LM3519MKEV National Semiconductor, LM3519MKEV Datasheet - Page 2

• Manufacturer Part Number: LM3519MKEV
• Description: BOARD EVALUATION LM3519MK
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LM3519MKEV

• Current - Output / Channel: 20mA
• Outputs And Type: 1, Non-Isolated
• Features: Dimmable
• Voltage - Input: 2.7 ~ 5.5V
• Utilized Ic / Part: LM3519
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Voltage - Output: -

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Connection Diagram and Package Information
Ordering Information
Pin Descriptions (SOT23-6)
PWM Dimming
If a PWM signal is used to adjust the brightness, a control
signal frequency between 17k Hz to 30kHz is recommended.
Although the LM3519 is capable of operating outside this
frequency range, it is not recommended to operate below
17kHz for the following reasons: 1) frequency below 100Hz
is likely to cause visible flicker in the light emitted by the LED
string, 2) frequency below 17kHz may induce audible noise
due to combinations of some capacitance and PCB. A PWM
frequency above 30kHz is possible but the current linearity
vs duty cycle will be affected.
If it is not possible to operate the dimming control above
17kHz, audible noise emission may be minimized by using
capacitors with low susceptibility to piezoelectric induced
stresses, such as poly film designs. Minimum audible noise
is most likely to occur when the PWM frequency is less than
2kHz. It is recommended that any application using a PWM
Pin#
1
2
3
4
5
6
Current
20mA
Name
En
Gnd
Vout
LED_rtn
Sw
Vin
Order Number
LM3519MK-20
LM3519MKX-20
Description
Device Enable Connection
Ground Connection
Output Voltage Connection
White LED Current Sensing Input Connection
Drain Connection of the Internal Power Field Effect Transistor (FET) Switch
Input or Supply Voltage Connection
FIGURE 2. SOT23-6, Top View
Package Marking
D52B
D52B
2
control signal below 17kHz be thoroughly evaluated for un-
desirable audible noise.
Layout Guidelines
The input capacitor, C
LM3519. Placing C
metal trace resistance effect on input voltage ripple. Metal
trace connections for the C
effective series resistance, which affects output voltage
ripple and efficiency. Trace connections to the inductor
should be short and wide to reduce power dissipation, in-
crease overall efficiency and reduce EMI radiation. The di-
ode, like the inductor, should have trace connections that are
short and wide to reduce power dissipation and increase
overall efficiency. For more details regarding layout guide-
lines for switching regulators, refer to Applications Note
AN-1149.
20168807
1000 Units, Tape-and-Reel
3000 Units, Tape-and-Reel
IN
close to the device will reduce the
IN
, must be placed close to the
OUT
Supplied As
capacitor can increase the