MIC3230/1/2
Constant Current
Boost Controller for
Driving High Power LEDs
Bringing the Power to Light™
General Description
The MIC3230/1/2 are constant current boost switching
•
6V to 45V input supply range
controllers specifically designed to power one or more
strings of high power LEDs. The MIC3230/1/2 have an
•
Capable of driving up to 70W
input voltage range from 6V to 45V and are ideal for a
•
Ultra low EMI via dithering on the MIC3231
variety of solid state lighting applications.
•
Programmable LED drive current
The MIC3230/1/2 utilizes an external power device which
•
Feedback voltage = 250mV ±3%
offers a cost conscious solution for high power LED
•
Programmable switching frequency (MIC3230/1) or
applications. The powerful drive circuitry can deliver up to
400kHz fixed frequency operation (MIC3232)
70W to the LED system. Power consumption has been
minimized through the implementation of a 250mV
•
PWM Dimming and separate enable shutdown
feedback voltage reference providing an accuracy of ±3%.
•
Frequency synchronization with other MIC3230s
The MIC323x family is dimmable via a pulse width
•
Protection features:
modulated (PWM) input signal and also features an enable
Over Voltage Protection (OVP)
pin for low power shutdown.
Over temperature protection
Multiple MIC3230 ICs can be synchronized to a common
Under-voltage Lock-out (UVLO)
operating frequency. The clocks of these synchronized
•
Packages:
devices can be used together in order to help reduce noise
and errors in a system.
VIN 1
10 VDD
An external resistor sets the adjustable switching
EN 2
9 DRV
frequency of the MIC3230/1. The switching frequency can
PWMD 3
8 PGND
COMP 4
7 OVP
be between 100kHz and 1MHz. Setting the switching
IADJ 5
6 IS
frequency provides the mechanism by which a design can
be optimized for efficiency (performance) and size of the
MIC3232
MIC3230/1
MIC3230/1
external components (cost). The MIC323x family of LED
MSOP-10
MLF-12
TSSOP-16
drivers also offer the following protection features: Over
voltage protection (OVP), thermal shutdown and under-
•
–40°C to +125°C junction temperature range
voltage lock-out (UVLO).
The MIC3231 offers a dither feature to assist in the
reduction of EMI. This is particularly useful in sensitive
Applications
EMI applications, and provides for a reduction or
•
Street Lighting
emissions by approximately 10dB.
•
Solid State Lighting
The MIC3232 is a 400kHz fixed frequency device offered
•
General Illumination
in a small MSOP-10 package. The MIC3230/1 are offered
in both the EPAD TSSOP-16 package and the
•
Architectural Lighting
®
3mm × 3mm MLF -12 package.
•
Constant Current Power Supplies
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
_________________________________________________________________________________________________
N/C
1
16 N/C
VIN
EN
1
2
3
12 VDD
11
DRV
Features
VIN
EN
2
3
4
5
6
7
8
15 VDD
14 DRV
13 PGND
12 OVP
11 IS
PWMD
10 PGND
9
8
7
OVP
PWMD
COMP
COMP
IADJ
FS
4
5
6
IS
IADJ
EPAD
SYNC/NC
FS
10 SYNC/NC
9 N/C
AGND
EPAD
Bringing the Power to Light is a trademark of Micrel, Inc.
MicroLead Frame and MLF 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
January 2009
M9999-011409-A
(408) 955-1690
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
MSOP-10 (MM)
MIC3232
3mmx3mmMLF
®
-12L (ML)
MIC3230, MIC3231
See Product Option Matrix for selection
TSSOP-16 (TSE)
MIC3230, MIC3231
See Product Option Matrix for selection
Pin Description
Pin Number
3x3MLF
--
1
2
Pin Number
TSSOP-16L
1
2
3
Pin Number
MSOP-10L
--
1
2
NC
VIN
EN
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 input. High signal terminates the output
power. Low Signal starts up the output power.
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
Pin Name
Pin Function
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
January 2009
3
M9999-011409-A
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-10 (θ
JA
) ..............................................130.5°C/W
EPAD TSSOP-16 (θ
JA
) ...................................36.5°C/W
3mmx3mm MLF
®
-12L (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
Over Voltage Protection
Driver Impedance
SINK
SOURCE
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
VEN = 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
1.203
0.315
1.5
0
360
360
109
400
950
400
±12
0.45
250
1.24
2.4
2
1.277
3.5
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
V
Ω
Ω
0.4
500
440
440
f
SW
F
DITHER
V
SENS
I
SENSE
V
OVP
January 2009
4
M9999-011409-A
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