
CAT4016
Doc. No. MD-5028 Rev. B
8
Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
PIN DESCRIPTION
Name
GND
SIN
CLK
LATCH
LED1-LED16
BLANK
SOUT
RSET
VDD
Function
Ground
Serial data input pin
Serial clock input pin
Latch serial data to output registers
LED channel 1 to 16 cathode terminals
Enable / disable all channels
Serial data output pin.
LED current set pin
Positive supply Voltage
TAB (TQFN
package only)
Connect to GND on the PCB
PIN FUNCTION
GND
is the ground reference pin for the device. This
pin must be connected to the ground plane on the
PCB.
SIN
is the serial data input. Data is loaded into the
internal register on each rising edge of CLK.
CLK
is the serial clock input. On each rising CLK
edge, data is transferred from SIN to the internal 16-
bit serial shift register.
LATCH
is the latch data input. On the rising edge of
LATCH, data is loaded from the 16-bit serial shift
register into the output register latch. On the falling
edge, this data is latched in the output register and
isolated from the state of the serial shift register.
LED1 - LED16
are the LED current sink channels.
These pins are connected to the LED cathodes. The
current sinks drive the LEDs with a current equal to 50
times RSET pin current. For the LED sink to operate
correctly, the voltage on the LED pin must be above
0.4V.
BLANK
is the LED channel enable and disable input
pin. When low, LEDs are enabled according to the
output latch register content. When high, all LEDs are
off, while preserving the data in the output latch
register.
SOUT
is the serial data output of the 16-bit serial shift
register. This pin is used to cascade several devices
on the serial bus. The SOUT pin is then connected to
the SIN input of the next device on the serial bus to
cascade.
RSET
is the LED current setting pin. A resistor is
connected between this pin and ground. Each LED
channel current is set to 50 times the current pulled
out of the pin. The RSET pin voltage is regulated to
1.2V.
VDD
is the positive supply pin voltage for the entire
device. A small 1μF ceramic is recommended close
to pin.