MIC3201 Datasheet, PDF (2/16 Pages) Micrel Semiconductor – High Brightness LED Driver with High-Side Current Sense

Micrel, Inc.
MIC3201
Ordering Information⁽¹⁾
Part Number
Marking
Junction Temp. Range
Package
MIC3201YME
MIC3201YME
-40°C to +125°C
8-Pin ePAD SOIC
Note:
1. YME^® is a GREEN RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
Pin Configuration
Lead Finish
Pb-Free
8-Pin ePAD SOIC (ME)
Pin Description
Pin Number
1
2
3
4
5
6
7
8
ePAD
Pin Name
VCC
CS
VIN
AGND
EN
DIM
PGND
LX
GND
Pin Function
Voltage Regulator Output. The V_CC pin supplies the power to the internal circuitry. The VCC in
the output of a linear regulator which is powered from VIN. A 1µF ceramic capacitor is
recommended for bypassing and should be placed as close as possible to the VCC and AGND
pins. Do not connect to an external load.
Current Sense Input. The CS pin provides the high-side current sense to set the LED current
with an external sense resistor.
Input Power Supply. VIN is the input supply pin to the internal circuitry and the positive input to
the current sense comparator. Due to the high frequency switching noise, a 10µF ceramic
capacitor is recommended to be placed as close as possible to VIN and the power ground
(PGND) pin for bypassing. Please refer to layout recommendations.
Ground pin for analog circuitry. Internal signal ground for all low power sections.
Enable Input. The EN pin provides a logic level control of the output and the voltage has to be
2.0V or higher to enable the current regulator. The output stage is gated by the DIM pin. When
the EN pin is pulled low, the regulator goes to off state and the supply current of the device is
greatly reduced (below 1µA). In the off state, the output drive is placed in a "tri-stated" condition,
where MOSFET is in an “off” or non-conducting state. Do not drive the EN pin above the supply
voltage.
PWM Dimming Input. The DIM pin provides the control for brightness of the LED. A PWM input
can be used to control the brightness of LED. DIM high enables the output and its voltage has to
be at least 2.0V or higher. DIM low disables the output, regardless of EN “high” state.
Power Ground pin for Power FET. Power Ground (PGND) is the ground path for the high current
hysteretic mode. The current loop for the power ground should be as small as possible and
separate from the Analog ground (AGND) loop. Refer to the layout considerations for more
details.
Drain of Internal Power MOSFET. The LX pin connects directly to the inductor and provides the
switching current necessary to operate in hysteretic mode. Due to the high frequency switching
and high voltage associated with this pin, the switch node should be routed away from sensitive
nodes.
Connect to PGND.
January 2010
2
M9999-011210-B