A6260KLJTR-T Allegro Microsystems Inc, A6260KLJTR-T Datasheet - Page 5

• Manufacturer Part Number: A6260KLJTR-T
• Description: IC LED DRIVER AUTOMOTIVE 8-SOIC
• Manufacturer: Allegro Microsystems Inc
• Type: Automotiver

Specifications of A6260KLJTR-T

• Topology: Linear (LDO), PWM
• Constant Current: Yes
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Automotive
• Type - Secondary: High Brightness LED (HBLED)
• Voltage - Supply: 6 V ~ 40 V
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width) Exposed Pad, 8-eSOIC. 8-HSOIC
• Operating Temperature: -40°C ~ 125°C
• Current - Output / Channel: 350mA
• Internal Switch(s): Yes
• Led Driver Application: Automotive
• No. Of Outputs: 1
• Output Current: 367mA
• Output Voltage: 3V
• Input Voltage: 6V To 40V
• Dimming Control Type: PWM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Frequency: -
• Efficiency: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 620-1252-2; A6260KJPTR-T

A6260
The A6260 is a linear current regulator that is designed to provide
drive current and protection for series-connected, high bright-
ness LEDs in automotive applications. It provides programmable
current output at load voltages up to 3 V below the main supply
voltage. For automotive applications optimum performance is
achieved when driving 1 to 3 LEDs at currents up to 350 mA.
The LED current is set by a single low-power sense resistor and
the LED brightness can be further controlled by a PWM input to
the EN pin. The EN input can also be used as an on/off switched
input and the A6260 will enter a low current (<10 μA) sleep
mode if EN is held low.
For incandescent replacement configurations, the EN input can
be connected directly to the VIN pin with the supply to VIN con-
trolled by a simple on/off switch.
The LEDs and the regulator are protected from excessive currents
caused by short circuits to ground or supply or by reversal of the
power supply connections.
Integrated thermal management circuits can be used to reduce
the regulated current level at high temperatures to limit power
dissipation.
Pin Functions
VIN Pin
bypass capacitor (typically 100 nF) should be connected from
close to this pin to the GND pin.
GND Pin
directly to the negative supply as close as possible to the bottom
(ground connection) of the sense resistor.
EN Pin
PWM input. Chip enters a low-power sleep mode when this pin is
held low.
THTH Pin
output current starts to be reduced with increasing temperature.
When this pin is left open, the threshold temperature will typi-
cally be the specified default value. A resistor connected between
THTH and GND can be used to increase the threshold tempera-
ture. A resistor connected between THTH and VIN can be used to
decrease the threshold temperature. Connecting THTH directly to
GND disables the thermal monitor function.
Logic input to enable operation. Can be used as a direct
Supply to the control circuit. A small-value ceramic
Ground reference connection. Should be connected
Sets the thermal monitor threshold, T
JM
, where the
Functional Description
High Brightness LED Current Regulator
LA Pin
anode of the LEDs.
LC Pin
LEDs.
LSS Pin
lator to power ground via a sense resistor. A current sense resistor
(240 mΩ to 3 Ω) is connected between LSS and power ground.
SENSE Pin
SENSE input should have an independent connection to the top
(LSS connection side) of the sense resistor.
LED Current Level
The LED current is controlled by the internal current regulator
between the LC and LSS pins. This current, defined as the current
into the LC pin, I
tor. The voltage across the sense resistor, measured between the
SENSE pin and the GND pin, is compared to a reference voltage,
nominally 102 mV, allowing the use of a low-value sense resistor
with low power dissipation.
The LED current is thus defined as:
conversely:
The nominal output current settings, I
setting resistor values, R
current level defined here is the 100% current level before any
current reduction effects due to the temperature monitor,
described later in this document.
Parallel operation
The A6260 is a constant current controller, that is, it controls the
output current irrespective of output voltage (within the compli-
ance range). This allows the outputs of two or more A6260s to be
connected in parallel (see figure 4e, in the Applications Infor-
mation section). In this configuration, each A6260 must have a
(mA)
350
300
250
200
150
Switched and protected current source connected to the
I
Controlled current sink connected to the cathode of the
LC
Low-side current sink connection from the current regu-
LED current sense input. The high impedance
(mΩ)
286
333
400
500
667
LC
R
S
Sense Resistor Selection
, is set by the value, R
R
I
P
LC
(mW)
S
S
D(RS)
, are given in the following table. The
35
30
25
20
15
= V
= V
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
SENREF
SENREF
(mA)
125
100
I
70
50
35
LC
LC
/ I
/ R
, versus the current
LC
S
S
, of the sense resis-
(mΩ)
1000
1429
2000
2857
800
R
S
P
(mW)
D(RS)
13
10
7
5
4
(1)
5