MIC2292/93C
High Frequency PWM White LED Drivers
with Internal Schottky Diode and OVP
General Description
The MIC2292C and MIC2293C are high frequency, Pulse
Width Modulator (PWM) boost regulators optimized for
constant-current, white LED driver applications. Because
of their constant PWM switching frequencies of 1.6MHz
and 2MHz, respectively, the MIC2292/93C can use the
smallest external components, allowing designers to avoid
sensitive IF bands in their RF applications.
The products feature an internal Schottky diode and two
levels of output overvoltage protection allowing a small
size and efficient DC/DC solution that requires only four
external components.
The 2.5V to 10V input voltage range of MIC2292/3C allows
direct operation from 1- and 2-cell Li Ion as well as 3- to 4-
cell NiCad/NiMH/Alkaline batteries. The MIC2292/3C pro-
ducts are available in a small size 8-pin 2mm × 2mm MLF
®
package and have a junction temperature range of
–40°C to +125°C.
Data sheets and support documentation can be found on
Micrel’s web site at
www.micrel.com.
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
2.5V to 10V input voltage
Output voltage up to 34V
Internal Schottky diode
1.6MHz PWM operation (MIC2292C)
2.0MHz PWM operation (MIC2293C)
Stable with ceramic capacitors
15V and 34V output overvoltage protection options
500mA switch current rating
95mV feedback voltage
<1% line and load regulation
<1µA shutdown current
Over-temperature protection
UVLO
8-pin 2mm × 2mm MLF
®
package
–40°C to +125°C junction temperature range
Applications
•
White LED driver for backlighting:
– Cell phones
– PDAs
– GPS systems
– Digital cameras
– MP3 players
– IP phones
•
Constant current power supplies
Typical Application
15µH
10µH
MIC2292C-15BML
VIN
Li Ion
1µF
EN
GND
SW
OUT
FB
95mV
0.22µF
16V
Li Ion
1µF
MIC2293C-15BML
VIN
SW
OUT
EN
GND
FB
95mV
0.22µF
16V
1.6MHz PWM White LED Driver with 15V OVP
MLF and
MicroLeadFrame
are registered trademarks of Amkor Technology, Inc.
2MHz PWM White LED Driver with 15V OVP
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
September 2006
1
M9999-090706
Micrel, Inc.
MIC2292/93C
Ordering Information
Part Number
MIC2292C-15BML
MIC2292C-15YML
MIC2292C-34BML
MIC2292C-34YML
MIC2293C-15BML
MIC2293C-15YML
MIC2293C-34BML
MIC2293C-34YML
Marking
Code
Overoltage
Protection
15V
15V
34V
34V
15V
15V
34V
34V
Junction
Temp. Range
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Package
8-Pin 2mm x 2mm MLF
®
Lead Finish
Standard
Pb-Free
Standard
Pb-Free
Standard
Pb-Free
Standard
Pb-Free
8-Pin 2mm x 2mm MLF
®
8-Pin 2mm x 2mm MLF
®
8-Pin 2mm x 2mm MLF
®
8-Pin 2mm x 2mm MLF
®
8-Pin 2mm x 2mm MLF
8-Pin 2mm x 2mm MLF
®
®
8-Pin 2mm x 2mm MLF
®
Pin Configuration
Denotes Pb-Free
OUT
VIN
EN
AGND
1
2
3
4
8
7
6
PGND
SW
FB
NC
Denotes MIC2292/93C
???
EP
5
8-Pin MLF
®
(ML)
(Top View)
Fused Lead Frame
Pin Description
Pin Number
1
2
3
4
5
6
7
8
EP
Pin Name
OUT
VIN
EN
AGND
NC
FB
SW
PGND
GND
Pin Name
Output Pin and Overvoltage Protection (Output): Connect to the output capacitor and LEDs.
Supply (Input): Input Voltage.
Enable (Input): Logic high enables regulator. Logic low shuts down regulator.
Analog ground.
No connect (no internal connection to die).
Feedback (Input): Output voltage sense node. Connect the cathode of the LED to this pin.
A resistor from this pin to ground sets the LED current.
Switch node (Input): Internal power transistor collector.
Power ground.
Ground (Return): Exposed backside pad.
September 2006
2
M9999-090706
Micrel, Inc.
MIC2292/93C
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) .......................................................12V
Switch Voltage (V
SW
)....................................... –0.3V to 34V
Enable Pin Voltage (V
EN
)................................... –0.3V to V
IN
FB Voltage (V
FB
)...............................................................6V
Switch Current (I
SW
) .........................................................2A
Ambient Storage Temperature (T
s
) ...........–65°C to +150°C
Schottky Reverse Voltage (V
DA
).....................................34V
EDS Rating
(3)
.................................................................. 2kV
Operating Ratings
(2)
Supply Voltage (V
IN
)........................................ 2.5V to +10V
Output Voltage (V
IN
) ............................................ V
IN
to V
OVP
Junction Temperature (T
J
) ........................ –40°C to +125°C
Package Thermal Resistance
2mm x 2mm MLF
®
(θ
JA
).....................................93°C/W
Electrical Characteristics
(4)
T
A
= 25°C, V
IN
= V
EN
= 3.6V, V
OUT
= 15V, I
OUT
= 20mA, unless otherwise noted.
Bold
values indicate –40°C< T
J
< +125°C.
