MIC4833YML-TR [MICROCHIP]
EL DISPLAY DRIVER, DSO12;
| 型号： | MIC4833YML-TR |
| 厂家： | 
MICROCHIP |
| 描述： | EL DISPLAY DRIVER, DSO12 驱动 接口集成电路 |
| 文件： | 总12页 (文件大小：1108K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MIC4833
Low Noise Dual 220 VPP EL Driver
With Output Voltage Slew Rate Control
General Description
Features
•
Drives two EL panels, up to 4 in2 each at full
brightness
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.
•
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
–40oC to +125oC junction temperature range
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.
Applications
•
•
•
•
•
•
•
Mobile Phones
MP3s/Portable Media Players (PMP)
Clocks/ Watches
Remote Controls
Cordless Phones
GPS Devices
The MIC4833 is available in a 12 pin 3mmx3mm MLF®
package, and has an operating junction temperature range
of –40°C to +125°C.
PDAs
_________________________________________________________________________________________________
Typical Application
High
50k
Low
ENA
VDD
RSW
REL
ENB
GND
SLEW
ELA
ELB
COM
CS
VIN
Li Ion
3V to 4.2V
EL Lamp A
EL Lamp B
332k
0.01µF
MIC4833
1.78M
High
High
Low
Low
SW
VIN
Li Ion
3V to 4.2V
220µH
2.2nF
250V
10µF
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
M9999-100308
(408) 955-1690
October 2008
Micrel
MIC4833
Ordering Information
Part Number
Package
Operating Junction Temp
Range
Lead Finish
12 pin 3mmx3mm
MLF®
MIC4833YML
Pb-free / RoHS Compliant
-40°C to +125°C
Pin Configuration
ENA
1
12 SLEW
11 ELA
10 ELB
VDD
RSW
REL
2
3
4
5
6
EP
9
8
7
COM
CS
ENB
GND
SW
12-Pin 3mm × 3mm MLF® (ML) – Top View
Pin Description
Pin Number
Pin Name
Pin Function
1
ENA
EL Panel A Enable Pin: Logic high enables ELA and logic low disables
ELA output.
2
3
VDD
RSW
DC Input Supply Voltage: 2.3V to 5.8V
RSW pin: Sets internal boost converter switch frequency by
connecting an external resistor (RSW) to VDD. Connecting the RSW
resistor to GND shuts down the device.
4
REL
REL pin: Sets internal H-bridge driver frequency by connecting an
external resistor (REL) to VDD. Connecting the REL to GND disables
the EL oscillator.
5
ENB
EL Panel B enable pin: Logic high enables ELB and logic low disables
ELB output.
6
7
GND
SW
Ground.
Switch Node: Drain of internal high-voltage power MOSFET for boost
circuit.
8
9
CS
COM
ELB
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.
10
11
ELA
EL Panel A output: Connect the other end of the EL panel A to this
pin.
12
SLEW
HS Pad
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.
EPad
M9999-100308
(408) 955-1690
October 2008
2
Micrel
MIC4833
Absolute Maximum Rating (1)
Operating Range (2)
Supply voltage (VDD)…………………………..-0.5V to 6.5V
Output voltage (VCS) …………..……….…... -0.5V to 130V
Switch Node (VSW)……...…………………….-0.5V to 130V
Enable Voltage (VENA, VENB) ..…...……………-0.5V to 6.5V
Voltage (VREL, VRSW, VSLEW) ......………...….…-0.5V to 6.5V
Ambient Storage Temperature (TS) …. ..... -65°C to +150°C
ESD Rating(3)…..……………………..………ESD Sensitive
Supply Voltage (VDD) ..………………………...2.3V to 5.8V
Panel Drive Frequency (fEL)……………..100Hz to 1500Hz
Switching MOSFET Frequency (fSW)…...35kHz to 350kHz
Enable Voltage (VENA, VENB) ……………………...0V to VDD
Junction Temperature Range (TJ) ………-40°C to +125°C
Package Thermal Impedance
θJA MLF®-12L …………………….................... 60°C/W
Electrical Characteristics(4)
TA=25oC, Vdd = 3.0V unless otherwise noted. Bold values indicate -40°C ≤ TJ ≤ 85°C.
