The LC75847T is 1/3 duty and 1/4 duty general-purpose LCD driver that can
be used for frequency display in electronic tuners under the control of a
microcontroller. The LC75847T can drive an LCD with up to 420 segments
directly. The LC75847T can also control up to 8 general-purpose output ports.
Features
Switching between 1/3 duty and 1/4 duty drive techniques under serial data
control.
Switching between 1/2 bias and 1/3 bias drive techniques under serial data
control.
Up to 318 segments for 1/3 duty drive and 420 segments for 1/4 duty drive
can be displayed.
Serial data input supports CCB* format communication with the system
controller.
Serial data control of the power-saving mode based backup function and all
the segments forced off function.
Serial data control of switching between the segment output port and the
general-purpose output port functions.
Serial data control of frame frequency for common and segment output
waveforms.
High generality, since display data is displayed directly without decoder
intervention.
Built-in display contrast adjustment circuit
Independent V
LCD
for the LCD driver block
The INH pin can force the display to the off state.
RC oscillator circuit
Specifications
Absolute Maximum Ratings
at Ta = 25C, VSS = 0 V
Parameter
Maximum supply voltage
Symbol
VDD max
VLCD max
VIN1
VIN2
VIN3
VOUT1
VOUT2
IOUT1
IOUT2
IOUT3
Allowable power dissipation
Operating temperature
Storage temperature
Pd max
Topr
Tstg
Conditions
VDD
VLCD
CE, CL, DI, INH
OSC
VLCD1, VLCD2
OSC
V
LCD
0, S1 to S106, COM1 to COM4, P1 to P8
S1 to S106
COM1 to COM4
P1 to P8
Ta = 85°C
Ratings
–0.3 to +7.0
–0.3 to +7.0
–0.3 to +7.0
–0.3 to VDD +0.3
–0.3 to VLCD +0.3
–0.3 to VDD +0.3
–0.3 to VLCD +0.3
300
3
5
200
–40 to +85
–55 to +125
V
unit
V
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TQFP120 14x14 / TQFP120
Input voltage
Output voltage
V
A
mA
mA
mW
C
C
Output current
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed,
damage may occur and reliability may be affected.
*
Computer Control Bus (CCB) is an ON Semiconductor’s original bus format and
the bus addresses are controlled by ON Semiconductor.
ORDERING INFORMATION
See detailed ordering and shipping information on page 28 of this data sheet.
Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond the Recommended
Operating Ranges limits may affect device reliability.
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LC75847T
Electrical Characteristics
for the allowable operating ranges
Parameter
Hysteresis
Input high level current
Input low level current
Output high level voltage
Symbol
V
H
I
IH
I
IL
V
OH
1
V
OH
2
V
OH
3
V
OL
1
Output low level voltage
V
OL
2
V
OL
3
V
MID
1
V
MID
2
Output middle level voltage*
1
V
MID
3
V
MID
4
V
MID
5
Oscillator frequency
f
OSC
I
DD
1
I
DD
2
I
LCD
1
I
LCD
2
Current drain
I
LCD
3
I
LCD
4
I
LCD
5
CE, CL, DI, INH
CE, CL, DI, INH: V
I
= 6.0 V
CE, CL, DI, INH: V
I
= 0 V
S1 to S106: I
O
= –20
μA
COM1 to COM4: I
O
= –100
μA
P1 to P8: I
O
= –1 mA
S1 to S106: I
O
= 20
μA
COM1 to COM4: I
O
= 100
μA
P1 to P8: I
O
= 1 mA
COM1 to COM4: 1/2 bias, I
O
= ±100
μA
S1 to S106: 1/3 bias, I
O
= ±20
μA
S1 to S106: 1/3 bias, I
O
= ±20
μA
COM1 to COM4: 1/3 bias, I
O
= ±100
μA
COM1 to COM4: 1/3 bias, I
O
= ±100
μA
OSC: R
OSC
= 39 k, C
OSC
= 1000 pF
V
DD
:
Power-saving mode
V
DD
: V
DD
= 6.0 V, output open, f
OSC
= 38 kHz
V
LCD
:
Power-saving mode
V
LCD
:
V
LCD
= 6.0 V, output open, 1/2 bias, f
OSC
= 38 kHz,
V
LCD
0 = 0.70 V
LCD
to 0.95 V
LCD
V
LCD
:
V
LCD
= 6.0 V, output open, 1/2 bias, f
OSC
= 38 kHz,
V
LCD
0 = V
LCD
V
LCD
:
V
LCD
= 6.0 V, output open, 1/3 bias, f
OSC
= 38 kHz,
V
LCD
0 = 0.70 V
LCD
to 0.95 V
LCD
V
LCD
:
V
LCD
= 6.0 V, output open, 1/3 bias, f
OSC
= 38 kHz,
V
LCD
0 = V
LCD
400
350
300
250
250
1/2 V
LCD
0
– 0.9
2/3 V
LCD
0
– 0.9
1/3 V
LCD
0
– 0.9
2/3 V
LCD
0
– 0.9
1/3 V
LCD
0
– 0.9
30.4
38
–5.0
V
LCD
0 – 0.9
V
LCD
0 – 0.9
V
LCD
– 0.9
0.9
0.9
0.9
1/2 V
LCD
0
+ 0.9
2/3 V
LCD
0
+ 0.9
1/3 V
LCD
0
+ 0.9
2/3 V
LCD
0
+ 0.9
1/3 V
LCD
0
+ 0.9
45.6
5
500
5
800
700
600
500
μA
kHz
V
V
V
Conditions
Ratings
min
typ
0.1 V
DD
5.0
max
Unit
V
μA
μA
Note:
*1
Excluding the bias voltage generation divider resistors built in the V
LCD
0, V
LCD
1, V
LCD
2, and V
SS
. (See Figure 1.)
