MITSUBISHI(Standard Linear ICs)
M62295GP
M62295GP
LCDPC
BACK-LIGHT
BACK- LIGHTCONTROL
CONTROL ICIC
DESCRIPTION
M62295GP is a semiconductor integrated circuit designed for PC
back- light control, which employs 2 output totempole output circuit
specifically suitable for inverter drive with piezo device.
Such necessary functions as light control, protection circuit are
housed in 16pin SSOP package. This allows for simplified peripheral
circuit as well as compact and thin set design.
PIN CONFIGURATION (TOP VIEW)
G2 1
16 G1
GND 2
15 Vcc
FEATURES
N.C 3
14 P/C
• Direct drive to n-ch/ p-ch MOSFET
• Fixed output duty: 45%
• Output current (peak) : ± 300mA
• Light control
• Pulse synchronous control
Output OFF period is adjusted synchronous with the OSC
frequency (1kHz-200kHz).
• Light control available from 10%(MIN.) up to 100% by the
voltage applied from outside (Adj2 terminal).
• Protection functions
• 2 kinds of timer-latch time setting available by 3 triggers
(few seconds, several tens of seconds set by external capacitor)
Adj2 4
13 CT2
Vref 5
12 CT1
Cscp1 6
11 RT
Cscp2 7
10 FB
Iscp 8
9 IN Outline 16P2E-A
N.C : NO CONNECTION
APPLICATION
• CLD Back-light contorol for Note P.C etc.
BLOCK DIAGRAM
Vcc
15
P/C
RT
CT1
CT2
14
11
12
13
VCC
5
UVLO
Ref. volt.
ON/OFF
OSC.
Vref
1
G2
VCC
9
2.5V
IN 1.25V
Protection
Circuit
0.25V
2
10
GND
FB
16
G1
(Timer Latch)
6
7
8
Cscp1 Cscp2 Iscp
(1/7)
3
4
N.C Adj2
MITSUBISHI(Standard Linear ICs)
M62295GP
PC BACK- LIGHT CONTROL IC
ABSOLUTE MAXIMUM RATINGS (Ta=25°C, unless otherwise noted)
Symbol
Parameter
Vcc
Supply voltage
IOUT
Output current
Pd
Topr
Tstg
Conditions
Power dissipation
Operating temperature
Storage temperature
Continuous
Peak
Ta=25°C
Ratings
Unit
28
± 50
± 300
400
-20 ~ +85
-40 ~ +125
V
mA
mA
mW
°C
°C
ELECTRICAL CHARACTERISTICS (Ta=25°C, Vcc=15V, unless otherwise noted)
Symbol
Parameter
Test conditions
Limits
Min.
Vcc
Operating supply voltage range
3.6
Icc
Circuit current
Circuit current
in power control state
4.5
Icc(PC)
VTH ON
ON threshold voltage
VTH OFF
OFF threshold voltage
Vhys
Input bias current
AV
Open loop gain
GB
Max.
Unit
26
V
6
7.5
mA
15
30
55
µA
3.27
3.43
3.59
V
V
3.36
Hysterisis
IB
Typ.
35
70
-500
-30
nA
80
dB
0.6
MHz
2.8
V
Gain bandwidth product
140
mV
VFB+
Max. output voltage
VFB-
Min. output voltage
IFB+
Max. sink current
1
2
mA
IFB-
Max. source current
-50
-80
µA
VREF
Reference voltage
2.40
2.50
LINE
Line regulation
Iref(Max)
fosc
fosc(Max)
VRT
2.65
100
1
Max. load current
Oscillating frequency
200
2.60
mV
V
5
mV
5
mA
100
KHz
Max. oscillating frequency
200
KHz
RT termina voltage
1.1
1.25
1.4
V
VAdj2(Min)
Adj2 voltage at min. duty
2.3
2.4
2.5
V
Min Duty
Min. duty for light control
5
10
15
%
VAdj2(Max)
Adj2 voltage at 100% duty
0.1
0.2
0.3
V
-100
-10
+100
nA
IAdj2
Adj2 terminal current
fosc(CT2)
Light control frequency
VAdj2=Vref
fosc = 100KHz
KHz
1
FB VTH(H)
FB terminal H threshold volt.
