ROHM BU2872AK Datasheet
1
Standard ICs
FL tube driver
BU2872AK
The BU2872AK is a driver IC for the FL display unit. It has a total of 22 high withstanding voltage output pins, and
supports displays ranging from 11-segment 11-character displays to 16-segment 4-character displays. A key scan
function, LED drive output, and a general-purpose input pin make this IC ideal for use in the front panels of VTRs
and other equipment. A serial interface enables control of all functions through a microcomputer.
•
Applications
VCRs
•
Block diagram
SEGMENT Driver
S1
S11
VEE
latch
K1
K4
4bit
data
L4
L1
SW4
SW1
GRID
Driver
G1
G6
CONTROL
LOGIC
OSC
16bit latch
16bit × 11word
Display DATA RAM
CS
SCKSISO
OSC
VDD
VSS
S / G Driver
G11 / S12
G7 / S16
8bit shift - REG.
LED
Driver
(4 × 6)
KEY DATA
•
Features
1) High withstanding voltage output.
2) Display modes: 11S × 11G ~16S × 4G
3) Variable display luminance (7 steps).
4) 3-wire serial interface.
5) Key scanning function (6 × 4).
6) Internal pull-down resistance (high withstanding voltage output).
7) QFP 44-pin package.
2
Standard ICs BU2872AK
•
Pin descriptions
44
6
5
8
9
27
1 ~ 4
10 ~ 13
42 ~ 39
26, 28 ~ 31
37 ~ 32
15 ~ 25
7, 43
14, 38
Pin No.
Pin I / O
V
DD I
I / O
I
I
O
I
I
O
I
O
O
O
I
I
Connected to the power supply of the system
Connected to the oscillation capacitor
Connected to the ground of the system
Serial data input starting from MSB
Serial data output starting from MSB
Serial data read at rising edge
Serial initialization at "L", effective at "H"
Output pin for segment
Output: Pch open drain + pull-down resistance
Pull-down resistance connection for FLP driver
Output pin for grid
Output: Pch open drain + pull-down resistance
Segment / grid output selectable pin
Output: Pch open drain + pull-down resistance
Output pin for LED; output is CMOS output
Data input pin for key scanning
General-purpose input pin
Input data sent to microcomputer in serial format
OSC
V
SS
SI
SO
SCK
CS
V
EE
Power supply pin 1
Oscillation pin
GND pin
Serial data input
Serial data output
Serial clock input
Serial chip select
High withstanding voltage
output pin for segment
Power supply pin 2
High withstanding voltage
output pin for grid
High withstanding voltage
output pin for segment / grid
Output pin for LED
Key data input pin
General-purpose input pin
S1 ~ S11
G1 ~ G6
L1 ~ L4
K1 ~ K4
SW1 ~ SW4
Function
S12 / G11 ~ S16 / G7
Name
•
Absolute maximum ratings (Ta = 25°C, VSS = 0V)
Parameter Symbol Limits Unit
V
DD V
V
EE VDD + 0.3 ~ VDD – 35 V
V
IN – 0.3 ~ VDD + 0.3 V
Pd mW
Topr °C
Tstg °C
Applied voltage 1
Applied voltage 2
Input voltage
Power dissipation
Operating temperature
Storage temperature
850
∗
Note) Operation is not guaranteed at these values.
Power dissipation is reduced by 8.5mW for each increase in Ta of 1°C over
25°C.
∗
When mounted on a 70mm × 70mm × 1.6mm glass epoxy board
– 25 ~ + 75
– 55 ~ + 125
– 0.3 ~ + 7.0
•
Recommended operating conditions (Ta = 25°C, VSS = 0V)
Parameter Symbol Min. Typ. Max. Unit
Operating power supply voltage 1
Operating power supply voltage 2
V
DD 4.5 5.0 5.5 V
V
EE VDD – 32 VDD – 30 VDD – 0V
Loading...