MAX6921AUI+T Maxim Integrated Products, MAX6921AUI+T Datasheet - Page 10

• 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

A multiplexed tube dissipation example follows:
Thus, for a 28-pin wide TSSOP package (T
= 78.125°C/W from Absolute Maximum Ratings ), the
maximum allowed ambient temperature T
So T
This means that the driver can be operated in this
application up to the MAX6921/MAX6931s’ +125°C
maximum operating temperature.
The MAX6921/MAX6931 operate with multiple power-
supply voltages. Bypass the V
(MAX6931 only) power-supply pins to GND with 0.1µF
capacitors close to the device. The MAX6931 can be
operated with V
supply is not required. For multiplex applications, it
may be necessary to add an additional bulk electrolytic
capacitor of 1µF or greater to the V
The order of the power-supply sequencing is not impor-
tant. The MAX6921/MAX6931 will not be damaged if
any combination of V
is grounded while the other supply or supplies are
maintained up to their maximum ratings. However, as
with any CMOS device, do not drive the MAX6921/
MAX6931s’ logic inputs if the logic supply V
operational because the input protection diodes clamp
the signals.
Multiple MAX6921s can be cascaded, as shown in the
Typical Application Circuit , by connecting each driver’s
DOUT to DIN of the next drivers. Devices can be cas-
caded at the full 5MHz CLK speed when V
When V
limits the maximum cascaded CLK to 4MHz.
20-Output, 76V, Serial-Interfaced
VFD Tube Drivers
10
T
V
P
J(MAX)
CC
D
A
______________________________________________________________________________________
= +140.5°C.
= (5.25V x 1mA)+ (42V x 1.4mA)
+ ((2.5V x 0.4mA/25mA) x 0.4mA x 12)
+ ((2.5V x 24mA/25mA) x 24mA) = 122mW
= 5V ±5%, V
CC
I
ANODE
Cascading Drivers (MAX6921 Only)
= T
x 78.125°C/W)
<4.5V, the longer propagation delay (t
A
SS
+ (P
Power-Supply Considerations
= 0.4mA, I
connected to GND if a negative bias
BB
D
CC
Power-Supply Sequencing
x T
= 36V to 42V, A = 12, G = 8,
, V
JA
BB
) = 150°C = T
GRID
, and V
= 24mA
BB
CC
SS
supply.
, V
(MAX6931 only)
A
JA
A
BB
is given by:
+ (0.122
= 1 / 0.0128
, and V
CC
CC
≥ 4.5V.
is not
DO
SS
)
MAX685x
VFBLANK
VFDOUT
VFLOAD
VFCLK
Typical Application Circuit
DIN
CLK
LOAD
BLANK
DIN
CLK
LOAD
BLANK
DIN
CLK
LOAD
BLANK
MAX6921
MAX6921
MAX6921
DOUT
DOUT
DOUT