Datasheet

13
Atmel MSL2010 [DATASHEET]
42072A–AVR–05/2013
CGND 8
Connect to Ground
Connect CGND to AGND
REXT 9
External Resistor
Connect a 46.4k, 1% resistor from REXT to AGND.
TOFF 10
Off-Time Set Input
A resistor from TOFF to AGND controls the constant off time for the Boost converter, where
R
TOFF
=t
OFF
 (90.9 x 10
9
), with t
OFF
in seconds and R
TOFF
in Ohms. For example, an off time of 4.4s
results in a resistor value of 402k (to the nearest 1% value).
EAO 11
Error Amp Out
Output of the switch-mode error amplifier. Connect the compensation network between EAO
and FB.
FB 12
Feedback Input for Boost Regulator
Connect FB to the middle node of the Boost regulator voltage setting resistor divider. Also, connect
FBO to FB to allow the MSL2010 to optimize V
LED
.
CS 13
Current Sense Input for the Boost Converter
Connect CS to the external current sense resistor of the Boost regulator. The current sense threshold
is 200mV. For more information see the section “Boost Reference Voltage register (CSREF, 0x21)” on
page 20.
PGND 14
Power Ground
PGND is the ground connection for the FET gate drivers. Connect PGND to AGDN close to the
MSL2010.
DRV 15
Gate Drive for Boost Regulator MOSFET
Connect DRV to the gate of the Boost regulator power MOSFET.
PVIN 16
Power Voltage Input
PVIN powers DRV, the Boost regulator FET gate driver. Connect PVIN to a power supply of 10V to
15V. Bypass PVIN to PGND with a 1.0µF or greater capacitor.
S 18
Source Sense Input for LED String Drive MOSFET
Connect S to the source of the LED string drive external MOSFET, and to the current sense resistor
for the LED string. The current sense threshold is 200mV. For more information see the section “LED
String Reference Voltage register (SREF, 0x20)” on page 20.
G 19
Gate Output for LED String MOSFET
Connect G to the gate of the LED string drive external MOSFET. Minimum on-time is 2µs.
D 20
Drain Output for LED String MOSFET
Connect D to the drain of the LED string drive external MOSFET.
AVIN 21
Analog Voltage Input (12V)
AVIN is the power input to the MSL2010. Bypass AVIN to AGND with a 1.0µF or greater capacitor
placed close to AVIN.
VCC 22
5V Internal Voltage
Connect 10µF bypass capacitor from VCC to AGND.
AGND 23
Analog Ground
Connect AGND to system ground.
VDD 24
2.5V Internal Voltage
Connect 10uF bypass capacitor from VDD to AGND.
EP EP
Exposed Pad
EP is the main thermal path for heat to escape the die. Connect EP to a large copper plane connected
to PGND and AGND.
Name Pin Description