ISL1904FAZ-T7A Intersil, ISL1904FAZ-T7A Datasheet - Page 19
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ISL1904FAZ-T7A
Manufacturer Part Number
ISL1904FAZ-T7A
Description
LED Lighting Drivers Dimmable Buck LED Driver IC
Manufacturer
Intersil
Datasheet
1.ISL1904FAZ-T7A.pdf
(21 pages)
Specifications of ISL1904FAZ-T7A
Rohs
yes
Input Voltage
9 V to 20 V
Operating Frequency
1 MHz
Maximum Supply Current
7.8 mA
Maximum Operating Temperature
+ 125 C
Mounting Style
SMD/SMT
Package / Case
QSOP-16
and can be estimated using Equation 21.
t
DHC (Dimmer Holding Current)
The DHC pin provides a method to pre-load a triac-based dimmer
during the period of time when the AC is blocked, with overlap at
each edge of the AC conduction period to ensure adequate
holding current. DHC is an open drain FET used to control an
external resistor to act as the load.
DHC controls a resistor on the external high voltage start-up bias
regulator. See “Typical Application - Dimmable Isolated Flyback”
on page 3 for an example of its usage. Note the series resistor
and diode connecting VDD to the gate of the start-up bias FET. It
is required to keep the device on when the AC voltage is near the
zero-crossing.
delay
≈
73.33
+
10.2 R
⋅
DELADJ
19
(
kΩ
)
ns
(EQ. 21)
ISL1904
Gate Drive
The ISL1904 output is capable of sourcing and sinking up to 1A.
The OUT high level is limited to the OUT clamp voltage or VDD,
whichever is lower.
Thermal Protection
Internal die over-temperature protection is provided. An
integrated temperature sensor protects the device should the
junction temperature exceed +160°C. There is approximately
+10°C of hysteresis.
Ground Plane Requirements
Careful layout is essential for satisfactory operation of the device.
A good ground plane must be employed. VDD and VREF should
be bypassed directly to GND with good high frequency
capacitance.
September 20, 2012
FN8286.1