Parameter
Symbol Condition
Min Typ Max Units
Supply Voltage Range
VDD
2.3
5.8
220
1
V
Input Supply Current
RSW=High; VCS=105V;
ELA, ELB, COM, SLEW = Open
RSW=Low; VDD=5.8v
ISW=100mA, VCS=105V
IDD
ISD
152
0.1
6.0
µA
µA
Ω
Shutdown Current
On-resistance Of Switching
Transistor
RDS(ON)
12.0
Output voltage Regulation
VDD=2.3V to 5.8v
VCS
90
25
75
109
35
120
45
V
VDD=3.0V
kHz
kHz
(RSW = 1.3MΩ )
VDD=3.0V
(RSW = 450kΩ)
Boost Switching Frequency
fSw
100
125
V
DD=3.0V
250
175
445
80
350
235
565
450
295
685
95
kHz
Hz
Hz
%
(RSW = 125kΩ)
VDD=3.0V
(REL = 1.8 MΩ) ELA, ELB = Open
Vdd=3.0V
ELA, ELB and COM Drive
Frequency
fEL
D
(REL = 712kΩ) ELA, ELB = Open
Switching Transistor Duty
Cycle
2.5
7
5
7.5
13
mA
mA
SLEW = Open
Output Current Drive Limit
Programmability
ISLEW
10
RSLEW =10kΩ
Enable Logic Threshold
Enable Logic Hysteresis
Enable Input Current
VENA, VENB
VHYS
IENA, IENB
0.4
20
1.2
150
1
V
mV
µA
50
0.1
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF.
4. Specification for packaged product only.
M9999-100308
(408) 955-1690
October 2008
3
Micrel
MIC4833
Typical Characteristics
Switching Frequency
EL Frequency
vs EL Resistor
Input Current vs.
EL Frequency (Single EL Lamp)
vs SW Resistor
400
60
1600
1400
1200
1000
800
600
400
200
0
VIN = 3.6V
350
300
250
200
150
100
50
4 in2
3 in2
f
SW = 75kHz
50
40
30
20
10
0
2 in2
1 in2
0
0
1
2
3
4
5
ELRESISTOR (MOhm)
EL FREQUENCY (Hz)
SWITCHING RESISTOR (kOhm)
Input Current vs.
EL Frequency (Dual EL Lamp)
Recommended Switching
Frequency vs. Total Lamp Size
Total Input Current
vs. Input Voltage
fEL = 200Hz
60
160
40
35
30
25
20
15
10
5
2× 4 in2
55
140
120
100
80
COUT = 2.2nF
150Hz
200Hz
50
2× 3 in2
2× 2 in2
45
fSW = 100kHz
Size = 2in2
40
35
300Hz
2× 1 in2
30
60
400Hz
25
40
20
VIN = 3.6V
fSW = 122kHz
Size = 1in2
20
15
f
SW = 75kHz
VIN = 3.0V
10
0
0
0
1
2
3
4
5
2
6
6
6
2
2.5
3
3.5
4
4.5
5
5.5
6
INPUT VOLTAGE (V)
TOTAL LAMP SIZE (in )
EL FREQUENCY (Hz)
Total Input Current
vs. Input Voltage
fEL = 200Hz
Total Input Current
vs. Input Voltage
fEL = 200Hz
CS Voltage
vs. Input Voltage
60
55
50
45
40
35
30
25
20
15
10
80
75
70
65
60
55
50
45
40
35
30
120
100
80
60
40
20
0
COUT = 2.2nF
COUT = 2.2nF
fSW = 68kHz
Size = 4in2
fSW = 47kHz
Size = 6in2
fSW = 45kHz
EL = 200Hz
OUT = 2.2nF
2.5 3.5
INPUT VOLTAGE (V)
fSW = 88kHz
Size = 3in2
fSW = 55kHz
Size = 5in2
f
C
2
2.5
3
3.5
4
4.5
5
5.5
6
2
2.5
3
3.5
4
4.5
5
5.5
2
3
4 4.5 5 5.5 6
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Output Voltage
vs. Input Voltage
Brightness
vs. Input Voltage
240
200
160
120
80
16
14
12
10
8
6
Distance = 2 in
fSW = 135kHz
fSW = 45kHz
EL = 200Hz
4
f
fEL = 225Hz
40
2
C
OUT = 2.2nF
L = 220µH
0
0
2
2.5 3.5
3
4
4.5
5
5.5
6
2
2.5
3
3.5
4
4.5
5
5.5
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
M9999-100308
(408) 955-1690
October 2008
4
Micrel
MIC4833
Functional Diagram
220µH
VDD
SW
CS
VCS
2.2nF
VDD
Output
ELA
RSW
SW
Oscillator
SW
Driver
Driver
PGND
VCS
VREF
PGND
VSENSE
Output
Driver
COM
Driver Logic
&
PWM Dimming
REL
EL
Oscillator
PGND
VCS
VDD
Output
Driver
ENA
ENB
EL-A Enable
EL-B Enable
0
ELB
VDD
0
Output
Wave-Shaping
SLEW
PGND
PGND
GND
GND
Figure 1. MIC4833 Block Diagram
M9999-100308
(408) 955-1690
October 2008
5
Micrel
MIC4833
Functional Description
RSW and VDD. The switching frequency increases
Overview
as the resistor value decreases. In general, the
lower the switching frequency, the greater the input
current is drawn to deliver more power to the output.
