MIC4833
Low Noise Dual 220 V
PP
EL Driver
With Output Voltage Slew Rate Control
General Description
The MIC4833 is a low noise dual Electroluminescent (EL)
Panel driver used in backlighting applications. The
MIC4833 converts a low DC voltage to a high DC voltage
using a boost converter and then alternates the high DC
voltage across the EL panels using an H-bridge. The
MIC4833 incorporates internal wave-shaping circuitry
specifically designed to reduce audible noise emitted by
EL panels. The two EL panels may be dimmed by applying
a PWM signal to the device. The MIC4833 drives two
outputs from a single inductor and requires a minimum
number of passive components. It features an operating
input voltage range of 2.3V to 5.8V, making it suitable for
1-cell Li-ion and 2- or 3-cell alkaline/NiCad/NiMH battery
applications.
An external resistor may be used to adjust the output
voltage slew rate to reduce audible noise. The MIC4833
features separate oscillators for the boost and H-bridge
stages to allow independent control. External resistors set
the operating frequencies of each stage allowing the EL
circuit to optimize efficiency and brightness.
®
The MIC4833 is available in a 12 pin 3mmx3mm MLF
package, and has an operating junction temperature range
of –40°C to +125°C.
Features
•
•
•
•
•
•
•
•
•
•
•
Drives two EL panels, up to 4 in
2
each at full
brightness
Independent input control for each of the two panels
and allows PWM dimming.
220Vpp regulated AC output waveform
2.3V to 5.8V DC input voltage
Wave-shaping circuit to reduce audible noise
Adjustable slew rate for audible noise reduction
Independently adjustable boost converter and EL
panel frequency
Single inductor to power both panels
0.1uA typical shutdown current
®
12 pin 3mmx3mm MLF package
–40
o
C to +125
o
C junction temperature range
Applications
•
Mobile Phones
•
MP3s/Portable Media Players (PMP)
•
Clocks/ Watches
•
Remote Controls
•
Cordless Phones
•
GPS Devices
•
PDAs
_________________________________________________________________________________________________
High
Low
Typical Application
ENA
VDD
332k
1.78M
High
Low
Low
High
SLEW
ELA
ELB
MIC4833
COM
CS
SW
50k
VIN
Li Ion
3V to 4.2V
0.01µF
EL Lamp A
EL Lamp B
RSW
REL
ENB
GND
VIN
Li Ion
3V to 4.2V
10µF
220µH
2.2nF
250V
Low Noise Dual EL Driver
MLF and MicroLead Frame are registered trademark of Amkor Technologies
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
408
) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
October 2008
M9999-100308
(408) 955-1690
Micrel
MIC4833
Ordering Information
Part Number
MIC4833YML
Package
12 pin 3mmx3mm
®
MLF
Operating Junction Temp
Range
-40°C to +125°C
Lead Finish
Pb-free / RoHS Compliant
Pin Configuration
ENA
VDD
RSW
REL
ENB
GND
1
2
3
4
5
6
EP
12 SLEW
11
10
9
8
7
ELA
ELB
COM
CS
SW
®
12-Pin 3mm × 3mm MLF (ML) – Top View
Pin Description
Pin Number
1
2
3
4
Pin Name
ENA
VDD
RSW
REL
Pin Function
EL Panel A Enable Pin: Logic high enables ELA and logic low disables
ELA output.
DC Input Supply Voltage: 2.3V to 5.8V
RSW pin: Sets internal boost converter switch frequency by
connecting an external resistor (R
SW
) to VDD. Connecting the R
SW
resistor to GND shuts down the device.
REL pin: Sets internal H-bridge driver frequency by connecting an
external resistor (R
EL
) to VDD. Connecting the R
EL
to GND disables
the EL oscillator.
EL Panel B enable pin: Logic high enables ELB and logic low disables
ELB output.
Ground.
Switch Node: Drain of internal high-voltage power MOSFET for boost
circuit.
Regulated Boost Output: Connect to the output capacitor of the boost
regulator and to the cathode of the diode.
EL output: Common EL output terminal to both ELA and ELB. Connect
one end of each EL panel to this pin.