Symbol
V
IN
V
UVLO
I
VIN
I
SD
V
FB
I
FB
Parameter
Supply Voltage Range
Under Voltage Lockout
Quiescent Current
Shutdown Current
Feedback Voltage
Feedback Input Current
Line Regulation
(6)
Load Regulation
(6)
D
MAX
I
SW
V
SW
I
SW
V
EN
I
EN
f
SW
V
D
I
RD
V
OVP
T
J
Notes:
1. Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating
the device outside of its operating ratings. The maximum allowable power dissipation is a function of the maximum junction temperature, T
J(max)
, the
junction-to-ambient thermal resistance,
θ
JA
, and the ambient temperature, T
A
. The maximum allowable power dissipation will result in excessive die
temperature, and the regulator will go into thermal shutdown.
2. The device is not guaranteed to function outside its operating rating.
3. Devices are ESD sensitive. Handling precautions recommended. Human body model.
4. Specification for packaged product only.
5. I
SD
= I
VIN
.
6. Guaranteed by design
Condition
Min
2.5
1.8
Typ
2.1
2.5
0.1
Max
10
2.4
5
1
105
Units
V
V
mA
µA
mV
nA
%
%
%
mA
mV
V
FB
> 200mV, (not switching)
V
EN
= 0V
(±10%)
V
FB
= 95mV
3V
≤
V
IN
≤
5V
5mA
≤
I
OUT
≤
20mA
85
I
SW
= 0.5A
V
EN
= 0V, V
SW
= 10V
TURN ON
TURN OFF
V
EN
= 10V
MIC2292C
MIC2293C
I
D
= 150mA
V
R
= 30V
MIC2292/93C-15
MIC2292/93C-34
Hysteresis
11.4
27
1.4
1.75
1.5
(5)
85
95
–450
0.5
0.5
90
750
450
0.01
Maximum Duty Cycle
Switch Current Limit
Switch Saturation Voltage
Switch Leakage Current
Enable Threshold
Enable Pin Current
Oscillator Frequency
Schottky Forward Drop
Schottky Leakage Current
Overvoltage Protection
Overtemperature
Threshold Shutdown
5
0.4
µA
V
V
µA
MHz
MHz
V
µA
V
V
°C
°C
20
1.6
2.0
0.8
14
32
150
10
40
1.8
2.25
1
4
16.5
37
September 2006
3
M9999-090706
Micrel, Inc.
MIC2292/93C
Typical Characteristics
100
99
FB VOLTAGE (mV)
98
97
96
95
94
93
92
91
90
0
2
4
6
V
IN
(V)
8
10
12
Feedback Voltage
vs. Input Voltage
SHUTDOWN CURRENT (µA)
5
4
3
2
1
0
Shutdown Voltage
vs. Input Voltage
QUIESCENT CURRENT (mA)
5
4
3
2
1
0
Quiescent Current
vs. Input Current
0
2
4
6
V
IN
(V)
8
10
12
0
2
4
6
V
IN
(V)
8
10
12
SCHOTTKY FORWARD CURRENT (mA)
SWITCHING FREQUENCY (MHz)
1.4
1.2
Switch Frequency
vs. Temperature
50
45
40
IENABLE (µA)
EN Pin Bias Current
vs. Temperature
700
600
500
400
300
200
100
Schottky Forward
Voltage Drop
1.0
0.8
0.6
0.4
0.2
0
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
35
I = 10V
30
E N
25
20
I = 4.2V
15
E N
I
10
5 I = 3.0V
EN
0
-50
0
50
TEMPERATURE (°C)
EN
= 3.6V
1050
100
SCHOTTKY FORWARD VOLTAGE DROP (mV)
SCHOTTKY LEAKAGE CURRENT (µA)
2.5
2
1.5
1
0.5
Schottky Reverse
Leakage Current
SATURATION VOLTAGE (mV)
550
500
450
400
350
300
-40
Saturation Voltage
vs. Temperature
900
CURRENT LIMIT (mA)
850
800
750
700
650
Current Limit
vs. Temperature
V
R
= 25V
V
R
= 16V
V
R
= 10V
0
30
40
50 60 70 80 90 100
TEMPERATURE (°C)
I
S W
= 500mA
0
40
80
TEMPERATURE (°C)
120
V
IN
= 2.5V
600
-40
0
40
80
TEMPERATURE (°C)
SWITCHING FREQUENCY (MHz)
SATURATION VOLTAGE (mV)
2
1.6
1.2
0.8
0.4
0
-40
Switch Frequency
vs. Temperature
600
500
400
300
200
100
Switch Saturation Voltage
vs. Current
V
IN
= 2.5V
V
IN
= 5V
0
40
80
TEMPERATURE (°C)
120
0
0
100
200 300
I
SW
(mA)
400
500
September 2006
4
M9999-090706
1150
450
550
650
750
850
950
0
120
Micrel, Inc.
MIC2292/93C
Functional Characteristics
6-Series LED Circuit with External Soft-Start
6-Series LED Circuit without External Soft-Start
OUTPUT VOLTAGE
INPUT CURREN
T
ENABLE
(200mA/div)
(2V/div)
OUTPUT VOLTAGE
INPUT CURREN
T
ENABLE
(200mA/div)
(2V/div)
L = 10µH
C
IN
= 1µF
C
OUT
= 0.22µF
V
IN
= 3.6V
I
OUT
= 20mA
6 LEDs
C
SS
= 2200pF
L = 10µH
C
IN
= 1µF
C
OUT
= 0.22µF
V
IN
= 3.6V
I
OUT
= 20mA
6 LEDs
September 2006
5
M9999-090706
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