IRS2980STRPBF International Rectifier, IRS2980STRPBF Datasheet - Page 14

• Manufacturer Part Number: IRS2980STRPBF
• Description: An LED Driver Control IC
• Manufacturer: International Rectifier

Specifications of IRS2980STRPBF

• Package: 8-lead SOIC
• Circuit: LED Driver
• Offset Voltage (v): 600
• Output Source Current Min (ma): 180
• Output Sink Current Min (ma): 260
• Pbf: Yes
• T R (ns): 120
• T F (ns): 50

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Figure 5: LED current during dimming.
The dimming level can also be controlled from a
digital input by replacing CRAMP with a 68k
resistor. This sets a DC threshold at the RAMP
pin to approximately 1V so that a logic level PWM
dimming control signal can be applied to the ADIM
pin to directly switch the output on and off.
PCB Layout Guidelines
Proper care should be taken when laying out a
PCB board ensure correct functionality of the
IRS2980S. Transients caused by high dV/dt
during switching could potentially cause some
false triggering of the hysteretic circuit therefore a
small
recommended. CF should be located close to the
IC pins with the trace from HV to RCS and the
traces from RCS to CS through RF kept as short
as possible. The 0V load return power ground
should be connected to the IC COM pin and at a
single point to avoid ground loops. The values of
RF and CF are normally chosen to provide noise
filtering without adding excessive delay to the
circuit,
deliberately made larger to lower the running
frequency as this reduces switching losses and
ICC current.
The following guidelines should be followed during
PCB board layout:
1) Place VCC supply decoupling capacitor
2) Place high side decoupling capacitor (CVF) as
3) If the IRS2980S is being used in non-dimming
(CVCC) as close as possible to the VCC and
COM pins.
close as possible to the HV and VS pins.
mode connect the ADIM pin to VCC. If it is
filter
however
comprising
in
some
RF
case
and
these
CF
are
is
14
4) If the IRS2980S is being used in non-dimming
5) Connect IC COM to power GND at one
being used in dim mode place a capacitor
CDIM from the ADIM pin to COM and keep
the capacitor as close to the IC as possible
with the shortest possible traces.
mode the RAMP pin can be connected to
COM. If it is being used in dimming mode
CRAMP should be located close to the IC with
the shortest possible traces to the RAMP pin
and COM.
connection only. Do NOT route power GND
through the programming components or IC
COM.
© 2011 International Rectifier
IRS2980S