CL325 DATA SHEET (09/15/2008) DOWNLOAD

CL325
3-Channel 25mA Linear LED Driver
Features
General Description
► ±6% current accuracy @ 4.0 -15V
► 90V standoff voltage
► Separate enable pins for each channel allow for
PWM dimming
► Over-temperature protection
► 8-Lead SOIC (w/Heat Slug) package
The CL325 is designed to drive 3 strings of LEDs at a
constant current of 25mA.
Other drivers with currents in the range of 20 - 30mA are
available. The drive current is fixed, with a ±6% tolerance
over a VOUT range of 4 - 15V.
Separate enable pins for each channel allow for PWM
dimming, 3-step linear dimming, or individual disconnection
of faulty LED strings.
Applications
► LCD backlighting
► Indicator lamps
Over-temperature protection circuitry shuts down all 3
channels when the nominal die temperature reaches 135°C.
Normal operation resumes when the die temperature drops
by 30°C.
The CL325 is available in the 8-Lead SOIC (w/Heat Slug)
package and requires a single ceramic bypass capacitor
which may be shared among several drivers.
Block Diagram and Typical Application Circuit
6.5 - 90V
CIN
100nF
8
7
6
5
VIN
OUT1
OUT2
OUT3
REG
Host
Controller
1
EN1
2
EN2
3
EN3
VDD
GND
CL325
4
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
CL325
Ordering Information
8-Lead SOIC (w/Heat Slug)
Device
4.90x3.90mm body
1.70mm height (max)
1.27mm pitch
CL325
CL325SG-G
-G indicates package is RoHS compliant (‘Green’)
Pin Configuration
Absolute Maximum Ratings
Parameter
Value
Supply voltage, VIN
-0.5V to +100V
Output voltage, VOUT
-0.5V to +100V
Enable voltage, VEN
-0.5V to +6.5V
Operating temperature
OUT3
OUT2
OUT1
VIN
Underside plate
is ground
-40°C
(1)
Storage temperature
EN1
-65°C to +150°C
EN2
EN3
GND
8-Lead SOIC (w/Heat Slug) (SG)
Absolute Maximum Ratings are those values beyond which damage to
the device may occur. Functional operation under these conditions is not
implied. Continuous operation of the device at the absolute rating level
may affect device reliability. All voltages are referenced to device ground.
Product Marking
YY = Year Sealed
WW = Week Sealed
L = Lot Number
= “Green” Packaging
YYWW
Note:
1. Maximum junction temperature internally limited.
CL325
LLLL
8-Lead SOIC (w/Heat Slug) (SG)
Recommended Operating Conditions (all voltages with respect to GND pin)
Sym
Parameter
Min
Typ
Max
Units
VIN
Supply voltage
6.5
-
90
V
---
VOUT
Output voltage
4.0
-
15
V
EN = 0
90
V
EN = 1
0
-
100
kHz
---
-40
-
119
C
---
-
100
-
nF
---
Min
Typ
Max
-
48
-
120
135
150
O
-
30
-
O
fEN
Enable toggling frequency
TJ
Junction temperature
CIN
VIN capacitor
o
Conditions
Thermal Characteristics
Sym
Parameter
θJA
Thermal resistance,
junction to ambient
TLIM
Over-temperature limit
THYS
Over-temperature hysteresis
Units Conditions
C/W Mounted on JEDEC test PCB (2s 2p)
O
C
---
C
---
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
2
CL325
Electrical Characteristics (Over recommended operating conditions. T
A
Sym
Parameter
IIN
VIN supply current
IOUT(OFF)
Output current, off
IOUT(ON)
Output current, on
@ 25OC unless otherwise specified.)
Min
Typ
Max
Units Conditions
-
220
250
µA
EN1-3 = 1
-
2.2
2.3
mA
EN1-3 = 0
-
4.0
10
µA
ENX = 1
-
-
26.5
23.5
25.0
26.5
22.5
25.0
27.5
ENX = 0, VOUT = 0 - 4.0V
mA
ENX = 0, VOUT = 4.0 - 15V
ENX = 0, VOUT = 15 - 90V
VEN(ON)
Enable voltage, on
-
-
0.8
V
---
VEN(OFF)
Enable voltage, off
2.4
-
-
V
---
CEN
Enable input capacitance
-
5.0
10
pF
---
IENL
Enable low input current
-
-
1.0
µA
VEN = 0V
IENH
Enable high input current
-
-
1.0
µA
VEN = 5.0V
tON
Enable on delay
-
2.0
2.4
µs
---
tRISE
Output current rise time
-
1.0
1.2
µs
---
tOFF
Enable off delay
-
440
800
ns
---
tFALL
Output current fall time
-
170
250
ns
---
Timing
EN
VEN(OFF)
VEN(ON)
tON
tOFF
tRISE
tFALL
90% IOUT(ON)
IOUT
10% IOUT(ON)
Current (Normalized to 25°C)
Temperature Effects
1.05
1.00
0.95
0.90
0.85
0.80
-50
-40
0
25
50
100
120
150
Junction Temperature (°C)
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
3
CL325
IOUT (normalized to nominal)
Load Regulation
1.20
1.00
0.80
0.60
0.40
0.20
0
scale change
0
5
10
15
20
40
60
80
100
VOUT (V)
Recommended PCB Layout
1cm2 exposed copper
Underside plate soldered
to copper area
Exposed copper area
may be plated
1cm2 exposed copper
Higher LED Current
VLL
CIN
100nF
8
VIN
REG
Host
Controller
1
EN1
2
EN2
3
EN3
7
6
5
OUT1
OUT2
OUT3
VDD
GND
CL325
4
By paralleling outputs, higher LED currents can be achieved. In addition, linear dimming in 3 discrete steps may be obtained
by enabling 1, 2, or 3 outputs.