2.35
2.5
2.65
V
FB VTH(L)
FB terminal L threshold volt.
0.2
0.25
0.3
V
Iscp VTH(L)
IscpL detection voltage.
1.1
1.25
1.4
V
(2/7)
MITSUBISHI(Standard Linear ICs)
M62295GP
PC BACK- LIGHT CONTROL IC
ELECTRICAL CHARACTERISTICS (Ta=25°C, Vcc=15V, unless otherwise noted)
Symbol
P/C
Parameter
Test conditions
Limits
Min.
Typ.
Max.
Unit
ICSCP1
CSCP1 charge current
-0.8
-1.3
-1.8
µA
ICSCP2
CSCP2 charge current
-0.8
-1.3
-1.8
µA
CSCP1VTH
CSCP1 detection voltage
2.35
2.5
2.65
V
CSCP2VTH
CSCP2 detection voltage
1.1
1.25
1.4
V
Itimer-L
Circuit current at timer-latch
1.2
2.2
3.2
mA
IP/C
P/C terminal flow-in current
1
2
4
µA
0.4
0.7
1.0
V
42
45
48
%
0.05
0.4
V
VTH(ON)
P/C threshold voltage
Duty
Output duty
VOL
Output Low voltage
VOH
Output High voltage
RT=12.4KΩ, CT1= 470pF
13.0
(3/7)
13.5
V
MITSUBISHI(Standard Linear ICs)
M62295GP
PC BACK- LIGHT CONTROL IC
Function description
• Output oscillation circuit and tooth-wave generating circuit for light control (RT, CT1, CT2)
As shown in Fig.1, charge/discharge current
for each oscillation circuit is set by connecting
resistors to RT terminal.
RT terminal is connected to FB terminal by
resistor to control the frequency for light control.
CT1 is the terminal for connecting capacitor for
output oscillation circuit, generating triangularwave oscillating between lower limit (approx. 0.25V)
and upper limit (approx. 1.25V) by the charge
current set at RT terminal.
CT2 is the terminal for connecting capacitor for
tooth-wave for light control, into which one twentieth
of charge current of CT1 terminal flows generating
tooth-wave oscillating between lower limit (approx.
0.25V) and upper limit (approx. 1.25V).
Each charge current and oscillation frequency is
decided by the formula shown below.
RT (1.25V)
CT1
CT1
Ro
FB
CT2
CT2
Fig.1 Connections of RT,CT1, CT2
1.25V
CT1 charge/ discharge current =
(ICT1charge)
1.25
Ro
CT2 charge/ discharge current =
(ICT2charge)
1.25
1
Ro * 20
0.8V
0.7V
CT1
T
Output freq. (Fosc) = 1
G1
(POUT)
1
=
T
CT1 *
0.25V
G2
(NOUT)
2
ICT1charge
1.25V
1
Tooth - wave freq. (CT2osc) =
CT2 *
Tooth - wave freq. (CT2osc)
Output freq. (Fosc)
CT2
1
ICT2charge
0.25V
CT1
(divided ratio) = CT2 * 10
Fig.2 Waveform for CT1, CT2, and G1, G2
• ON/OFF control function (P/C)
ON/OFF control is available using P/C terminal.
As shown in Fig.3, ON/OFF control is made by
connecting P/C terminal to Vcc or GND or by making
P/C terminal open.
Vcc
P/C
P/C = Vcc : IC in normal operation mode
P/C = GND&OPEN : IC operation at halt
Fig.3 Connection example for P/C
(4/7)
MITSUBISHI(Standard Linear ICs)
M62295GP
PC BACK- LIGHT CONTROL IC
• Light control function (Adj2)
Fig.4 shows the connections of Adj2 terminal.
When the light control voltage is 2.4V or more,
divided voltage by the resistors is applied. Light
control is decided by the OSC. frequency of CT2
and the applied voltage to Adj2 terminal.
Fig.5 shows how the applied voltage to Adj2
terminal relates itself to light control.
The voltage range of Adj2 terminal available for
light control is 0.1V to 2.4V.