Lowering the switching frequency can be used to
drive larger panels. However, the switching
frequency should not be so low as to allow the
voltage at the switch node or the CS pin to exceed
the absolute maximum voltage of those pins. For
resistor value selections, see the “Typical
Characteristics: Switching Frequency vs. SW
Resistor” graph on Page 4 or use the equation
below. The switching frequency range is 35kHz to
350kHz, with an accuracy of ±20%.
The MIC4833 is a high-voltage dual output EL driver
with a peak-to-peak AC output voltage of 220V
capable of driving two 4 in2 EL panels. The MIC4833
drives EL panels by converting a low DC input
voltage to a DC high output voltage using the boost
regulator circuit and then alternating the high DC
voltage across the EL panel using an H-Bridge.
Input supply current for the MIC4833 is typically
152µA. The high voltage EL driver has two internal
oscillators to control the boost switching frequency
and the H-bridge driver frequency. Both of the
internal oscillators’ frequencies can be individually
programmed through external resistors to maximize
efficiency and brightness of the EL panel. The
MIC4833 can be dimmed using a PWM signal
applied to the REL pin with an external capacitor. An
external resistor can be used to adjust the internal
wave shaping circuit to reduce audible noise.
46
f
(kHz) =
SW
R
(
MΩ
)
SW
EL Frequency
The EL panel frequency is controlled via an external
resistor (REL) connected between REL and VDD.
The panel frequency increases as the resistor value
decreases. In general, as the EL panel frequency
increases, the amount of current drawn from the
battery will increase. The EL panel brightness is
dependent upon its frequency. For resistor value
selections, see the “Typical Characteristics: EL
Frequency vs. EL Resistor” graph on Page 4 or use
the equation below. The EL panel frequency range
is 100Hz to 1500Hz, with an accuracy of ±20%.
Regulation
Referring to Figure 1, power is initially applied to
VDD. When the internal feedback voltage is less than
the reference voltage, the internal comparator
enables switching in the boost circuit. When the
boost regulator is switching, current flows through
the inductor into the switch. The switching MOSFET
will typically turn on for 90% of the switching period.
During the on-time, energy is stored in the inductor.
When the switching MOSFET turns off, current
flowing into the inductor forces the voltage across
the inductor to reverse polarity. The voltage across
the inductor rises until the external diode conducts
and clamps the voltage at VOUT + VD1. The energy in
the inductor is then discharged into the COUT
capacitor. The internal comparator continues to turn
the switching MOSFET on and off until the internal
feedback voltage is above the reference voltage.
Once the internal feedback voltage is above the
reference voltage, the internal comparator disables
switching. The control circuit will continue to turn the
MOSFET’s on and off to maintain a constant DC
voltage at the CS pin.
425
f
(
Hz =
)
EL
R
(Mꢀ
)
EL
Enable Function
There are a few different ways to enable and disable
the MIC4833. The boost regulator may be disabled
by pulling the RSW resistor to ground. This turns off
both the EL panels by cutting power to the device
completely. The EL panels can also be turned off by
pulling the REL resistor to ground. Although this turns
off the H-Bridge and the EL panels, the MIC4833
boost regulator will continue regulate. For individual
panel control, the ENA and ENB pins can be used to
enable ELA and ELB, respectively. Pulling ENA or
ENB high or low will turn ELA and ELB panels on or
off.
