ISL97672AIRZ-T Datasheet, PDF (1/17 Pages) Intersil Corporation – 6-Channel LED Driver with Ultra Low Dimming Capability

6-Channel LED Driver with Ultra Low Dimming
Capability
ISL97672A
The ISL97672A is an integrated power LED driver that controls
six channels of LED current for LCD backlight applications. The
ISL97672A is capable of driving LEDs from 4.5V to 26.5V, with
a maximum output of 45V.
The ISL97672A employs an adaptive boost switching
architecture that allows Direct PWM dimming with linearity as
low as 0.007% at 200Hz or 0.8% at 20kHz. Dimming can be as
high as 30kHz.
The ISL97672A can compensate for non-uniformity of forward
voltage drops in the LED strings. Its headroom control circuit
monitors the highest LED forward voltage string for output
regulation to minimize voltage headroom and power loss in a
typical multi-string operation. Typical current matching between
channels is ±0.7%.
The ISL97672A features extensive protection functions that
flag whenever a fault occurs. The protections include
string-open and short-circuit detections, OVP, OTP, and an
optional output short-circuit protection with a fault disconnect
switch.
The ISL97672A is offered in a compact 20 Ld QFN 3x4
package and can operate in ambient temperatures of -40°C to
+85°C.
Features
• 6 x 50mA Channels
• 4.5V to 26.5V Input
• 45V Output Max
• Adaptive Boost Switching Architecture
• Direct PWM Dimming with Dimming Linearity of
0.007%~100% at 200Hz or 0.8%~100% <20kHz
• Adjustable 200kHz to 1.4MHz Switching Frequency
• Dynamic Headroom Control
• Fault Protections with Latched Flag Indication
- String Open/Short Circuit
- OVP
- OTP
- Optional Output Short-Circuit Fault Protection Switch
• Current Matching ±0.7%
• 20 Ld 3x4 QFN Package
Applications
• Notebook Displays LED Backlighting
• LCD Monitor LED Backlighting
• Multi-Function Printer Scanning Light Source
Typical Application Circuit
V_IN = 4.5V~26.5V
Q1 OPTIONAL
V_OUT = 45V*, 6 x 50mA
ISL97672A
1 FAULT
2 VIN
4 VDC
LX 20
OVP 16
6 /FLAG
18 COMP
3 EN
5 PWM
17 RSET
8 _FSW
9 AGND
PGND 19
CH0 10
CH1 11
CH2 12
CH3 13
CH4 14
CH5 15
* V_IN > 12V
FIGURE 1. ISL97672A TYPICAL APPLICATION DIAGRAM
May 2, 2011
FN7710.2
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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