Äîêóìåíòàöèÿ è îïèñàíèÿ www.docs.chipfind.ru
General Description
The MAX6852 compact vacuum-fluorescent display
(VFD) controller provides microprocessors with the mul-
tiplex timing for 5 x 7 matrix VFD displays up to 96
characters and controls industry-standard, shift-regis-
ter, high-voltage grid/anode VFD tube drivers. The
device supports display tubes using either one or two
digits per grid, as well as universal displays. The
MAX6852 provides an internal crosspoint switch to
match any tube-driver shift-register grid/anode order,
and is compatible with both chip-in-glass and external
tube drivers. Hardware is included to simplify the gener-
ation of cathode bias and filament supplies and to pro-
vide up to five logic outputs, including a buzzer driver.
The MAX6852 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 MAX6852 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 MAX6852 is
compatible with SPITM and QSPITM.
For a 2-wire interfaced version, refer to the MAX6853
data sheet.
Applications
Features
o High-Speed 26MHz SPI-/QSPI-/MICROWIRETM-
Compatible Serial Interface
o 2.7V to 3.6V Operation
o Controls Up to 96 5 x 7 Matrix Characters
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
MAX6852
4-Wire Interfaced, 5
7 Matrix Vacuum-
Fluorescent Display Controller
________________________________________________________________ Maxim Integrated Products
1
Ordering Information
19-2537; Rev 1; 11/02
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
PART
TEMP RANGE
PIN-PACKAGE
MAX6852AEE
-40
°C to +125°C
16 QSOP
Display Modules
Retail POS Displays
Weight and Tare
Displays
Bar Graph Displays
Industrial Controllers
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
MAX6852
VFCLK
VFDOUT
VFLOAD
VFBLANK
OSC2
DIN
SCLK
OSC1
CS
DOUT
SCLK
CS
MICROCONTROLLER
56pF
0.1
µF
GND
CHIP-ON-GLASS VFD
VFD SUPPLY VOLTAGE
10k
Typical Application Circuit
Pin Configuration and Functional Diagram appear at end of
data sheet.
MAX6852
4-Wire Interfaced, 5
7 Matrix Vacuum-
Fluorescent Display Controller
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Voltage (with respect to GND)
V+ .............................................................................-0.3V to +4V
DIN, SCLK, CS ......................................................-0.3V to +5.5V
All Other Pins................................................-0.3V to (V+ + 0.3V)
Current
V+..................................................................................200mA
GND .............................................................................-200mA
PHASE1, PHASE2, PORT0, PORT1, PUMP................±150mA
VFCLK, VFDOUT, VFLOAD, VFBLANK ......................±150mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin QSOP (derate at 8.34mW/°C above +70°C).....667mW
Operating Temperature Range (T
MIN
, T
MAX
)
MAX6852AEE................................................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
DC ELECTRICAL CHARACTERISTICS
(Typical operating circuit, V+ = 2.7V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Operating Supply Voltage
V+
2.7
3.6
V
T
A
= T
MIN
to
T
MAX
85
Shutdown Supply Current
I
SHDN
Shutdown mode, all digital
inputs at V+ or GND
T
A
= +25°C
9
30
µA
T
A
= T
MIN
to
T
MAX
3.5
Operating Supply Current
I+
OSC = 4MHz
VFLOAD, VFDOUT, VFCLK,
VFBLANK, loaded 100pF
T
A
= +25°C
