-
SP7616
High Accuracy 4-Channel Low Side
LED Driver for CCFL Replacement
FEATURES
Wide 4.5V to 30V operating range
60mA LED current per channel
1.5% channel to channel current matching
Analog Dimming control
PWM operation up to 5kHz with 10% Duty Cycle
Low dropout: 150mV @ 20mA
Built-in Over Temperature Protection
Lead Free, RoHS Compliant Packaging:
Small 2X3mm DFN
Connect heat sink
pad to GND
DESCRIPTION
The SP7616 is a 30V 4-Channel linear low side LED driver. It is capable of powering up to four
LED strings of nine LEDs @ 60mA per string for a total of 36 LEDs with 1.5% typical current
matching between channels. The desired LED current can be adjusted with an external resistor,
and the precision string-to-string current matching ensures consistent color temperature across
the whole display. The device also features very low dropout voltage to maximize system
efficiency and avoid difficult thermal design constraints. Dimming can be achieved by feeding a
PWM signal to the PWM pin, or use an analog signal to control the I
SET
current, this allows
brightness control without unwanted color shifts. Fast LED current turn-on/off time allows up to 5
kHz PWM dimming frequencies with as low as 10% duty cycle, completely eliminating flicker. The
built-in thermal protection prevents damage to the device under fault conditions.
TYPICAL APPLICATION CIRCUIT
R
SET
Mar 22-07 RevD
SP7616: Low Side LED Driver
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2007 Sipex Corporation
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ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation
of the device at these ratings or any other above those
indicated in the operation sections of the specifications
below is not implied. Exposure to absolute maximum
rating conditions for extended period of time may affect
reliability.
V
IN
……….…………………………………….…-0.3V to 32V
LED1, LED2, LED3, LED4 ……………..…... -0.3V to 32V
I
SET
, PWM …..…………………..………….. -0.3V to 6.0V
Storage Temperature..…………………… -65
°C
to 150
°C
Junction Temperature.............................. -40°C to +150°C*
Lead Temperature (Soldering, 10 sec)....……………300°C
* Internally protected
ELECTRICAL SPECIFICATIONS
Unless otherwise specified: V
IN
=
4.5V - 30V, C
IN
= 1µF, -40°C < T
A
< 85°C, - 40°C <T
J
< 125°C.
Bold
values apply over the full
operating temperature range.
PARAMETER
Operating Input Voltage Range
Shutdown Supply Current
Quiescent Supply Current
Quiescent Supply Current
Quiescent Supply Current
LED Current Matching
LED Current Line Regulation
Line Regulation
Maximum LED Current per channel
LED Leakage Current
Dropout Voltage
Output/I
SET
Current Multiplication
Ratio
Thermal Shutdown Die Temperature
Thermal Shutdown Hysteresis
PWM Pin Logic LOW
PWM Pin Logic HIGH
PWM pin Hysteresis
I
SET
Voltage
I
SET
Shutdown Threshold
I
SET
Shutdown Threshold Hysteresis
PWM Dimming Frequency Range
PWM Dimming Duty Cycle Range
Turn-on time from Shutdown
Turn-off time into Shutdown
MIN
4.5
TYP
MAX
30
UNITS
V
µA
µA
mA
mA
%
%/V
%/V
mA
µA
V
CONDITIONS
Voltage at I
SET
is pulled to 3V;
V
IN
30V
No LED connected, VLED pins
are tied to GND. R
SET
=1M
I
LED
= 30mA
I
LED
= 60mA
To reference channel (channel 2)
-40°C < T
A
< 85°C
30
350
1
1.5
-3
1.5
0.5
0.05
40
500
1.5
3
3
1
0.1
60
2
0.3
0.2
950
150
15
V
LED
= 0.5V to 25V , V
IN
= 28V,
2
R
SET
=50kΏ
3
V
IN
= 4.5V to 25V, V
LED
=0.5V
R
SET
= 15.38KΏ,
PWM pin LOW’ VLED 1V; V
IN
5V
Note 4
+/- 4 Percent
-40°C < T
A
< 85°C
°C
°C
0.8
5.5
V
V
mV
2.4
0.985
400
1.00
I
LED
= 0mA. LED current will self
recover when temperature drops
below the trip point, minus
thermal shut down hysteresis.
Driver is disabled
Driver is active
1.015
3
V
V
kHz
%
µs
µs
If I
SET
is pulled above this
threshold the device goes into full
shutdown
Applied to PWM pin
Applied to PWM pin
V
MOD
from 5V to 0.0V, RSET =
50k
V
MOD
from 0.0V to 5V, RSET =
50k
0.3
0.1
10
100
5
90
300
20
Note
1.
2.
3.
4.
Reference channel I
LED
Variations from specified by R
SET
value
I
LED
Variations from specified by R
SET
value at V
LED
changing from 0.5 to 25V
I
LED
Variations from specified by R
SET
value at V
IN
changing from 4.5 to 25V
R
SET
= 31.6KΏ: Dropout voltage is measured as the V
LED
voltage where LED current drops 5% from nominal value
Mar 22-07 RevD
SP7616: Low Side LED Driver
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2007 Sipex Corporation
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PIN DESCRIPTION
PIN
NAME
V
IN
PWM
DESCRIPTION
Input voltage for the IC. Connect a 1uF decoupling
capacitor between this pin and ground.
This pin must be held high to enable the output drivers. It can
be used for PWM dimming up to 5 kHz.
Connect resistor R
SET
from this pin to ground to set output
current. Pulling this pin above the shutdown threshold
stated in the Electrical Specifications puts the IC into
shutdown mode
Ground return for LED currents and circuitry of the SP7616
Connect an LED between each pin and V
IN
. Current value
is controlled by R
SET
. The current level through each pin is
internally matched within 3%. Connect unused channel (s)
to GND to save current consumption.
PIN #
1
2
I
SET
GND
LED1-
LED4
3
4
5-8
BLOCK DIAGRAM
Mar 22-07 RevD
SP7616: Low Side LED Driver
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2007 Sipex Corporation
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TYPICAL PERFORMANCE CHARACTERISTICS
V
IN
V
IN
I
LED
20mA/Div
I
LED
20mA/Div
Typical Turn on Characteristics
Channel 1 V
IN
; Channel 4 I
LED
Turn on Maximum V
IN
Channel 1 V
IN
; Channel 4 I
LED
PWM Signal
PWM Signal
V
LED
(Cathode Voltage)
V
LED
(Cathode Voltage)
LED current
20mA/Div
LEDcurrent
20mA/Div
PWM Function 1kHz 50% Duty Cycle
PWM Function 1 kHz 10% Duty Cycle
PWM Signal
PWM Signal
V
LED
(Cathode Voltage)
V
LED
(Cathode Voltage)
LED
current
20mA/Div
LED current
20mA/Div
PWM Function 1 kHz 90% Duty Cycle
PWM Function 5 kHz 50% Duty Cycle
Mar 22-07 RevD
SP7616: Low Side LED Driver
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2007 Sipex Corporation
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TYPICAL PERFORMANCE CHARACTERISTICS
LED Current vs. LED voltage (cathode voltage)
V
IN
tied to Anode of LED chain
Shutdown current vs. input voltage
Voltage on
I
SET
pin = 3V
Mar 22-07 RevD
SP7616: Low Side LED Driver
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2007 Sipex Corporation
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