United States Patents: 6,504,422, 6,794,926
www.semtech.com
1
POWER MANAGEMENT
SC606
Low Noise Smart LED
Driver with Serial Interface
Description
August 31, 2006
Applications
Features
The SC606 is a very high efficiency charge pump white/color LED
driver from the mAhXLife
TM
family of products. It is optimized for
Li-Ion battery applications. The LED current is regulated to a value
configured by the user through an I
2
C compatible serial interface.
LED outputs are current-matched for consistent LED brightness.
Up to 6 LEDs are controlled in three zones for brightness control in
multiple displays. The 6 LED outputs are divided into 3 pairs of
LEDs. Each pair has current that is programmable independent of
the other pairs. Any combination of LEDs may be turned on using
the serial interface. The SC606 also has a float detect feature
that disables any current driver during normal operation when an
open-load condition is detected.
Patented low noise switching circuitry and constant output current
allow the use of extremely small input and output capacitors.
Very High Efficiency Over 90% of Battery Life
Current Regulation for 6 LEDs
Current Matching Tolerance of +/- 3.5% from LED to LED
Current Accuracy to +/- 6.5% of Specified Value
Current Range per LED [0.5mA - 32mA]
High Available Total LED Current = 6
I
LED
= 120mA
I
2
C Bus Limited Compatibility SC606
Low Shutdown Current: 0.1μA Typical
Soft-Start /In-rush Current Limiting
Short Circuit /Thermal Protection
MLP-16 [4x4] Package
1.33MHz and 250kHz Programmable Fixed Frequency
Separate Brightness Zones for Multiple Displays
Three Charge Pump Modes of Operation: 1x, 1.5x and 2x
Open LED Output Protection
Cellular Phones
LED Backlighting
PDA Power Supplies
Portable Devices
Electronic Books
Wireless Web Appliances
Typical Application Circuit
C3
1µF
C4
1µF
VBAT
1
2
3
4
5
6
7
8
9
10
SCL
SDA
EN
C2
1µF
VOUT
VIN
C1-
C1 +
C2-
C2+
GND
ILEDC2
ILEDA1
SDA
SCL
EN
ILEDA2
ILEDB2
ILEDC1
ILEDB1
D1
SC606
11
12
13
14
15
16
C1
1µF
D6
D5D4D3D2
Patent Pending
2© 2005 Semtech Corp. www.semtech.com
POWER MANAGEMENT
SC606
Absolute Maximum Ratings
Electrical Characteristics
Unless specified: T
A
= -40°C to 85°C, V
IN
= 2.85V to 5.5V, C1 = C2 = C3 = C4 = 1.0μF (ESR = 0.03Ω), Typical values @ T
A
=25°C, LED V
F
= 3.4V
This device is ESD sensitive. Use of standard ESD handling precautions is required.
retemaraPlobmySnoitidnoCniMpyTxaMstinU
tnerruCtnecseiuQI
Q
I,edomx1
TUO
V,Am0=
NI
V2.4=00510002Aµ
I,edomx2dnaedomx5.1
TUO
Am0=34Am
V,0=elbanE
NI
V2.4=1.07 Aµ
ycaruccAtnerruCDEL
I
RRE-DEL
Am5.0 ≤ I
nDEL
≤ Am0.4
)2()1(
V2.3 ≤ V
NI
≤ V2.4
062-001±062Aµ
Am5.4 ≤ I
nDEL
≤ Am51
V2.3 ≤ V
NI
≤ V2.4
5.6-2±5.6%
Am5.51 ≤ I
nDEL
≤ Am23
)3(
V2.3 ≤ V
NI
≤ V2.4
9-3±9
%
gnihctaMtnerruC
I
DEL-ot-DEL
Am5.0 ≤ I
nDEL
≤ Am0.4
)2(
V2.3 ≤ V
NI
≤ V2.4
041-05±041Aµ
Am5.4 ≤ I
nDEL
≤ Am51
V2.3 ≤ V
NI
≤ V2.4
3-1±3%
Am5.51 ≤ I
nDEL
≤ Am23
)3(
V2.3 ≤ V
NI
≤ V2.4
57.3-5.1±57.3%
gnillafedomx5.1otedomx1V
X1SNART
I
TUO
I,Am06=
nDEL
Am01=
)1(
85.3V
gnillafedomx2otedomx5.1
egatlovnoitisnart
V
X5.1SNART
I
TUO
I,Am06=
nDEL
Am01=
)1(
89.2V
retemaraPlobmySmumixaMstinU
egatloVylppuSV
NI
0.6+ot3.0-V
egatloVtuptuOV
TUO
0.6+ot3.0-V
noitaruDtiucriCtrohSTUOVCSetinifednI
tneibmAotnoitcnuJ,ecnatsiseRlamrehT
)1(
θ
AJ
04W/C°
esaCotnoitcnuJ,ecnatsiseRlamrehT
θ
CJ
4.2W/C°
tneibmAgnitarepOT
A
58+ot04-C°
egnaRerutarepmeTnoitcnuJT
CJ
051+ot04-C°
egnaRerutarepmeTegarotST
GTS
051+ot56-C°
TRTLMIA606CSerutarepmeTwolfeRRIT
DAEL
062C°
Exceeding the specifications below may results in permanent damage to the device or device malfunction.
Operation outside of the parameters specified in the Electrical Characteristics section is not required.
1) Calculated from package in still air, mounted to 3” x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.