ISL97682 Datasheet, PDF (1/17 Pages) Intersil Corporation – Compact 2-3-4-Ch LED Drivers with Phase Shift Control

Compact 2-3-4-Ch LED Drivers with Phase Shift Control
ISL97682, ISL97683, ISL97684
The ISL97682, ISL97683, ISL97684 are Intersil’s highly
integrated 2-3-4-channels LED drivers that are suitable for
medium size TFT-LCD backlights. These parts can drive multiple
channels of LEDs from inputs as low as 4V to outputs of up to
45V. They can also operate from inputs as low as 3V to outputs of
up to 26.5V in bootstrap configuration (see Figure 26 for 3V
operation).
The ISL97682, ISL97683, ISL97684 feature optional channels
phase shift control. This feature is used to minimize the input,
output ripple characteristics and load transient, which help
eliminate or reduce the video and audio noise interference from
the backlight driver operation.
The ISL97682, ISL97683, ISL97684 offer 8-bit PWM dimming for
systems that need frequency tuning flexibility. With the unique
adaptive boost switching architecture, the ISL97682, ISL97683,
ISL97684 also offer Direct PWM dimming with output, which
follows input and achieves linearity as low as 0.009% at 200Hz
or 1.35% at 30kHz.
The drivers incorporate dynamic headroom control that monitors
the highest LED forward voltage string and uses its feedback signal
for the minimum output regulation. The ISL97682, ISL97683,
ISL97684 incorporates extensive fault protection functions including
string open and short circuit detections, OVP, and OTP. The switching
frequency can be selected at either 600kHz or 1.0MHz in PFM or
PWM mode. These parts are available in the thin and compact
16 Ld 3mmx3mm TQFN package and operate in ambient
temperature from -40°C to +85°C.
Features
• ISL97682 - 2 x 100mA Channels
• ISL97683 - 3 x 50mA Channels
• ISL97684 - 4 x 50mA Channels
• Input Voltage 4.0V~26.5V with Max V_OUT of 45V
• Input Voltage 3.0V (see Figure 26)~24V with Max V_OUT of 26.5V
• PWM Dimming Linearity
- PWM Dimming with Adjustable Dimming Frequency with
Duty Cycle Linear from 0.4% to 100% <30kHz
- Direct PWM Dimming with Duty Cycle Linear from 0.009%
to 100% at 200Hz
• Current Matching of 0.7% typical from 1%~100% Dimming
• Selectable 600kHz or 1MHz Switching Frequency in PWM/PFM
Mode
• Dynamic Headroom Control
• Fault Protection
- String Open/Short Circuit Protections, OVP, OTP
• Thin and Compact TQFN-16 3mmx3mm Package
Applications
• Tablet to Notebook PC Displays LED Backlighting
• PMP LED Backlighting
VIN = 4~26.5V
Ci
10µF
0.1µF
1µF
L1
D1
10µH
7 VIN
11 VDC
ISL97684
LX 9
6 EN
OVP 12
5 PWMI
3 ^RSET
PGND 10
8 FPWM/DIRECTPWM
4 FSW
2 COMP
CH1 13
CH2 14
CH3 15
CH4 16
45V, 4 x 50mA*
Co
4.7µF
1 AGND
*VIN> = 9V AND WITH
GOOD LEDS MATCHING
VIN = 4~26.5V
Ci
L1
D1
10µH
10µF
0.1µF
1µF
7 VIN
11 VDC
ISL97684
6 EN
5 PWMI
3 RSET
8 FPWM/DIRECTPWM
4 FSW
2 COMP
LX 9
OVP 12
PGND10
CH1 13
CH2 ₁₄
CH3 15
CH4 16
45V, 4 x 50mA*
Co
4.7µF
1 AGND
*VIN >=9V AND WITH
GOOD LEDS MATCHING
FIGURE 1A. DIRECT PWM DIMMING
FIGURE 1B. PWM DIMMING WITH DIMMING FREQUENCY
ADJUSTMENT USING R_FPWM
FIGURE 1. ISL97684 TYPICAL APPLICATION DIAGRAMS
March 11, 2011
1
FN7689.0
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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