ISL97671A 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
ISL97671A
The ISL97671A 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 ISL97671A can drive six channels of LEDs
from input 4.5V~26.5V to output of up to 45V. It can also operate
from input as low as 3V to output of up to 26.5V in bootstrap
configuration (see Figure 40).
The ISL97671A 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 device can also be configured in Direct PWM Dimming with
minimum dimming duty cycle of 0.007% at 200Hz.
The ISL97671A can compensate for the non-uniformity of the forward
voltage drops in the LED strings and Its headroom control circuit
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 ISL97671A is offered in compact and thermally efficient
QFN-20 4mmx3mm package.
Features
• 6 x 50mA Channels
• 4.5V to 26.5V Input with Max 45V Output
• 3V (see Figure 40) to 21V Input with Max 26.5V Output
• PWM Dimming with Phase Shift Control
• SMBus/I²C controlled PWM or DC Dimming
• Direct PWM Dimming
• PWM Dimming Linearity
- PWM Dimming with Adjustable Dimming Freq and Duty
Cycle Linear from 0.4% to 100% <30kHz
- Direct PWM Dimming Duty Cycle Linear from 0.007% to
100% at 200Hz
• Current Matching ±0.7%
• 600kHz/1.2MHz selectable switching frequency
• Dynamic Headroom Control
• Fault Protection
- String Open/Short Circuit, OVP, OTP, and Optional Output
Short Circuit Fault Protection
• 20 Ld 4mmx3mm QFN Package
Applications
• Tablet PC to Notebook Displays LED Backlighting
• LCD Monitor LED Backlighting
• RGB LEDs or Field Sequential LED Backlighting
Typical Application Circuits
VIN = 4.5~26.5V
Q1 (optional)
ISL97671A
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
45V*, 6 x 50mA
*VIN > 12V
VIN = 4.5~26.5V
Q1 (optional)
ISL97671A
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
45V*, 6 x 50mA VIN = 4.5~26.5V
Q1 (optional)
*VIN > 12V
ISL97671A
1 FAULT
2 VIN
4 VDC
LX 20
OVP 16
8 FPWM
PGND 19
7 SMBCLK/SCL
6 SMBDAT/SDACH0 ¹⁰
5 PWM
3 EN
CH1 11
CH2 12
CH3 13
17 RSET
CH4 14
CH5 15
9 AGND
COMP 18
45V*, 6 x 50mA
*VIN > 12V
FIGURE 1A. SMBus/I²C CONTROLLED
DIMMING
FIGURE 1B. PWM DIMMING WITH
ADJUSTABLE DIMMING
FIGURE 1C. DIRECT PWM DIMMING
FIGURE 1. ISL97671A TYPICAL APPLICATION DIAGRAMS
March 24, 2011
1
FN7709.1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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