EL Panel B output: Connect the other end of the EL panel B to this
pin.
EL Panel A output: Connect the other end of the EL panel A to this
pin.
Optional resistor to set output current drive to control slew rate of load.
If left open, the default slew current limit is 5mA.
Heat Sink Pad. Connect to ground externally.
5
6
7
8
9
10
11
12
EPad
ENB
GND
SW
CS
COM
ELB
ELA
SLEW
HS Pad
October 2008
2
M9999-100308
(408) 955-1690
Micrel
MIC4833
Absolute Maximum Rating
(1)
Supply voltage (V
DD
)…………………………..-0.5V to 6.5V
Output voltage (V
CS
) …………..……….…... -0.5V to 130V
Switch Node (V
SW
)……...…………………….-0.5V to 130V
Enable Voltage (V
ENA,
V
ENB
) ..…...……………-0.5V to 6.5V
Voltage (V
REL,
V
RSW,
V
SLEW
) ......………...….…-0.5V to 6.5V
Ambient Storage Temperature (T
S
) …. ..... -65°C to +150°C
ESD Rating
(3)
…..……………………..………ESD Sensitive
Operating Range
(2)
Supply Voltage (V
DD
) ..………………………...2.3V to 5.8V
Panel Drive Frequency (f
EL
)……………..100Hz to 1500Hz
Switching MOSFET Frequency (f
SW
)…...35kHz to 350kHz
Enable Voltage (V
ENA,
V
ENB
) ……………………...0V to V
DD
Junction Temperature Range (T
J
) ………-40°C to +125°C
Package Thermal Impedance
θ
JA
MLF
®
-12L …………………….................... 60°C/W
Electrical Characteristics
(4)
Parameter
Supply Voltage Range
Input Supply Current
Shutdown Current
On-resistance Of Switching
Transistor
Output voltage Regulation
V
DD
I
DD
I
SD
T
A
=25
o
C, V
dd
= 3.0V unless otherwise noted.
Bold
values indicate -40°C
≤
T
J
≤
85°C.
Symbol Condition
R
SW
=High; V
CS
=105V;
ELA, ELB, COM, SLEW = Open
R
SW
=Low; V
DD
=5.8v
I
SW
=100mA, V
CS
=105V
V
DD
=2.3V to 5.8v
V
DD
=3.0V
(R
SW
= 1.3MΩ )
V
DD
=3.0V
(R
SW
= 450kΩ)
V
DD
=3.0V
(R
SW
= 125kΩ)
V
DD
=3.0V
(R
EL
= 1.8 MΩ) ELA, ELB = Open
Vdd=3.0V
(R
EL
= 712kΩ) ELA, ELB = Open
Min
2.3
Typ
152
0.1
6.0
Max
5.8
220
1
12.0
120
45
125
450
295
685
95
Units
V
µA
µA
Ω
V
kHz
kHz
kHz
Hz
Hz
%
mA
mA
V
mV
µA
R
DS
(ON)
V
CS
90
25
75
250
175
445
80
109
35
100
350
235
565
Boost Switching Frequency
f
Sw
ELA, ELB and COM Drive
Frequency
Switching Transistor Duty
Cycle
Output Current Drive Limit
Programmability
Enable Logic Threshold
Enable Logic Hysteresis
Enable Input Current
Notes:
1.
2.
3.
4.
f
EL
D
I
SLEW
V
ENA
, V
ENB
V
HYS
I
ENA
, I
ENB
SLEW = Open
R
SLEW
=10kΩ
2.5
7
0.4
20
5
10
50
0.1
7.5
13
1.2
150
1
Exceeding the absolute maximum rating may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF.
Specification for packaged product only.
October 2008
3
M9999-100308
(408) 955-1690
Micrel
MIC4833
Typical Characteristics
SWITCHING FREQUENCY (kHz)
400
350
300
250
200
150
100
50
0
200
400
600
800
1000
1200
1400
0
Switching Frequency
vs SW Resistor
1600
1400
EL FREQUENCY (Hz)
1200
1000
800
600
400
200
0
0
EL Frequency
vs EL Resistor
Input Current vs.
