MSL3086-IU Atmel, MSL3086-IU Datasheet - Page 4

• Manufacturer Part Number: MSL3086-IU
• Description: LED Lighting Drivers 8-Str LED Driver Internal Boost Cntr
• Manufacturer: Atmel

Specifications of MSL3086-IU

• Rohs: yes
• Input Voltage: 5 V
• Operating Frequency: 200 Hz
• Maximum Supply Current: 18 mA
• Output Current: 350 uA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: VQFN-24
• Minimum Operating Temperature: - 40 C
• Power Dissipation: 1850 mW

2.0 Pin Descriptions
Table 2.1 Pin Assignments
Name
COMP
CGND
PGND
SYNC
SCTH
STR0
STR1
STR2
STR3
STR4
STR5
STR6
STR7
PWM
GATE
ILED
PVIN
FLTB
GND
SDA
SCL
VIN
EN
CS
FB
EP
3086
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
EP
1
2
3
4
5
6
7
8
9
-
-
MSL
3088
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
EP
1
2
3
4
5
6
7
8
9
-
-
Pin Description
V
boost regulator output voltage. The feedback regulation voltage is 2.5V.
Power Supply Input: Power supply input. Apply 4.5V to 5.5V to VIN. Decouple VIN to GND a 1uF or greater capacitor placed close to VIN.
I²C Serial Data I/O: SDA is the I²C serial interface data input/output. Connect SDA to VIN when unused. For interface information see the
MSL3040/50/60/80/86/87/88/89 Programming Guide.
I²C Serial Clock Input: SCL is the I²C serial interface clock input. Connect SCL to VIN when unused. For interface information see the
MSL3040/50/60/80/86/87/88/89 Programming Guide.
PWM Synchronization Input: A signal of 20Hz to 50kHz applied to SYNC controls the LED PWM dimming frequency. The signal at PWM
controls the LED PWM dimming duty cycle. For serial interface controlled PWM dimming, connect SYNC to GND and refer to the register definitions
section for registers 0x10 through 0x14 in the MSL3040/50/60/80/86/87/88/89 Programming Guide.
String Short Circuit Threshold Level Setting Input: SCTH programs the LED string short-circuit detection threshold. Connect a resistor from
SCTH to GND to set the short-circuit threshold level to 4.9V (1kΩ), 5.8V (27kΩ), 6.8V (68kΩ) or 7.6V (330kΩ). A short circuit is detected when
the STRn voltage is above the threshold while STRn is on.
LED String 0 Current Sink: Connect the cathode end of series LED String 0 to STR0. If not used, connect STR0 to GND.
LED String 1 Current Sink: Connect the cathode end of series LED String 1 to STR1. If not used, connect STR1 to GND.
LED String 2 Current Sink: Connect the cathode end of series LED String 2 to STR2. If not used, connect STR2 to GND.
LED String 3 Current Sink: Connect the cathode end of series LED String 3 to STR3. If not used, connect STR3 to GND.
LED String 4 Current Sink: Connect the cathode end of series LED String 4 to STR4. If not used, connect STR4 to GND.
LED String 5 Current Sink: Connect the cathode end of series LED String 5 to STR5. If not used, connect STR5 to GND.
LED String 6 Current Sink: Connect the cathode end of series LED String 6 to STR6. If not used, connect STR6 to GND.
LED String 7 Current Sink: Connect the cathode end of series LED String 7 to STR7. If not used, connect STR7 to GND.
PWM Dimming and Synchronization Input: Drive PWM with a pulse-width modulated signal with duty cycle of 0% to 100% and frequency of
20Hz to 50kHz to control the duty cycle and the frequency of all LED strings. For serial interface controlled PWM dimming connect PWM to GND and
refer to the register definitions section for registers 0x10 through 0x14 in the MSL3040/50/60/80/86/87/88/89 Programming Guide.
PWM Dimming Input: Drive PWM with a pulse-width modulated signal with duty cycle of 0% to 100% and frequency of 20Hz to 50kHz to control
the duty cycle of all LED strings. The frequency of the signal applied to SYNC controls the LED PWM frequency. For serial interface controlled PWM
dimming, connect PWM to GND and refer to the register definitions section for registers 0x10 through 0x14 in the MSL3040/50/60/80/86/87/88/89
Programming Guide.
Connect To Ground: Connect to CGND to GND close to driver.
Maximum LED Current Control Input: Connect a resistor from ILED to GND to set the full-scale LED current. See the section “Setting the LED
Current” beginning on page15 for more information.
Power Ground: Ground of the boost regulator gate driver. Connect PGND to CGND and EP as close to the MSL3086/88 as possible.
Gate Drive Output: Connect GATE to the gate of the boost regulator switching MOSFET
Boost Regulator Power Supply Input: PVIN is the power supply input for the external MOSFET gate driver. Apply 4.5V to 5.5V to PVIN.
Decouple PVIN with two 1uF capacitors placed close to PVIN.
Fault Output: FLTB sinks current to GND when a fault is detected. The Boost Over-Voltage Fault does not latch; the fault goes away when the fault
condition no longer exists, all other faults latch. Clear faults by toggling EN low and then high, or by cycling input power off and on. Additionally,
fault control is available through the I
Enable Input: Drive EN high to turn on the device, drive it low to turn it off. For automatic startup connect EN to VIN. Toggle EN low then high to
reset FLTB.
Boost Regulator Current Sense Input: Connect the current sense resistor from CS and the MOSFET source to GND to set the boost regulator
current limit. The current limit threshold is 100mV. See the section “Setting the Current Limit” beginning on page 20 for more information.
Boost Regulator Compensation Node: Connect the compensation network components from COMP to FB to compensate the boost regulator
control loop, as shown in the Typical Applications Circuit on page 11. See the section “Loop Compensation” beginning on page 21 for more
information.
Signal Ground: Connect GND to EP as close to the device as possible.
Exposed Die-Attach Paddle : Connect EP to CGND, PGND and to the system ground. EP is the return path for the LED current as well as the
primary thermal path to remove heat generated in the MSL3086/88. Use a large circuit board trace to connect from EP to the boost supply output
capacitor ground and to the input supply ground return. Connect EP to a large copper ground plane for best thermal and electrical performance.
LED
Voltage Regulator Feedback Input: Connect a resistive voltage divider from the boost regulator output, V
2
C compatible serial interface; see the MSL3040/50/60/80/86/87/88/89 Programming Guide for information.
8-String 60mA LED Drivers with Integrated Boost Controller and Phase Shifted Dimming
Atmel MSL3086/MSL3088 Datasheet
LED
, to FB to set the un-optimized
4