When the voltage is 2.4V or more, light control
duty becomes minimum(10%), and when it is
0.1V or less, light control duty becomes 100%.
Minimum duty is available by connecting Adj2
terminal to Vref terminal.
Output waveform on above mentioned stage is
shown in Fig.6(a) to Fig.6(c). Fig6(a) shows
100% light controlled state, Fig.6(b) middle state
(50% light controlled), Fig6(c) minimum duty
state.
Light control
voltage
Adj2
2.4 - VAdj2
2.4
R2
(a). In the case of direct
applying to Adj2 terminal
Formula for light control level by light control voltage
ONDuty = (100 - ONDutyMin) *
R1
Light control
voltage
+ONDutyMin (%)
Adj2
(b). In the case of applying
to Adj2 terminal by the
division of resistors
Fig.4 Connections of Adj2 terminal
100
80
60
40
20
10
0.1
1.0 1.4
2.0 2.4
Adj2 terminal voltage (V)
VAdj2 : Adj2 terminal voltage (V)
ONDutyMin = 10 (%)
Fig.5 Adj2 terminal voltagelight control duty characteristics
G1 output
G2 output
CT2 wave form
Fig.6(a) 100% light control
G1 output
G2 output
CT2 wave form
Fig.6(a) 50% light control
G1 output
G2 output
CT2 wave form
Fig.6(a) 10% light control
(5/7)
MITSUBISHI(Standard Linear ICs)
M62295GP
PC BACK- LIGHT CONTROL IC
• Protection function (timer-latch) (Cscp1, Cscp2, Iscp)
Application for timer-latch by detecting tube current
and feecback voltage is available by using Iscp,
Cscp1, Cscp2 terminal.
Two kinds of setting for timer-latch time is available
by the setting of Cscp1, Cscp2. Each timer-latch
time is set by the formula below.
Cscp1 :
Terminal for capacitance for timer-latch set (few sec.)
Timer-L (Cscp1) = Cscp1 *
2.5
1.3 * 10 -6
Cscp1
Cscp2
Cscp1
Cscp2
Cscp2 :
Terminal for capacitance for timer-latch set (few msec.)
Timer-L (Cscp2) = Cscp2 *
Fig.7 Connections of Cscp1, Cscp2
1.25
1.3 * 10 -6
Detection of tube current
Detection of tube current is made by Iscp terminal.
Detection voltage for Iscp terminal is set 1.25V.
After power is on, when Iscp voltage does not rise
up to 1.25V by timer-L(Cscp1) time, or when Iscp
voltage becomes 1.25V or less after start-up,
abnormality is detected to move on to the protection
operation mode in Fig.1.
If Iscp voltage is less than 1.25V, light control is
not made(100%).
BL tube current detection
Iscp
Detection of feedback voltage
Detection of feedback voltage is made by FB
terminal.
When FB terminal voltage goes down to FB low
detection voltage (0.25V) or less, or when it rise up
to FB terminal high detection voltage or more,
abnormality is detected to move on to the protection
operation mode in Fig.1.
Triggers for protection operation
Protection
operation mode
Operation state
Fig.8 Connections of Iscp terminal
Ampout="H" Ampout="L"
Timer-latch time
Io=0
Normal start-up
Io=Max
Start-up in
shortcircuited state Io=0
Start-up in open state
Start-up in black
mode
Operation stop after 10ms
Operation stop instantaneously
Operation stop after 2sec.
OFF
Operation stop after 2sec.
ON
Normal start-up if turn-on
is made within 2sec.
Shortcircuit while Io=Max
in operation
Io=0
Operation stop instantaneously
Open while in operation
Operation stop instantaneously
Operation stop instantaneously
Table 1. Protection operation mode at a glance
Note 1. Timer-latch time refers to the time under Cscp=1uF, Cscp2=0.1uF.
2. Amp. output is "H" when tube current I0 equals to 0, "L" when it is at
its minimum. Detection voltage is 2.5V("H" side), 0.25V("L" side).
(6/7)
2sec
10msec
MITSUBISHI(Standard Linear ICs)
M62295GP
PC BACK- LIGHT CONTROL IC
(7/7)