cat4101 ON Semiconductor, cat4101 Datasheet - Page 6

• Manufacturer Part Number: cat4101
• Description: 1 A Constant-current Led Driver With Pwm Dimming
• Manufacturer: ON Semiconductor

CAT4101
PIN DESCRIPTIONS
PIN FUNCTION
VIN is the supply pin for the device. A small 0.1 µF
ceramic bypass capacitor is optional for noisy
environments. The maximum operating voltage is
6.0 V. Whenever the input supply falls below the
under-voltage
automatically be disabled.
EN/PWM is the enable and one wire dimming input for
the LED channel. Guaranteed levels of logic high and
logic low are set at 1.3 V and 0.4 V respetively. When
EN/PWM is initially taken high, the device becomes
enabled and the LED current is set at a gain of 400
times the current in RSET. To place the device into
zero current shutdown mode, the EN/PWM pin must
be held low for 5 ms typical.
LED pin is conneted to the bottom LED cathode and
provides a regulated current sink. The pin enters a
Doc. No. MD-5036, Rev. D
EN/PWM
Name
RSET
GND
LED
TAB
VIN
threshold,
Pin
1
2
3
4
5
–
the
current
Function
Device enable (active high) and PWM control.
Device supply input, connect to battery or supply.
Ground reference.
A resistor connected between this pin and ground sets the LED current.
Bottom LED cathode terminal.
Connect TAB to the Ground plane.
sink
will
6
high-impedance zero-current state whenever the
device is placed in shutdown mode.
RSET pin is connected to an external resistor to set
the LED current. The ground side of the external
resistor should be star connected to the GND of the
PCB. The pin source current mirrors the current to the
LED sink. The voltage at this pin is regulated to 1.2 V.
GND is the ground reference for the device. The pin
must be connected to the ground plane on the PCB.
TAB is the exposed pad underneath the package. For
best thermal performance, the tab should be soldered
to the PCB and connected to the ground plane.
Characteristics subject to change without notice
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