0.71
3.0
mA
Master Clock Frequency (OSC
Internal Oscillator)
f
OSC
OSC1 fitted with C
OSC
= 56pF, OSC2 fitted
with R
OSC
= 10k
; see the Typical
Operating Circuit
4
MHz
Master Clock Frequency (OSC
External Oscillator)
OSC1 overdriven with external f
OSC
2
8
MHz
Dead-Clock Protection
Frequency
200
kHz
OSC High Time
t
CH
50
ns
OSC Low Time
t
CL
50
ns
Fast or Slow Segment Blink Duty
Cycle
(Note 2)
49.5
50.5
%
LOGIC INPUTS AND OUTPUTS
Input Leakage Current DIN,
SCLK, CS
I
IH
, I
IL
0.2
1
µA
Logic-High Input Voltage DIN,
SCLK, CS
V
IH
2.4
V
Logic-Low Input Voltage DIN,
SCLK, CS
V
IL
0.6
V
MAX6852
4-Wire Interfaced, 5
7 Matrix Vacuum-
Fluorescent Display Controller
_______________________________________________________________________________________
3
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Output Rise and Fall Time
PHASE1, PHASE2, PORT0,
PORT1, PUMP, VFLOAD,
VFDOUT, VFCLK, VFBLANK
t
RFT
C
LOAD
= 100pF
25
ns
Output High-Voltage
PHASE1, PHASE2, PORT0,
PORT1, PUMP, VFLOAD,
VFDOUT, VFCLK, VFBLANK
V
OH
I
SOURCE
= 10mA
V + - 0.6
V
Output Low-Voltage
PHASE1, PHASE2, PORT0,
PORT1, PUMP, VFLOAD,
VFDOUT, VFCLK, VFBLANK
V
OL
I
SINK
= 10mA
0.4V
V
Output Short-Circuit Source
Current PHASE1, PHASE2,
PORT0, PORT1, PUMP, VFLOAD,
VFDOUT, VFCLK, VFBLANK
I
OHSC
Output programmed high, output short
circuit to GND (Note 2)
62
125
mA
Output Short-Circuit Sink Current
PHASE1, PHASE2, PORT0,
PORT1, PUMP, VFLOAD,
VFDOUT, VFCLK, VFBLANK
I
OLSC
Output programmed low, output short
circuit to V+ (Note 2)
72
125
mA
4-WIRE SERIAL INTERFACE TIMING CHARACTERISTICS (Figure 6)
SCLK Clock Period
t
CP
38.4
ns
SCLK Pulse Width High
t
CH
19
ns
SCLK Pulse Width Low
t
CL
19
ns
CS Fall to SCLK Rise Setup Time
t
CSS
9.5
ns
SCLK Rise to CS Rise Hold Time
t
CSH
5
ns
DIN Setup Time
t
DS
9.5
ns
DIN Hold Time
t
DH
2
ns
Minimum CS Pulse High
t
CSW
19
ns
DOUT Cascade Setup Time
PORT0, PORT1
t
CSU
PORT0 and/or PORT1 enabled as DOUT
9.5
ns
VFD INTERFACE TIMING CHARACTERISTICS (Figure 9)
VFCLK Clock Period
t
VCP
(Note 2)
250
1050
ns
VFCLK Pulse Width High
t
VCH
(Note 2)
125
ns
VFCLK Pulse Width Low
t
VCL
(Note 2)
125
ns
VFCLK Rise to VFD Load Rise
Hold Time
t
VCSH
(Note 2)
19
µs
VFDOUT Setup Time
t
VDS
(Note 2)
50
ns
VFLOAD Pulse High
t
VCSW
(Note 2)
245
ns
Note 1: All parameters tested at T
A
= +25°C. Specifications over temperature are guaranteed by design.
Note 2: Guaranteed by design.
DC ELECTRICAL CHARACTERISTICS (continued)
(Typical operating circuit, V+ = 2.7V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
MAX6852
4-Wire Interfaced, 5
7 Matrix Vacuum-
Fluorescent Display Controller
4
_______________________________________________________________________________________
Typical Operating Characteristics
(Typical operating circuit, V+ = 3.3V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX6852 toc01
V+ (V)
I SUPPLY
(mA)
3.4
3.2
3.1
2.9
1.6
1.7
1.8
1.9
2.0
2.1
2.2
1.5
2.7
3.6
T
A
= -40
°C
T
A
= +125
°C
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX6852 toc02
V+ (V)
I SUPPLY
(
µ
A)
3.5
3.3
3.1
2.9
5
15
20
35
40
45
50
0
2.7
T
A
= -40
°C
T
A
= +25
°C
T
A
= +125
°C
OSC1 = 0
10
25
30
FREQUENCY (MHz)
7
6
5
4
3
200
400
600
800
1000
1200
1400
0
2
8
SHUTDOWN SUPPLY CURRENT
vs. EXTERNAL OSC FREQUENCY
MAX6852 toc03
I SUPPLY
(
µ
A)
80
60
40
20
0
100
OUTPUT LOW VOLTAGE vs. I
SINK
MAX6852 toc04
ISINK
