MIC3230/1/2
Constant Current Boost Controller for
Driving High Power LEDs
General Description
The MIC3230/1/2 are constant current boost switching
controllers specifically designed to power one or more
strings of high power LEDs. The MIC3230/1/2 have an
input voltage range from 6V to 45V and are ideal for a
variety of solid state lighting applications.
The MIC3230/1/2 utilizes an external power device which
offers a cost conscious solution for high power LED
applications. The powerful drive circuitry can deliver up to
70W to the LED system. Power consumption has been
minimized through the implementation of a 250mV
feedback voltage reference providing an accuracy of ±3%.
The MIC323x family is dimmable via a pulse width
modulated (PWM) input signal and also features an enable
pin for low power shutdown.
Multiple MIC3230 ICs can be synchronized to a common
operating frequency. The clocks of these synchronized
devices can be used together in order to help reduce noise
and errors in a system.
An external resistor sets the adjustable switching
frequency of the MIC3230/1. The switching frequency can
be between 100kHz and1MHz. Setting the switching
frequency provides the mechanism by which a design can
be optimized for efficiency (performance) and size of the
external components (cost). The MIC323x family of LED
drivers also offer the following protection features: Over
voltage protection (OVP), thermal shutdown and under-
voltage lock-out (UVLO).
The MIC3231 offers a dither feature to assist in the
reduction of EMI. This is particularly useful in sensitive EMI
applications, and provides for a reduction or emissions by
approximately 10dB.
The MIC3232 is a 400kHz fixed frequency device offered
in a small 10-pin MSOP package. The MIC3230/1 are
offered in both the EPAD 16-pin TSSOP package and the
12-pin 3mm × 3mm MLF
®
package.
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Bringing the Power to Light™
Features
•
•
•
•
•
•
•
•
•
6V to 45V input supply range
Capable of driving up to 70W
Ultra low EMI via dithering on the MIC3231
Programmable LED drive current
Feedback voltage = 250mV ±3%
Programmable switching frequency (MIC3230/1) or
400kHz fixed frequency operation (MIC3232)
PWM Dimming and separate enable shutdown
Frequency synchronization with other MIC3230s
Protection features:
Over Voltage Protection (OVP)
Over temperature protection
Under-voltage Lock-out (UVLO)
Packages:
N/C
VIN
EN
PWMD
COMP
IADJ
FS
1
2
3
4
5
6
EPAD
12 VDD
11
DRV
•
1
2
3
4
5
6
7
8
EPAD
16 N/C
15 VDD
14 DRV
13 PGND
12 OVP
11 IS
10 SYNC/NC
9 N/C
VIN
EN
PWMD
COMP
IADJ
FS
AGND
VIN
EN
PWMD
COMP
IADJ
1
2
3
4
5
10 VDD
9
8
7
6
DRV
PGND
OVP
IS
10 PGND
9
8
7
OVP
IS
SYNC/NC
MIC3232
10-pin MSOP
MIC3230/1
®
12-pin MLF
MIC3230/1
16-pin TSSOP
•
–40°C to +125°C junction temperature range
Applications
•
•
•
•
•
Street lighting
Solid state lighting
General illumination
Architectural lighting
Constant current power supplies
Bringing the Power to Light is a trademark of Micrel, Inc.
MicroLeadFrame
and MLF are registered trademarks of Amkor Technology.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
March 2011
M9999-030311-D
Micrel, Inc.
MIC3230/1/2
Pin Configuration
N/C
1
2
3
4
5
6
7
8
EPAD
16 N/C
15 VDD
14 DRV
13 PGND
12 OVP
11 IS
10 SYNC/NC
9 N/C
VIN 1
EN 2
PWMD 3
COM 4
P
IADJ 5
10 VDD
9 DRV
8 PGND
7 OVP
6 IS
VIN
EN
PWMD
COMP
IADJ
FS
1
2
3
4
5
6
EPAD
12 VDD
11
DRV
VIN
EN
PWMD
COMP
IADJ
FS
AGND
10 PGND
9
8
7
OVP
IS
SYNC/NC
10-Pin MSOP (MM)
MIC3232
12-Pin 3mmx3mmMLF (ML)
MIC3230, MIC3231
See Product Option Matrix for selection
®
16-Pin TSSOP (TSE)
MIC3230, MIC3231
See Product Option Matrix for selection
Pin Description
Pin Number
MLF
--
1
2
®
Pin Number
TSSOP
1
2
3
Pin Number
MSOP
--
1
2
Pin Name
NC
VIN
EN
Pin Function
No Connect.
Input Voltage (power) 6V to 45V.
