AT9933DB1
High Bright LED Driver IC
Meeting Automotive Requirements
General Description
The AT9933DB1 is an LED driver capable of driving up
to 7 1-watt LEDs in series from an automotive input of
9 - 16V DC. The demo board uses Supertex’s AT9933
in a boost-buck topology. The converter operates at
frequencies in excess of 300kHz and has excellent output
current regulation over the input voltage range. It can also
withstand transients up to 42V and operate down to 6V
input. The converter is also protected against open LED
and output short circuit conditions. Protection against
reverse polarity up to 20V is also included.
Specifications
Parameter
Input voltage (steady state):
Input voltage (transient):
Output LED string voltage:
Output current:
Output current ripple:
Switching frequency:
Value
9.0VDC - 16VDC
42VDC
28V max
350mA +/-5%
5% typical
300kHz (9.0V input)
430kHz (13.5V input)
500kHz (16.0V input)
80% (at 13.5V input)
Included; clamps
output voltage at 33V
Included; limits current
at 350mA
-20V max
1.9A
Up to 1.0kHz
Meets SAE J1113
conducted EMI
standards
Board Layout
Efficiency:
Open LED protection:
Output short circuit protection:
Reverse polarity protection:
Input current limit:
PWM dimming frequency:
Conducted EMI:
Actual Size: 2.25” x 1.25”
Connections:
Input:
The input is connected between the terminals of connector
J1 as shown in the Connection Diagram.
Enable/PWM Dimming:
To just enable the board, short pins 1 and 2 of connector J3
as shown. For PWM dimming, connect the external push-pull
square wave source between terminals 1 and 3 of connector
J3 as shown by the dotted lines.
Note:
During PWM dimming, pin 2 of connector J3 should
be left open. Also, the PWM signal must have the proper
polarity with the positive connected to pin 1 of J3. Note that
pin 3 of J3 is internally connected to the return path of the
input voltage
Output:
The output is connected between the terminals of connector
J2 as shown.
SUPERTEX [ Supertex, Inc ]