When the MIC4833 EL Driver is enabled, ELA and
ELB will switch in opposite states with COM to
achieve a 220V peak-to-peak AC output signal
needed to drive the two EL panels.
Switching Frequency
The switching frequency of the converter is
controlled via an external resistor (RSW) between
M9999-100308
(408) 955-1690
October 2008
6
Micrel
MIC4833
PWM Dimming
The MIC4833 may be dimmed by adding a shunt
capacitor (CPWM) to the REL pin, shown in Figure 5.
The duty cycle of the PWM signal changes the
frequency of the EL panel, thereby changing its
brightness. Increasing the PWM duty cycle
increases the EL frequency to a maximum set by
REL (Duty Cycle = 100%). Decreasing the PWM duty
cycle decreases the EL frequency. The PWM duty
cycle should not be lowered to a level that may
cause the EL frequency to be lower than 100Hz,
since EL frequencies lower than 100Hz may cause
the panel to flicker. The frequency of the PWM
signal can range from 500Hz to 50kHz. The peak
voltage of the PWM signal should be equal to VDD.
Figure 2. 150Hz Output Waveform
Figure 3. 250Hz Output Waveform
Figure 4. 350Hz Output Waveform
REL
VDD
0V
REL pin
PWM
1kHz
CPWM
0.01µF
Figure 5. PWM Dimming Circuit
Slew Resistor
The MIC4833 is designed to reduce audible noise in
EL panels by the use of the internal wave-shaping
circuit. To further reduce audible noise, a Slew
Resistor (RSLEW) can be added to limit the rate of
change of the EL driver output voltage by limiting the
output current. A slower rate of change in voltage
across the EL panel creates less physical distortion
in the material and therefore reduces the amount of
audible noise. The lower the ISLEW, the slower the
output voltage across the EL panel will change. If
RSLEW is not used, the ISLEW is by default 5mA,
equivalent to using a 22kꢀ for RSLEW
.
RSLEW ISLEW
Open
125kꢀ
22kꢀ
10kꢀ
5mA
1mA
5mA
10mA
Table 1. Slew Resistor Setting
M9999-100308
(408) 955-1690
October 2008
7
Micrel
MIC4833
Output Capacitor
Application Information
Low ESR capacitors should be used at the regulated
boost output (CS pin), to minimize the switching
The MIC4833 is designed to use an inductance with
a value between 100µH to 330µH. Choosing the
output ripple voltage.
The larger the output
right inductor is always
a
balance of size,
capacitance, the lower the output ripple at the CS
pin. The reduced output ripple at the CS pin along
with a low ESR capacitor improves the efficiency of
the MIC4833 circuit. Selection of the capacitor value
depends upon the peak inductor current, inductor
size, and the load. The MIC4833 is designed for use
with an output capacitance as low as 2.2nF. For
minimum audible noise, the use of a C0G/NPO
dielectric output capacitor is recommended. TDK
and AVX offer C0G/NPO dielectric capacitors in
capacitances up to 2.7nF capacitance at 200V to
250V voltage rating in 0805 size.
inductance, efficiency, current rating and cost. A
TDK (VLS4012T-221M) 220µH inductor is
recommended based on size, efficiency and current
rating.
Generally, the lower the inductance, the more
current the inductor can handle. Lowering the
inductance allows the boost regulator to draw more
input current to deliver more energy every switching
cycle. As a result, a lower inductance may be used
to drive larger panels or brighten similar sized
panels. However, caution is required as using a low
inductance with a low switching frequency may
cause the voltage at the switch node and the CS pin
to exceed the absolute maximum rating. If the
application uses a low input voltage (2.3 to 3V), a
lower value inductor, such as 100µH, may be used
in order to drive the EL panel at maximum
brightness.
EL Panel Terminals (ELA, ELB, COM)
The two EL panels are connected from ELA to COM
and ELB to COM. The ELA and ELB terminals are in
phase with each other, while the COM is out of
phase with both ELA and ELB. Since ELA and COM
are out of phase, the high voltage generated by the
boost regulator is alternated across ELA and COM
by the H-Bridge. The frequency of each cycle is
determined by REL. The alternating 220V peak-to-
peak causes the EL panel to emit light. Similarly, the
ELB and COM are also out of phase and allows a
second EL panel to be driven at the same time. Both
EL panels may operate independently from each
other and do not have to be the same size. For
component selection, Table 2 lists recommended
values for various panel sizes up to a total of 8in2
(For example, two 4in2 panels). Driving overly large
panels will result in a dimmer display, but will not
cause damage to the device.