VLCD
CONTRAST
ADJUSTER
VLCD0
VLCD1
VLCD2
VSS
Except these resistors
To the common segment drivers
Figure 1
Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be
indicated by the Electrical Characteristics if operated under different conditions.
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3
LC75847T
1. When CL is stopped at the low level
VIH
CE
tøH
CL
VIH
50%
VIL
VIL
tøL
tr
VIH
tf
tcp
tcs
tch
DI
VIL
tds
tdh
2. When CL is stopped at the high level
VIH
CE
tøL
CL
tf
DI
tds
tdh
tr
VIH
VIL
VIL
tøH
VIH
50%
VIL
tcp
tcs
tch
Figure 2
Block Diagram
COM1
COM2
COM3
COM4/S106
S8/P8
COMMON
DRIVER
SEGMENT DRIVER & LATCH
OSC
VDD
VLCD
CLOCK
GENERATOR
SHIFT REGISTER
CONTRAST
ADJUSTER
VLCD0
VLCD1
VLCD2
VSS
ADDRESS
DETECTOR
INH
DI
CL
CE
S2/P2
S1/P1
S105
S104
S9
Page 4
LC75847T
Pin Functions
Symbol
S1/P1 to S8/P8
S9 to S105
Pin No.
1 to 8
Function
Active
I/O
Handling
when unused
Segment outputs for displaying the display data transferred by serial data input. The
pins S1/P1 to S8/P8 can be used as general-purpose output ports when so set up by
9 to 105
the control data.
Common driver outputs.
The frame frequency is f
O
Hz.
The COM4/S106 pin can be used as a segment output in 1/3 duty.
Oscillator connection.
—
O
Open
COM1 to COM3
COM4/S106
109 to 107
106
—
O
Open
OSC
116
An oscillator circuit is formed by connecting an external resistor and capacitor to this
pin.
Serial data transfer inputs. These pins are connected to the control microprocessor.
CE: Chip enable
CL: Synchronization clock
DI: Transfer data
Display off control input
• INH = low (V
SS
) ....Off
S1/P1 to S8/P8 = low (V
SS
)
(These pins are forcibly set to the segment output port function
and fixed at the V
SS
level.)
S9 to S105 = low (V
SS
)
COM1 to COM3 = low (V
SS
)
COM4/S106 = low (V
SS
)
• INH = high (V
DD
) ..On
Note that serial data transfers can be performed when the display is forced off by this
pin.
LCD drive 3/3 bias voltage (high level) supply. This level can be modified using the
display contrast adjustment circuit. However, note that V
LCD
0 must be greater than or
equal to 2.7 V. Also, since this IC provides the built-in display contrast adjustment
circuit, applications must not attempt to provide this level from external circuits.
LCD drive 2/3 bias voltage (middle level) supply. It is possible to supply the 2/3 V
LCD
0
voltage to this pin externally. This pin must be shorted to V
LCD
2 if 1/2 bias is used.
LCD drive 1/3 bias voltage (middle level) supply. It is possible to supply the 1/3 V
LCD
0
voltage to this pin externally. This pin must be shorted to V
LCD
1 if 1/2 bias is used.
Logic block power supply. Provide a voltage in the range 2.7 to 6.0 V.
LCD driver block power supply. When V
LCD
0 is between 0.70 V
LCD
and 0.95 V
LCD
,
supply a voltage in the range 4.0 to 6.0 V. When V
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