Enable Control (Input). Logic High (≥1.5V) enables the
regulator. Logic Low (≤0.4V) shuts down the regulator.
Connect a 100kΩ resistor from EN to VIN.
PWM Dimming Input. Logic Low will disable the brightness
control of the LED drivers.
Compensation (output): for external compensation.
Feedback (input).
Frequency Select (input). Connected to a Resistor to
determine the operating frequency.
Analog Ground.
No Connect.
Sync (output). Connect to another MIC3230 to synchronize
multiple converters.
Current Sense (input). Connected to external current sense
resistor which in turn is connected to the source of the external
FET as well as an external slope compensation resistor.
OVP divider connection (output). Connect the top of the
divider string to the output. If the load is disconnected, the
output voltage will rise until OVP reaches 1.25V and then will
regulate around this point.
Power Ground.
Drive Output: connect to the gate of external FET (output).
VDD Filter for internal power rail. Do not connect an external
load to this pin. Connect 10µF to GND.
No Connect.
Connect to AGND.
3
4
5
6
--
--
7
8
4
5
6
7
8
9
10
11
3
4
5
--
--
--
--
6
PWMD
COMP
IADJ
FS
AGND
NC
SYNC
IS
9
12
7
OVP
10
11
12
--
--
13
14
15
16
--
8
9
10
--
--
PGND
DRV
VDD
NC
EPAD
March 2011
3
M9999-030311-D
Micrel, Inc.
MIC3230/1/2
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) .....................................................+48V
Enable Pin Voltage........................................... -0.3V to +6V
IADJ Voltage ..................................................................+6V
Lead Temperature (soldering, sec.) ........................... 260°C
Storage Temperature (Ts)..........................-65°C to +150°C
ESD Rating
(3)
MIC3230 ....................................... 1500V HB, 100VMM
MIC3232 ........................................... 2kV HB, 100VMM
MIC3231 ....................................... 1500V HB, 150VMM
Operating Ratings
(2)
Supply Voltage (V
IN
)......................................... +6V to +45V
Junction Temperature (TJ)........................ –40°C to +125°C
Junction Thermal Resistance
MSOP (θ
JA
) ...................................................130.5°C/W
EPAD TSSOP (θ
JA
).........................................36.5°C/W
MLF
®
(θ
JA
).......................................................60.7°C/W
Electrical Characteristics
(4)
V
IN
= 12V; V
EN
= 3.6V; L = 47µH; C = 4.7µF; T
J
= 25°C,
Bold
values indicate –40°C≤ T
J
≤
+125°C, unless noted.
Symbol
V
IN
UVLO
I
VIN
I
SD
V
IADJ
I
ADJ
Parameter
Supply Voltage Range
Under Voltage Lockout
Quiescent Current
Shutdown Current
Feedback Voltage (at IADJ)
Feedback Input Current
Line Regulation
Load Regulation
D
MAX
V
EN
I
EN
V
PWM
f
PWMD
f
SW
Maximum Duty Cycle
Enable Threshold
Enable Pin Current
PWMD Threshold
PWMD Frequency Range
Programmable Oscillator
Frequency
Fixed Frequency Option
Low EMI (MIC3231)
Current Limit Threshold Voltage
I
SENSE
Peak Current Out
V
FB
> 275mV (to ensure device is not
switching)
V
EN
= 0V
Room temperature (3%)
–40°C≤ T
J
≤
+125°C (5%)
V
FB
= 250mV
V
IN
= 12V to 24V
V
OUT
to 2 × V
OUT
MIC3230 & MIC3232
MIC3231
Turn ON
Turn OFF
V
EN
= 3.3V
REN = 100kΩ
Turn ON
Turn OFF
Note 5
(L = 47µH; C = 4.7µF)
R
FREQ
= 82.5kΩ
R
FREQ
= 21kΩ
R
FREQ
= 8.25kΩ
(MIC3232YMM)
Frequency dither shift from nominal
R
SENSE
= 390Ω
R
SENSE
= 390Ω
0.315
1.5
0
360
360
109
400
950
400
±12
0.45
250
0.585
90
88
1.5
1.15
1.1
17
0.75
0.7
0.4
30
242.5
237.5
Condition
Min
6
3.5
4.9
3.2
30
250
250
1.2
2
2
257.5
262.5
3
Typ
Max
45
5.5
10
Units
V
V
mA
µA
mV
mV
µA
%
%
%
%
V
V
µA
V
V
Hz
kHz
kHz
kHz
kHz
%
V
µA
0.4
500
440
440
f
SW
F
DITHER
V
SENS
I
SENSE
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.
5. Guaranteed by design
March 2011
4
M9999-030311-D
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