(mA)
V
OL
(V)
0.2
0.6
0.8
1.4
1.6
1.8
2.0
0
T
A
= -40
°C
0.4
1.0
1.2
V+ = 3.3V
V+ = 3.6V
V+ = 2.7V
80
60
40
20
0
100
OUTPUT LOW VOLTAGE vs. I
SINK
MAX6852 toc05
ISINK
(mA)
V
OL
(V)
0.2
0.6
0.8
1.4
1.6
1.8
2.0
0
T
A
= +25
°C
0.4
1.0
1.2
V+ = 3.6V
V+ = 2.7V
V+ = 3.3V
80
60
40
20
0
100
OUTPUT LOW VOLTAGE vs. I
SINK
MAX6852 toc06
ISINK
(mA)
V
OL
(V)
0.2
0.6
0.8
1.4
1.6
1.8
2.0
0
T
A
= +125
°C
0.4
1.0
1.2
V+ = 3.6V
V+ = 2.7V
V+ = 3.3V
80
60
40
20
0
100
V
IN
-
V
OH
vs. I
SOURCE
MAX6852 toc07
ISOURCE
(mA)
V
OL
(V)
0.5
1.5
2.0
0
1.0
T
A
= -40
°C
V+ = 3.6V
V+ = 2.7V
V+ = 3.3V
80
60
40
20
0
100
V
IN
-
V
OH
vs. I
SOURCE
MAX6852 toc08
ISOURCE
(mA)
V
OL
(V)
0.2
0.6
0.8
1.4
1.6
1.8
2.0
0
T
A
= +25
°C
0.4
1.0
1.2
V+ = 3.6V
V+ = 2.7V
V+ = 3.3V
80
60
40
20
0
100
V
IN
-
V
OH
vs. I
SOURCE
MAX6852 toc09
ISOURCE
(mA)
V
OL
(V)
0.5
1.5
2.0
0
1.0
T
A
= +125
°C
V+ = 3.6V
V+ = 2.7V
V+ = 3.3V
MAX6852
4-Wire Interfaced, 5
7 Matrix Vacuum-
Fluorescent Display Controller
_______________________________________________________________________________________
5
f
OSC
vs. TEMPERATURE
MAX6852 toc10
TEMPERATURE (
°C)
f
OSC
(MHz)
110
95
80
65
50
35
20
5
-10
-25
0.5
1.0
1.5
2.0
2.5
0
-40
125
V+ = 2.7V
V+ = 3.3V
V+ = 3.6V
DEAD-CLOCK OSC FREQUENCY
vs. TEMPERATURE
MAX6852 toc11
TEMPERATURE (
°C)
FREQUENCY (MHz)
110
95
80
65
50
35
20
5
-10
-25
-40
125
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0
V+ = 2.7V
V+ = 3.6V
V+ = 3.3V
Typical Operating Characteristics (continued)
(Typical operating circuit, V+ = 3.3V, T
A
= +25°C, unless otherwise noted.)
Pin Description
PIN
NAME
FUNCTION
1
VFCLK
Serial-Clock Output to External Driver. Push-pull clock output to external display driver. On VFCLK's
falling edge, data is clocked out of VFDOUT.
2
VFDOUT
Serial-Data Output to External Driver. Push-pull data output to external display driver.
3
VFLOAD
Serial-Load Output to External Driver. Push-pull load output to external display driver. Rising edge is
used by external display driver to load serial data into display latch.
4
VFBLANK
Display Blanking Output to External Driver. Push-pull blanking output to external display driver used for
PWM intensity control.
5
PUMP
Charge-Pump Output and General-Purpose Output. User-configurable push-pull logic output can also
be used as a driver for external charge pump.
6
PHASE1
Filament Drive PHASE1 Output and General-Purpose Output. User-configurable push-pull logic output
can also be used as a driver for external filament bridge drive.
7
PHASE2
Filament Drive PHASE2 Output and General-Purpose Output. User-configurable push-pull logic output
can also be used as a driver for external filament bridge drive.
8
V+
Positive Supply Voltage. Bypass V+ to GND with a 0.1µF ceramic capacitor.
9
GND
Ground
10
PORT0
PORT0 General-Purpose Output. User-configurable push-pull logic output.
11
SCLK
Serial-Clock Input. On SCLK's rising edge, data shifts into the internal shift register, and data is
clocked out of DOUT. SCLK is active only while CS is low.
12
DIN
Serial-Data Input. Data from DIN loads into the internal 16-bit shift register on SCLK's rising edge.
13
CS
Chip-Select Input. Serial data is loaded into the shift register while CS is low. The most recent 16 bits of
data latch on CS's rising edge.
14
PORT1
PORT1 General-Purpose Output. User-configurable push-pull logic output.
PDF 
ZIP