MAX6921AUI+T Maxim Integrated Products, MAX6921AUI+T Datasheet - Page 8

• Manufacturer Part Number: MAX6921AUI+T
• Description: IC DRVR VFD TUBE SRL 28-TSSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX6921AUI+T

• Display Type: Vacuum Fluorescent (VF)
• Interface: 4-Wire Serial
• Current - Supply: 1.65mA
• Voltage - Supply: 8 V ~ 76 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 28-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Configuration: -
• Digits Or Characters: -
• Lead Free Status / Rohs Status: Details

20-Output, 76V, Serial-Interfaced
VFD Tube Drivers
The MAX6921/MAX6931 are normally written using the
following sequence:
1) Take CLK low.
2) Clock 20 bits of data in order D19 first to D0 last
3) Load the 20 output latches with a falling edge
LOAD can be high or low during a transmission. If
LOAD is high, then the data shifted into the shift regis-
ter at DIN appear at the OUT0 to OUT19 outputs.
Figure 4. 4-Wire Serial Interface Timing Diagram
Table 1. 4-Wire Serial Interface Truth Table
L = Low logic level.
H = High logic level.
X = Don’t care.
P = Present state (shift register).
R = Previous state (latched).
8
SERIAL
INPUT
DATA
DOUT
LOAD
DIN
CLK
DIN
H
X
_______________________________________________________________________________________
L
into DIN, observing the data setup and hold times.
on LOAD.
CLOCK
INPUT
CLK
Writing Device Registers Using the
SHIFT REGISTER CONTENTS
D0 D1 D2 … Dn-1
R0 R1 R2 … Rn-1
P0
H
L
X
R0 R1 … Rn-2 Rn-1
R0 R1 … Rn-2 Rn-1
P1 P2 … Pn-1
X
X
4-Wire Serial Interface
…
X
t
DS
D19
t
DH
Dn
Rn
Pn
X
INPUT
LOAD
LOAD D0 D1 D2 … Dn-1 Dn
H
L
t
CL
D18
R0 R1 R2
P0 P1 P2
X
t
CH
LATCH CONTENTS
X
CLK and DIN can be used to transmit data to other
peripherals. Activity on CLK always shifts data into the
MAX6921/MAX6931s’ shift register. However, the
MAX6921/MAX6931 only update their output latch on
the rising edge of LOAD, and the last 20 bits of data
are loaded. Therefore, multiple devices can share CLK
and DIN, as long as they have unique LOAD controls.
The outputs are CMOS drivers, and have a resistive
characteristic. The typical and maximum sink and
source output resistances can be calculated from the
V
resistance to determine the output voltage drop at dif-
ferent output currents.
X
H
and V
Determining Driver Output Voltage Drop
… Rn-1 Rn
… Pn-1 Pn
…
D1
L
t
X
DO
electrical characteristics. Use this calculated
X
t
CP
BLANKING
BLANK
INPUT
D0
L
H
t
CSH
D19
D0 D1 D2 …
P0 P1 P2
L
t
OUTPUT CONTENTS
CSW
L
L
…
…
Dn-1 Dn
Pn-1 Pn
L
L