ISL97671_10 Datasheet, PDF (1/28 Pages) Intersil Corporation – 6-Channel SMBus/I2C or PWM Dimming LED Driver with Phase Shift Control

6-Channel SMBus/I²C or PWM Dimming LED Driver
with Phase Shift Control
ISL97671
The ISL97671 is a 6-Channel 45V dual dimming capable
LED driver that can be used with either SMBus/I²C or
PWM signal for dimming control. The ISL97671 drives 6
channels of LED to support 78 LEDs from 4.5V to 26V or
48 LEDs from a boost supply of 2.7V to 26V and a
separate 5V bias on the ISL97671 VIN pin.
The ISL97671 compensates for non-uniformity of the
forward voltage drops in the LED strings with its 6 voltage
controlled-current source channels. Its headroom control
monitors the highest LED forward voltage string for output
regulation, to minimize the voltage headroom and power
loss in a typical multi-string operation.
The ISL97671 features optional channel phase shift
control to minimize the input, output ripple
characteristics and load transients as well as spreading
the light output to help reduce the video and audio
interference from the backlight driver operation. The
phase shift can be programmed with equal phase angle
or adjustable in 7-bit resolution.
The ISL97671 has a full range of dimming capabilities
that include SMBus/I²C controlled PWM dimming or DC
dimming. It can also do direct PWM dimming with as low
as 350nS pulse on PWM pin which translates to a duty-
cycle of 0.007% at a 200Hz dimming frequency.
Features
• 6 Channels
• 4.5V to 26.5V Input
• 45V Output Max
• Up to 40mA LED Current per channel
• Extensive Dimming Control
- PWM/DPST Dimming, I²C 8-bit with equal phase
shift, and 0.007% Direct PWM dimming at 200Hz
• Optional Master Fault Protection
• PWM Dimming Linearity 0.4%~100% <30kHz
• 600kHz/1.2MHz selectable switching frequency
• Dynamic Headroom Control
• Protections with Flag Indication
- String Open/Short Circuit, V_OUT Short Circuit,
Overvoltage and Over-Temperature Protections
- Optional Master Fault Protection
• Current Matching ±0.7%
• 20 Ld 4mmx3mm QFN Package
Applications*(see page 27)
• Notebook Displays WLED or RGB LED Backlighting
• LCD Monitor LED Backlighting
• Automotive Displays LED Backlighting
• Automotive or Traffic Lighting
Typical Application Circuit
V_IN = 4.5~26.5V
V_OUT = 45V*, 40mA PER STRING
ISL97671
1 _FAULT
2 VIN
4 _VDC
LX 20
OVP 16
PGND 19
7 _SMBCLK/SCL
6 SMBDAT/SDACH0 ¹⁰
5 PWM
3 EN
CH1 11
CH2 12
CH3 13
17 _RSET
CH4 14
8 _FPWM
CH5 15
9 AGND
COMP ₁₈
*V_IN > 12V
June 24, 2010
FN7631.0
FIGURE 1. ISL97671 TYPICAL APPLICATION DIAGRAM WITH SMBus/I²C CONTROL
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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