EL Frequency (Single EL Lamp)
60
V
IN
= 3.6V
4 in
3 in
INPUT CURRENT (mA)
50 f
SW
= 75kHz
40
30
20
10
100
150
200
250
300
350
400
450
2
2
2
2 in
2
1 in
2
SWITCHING RESISTOR (kOhm)
1
2
3
4
ELRESISTOR (MOhm)
5
EL FREQUENCY (Hz)
SWITCHING FREQUENCY (kHz)
60
55
INPUT CURRENT (mA)
50
45
40
35
30
25
20
15
10
Input Current vs.
EL Frequency (Dual EL Lamp)
2× 4 in
2× 3 in
2× 2 in
2
2
2
160
140
120
100
Recommended Switching
Frequency vs. Total Lamp Size
INPUT CURRENT (mA)
150Hz
200Hz
40
35
30
25
20
15
10
5
f
SW
Total Input Current
vs. Input Voltage
f
EL
= 200Hz
= 2.2nF
C
f
OUT
2
SW
= 100kHz
80
60
40
20
Size = 2in
2× 1 in
V
IN
= 3.6V
f
150
200
250
300
SW
300Hz
400Hz
= 122kHz
2
= 75kHz
400
450
500
100
350
V
IN
= 3.0V
0
0
1
2
3
4
5
2
6
EL FREQUENCY (Hz)
TOTAL LAMP SIZE (in )
Size = 1in
0
2 2.5 3 3.5 4 4.5 5 5.5 6
INPUT VOLTAGE (V)
60
55
INPUT CURRENT (mA)
50
45
40
35
30
Total Input Current
vs. Input Voltage
f
EL
= 200Hz
OUT
INPUT CURRENT (mA)
C
f
= 2.2nF
80
75
70
65
60
55
50
Total Input Current
vs. Input Voltage
f
EL
= 200Hz
= 2.2nF
CS VOLTAGE (V)
120
100
80
60
40
f
CS Voltage
vs. Input Voltage
C
f
OUT
SW
= 68kHz
SW
= 47kHz
Size = 4in
2
Size = 6in
2
25
20 f = 88kHz
SW
15
Size = 3in
2
10
2 2.5 3 3.5 4 4.5 5 5.5 6
INPUT VOLTAGE (V)
45
40 f = 55kHz
SW
35
Size = 5in
2
30
2 2.5 3 3.5 4 4.5 5 5.5 6
INPUT VOLTAGE (V)
SW
= 45kHz
20 f
EL
= 200Hz
C
OUT
= 2.2nF
0
2 2.5 3 3.5 4 4.5 5 5.5 6
INPUT VOLTAGE (V)
Output Voltage
vs. Input Voltage
240
OUTPUT VOLTAGE (V
P-P
)
200
BRIGHTNESS (lux)
160
120
80 f
= 45kHz
16
14
12
10
8
6
4
2
Brightness
vs. Input Voltage
SW
40 f
EL
= 200Hz
C
= 2.2nF
OUT
0
2 2.5 3 3.5 4 4.5 5 5.5 6
INPUT VOLTAGE (V)
Distance = 2 in
f
SW
= 135kHz
f
EL
= 225Hz
L = 220µH
0
2 2.5 3 3.5 4 4.5 5 5.5 6
INPUT VOLTAGE (V)
October 2008
4
M9999-100308
(408) 955-1690
500
0
Micrel
MIC4833
Functional Diagram
220µH
VDD
SW
CS
VCS
VDD
Output
ELA
RSW
SW
Oscillator
SW
Driver
Driver
2.2nF
VREF
PGND
PGND
VCS
VSENSE
Output
COM
Driver
REL
EL
Oscillator
Driver Logic
&
PWM Dimming
PGND
VCS
VDD
0
VDD
0
ENA
ENB
EL-A Enable
EL-B Enable
Output
Wave-Shaping
Output
ELB
Driver
SLEW
PGND
GND
GND
PGND
Figure 1. MIC4833 Block Diagram
October 2008
5
M9999-100308
(408) 955-1690
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
