ABSOLUTE MAXIMUM RATINGS (Note)
Input Voltage, VDD
Output Voltage, VOUT
Maximum Operating Junction Temperature, TJ
Storage Temperature Range
Lead Temperature (soldering, 10 seconds)
Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground.
Currents are positive into, negative out of the specified terminal.
-65°C to 150°C
Output pin. Sink current is decided by the current on RSET connected to ISET.
IOUT = 500 × ISET.
Output stage enable control pin. High enable the OUT pin.
Output current set input. Connect a resistor from ISET to GND to set the LED bias current.
ISET = 1.2V/RSET.
Thermal Resistance from Junction to Ambient, θ JA
Junction Temperature Calculation: TJ = TA+ (PD × θ JA).
The θJA numbers are guidelines for the thermal performance of the device/pc-board system.
Connect the ground pin to ground using a large pad or ground plane for better heat dissipation.
All of the above assume no ambient airflow.
80 OC /W
Maximum Power Calculation:
TJ(MAX) – TA(MAX)
Maximum recommended junction temperature
Ambient temperature of the application
θJA(OC /W): Junction-to-Ambient temperature thermal resistance of the package, and other heat dissipating materials.
The maximum power dissipation for a single-output regulator is:
PD(MAX) = [(VIN(MAX) - VOUT(NOM))] × IOUT(NOM) + VIN(MAX) × IQ
VOUT(NOM) = the nominal output voltage
IOUT(NOM) = the nominal output current, and
IQ = the quiescent current the regulator consumes at IOUT(MAX)
VIN(MAX) = the maximum input voltage
θJA = (+150 OC – TA)/PD
Copyright © 2007 ADDtek Corp.
2 DD032_B -- APRIL 2007