Diode
The diode must have a high reverse voltage (150V),
since the output voltage at the CS pin can reach up
to 130V. A fast switching diode with lower forward
voltage and higher reverse voltage (150V), such as
BAV20WS/BAS20W, can be used to enhance
efficiency.
M9999-100308
(408) 955-1690
October 2008
8
Micrel
MIC4833
Application Circuit
RSLEW
50k
High
Low
ENA
VDD
RSW
REL
ENB
GND
SLEW
ELA
ELB
COM
CS
VIN
Li Ion
EL Lamp A
EL Lamp B
3V to 4.2V
RSW
332k
C1
0.01µF
REL
1.78M
MIC4833
High
High
Low
Low
SW
L1
220µH
VIN
Li Ion
3V to 4.2V
C3
2.2nF
250V
C2
10µF
Figure 6: Typical Li-Ion Powered MIC4833 Circuit
Note: Table 2 applies to circuit shown in Figure 6.
Total
Panel
Area
Panel
Frequency
(Hz)
150
200
250
300
350
400
500
Capacitance
(nF)
(inch2)
REL (MΩ)
RSW (kΩ)
fSW (kHz)
RSW (kΩ)
fSW (kHz)
RSW (kΩ)
fSW (kHz)
RSW (kΩ)
fSW (kHz)
RSW (kΩ)
fSW (kHz)
RSW (kΩ)
fSW (kHz)
RSW (kΩ)
fSW (kHz)
RSW (kΩ)
fSW (kHz)
2.80
324
138
357
125
402
112
464
98
523
86
619
72
2.10
340
132
365
122
453
100
511
88
665
68
825
55
1.69
357
126
392
116
487
92
590
77
750
60
1.40
383
118
422
108
549
83
698
65
909
50
1.21
392
116
442
102
590
76
768
58
1000
45
1.05
402
112
475
95
649
70
909
50
.850
442
102
511
88
681
66
1000
45
0.4
2
1
2
3
4
5
6
8
5
10
15
20
25
30
40
1000
45
909
50
1000
45
698
65
1000
45
953
47
1000
45
Table 2: Recommended RSW & REL Values For Total Panel Sizes
M9999-100308
(408) 955-1690
October 2008
9
Micrel
MIC4833
Bill of Materials
Item
C1
Part Number
Manufacturer
TDK(1)
Description
0.01µF Ceramic Capacitor, 10V, X7R, Size 0603
10 µF Ceramic Capacitor, 6.3V, X5R, Size 0603
0.0022µF Ceramic Capacitor, 250V, C0G, Size 0805
220µH, 210mA ISAT. (4mmx4mmx1.2mm)
200V/200mA Hi-Voltage Switching Diode
332kꢀ, 1%, 1/16W, Size 0603
Qty
C1608X7R1A103K
C1608X5R0J106K
1
C2
TDK(1)
TDK(1)
TDK(1)
Vishay(2)
Vishay(2)
Vishay(2)
1
C3
C2012C0G2E2222J
VLS4012T-221M
1
L1
1
D1
BAS20-V-GS18
1
R1 or RSW
R2 or REL
RSLEW
U1
CRCW06033323FKEYE3
CRCW06031784FKEYE3
1
1.78Mꢀ, 1%, 1/16W, Size 0603
1
Optional
1
MIC4833YML
Micrel(3)
Low Noise Dual 220Vp-p EL Driver with Output Slew Control
Notes:
1. TDK: www.tdk.com
2. Vishay: www.vishay.com
3. Micrel, Inc.: www.micrel.com
M9999-100308
(408) 955-1690
October 2008
10
Micrel
MIC4833
Layout Recommendation
Top Layer
Bottom Layer
M9999-100308
(408) 955-1690
October 2008
11
Micrel
MIC4833
Package Information
12-Pin 3mm x 3mm MLF® (ML)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http:/www.micrel.com
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its
use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product
can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant
into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A
Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2008 Micrel, Incorporated.
M9999-100308
(408) 955-1690
October 2008
12
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