AOZ1977 Datasheet, PDF (1/16 Pages) Alpha & Omega Semiconductors – High Voltage LED Driver IC

AOZ1977
High Voltage LED Driver IC
General Description
The AOZ1977 is a high-efficiency LED driver controller
for high voltage LED backlighting applications. It is
designed to drive a high-brightness LED light bar in LED
TV applications. The AOZ1977 can support a wide range
of input and output voltages. The input bias voltage of the
AOZ1977 is from 8 V to 30 V.
The AOZ1977 has multiple features to protect the
regulator under fault conditions. A control pin can disable
an external switch to disconnect the LEDs current path
from the output in PWM dimming or under catastrophic
failure conditions. Cycle-by-cycle current protection limits
the peak inductor current. Thermal shutdown provides an
additional level of protection.
Low feedback voltage (500 mV) helps reduce power loss.
The AOZ1977 features a sync function to allow for
synchronization with an external clock or multiple
AOZ1977 devices.
The AOZ1977 is available in a standard SO-16 package
and operates over the -40 C to +85 C temperature
range.
Features
 8 V to 30 V input bias voltage
 Up to 16 V driving capability at GATE pin and
DPWM pin.
 Disconnect control pin for PWM dimming or fault
conditions.
 Bi-directional clock synchronization
 500 mV feedback regulation
 8 bit PWM dimming resolution
 Cycle-by-cycle current limit
 Output over-voltage protection
 LED short and open protection
 Thermal shutdown protection
 SO-16 package
Applications
 LCD TV LED backlight
 Monitor LED backlight
Typical Application
PVIN
L1
D1
C1
DBRT
8V-30V
C3
C4
Q1
RS
CAuto
AOZ1977
1 _VIN
FB ¹⁶
2 _VDD
ISET ¹⁵
3 _GATE
COMP ¹⁴
4 _GND
DBRT ¹³
5 _CS
OVP ¹²
6 _AUTO
DPWM ¹¹
7 _OSC
VREF ¹⁰
8 _SYNC
Rosc
ILIM ⁹
RL1
RL2
Rc
Rr1
Cc
Rr2
C2
Rov1
Q2
RFB
Rov2
SYNC
Rev. 2.1 May 2012
www.aosmd.com
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