputs (Figure 5).
The enable/disable control is modulated by the
MAX6852 for both PWM intensity control and interdigit
blanking, and disables the tube driver in shutdown. The
°C °F pH mW
_______________________________________________________________________________________
GRID 1
4-Wire Interfaced, 5
4 ANNUNCIATOR SEGMENTS
5 x 7 MATRIX CHARACTER
WITH 35 SEGMENTS
DECIMAL POINT (DP) SEGMENT
CURSOR SEGMENT
✕
7 Matrix Character, DP
GRID 2
GRID 3
Fluorescent Display Controller
GRID 4
controller multiplexes the display by enabling each grid
of the VFD in turn for 100µs (OSC = 4MHz) with the cor-
rect segment (anode) data. The data for the next grid is
transferred to the tube drivers during the display time of
the current grid.
The controller uses an internal output map to match any
tube-driver’s shift-register grid/anode order, and is
therefore compatible with all VFD internal chip-in-glass
or external tube drivers.
The MAX6852 provides five high-current output ports,
which can be configured for a variety of functions:
The PUMP output can be configured as either an
80kHz (OSC = 4MHz) clock intended for DC-DC con-
verter use, the 4-wire serial interface’s DOUT data out-
put, or a general-purpose logic output.
The PHASE1 and PHASE2 outputs can be individually
configured as either 10kHz PWM outputs (OSC =
4MHz) intended for filament driving, blink status out-
puts, or general-purpose logic outputs.
Figure 4. Connection of the MAX6852 to VFD Driver and VFD Tube
GRID 5
MICROCONTROLLER
✕
DOUT
SCLK
GRID 6
CS
7 Matrix Vacuum-
DIN
SCLK
CS
MAX6852
GRID 7
VFBLANK
VFDOUT
VFLOAD
VFCLK
GRID 8
VFDIN
VFCLK
VFLOAD
VFBLANK
VFD TUBE DRIVER
GRID/
ANODE
DRIVERS
7