MITSUMI
Step-Up IC For EL Backlights MM1365
Step-Up IC For EL Backlights
Monolithic IC MM1365
Outline
This is a step-up IC developed for use in EL backlights.
Because of their ability to light the entire panel uniformly, EL backlights are gradually becoming more
widespread compared with LEDs.
In particular, recently there has been a strong tendency toward smaller sizes and lighter weights, and more
manufacturers are adopting ICs in place of transformers to step up voltages.
This IC was designed to meet these market needs.
Features
1. Low-voltage driving possible
V
IN
=0.95V min.
2. Brightness can be adjusted
The brightness can be adjusted by changing the oscillation
frequency through the externally mounted capacitance
3. Can be driven using a small coil
Coil inductance of about 820H required
4. On/off control possible
Current consumption while off=10A or less
Package
VSOP-8
Pin Assignment
1
4
3
2
8
5
6
7
VSOP-8
1
GND
GND
2
N.C
3
CT1
For setting discharge frequency
4
CT2
For setting charging frequency
5
Power supply
H to turn on, L to turn off
switch
6
V
CC
Power supply pin
7
O2
Charging frequency setting; drives
external transistor
8
O1
Discharge frequency setting; drives
external transistor
Applications
1. Pagers
2. Portable phones, PHS
3. Wristwatches
4. Display components of remote-controlled minidiscs, CD players, headphone stereos, other equipment
MITSUMI
Step-Up IC For EL Backlights MM1365
Absolute Maximum Ratings
Item
Symbol
Ratings
Units
Storage temperature
T
STG
-40~+125
C
Operating temperature
T
OPR
-20~+75
C
Power supply voltage
V
CC
max.
-0.3~+6
V
Operating power supply voltage
V
CCOP
0.95~+6
V
Voltage applied to O1, O2 output pins
V
O
max.
-0.3~V
CC
V
Allowable loss
Pd
300
mW
Electrical Characteristics
(Except where noted otherwise, Ta=25C, V
CC
=1.5V, V
CONT
=1.5V)
Item
Symbol
Measurement
Measurement conditions
Min. Typ. Max. Units
circuit
Consumption current for complete circuit 1
C1=39nF, C2=1.5nF
(under recommended circuit
I
CC
1
1
SW1 OFF, SW2 ON
15
25
35
mA
operating conditions for EL)
Consumption current for 2 IC only
C1=39nF, C2=1.5nF
(under recommended circuit
I
CC
2
1
SW1 ON, SW2 OFF
1.3
2.5
4.5 mA
operating conditions for EL)
Current consumption 3
I
CC
3
1
V
CONT
=0V, SW1 ON, SW2 OFF
1.0
A
(entire circuit off)
O1 pin output current
I
SOU
1
2
VO1=0V, VCT1=0.8V
(charge signal)
O1 output current measurement
25
50
75
A
O1 pin sync current
I
SIN
2
VCT1=0V, VO1=0.3V
(charge signal)
VCT2=0V
1.00 2.50
mA
O2 pin output current
I
SOU
2
2
VCT1=0V, VCT2=0V
1.00 1.80 3.00 mA
(discharge signal)
C
T
1 charge current
I
CT
1
2
VCT1=0.3V, CT2=OPEN
(Discharge setting pin)
C
T
1 output current
1.2
2.0
2.7
A
C
T
2 charge current
I
CT
2
2
VCT1=0V, VCT2=0.3V
(charge setting pin)
C
T
2 output current
10
18
25
A
C
T
1 pin "H" threshold
V
THH
1
1
SW1 OFF, SW2 ON
0.65
V
C
T
2 pin "H" threshold
V
THH
2
1
SW1 OFF, SW2 ON
0.65
V
C
T
1 pin "L" threshold
V
THL
1
1
SW1 OFF, SW2 ON
0.15
V
C
T
2 pin "L" threshold
V
THL
2
1
SW1 OFF, SW2 ON
0.18
V
Charge signal oscillation frequency
fct2
1
C1=39nF, C2=1.5nF
(C
T
2 measurement)
SW1 OFF, SW2 ON
20
kHz
MITSUMI
Step-Up IC For EL Backlights MM1365
Block Diagram/Application Circuits
Note 1: C3 is a capacitance used to suppress abnormal voltages at the O1
pin due to the coil.
Note 2: The O2 frequency and O1 frequency are set to 20 kHz and 100 Hz
respectively.
Measuring Circuit
Measuring Circuit 1
MITSUMI
Step-Up IC For EL Backlights MM1365
Measuring Circuit 2
Timing Chart
V
CC
CONT
02
C
T
2
C
T
1
01
V
ELOUT
1.5V
1.5V
0V
V
THH2
V
THL2
V
THL1
V
THH1
0V
fCT1
fCT2
Unsettled
Characteristics
O1, O2 capacitances vs. frequency
1000000
10000
1000
0.1
1
10
Capacitance (nF)
O2 pin
Oscillation
frequency
(charging)
O2 pin frequency
Frequency (Hz)
1000
100
10
1
10
100
1000
Capacitance (nF)
O1 pin
Oscillation
frequency
(charging)
O1 pin frequency
Frequency (Hz)
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