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
4
CL325
Lowering CL325 Power Dissipation: Separate VIN Supply
VLL
VIN
CIN
100nF
8
7
6
5
VIN
OUT1
OUT2
OUT3
REG
Host
Controller
1
EN1
2
EN2
3
EN3
VDD
GND
4
CL325
CL325 power dissipation may be lowered by supplying the CL325 from a voltage source (VIN) that is lower in voltage than
the LED supply (VLL).
Lowering CL325 Power Dissipation: Dropping Resistor
VLL
RDROP
CIN
100nF
8
7
6
5
VIN
OUT1
OUT2
OUT3
REG
Host
Controller
1
EN1
2
EN2
3
EN3
RDROP <
VLL(MIN) - 6.5V
2.3mA
where: RDROP = Dropping resistance
VLL(MIN) = minimum supply voltage
VDD
GND
CL325
4
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
5
CL325
Lowering CL325 Power Dissipation: Zener Diode
VLL
ZDROP
CIN
100nF
8
7
6
5
VIN
OUT1
OUT2
OUT3
REG
Host
Controller
1
EN1
2
EN2
3
EN3
VDD
VZ < (VLL(MIN) - 6.5V)
where: VZ = Zener Voltage
VLL(MIN) = minimum supply voltage
GND
CL325
4
Pin Description
Pin #
Name
Description
1
EN1
2
EN2
3
EN3
4
GND
5
OUT3
6
OUT2
7
OUT1
8
VIN
Supply voltage. 6.5V to 90V. Bypass locally with a 100nF capacitor to ground.
Underside
Plate
GND
The exposed underside plate is internally connected to the GND pin. The plate may either
be left floating or connected to ground. Solder the plate to an exposed copper area on the
PCB for heatsinking purposes (see recommended layout).
Output enable, active low.
Circuit common.
Constant current output (sinking). Connect the cathodes of the LEDs to these pins.
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: 408-222-8888 ● www.supertex.com
6
CL325
8-Lead SOIC (Narrow Body w/Heat Slug) Package Outline (SG)
4.90x3.90mm body, 1.70mm height (max), 1.27mm pitch
D1
D
8
8
Exposed
Thermal
Pad Zone
E2
E
E1
Note 1
(Index Area
D/2 x E1/2)
1
1
Top View
Bottom View
A
θ1
View B
h
h
A
A2
Note 1
Seating
Plane
e
A1
b
L1
A
Side View
View A - A
L
L2
Gauge
Plane
θ
Seating
Plane
View B
Notes:
1. A Pin 1 identifier must be located in the index area indicated. The Pin 1 identifier can be: a molded mark/identifier; an embedded metal marker; or
a printed indicator.
Symbol
MIN
Dimension
NOM
(mm)
MAX
A
A1
A2
b
1.25*
0.00
1.25
0.31
-
-
-
-
1.70
0.15
1.55*
0.51
D
D1
E
E1
E2
e
4.80* 3.30† 5.80* 3.80* 2.29†
4.90
-
5.00* 3.81
6.00
†
3.90
-
6.20* 4.00* 2.79
†
1.27
BSC
h
L
0.25
0.40
-
-
0.50
1.27
L1
1.04
REF
L2
0.25
BSC
θ
θ1
0O
5O
-
-
8
15O
O
JEDEC Registration MS-012, Variation BA, Issue E, Sept. 2005.
* This dimension is not specified in the original JEDEC drawing. The value listed is for reference only.
† This dimension is a non-JEDEC dimension.
Drawings not to scale.
Supertex Doc. #: DSPD-8SOSG, Version C090408.
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline
information go to http://www.supertex.com/packaging.html.)
Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives an
adequate “product liability indemnification insurance agreement.” Supertex inc. does not assume responsibility for use of devices described, and limits its liability to the
replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and specifications
are subject to change without notice. For the latest product specifications refer to the Supertex inc. website: http//www.supertex.com.
©2008
Doc.# DSFP-CL325
A091508
All rights reserved. Unauthorized use or reproduction is prohibited.
1235 Bordeaux Drive, Sunnyvale, CA 94089
Tel: 408-222-8888
www.supertex.com
7
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